Inhalational anthrax - Epidemiology, diagnosis, and management

Anthrax, a disease of great historical interest, is once again making headl ines as an agent of biological warfare. Bacillus anthracis, a rod-shaped, s pore-forming bacterium, primarily infects herbivores. Humans can acquire an thrax by agricultural or industrial exposure to infected animals or animal products. More recently, the potential for intentional release of anthrax s pores in the environment has caused much concern. The common clinical manif estations of anthrax are cutaneous disease, pulmonary disease from inhalati on of anthrax spores, and GI disease. The course of inhalational anthrax is dramatic, from the insidious onset of nonspecific influenza-like symptoms to severe dyspnea, hypotension, and hemorrhage within days of exposure, A r apid decline, culminating in septic shock, respiratory distress, and death within 24 h is not uncommon. The high mortality seen in inhalational anthra x is in part due to delays in diagnosis, Classic findings on the chest radi ograph include widening of the mediastinum as well as pleural effusions. Pn eumonia is less common; key pathologic manifestations include severe hemorr hagic mediastinitis, diffuse hemorrhagic lymphadenitis, and edema. Diagnosi s requires a high index of suspicion. Treatment involves supportive care in an intensive care facility and high doses of penicillin. Resistance to thi rd-generation cephalosporins has been noted, Vaccines are currently availab le and have been shown to be effective against aerosolized exposure in anim al studies.