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eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

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eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

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eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

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eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

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eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

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eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

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eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

View in Context

eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

View in Context

eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

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eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

View in Context

eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

View in Context

eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

View in Context

eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

View in Context

eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

View in Context

eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

View in Context

eFigure 37–9. Life cycle of Plasmodium. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells  and mature into schizonts , which rupture and release merozoites . (Of note, in Plasmodium vivax and Plasmodium ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect RBCs . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) , which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of malarial parasite.

Current Medical Diagnosis & Treatment 2024 > Malaria

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eFigure 37–15. Life cycle of Entamoeba histolytica. Cysts and trophozoites are passed in feces . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts  in fecally contaminated food, water, or hands. Excystation  occurs in the small intestine and trophozoites  are released, which migrate to the large intestine. The trophozoites multiply by binary fission and produce cysts , and both stages are passed in the feces . Because of the protection conferred by their walls, the cysts can survive days to weeks in the external environment and are responsible for transmission. Trophozoites passed in the stool are rapidly destroyed once outside the body and would not survive exposure to the gastric environment if ingested. In many cases, the trophozoites remain confined to the intestinal lumen (: noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool. In some patients, the trophozoites invade the intestinal mucosa (: intestinal disease) or through the bloodstream, extraintestinal sites such as the liver, brain, and lungs (: extraintestinal disease), with resultant pathologic manifestations. It has been established that the invasive and noninvasive forms represent two separate species, respectively E histolytica and E dispar. These two species are morphologically indistinguishable unless E histolytica is observed with ingested RBCs (erythrophagocytosis). Transmission can also occur through exposure to fecal matter during sexual contact (in which case not only cysts, but also trophozoites could prove infective). (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of Entamoeba histolytica.

Current Medical Diagnosis & Treatment 2024 > Amebiasis

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eFigure 37–15. Life cycle of Entamoeba histolytica. Cysts and trophozoites are passed in feces . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts  in fecally contaminated food, water, or hands. Excystation  occurs in the small intestine and trophozoites  are released, which migrate to the large intestine. The trophozoites multiply by binary fission and produce cysts , and both stages are passed in the feces . Because of the protection conferred by their walls, the cysts can survive days to weeks in the external environment and are responsible for transmission. Trophozoites passed in the stool are rapidly destroyed once outside the body and would not survive exposure to the gastric environment if ingested. In many cases, the trophozoites remain confined to the intestinal lumen (: noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool. In some patients, the trophozoites invade the intestinal mucosa (: intestinal disease) or through the bloodstream, extraintestinal sites such as the liver, brain, and lungs (: extraintestinal disease), with resultant pathologic manifestations. It has been established that the invasive and noninvasive forms represent two separate species, respectively E histolytica and E dispar. These two species are morphologically indistinguishable unless E histolytica is observed with ingested RBCs (erythrophagocytosis). Transmission can also occur through exposure to fecal matter during sexual contact (in which case not only cysts, but also trophozoites could prove infective). (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of Entamoeba histolytica.

Current Medical Diagnosis & Treatment 2024 > Amebiasis

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eFigure 37–15. Life cycle of Entamoeba histolytica. Cysts and trophozoites are passed in feces . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts  in fecally contaminated food, water, or hands. Excystation  occurs in the small intestine and trophozoites  are released, which migrate to the large intestine. The trophozoites multiply by binary fission and produce cysts , and both stages are passed in the feces . Because of the protection conferred by their walls, the cysts can survive days to weeks in the external environment and are responsible for transmission. Trophozoites passed in the stool are rapidly destroyed once outside the body and would not survive exposure to the gastric environment if ingested. In many cases, the trophozoites remain confined to the intestinal lumen (: noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool. In some patients, the trophozoites invade the intestinal mucosa (: intestinal disease) or through the bloodstream, extraintestinal sites such as the liver, brain, and lungs (: extraintestinal disease), with resultant pathologic manifestations. It has been established that the invasive and noninvasive forms represent two separate species, respectively E histolytica and E dispar. These two species are morphologically indistinguishable unless E histolytica is observed with ingested RBCs (erythrophagocytosis). Transmission can also occur through exposure to fecal matter during sexual contact (in which case not only cysts, but also trophozoites could prove infective). (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of Entamoeba histolytica.

