Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 33-25: Plague + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ History of exposure to rodents in endemic area Sudden onset of high fever, muscular pains, and prostration Axillary, cervical, or inguinal lymphadenitis (bubo) Pustule or ulcer at inoculation site Positive smear and culture from bubo and positive blood culture +++ General Considerations ++ An infection of wild rodents with Yersinia pestis, a small bipolar-staining gram-negative rod It is transmitted among rodents and to humans by the bites of fleas or from contact with infected animals Following the flea bite, the organisms spread through the lymphatics to the lymph nodes, which become greatly enlarged (bubo). They may then reach the bloodstream to involve all organs If pneumonia develops in a patient with plague, the infection can be transmitted by droplets to other individuals The incubation period is 2–10 days Because of its extreme virulence, its potential for dissemination and person-to-person transmission, and efforts to develop the organism as an agent of biowarfare, plague bacillus is considered a high-priority agent for bioterrorism +++ Demographics ++ It is endemic in California, Arizona, Nevada, and New Mexico Worldwide, Madagascar accounts for three-quarters of the global burden + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Onset is sudden, with high fever, malaise, tachycardia, intense headache, and severe myalgias The patient appears profoundly ill. Delirium may ensue A pustule or ulcer at the site of inoculation and lymphangitis may be observed Axillary, inguinal, or cervical lymph nodes become enlarged and tender and may suppurate and drain Signs of meningitis may develop With hematogenous spread, the patient may rapidly become toxic and comatose, with purpuric spots (black plague) appearing on the skin Primary plague pneumonia is a fulminant pneumonitis with bloody, frothy sputum and sepsis If pneumonia develops, tachypnea, productive cough, blood-tinged sputum, and cyanosis also occur +++ Differential Diagnosis ++ Tularemia Lymphadenopathy of extremity due to bacterial infection Genital lymphadenopathy due to lymphogranuloma venereum, syphilis Typhoid fever Influenza Rickettsial disease, eg, epidemic typhus, Q fever Anthrax Other bacterial pneumonia Hantavirus pulmonary syndrome Sepsis due to other causes + Diagnosis Download Section PDF Listen +++ ++ The plague bacillus may be found in Gram-stained smears from aspirates of buboes Cultures from bubo aspirate or pus and blood are positive but may grow slowly In convalescing patients, an antibody titer rise may be demonstrated by agglutination tests + Treatment Download Section PDF Listen +++ +++ Medications ++ Therapy should be started immediately once plague is suspected Either streptomycin (the agent with which there is greatest experience), 1 g every 12 hours intravenously, or gentamicin, administered as a 2 mg/kg loading dose, then 1.7 mg/kg every 8 hours intravenously, is effective Alternatively, doxycycline, 100 mg twice daily orally or intravenously, may be used The duration of therapy is 10 days +++ Therapeutic Procedures ++ Patients with plague pneumonia are placed in strict respiratory isolation and caregivers are given prophylactic therapy + Outcome Download Section PDF Listen +++ +++ Prevention ++ Avoiding exposure to rodents and fleas in endemic areas Drug prophylaxis may provide temporary protection for persons exposed to plague, particularly by the respiratory route. Doxycycline, 100 mg twice daily orally, or ciprofloxacin, 500 mg twice daily orally for 7 days, is effective No vaccine is available +++ Prognosis ++ Pneumonia or meningitis is usually fatal +++ When to Refer ++ All suspected cases should be referred to an infectious disease specialist All cases must be reported to the public health authorities +++ When to Admit ++ All suspected or known cases + References Download Section PDF Listen +++ + +Burki T. Plague in Madagascar. Lancet Infect Dis. 2017 Dec;17(12):1241. [PubMed: 29173885] + +Yang R. Plague: recognition, treatment, and prevention. J Clin Microbiol. 2017 Dec 26;56(1). [PubMed: 29070654]