Anthrax can occur in three forms depending on the portal of entry. Inhalational anthrax is the form of anthrax with the highest fatality rate. Following an incubation period that often is between one and seven days (but can be up to 60 days), a prodromal illness with fever, malaise, fatigue cough and mild chest discomfort is followed by severe respiratory distress with dyspnea, diaphoresis, stridor and cyanosis. There should be radiologic evidence of mediastinal widening.

Gastrointestinal anthrax also has an incubation period ranging from one to seven days. This form may present as severe abdominal distress followed by fever and signs of septicemia. There may be lesions at the base of the tongue, sore throat, dysphagia, fever and regional lymphadenopathy. This form of anthrax can also include vomiting blood and bloody diarrhea.

Cutaneous anthrax usually occurs one day to 12 days following exposure. This skin infection begins as a small papule and progresses to a vesicle in one to two days followed by a necrotic ulcer. The lesion is usually painless and may be accompanied by fever, malaise, headache and regional lymphadenopathy.

Primary culture for Bacillus anthracis should be performed by local laboratories such as hospital laboratories. The Illinois Department of Public Health laboratories will be available to confirm organisms presumptively identified as B. anthracis.

Smallpox has not occurred in the United States since the late 1940s. The clinical manifestations begin acutely with malaise, fever, rigors, vomiting, headache and backache. Two days to three days later lesions appear which rapidly progress from macules to papules and eventually to pustular vesicles. They are more abundant on the extremities and face and develop synchronously.

Plague has two forms, pneumonic and bubonic. Pneumonic plague has onset of symptoms two days to three days following exposure to airborne droplets from another infected person. Initially symptoms of high fever, chills, headache, hemoptysis and toxemia progress rapidly to dyspnea, stridor and cyanosis. Death results from respiratory failure, circulatory collapse and a bleeding diathesis. Bubonic plague develops two to 10 days following the bite of an infected flea. Initial symptoms of malaise, high fever and tender lymph nodes (buboes) may progress to a septicemia with spread to the central nervous system, lungs and other anatomic sites.