Current Medical Diagnosis & Treatment 2024 > Amebiasis

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eFigure 37–15. Life cycle of Entamoeba histolytica. Cysts and trophozoites are passed in feces . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts  in fecally contaminated food, water, or hands. Excystation  occurs in the small intestine and trophozoites  are released, which migrate to the large intestine. The trophozoites multiply by binary fission and produce cysts , and both stages are passed in the feces . Because of the protection conferred by their walls, the cysts can survive days to weeks in the external environment and are responsible for transmission. Trophozoites passed in the stool are rapidly destroyed once outside the body and would not survive exposure to the gastric environment if ingested. In many cases, the trophozoites remain confined to the intestinal lumen (: noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool. In some patients, the trophozoites invade the intestinal mucosa (: intestinal disease) or through the bloodstream, extraintestinal sites such as the liver, brain, and lungs (: extraintestinal disease), with resultant pathologic manifestations. It has been established that the invasive and noninvasive forms represent two separate species, respectively E histolytica and E dispar. These two species are morphologically indistinguishable unless E histolytica is observed with ingested RBCs (erythrophagocytosis). Transmission can also occur through exposure to fecal matter during sexual contact (in which case not only cysts, but also trophozoites could prove infective). (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of Entamoeba histolytica.

Current Medical Diagnosis & Treatment 2024 > Amebiasis

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eFigure 37–15. Life cycle of Entamoeba histolytica. Cysts and trophozoites are passed in feces . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts  in fecally contaminated food, water, or hands. Excystation  occurs in the small intestine and trophozoites  are released, which migrate to the large intestine. The trophozoites multiply by binary fission and produce cysts , and both stages are passed in the feces . Because of the protection conferred by their walls, the cysts can survive days to weeks in the external environment and are responsible for transmission. Trophozoites passed in the stool are rapidly destroyed once outside the body and would not survive exposure to the gastric environment if ingested. In many cases, the trophozoites remain confined to the intestinal lumen (: noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool. In some patients, the trophozoites invade the intestinal mucosa (: intestinal disease) or through the bloodstream, extraintestinal sites such as the liver, brain, and lungs (: extraintestinal disease), with resultant pathologic manifestations. It has been established that the invasive and noninvasive forms represent two separate species, respectively E histolytica and E dispar. These two species are morphologically indistinguishable unless E histolytica is observed with ingested RBCs (erythrophagocytosis). Transmission can also occur through exposure to fecal matter during sexual contact (in which case not only cysts, but also trophozoites could prove infective). (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of Entamoeba histolytica.

Current Medical Diagnosis & Treatment 2024 > Amebiasis

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eFigure 37–15. Life cycle of Entamoeba histolytica. Cysts and trophozoites are passed in feces . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts  in fecally contaminated food, water, or hands. Excystation  occurs in the small intestine and trophozoites  are released, which migrate to the large intestine. The trophozoites multiply by binary fission and produce cysts , and both stages are passed in the feces . Because of the protection conferred by their walls, the cysts can survive days to weeks in the external environment and are responsible for transmission. Trophozoites passed in the stool are rapidly destroyed once outside the body and would not survive exposure to the gastric environment if ingested. In many cases, the trophozoites remain confined to the intestinal lumen (: noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool. In some patients, the trophozoites invade the intestinal mucosa (: intestinal disease) or through the bloodstream, extraintestinal sites such as the liver, brain, and lungs (: extraintestinal disease), with resultant pathologic manifestations. It has been established that the invasive and noninvasive forms represent two separate species, respectively E histolytica and E dispar. These two species are morphologically indistinguishable unless E histolytica is observed with ingested RBCs (erythrophagocytosis). Transmission can also occur through exposure to fecal matter during sexual contact (in which case not only cysts, but also trophozoites could prove infective). (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of Entamoeba histolytica.

