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 33-24: Tularemia + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ History of outdoor activity Possible contact with rabbits, other rodents, and biting arthropods (eg, ticks in summer) in endemic area Fever, headache, nausea, and prostration Papule progressing to ulcer at site of inoculation Enlarged regional lymph nodes Serologic tests or culture of ulcer, lymph node aspirate, or blood confirm the diagnosis +++ General Considerations ++ An infection of wild rodents—particularly rabbits and muskrats—with Francisella (Pasteurella) tularensis Usually acquired by contact with animal tissues (eg, trapping muskrats, skinning rabbits), from ticks, or from biting flies Risk factors for pneumonic tularemia include lawn-mowing and brush-cutting, underscoring the potential for probable aerosol transmission of the organism The incubation period is 2–10 days F tularensis has been classified as a high-priority agent for potential bioterrorism use because of its virulence and relative ease of dissemination + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Papule Develops at inoculation site and soon ulcerates May be on the skin of an extremity or in the eye Widespread organ involvement may occur but may be entirely asymptomatic Fever, headache, and nausea begin suddenly Regional lymph nodes May become enlarged and tender May suppurate Pneumonia May develop from hematogenous spread of the organism or May be primary after inhalation of infected aerosols, which are responsible for human-to-human transmission Following ingestion of infected meat or water, an enteric form may be manifested by Gastrointestinal symptoms Stupor Delirium In any type of involvement, the spleen may be enlarged and tender and there may be nonspecific rashes, myalgias, and prostration +++ Differential Diagnosis ++ Anthrax Cat-scratch disease Infectious mononucleosis Plague Typhoid fever Lymphoma Rickettsial disease, eg, epidemic typhus, Q fever Rat-bite fever Meningococcemia Sporotrichosis Herpes simplex virus conjunctivitis + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests ++ Culturing the organism from blood or infected tissue requires special media. For this reason and because cultures of F tularensis may be hazardous to laboratory personnel, the diagnosis is usually made serologically A positive agglutination test (> 1:80) develops within 2 weeks and may persist for several years Culture of ulcer, lymph node aspirate, or blood confirms the diagnosis + Treatment Download Section PDF Listen +++ +++ Medications ++ Streptomycin Dosage: 7.5–10.0 mg/kg every 12 hours intramuscularly or intravenously for 10 days Drug of choice Gentamicin Dosage: 5 mg/kg once daily intramuscularly or intravenously for 10 days Generally less toxic than streptomycin However, some case series report lower treatment success rates Doxycycline Dosage: 200 mg/day orally Also effective but has a higher relapse rate Should only be used for the less seriously ill + Outcome Download Section PDF Listen +++ +++ Complications ++ Hematogenous spread may produce Meningitis Perisplenitis Pericarditis Pneumonia Osteomyelitis +++ When to Refer ++ Early referral to an infectious disease specialist may aid in management +++ When to Admit ++ Serious cases Any complications from hematogenous spread + References Download Section PDF Listen +++ + +Maurin M et al. Tularaemia: clinical aspects in Europe. Lancet Infect Dis. 2016 Jan;16(1):113–24. [PubMed: 26738841] + +Yanes H et al. Evaluation of in-house and commercial serological tests for diagnosis of human tularemia. J Clin Microbiol. 2018 Jan;56(1). pii: e01440–17. [PubMed: 29118164]