administration of antitoxin is unlikely to reverse disease (the antitoxin is most effective when given during the clinically asymptomatic, or latent, period), it may be useful in preventing progression when administered to exposed persons In addition, a licensed human botulinum immunoglobulin is available to treat infant botulism While the product (BabyBIG) contains antibody against botulinum toxin types A to E, it has only been studied, and is thus only licensed, to treat type A and B intoxication Botulism is not contagious, and standard precautions are adequate for patient care Tularemia Tularemia is a highly infectious plague-like disease caused by the gram-negative coccobacillus Francisella tularensis Several clinical forms of naturally occurring tularemia are known, but pneumonic tularemia would presumably be the most likely clinical presentation in the event of an intentional aerosol release of F tularensis The onset of symptoms may be abrupt and include fever, nonproductive cough, substernal tightness, pleuritic chest pain, occasional hemoptysis, chills, headache, malaise, anorexia, and fatigue Chest radiographs may show infiltrates, hilar adenopathy, pleural effusion, or miliary infiltrates (may mimic tuberculosis) Tularemia is not contagious, and standard precautions are adequate in patient care However, because of the very low infectious dose by aerosol, processing tularemia bacterial cultures is an extreme health risk to laboratory staff, who therefore must be notified of a suspected case, and special precautions are warranted See Table 132.3B for detailed treatment recommendations for children VIRAL HEMORRHAGIC FEVERS The viral hemorrhagic fevers are a heterogeneous group of illnesses caused by infection with lipid-enveloped RNA viruses belonging to the families Arenaviridae, Bunyaviridae, Filoviridae, and Flaviviridae These viruses may cause deadly, fulminant illnesses with fever, hypotension, and bleeding diatheses A high mortality rate, with a capacity for human-to-human transmission by direct contact with body fluids makes the filoviruses (e.g., Ebola and Marburg viruses) and arenaviruses (e.g., Lassa fever virus) particularly concerning Bunyaviridae such as Crimean-Congo Hemorrhagic Fever virus can also be transmitted to healthcare providers Supportive care remains the cornerstone of therapy for most of the viral hemorrhagic fevers Intravenous ribavirin appears somewhat efficacious in treating disease due to the Arenaviridae