Current Medical Diagnosis & Treatment 2024 > Amebiasis

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eFigure 37–15. Life cycle of Entamoeba histolytica. Cysts and trophozoites are passed in feces . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts  in fecally contaminated food, water, or hands. Excystation  occurs in the small intestine and trophozoites  are released, which migrate to the large intestine. The trophozoites multiply by binary fission and produce cysts , and both stages are passed in the feces . Because of the protection conferred by their walls, the cysts can survive days to weeks in the external environment and are responsible for transmission. Trophozoites passed in the stool are rapidly destroyed once outside the body and would not survive exposure to the gastric environment if ingested. In many cases, the trophozoites remain confined to the intestinal lumen (: noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool. In some patients, the trophozoites invade the intestinal mucosa (: intestinal disease) or through the bloodstream, extraintestinal sites such as the liver, brain, and lungs (: extraintestinal disease), with resultant pathologic manifestations. It has been established that the invasive and noninvasive forms represent two separate species, respectively E histolytica and E dispar. These two species are morphologically indistinguishable unless E histolytica is observed with ingested RBCs (erythrophagocytosis). Transmission can also occur through exposure to fecal matter during sexual contact (in which case not only cysts, but also trophozoites could prove infective). (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of Entamoeba histolytica.

Current Medical Diagnosis & Treatment 2024 > Amebiasis

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eFigure 37–15. Life cycle of Entamoeba histolytica. Cysts and trophozoites are passed in feces . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts  in fecally contaminated food, water, or hands. Excystation  occurs in the small intestine and trophozoites  are released, which migrate to the large intestine. The trophozoites multiply by binary fission and produce cysts , and both stages are passed in the feces . Because of the protection conferred by their walls, the cysts can survive days to weeks in the external environment and are responsible for transmission. Trophozoites passed in the stool are rapidly destroyed once outside the body and would not survive exposure to the gastric environment if ingested. In many cases, the trophozoites remain confined to the intestinal lumen (: noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool. In some patients, the trophozoites invade the intestinal mucosa (: intestinal disease) or through the bloodstream, extraintestinal sites such as the liver, brain, and lungs (: extraintestinal disease), with resultant pathologic manifestations. It has been established that the invasive and noninvasive forms represent two separate species, respectively E histolytica and E dispar. These two species are morphologically indistinguishable unless E histolytica is observed with ingested RBCs (erythrophagocytosis). Transmission can also occur through exposure to fecal matter during sexual contact (in which case not only cysts, but also trophozoites could prove infective). (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of Entamoeba histolytica.

Current Medical Diagnosis & Treatment 2024 > Amebiasis

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eFigure 37–15. Life cycle of Entamoeba histolytica. Cysts and trophozoites are passed in feces . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts  in fecally contaminated food, water, or hands. Excystation  occurs in the small intestine and trophozoites  are released, which migrate to the large intestine. The trophozoites multiply by binary fission and produce cysts , and both stages are passed in the feces . Because of the protection conferred by their walls, the cysts can survive days to weeks in the external environment and are responsible for transmission. Trophozoites passed in the stool are rapidly destroyed once outside the body and would not survive exposure to the gastric environment if ingested. In many cases, the trophozoites remain confined to the intestinal lumen (: noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool. In some patients, the trophozoites invade the intestinal mucosa (: intestinal disease) or through the bloodstream, extraintestinal sites such as the liver, brain, and lungs (: extraintestinal disease), with resultant pathologic manifestations. It has been established that the invasive and noninvasive forms represent two separate species, respectively E histolytica and E dispar. These two species are morphologically indistinguishable unless E histolytica is observed with ingested RBCs (erythrophagocytosis). Transmission can also occur through exposure to fecal matter during sexual contact (in which case not only cysts, but also trophozoites could prove infective). (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of Entamoeba histolytica.

Current Medical Diagnosis & Treatment 2024 > Amebiasis

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eFigure 37–15. Life cycle of Entamoeba histolytica. Cysts and trophozoites are passed in feces . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts  in fecally contaminated food, water, or hands. Excystation  occurs in the small intestine and trophozoites  are released, which migrate to the large intestine. The trophozoites multiply by binary fission and produce cysts , and both stages are passed in the feces . Because of the protection conferred by their walls, the cysts can survive days to weeks in the external environment and are responsible for transmission. Trophozoites passed in the stool are rapidly destroyed once outside the body and would not survive exposure to the gastric environment if ingested. In many cases, the trophozoites remain confined to the intestinal lumen (: noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool. In some patients, the trophozoites invade the intestinal mucosa (: intestinal disease) or through the bloodstream, extraintestinal sites such as the liver, brain, and lungs (: extraintestinal disease), with resultant pathologic manifestations. It has been established that the invasive and noninvasive forms represent two separate species, respectively E histolytica and E dispar. These two species are morphologically indistinguishable unless E histolytica is observed with ingested RBCs (erythrophagocytosis). Transmission can also occur through exposure to fecal matter during sexual contact (in which case not only cysts, but also trophozoites could prove infective). (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of Entamoeba histolytica.

