Inhalational anthrax is the deadliest form of the disease. Infection can occur up to 60 days following exposure. The disease occurs in two stages: In the first stage, the patient experiences flu-like symptoms, such as fever, dyspnea, cough, headache, vomiting, chills, weakness, abdominal pain, and chest pain, for a few hours to a few days. In the second, fulminant, stage, there is rapid onset of fever, dyspnea, diaphoresis, and shock. The mean interval between onset of symptoms and death in these patients is three days. Because the disease progresses so rapidly during the second stage, even high dose antibiotics are only minimally effective in preventing death once severe symptoms appear. Diagnosis at the first stage is preferable, but requires a high index of suspicion due to the nonspecific nature of symptoms.

Confirmation of the diagnosis is most likely with blood culture (or culture of skin lesions in cases of cutaneous anthrax). The laboratory must be specifically instructed to look for anthrax, however, as other Bacillus species isolated on blood culture are frequently regarded as contaminants.  “Rapid” diagnostic tests such as ELISA for bacterial antigen and PCR are available at only a few national reference laboratories.

Treatment of suspected anthrax must take into account the source of exposure, size of the “event,” and susceptibility to available antibiotics. Ciprofloxacin (or an equivalent fluoroquinolone) is recommended as first line therapy until antibiotic susceptibilities of the strain in the index case are known. Treatment is recommended for 60 days due to the possibility of delayed spore germination and recurrence of disease. For cutaneous anthrax, oral penicillin is an appropriate choice, with oral doxycycline, fluoroquinolones, and amoxicillin acceptable alternatives if susceptibility is proven. Chemoprophylaxis following exposure has also been touted as a control measure. The same antibiotics (ciprofloxacin, doxycycline, or penicillin if susceptibility is demonstrated) for 60 days are currently recommended for this use.

The federal Centers for Disease Control (CDC) is working with the Federal Bureau of Investigation to locate the origin of current anthrax cases and to test hundreds of persons for exposure to anthrax and recommending preventive treatment where warranted. (See the CDC web site for updates.) The CDC assists local medical communities in detection, diagnosis, response to, and prevention of illnesses. The CDC has developed a stockpile of pharmaceuticals to be able to reach victims of an incident anywhere in the continental U.S. within 12 hours. (The agency demonstrated its rapid response for the first time on Sept. 11, when tons of medical supplies reached New York City within seven hours of deployment after the attacks on the World Trade Center.)

Many patients have inquired about vaccination for anthrax. The CDC has not recommended that citizens obtain or hoard supplies of anthrax vaccine. Human anthrax vaccine, licensed by the FDA in 1970, is currently produced by only one laboratory in the U.S. The U.S. military is in the process of immunizing all enlistees with a six-dose series. Apart from high-risk military personnel, the CDC currently recommends vaccine only for researchers who work with the organism in a laboratory, persons who work with imported animal hides or furs from areas where standards are insufficient to prevent exposure to anthrax spores, and those who handle potentially infected animal products in high-incidence areas.  Vaccine production at this time is not sufficient to conduct a large-scale civilian immunization program.    

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CDC web site: http://www.cdc.gov/