Plague prophylaxis

Prophylaxis For asymptomatic patients exposed to plague aerosol, or to a patient with suspected pneumonic plague, provide doxycycline at 100 mg orally twice daily for seven days, or for the duration of risk of exposure plus one week. Alternative antibiotics include ciprofloxacin, tetracycline, or chloramphenicol. No vaccine is currently available for plague propylaxis. The previously available licensed, killed vaccine was effective against bubonic plague, but not against aerosol exposure. 

Tetracyclines are classified as broad-spectrum antibiotics obtained from soil acti-nomycetes. All tetracyclines are slightly bitter solids and are weakly soluble in water. Although tetracyclines develop organism resistance, they are the drugs of first choice in venereal disease, atypical pneumonia, cholera, brucellosis, and plague. Tetracyclines also are used in urinary tract infections, amebiasis, acne, and as prophylaxis against meningitis. 

Table 2.11 Plague treatment in contained and mass casualty situation, and postexposure prophylaxis ...

Duration of treatment of plague in mass casualty settings is 10 days. Duration of postexposure prophylaxis to prevent plague infection is 7 days Tetracycline could be substituted for doxycycline... 

Aikimbayev, A., Kisselev U., et al. The effect of human plague isolates on eukaryotic cells [Russian], The plague epidemiological surveillance and prophylaxis measures. Almaty Kazakhstan, 1992, pp. 45 18. 

Antibiotics should be continued for 60 days in patients with anthrax infection. Postexposure antibiotic prophylaxis is recommended after exposure to anthrax, plague, and tularemia. 

Vaccines. Anthrax and smallpox vaccines can be used before exposure and also for postexposuie prophylaxis. A pentavalent (ABODE) botulinum toxoid is currently used for laboratory workers at high risk of exposure. It is not effective for postexposure prophylaxis. Vaccines are not currently available for plague, tularemia, or viral hemorrhagic fevers. 

At this time there is not a U.S. vaccine available for those at risk for exposure to plague. The old vaccine was discontinued in 1999. This is no great loss as it only protected against bubonic plague and did not protect against the aerosolized bacteria. Doxycycline (100 mg BID) is effective for prophylaxis for those who are known contacts of patients with plague (including pneumonic). Fluoroquinolones are known to be effective in animals and can also be used for prophylaxis. 

---