Current Medical Diagnosis & Treatment 2024 > Amebiasis

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 37–30. Life cycle of Echinococcus. The adult Echinococcus granulosus (3–6 mm long)  resides in the small bowel of the definitive hosts, dogs, or other canids. Gravid proglottids release eggs  that are passed in the feces. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses, camel), the egg hatches in the small bowel and releases an oncosphere  that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially the liver and lungs. In these organs, the oncosphere develops into a cyst  that enlarges gradually, producing protoscolices and daughter cysts that fill the cyst interior. The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host. After ingestion, the protoscolices  evaginate, attach to the intestinal mucosa , and develop into adult stages  in 32–80 days. The same life cycle occurs with Echinococcus multilocularis (1.2–3.7 mm), with the following differences: the definitive hosts are foxes, and to a lesser extent dogs, cats, coyotes, and wolves; the intermediate host are small rodents; and larval growth (in the liver) remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues. With Echinococcus vogeli (up to 5.6 mm long), the definitive hosts are bush dogs and dogs; the intermediate hosts are rodents; and the larval stage (in the liver, lungs and other organs) develops both externally and internally, resulting in multiple vesicles. Echinococcus oligarthrus (up to 2.9 mm long) has a life cycle that involves wild felids as definitive hosts and rodents as intermediate hosts. Humans become infected by ingesting eggs , with resulting release of oncospheres  in the intestine and the development of cysts , , , , ,  in various organs. (From Global Health, Division of Parasitic Diseases and Malaria, CDC.) A flowchart of the life cycle of cystic echinococcosis.

Current Medical Diagnosis & Treatment 2024 > Invasive Cestode Infections

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eFigure 9–20. Normal lung ventilation with xenon-133. With the patient’s single full breath, inhaled radioxenon is evenly distributed to all lung areas, reaching the terminal airways and alveoli in the normal patient (A, posterior view). There is a less noticeable gradient of activity from the upper to the lower lung fields than is seen in perfusion lung images. Fifteen-second images obtained during closed-system rebreathing of a xenon–oxygen mixture show uniform distribution at 120 seconds (B). Serial 15-second frames after switching the patient to room air breathing (C to G) show a homogeneous pattern of washout from all lung areas. This sequence mainly evaluates the posterior lung regions. To better localize gas trapping in specific lung segments or more anterior regions, the acquisition may be modified after the rebreathing phase by rotating the patient into posterior oblique positions. Selected images from a complete study include single breath (H, posterior view), the late phase of rebreathing (I, posterior view), posterior washout (J), left posterior oblique washout (K), and right posterior oblique washout (L). No gas is retained in this patient, which is normal, but in obstructive airway disease gas retention persists and is better localized in the oblique views than in a posterior view alone. A small amount of alveolar xenon normally crosses the alveolar membrane to reach the blood and be distributed throughout the body. Because it is highly soluble in lipids, xenon accumulates in adipose tissue, including the liver, which is faintly seen with prolonged rebreathing. Liver activity should not be mistaken for delayed washout of xenon from the base of the lung. Occasionally, splenic blood pool radioactivity or swallowed xenon in the stomach may also be seen. (SIN BRE = single breath, L REB = late rebreathe, WO = washout.) (Reproduced with permission from Grippi MA, Elias JA, Fishman JA, Kotloff RM, Pack AI, Senior RM, Siegel MD. Fishman’s Pulmonary Diseases and Disorders, 5e. 2015.) Four examples of normal ventilation scans compared with eight examples of abnormal scans.

Current Medical Diagnosis & Treatment 2024 > Pulmonary Venous Thromboembolism

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