The cornerstone for the diagnosis of parasitic infections is a thorough history of the patient's illness. Epidemiologic aspects of the illness are especially important because the risks of acquiring many parasites are closely related to occupation, recreation, or travel to areas of high endemicity. Without a basic knowledge of the epidemiology and life cycles of the major parasites, it is difficult to approach the diagnosis of parasitic infections systematically. Accordingly, the medical classification of important human parasites in this chapter emphasizes their geographic distribution, their transmission, and the anatomic location and stages of their life cycle in humans. The text and tables are intended to serve as a guide to the correct diagnostic procedures for the major parasitic infections; in addition, the reader is referred to other chapters that contain more comprehensive information about each infection (Chaps. 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, and 220). Tables e25-1, e25-2, and e25-3 summarize the geographic distributions, the anatomic locations, and the methods employed for the diagnosis of flatworm, roundworm, and protozoal infections, respectively.
Table e25-1 Flatworm Infections
| Favorite Table
Table e25-1 Flatworm Infections
|Parasite||Geographic Distribution||Intermediate (Transmission)||Definitive||Parasite Stage||Body Fluid or Tissue||Serologic Tests||Other|
|Taenia saginata (beef tapeworm)||Worldwide||Beef||Humans||Ova, segments||Feces||—||Motile segments|
|Hymenolepis nana (dwarf tapeworm)||Worldwide||Grain beetles||Humans, micea||Ova||Feces||—||—|
|Diphyllobothrium latum (fish tapeworm)||Worldwide||Copepods–fishb||Humans, other mammals||Ova, segments||Feces||—||Megaloblastic anemia in 1%|
|T. soliumc (pork tapeworm)||Worldwide||Swine||Humans||Ova, segments||Feces||WB||Especially Mexico, Central and South America, Africa|
|Echinococcus granulosus (hydatid disease)||Sheep-raising and hunting areas||Sheep, camels, humans, others||Dogs||Hydatid||Lung, liver||WB, EIA||Chest radiography, CT, MRI|
|E. multilocularis (hydatid disease)||Subarctic areas||Rodents, humans||Foxes, dogs, cats||Hydatid||Liver||—||May resemble cholangiocellular carcinoma|
|T. soliumc (pork tapeworm)||Worldwide||Swine, humans||Humans||Cysticercus||Muscles, CNS||WB||CT, MRI, radiography|
|Fasciolopsis buski||China, India||Snails–water chestnuts||Humans||Ova||Feces||—||—|
|Heterophyes heterophyes||Far East, India||Snails–fish||Humans||Ova||Feces||—||—|
|Metagonimus yokogawai||Far East, Balkans, North Africa||Snails–fish||Humans||Ova||Feces||—||—|
|Clonorchis sinensis||China, Southeast Asia||Snails–fish||Humans||Ova||Feces, bile||—||Recurrent bacterial cholangitis|
|Fasciola hepatica||Sheep-raising areas||Snails–watercress||Humans, sheep||Ova||Feces,d bile||EIA||Cirrhosis, portal hypertension|
|Paragonimus spp.||Orient, Africa, the Americas||Snails–crabs/crayfish||Humans, other mammals||Adults, ova||Lung, sputum, feces||WB, EIA||Chest radiography, CT, MRI|
|Schistosoma mansoni||Africa, Central and South America, West Indies||Snails||Humans||Ova, adults||Feces||EIA, WB||Rectal snips, liver biopsy|
|S. haematobium||Africa||Snails||Humans||Ova, adults||Urine||WB||Liver, urine, or bladder biopsy|
|S. japonicum||Far East||Snails||Humans||Ova, adults||Feces||WB||Liver biopsy|
Log In to View More
If you don't have a subscription, please view our individual subscription options below to find out how you can gain access to this content.
Want remote access to your institution's subscription?
Sign in to your MyAccess Profile while you are actively authenticated on this website
via your institution (you will be able to tell by looking in the top right corner
of any page – if you see your institution’s name, you are authenticated). You will
then be able to access your institute’s content/subscription for 90 days from any
location, after which you must repeat this process for continued access.
If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.
AccessMedicine Full Site: One-Year Subscription
Connect to the full suite of AccessMedicine content and resources including more than 250 examination and procedural videos, patient safety modules, an extensive drug database, Q&A, Case Files, and more.
Pay Per View: Timed Access to all of AccessMedicine
24 Hour Subscription $34.95
48 Hour Subscription $54.95
Pop-up div Successfully Displayed
This div only appears when the trigger link is hovered over.
Otherwise it is hidden from view.