There are various forms of plague, all caused by the bacteria Yersinia
pestis. Bubonic plague, historically the most common, is transmitted from
rats to humans by infected fleas. In 1346, a bubonic plague pandemic known as
the Black Death erupted in Europe and eventually killed 20-30 million people, a
third of the population.
During World War II, the Japanese army reportedly dropped plague-infested fleas
over China. It is possible that infected insects again could be used as
weapons. But experts see a much greater risk in the spraying of Y. pestis
in aerosols; inhaled bacteria would trigger cases of highly lethal
Experts consider plague a bioweapons threat for several reasons: The virus has
been widely available in microbe banks for military and civilian researchers.
Techniques to mass-produce and aerosolize plague were developed in the Soviet
Union, and hundreds of former Soviet scientists may have this know-how.
Finally, even a small number of plague cases are likely to sow panic given the
infamous history of the disease.
chest pain, cough, bloody or watery sputum (pneumonic)
How it would be spread
Aerosol or person-to-person. Pneumonic plague is contagious through respiratory
A variety of antibiotics can treat the disease but must be given soon after
symptoms appear. Antibiotics given immediately after exposure may prevent
No vaccine is available to the general public. A vaccine to prevent bubonic
plague was licensed in the U.S. but discontinued by its manufacturers in 1999.
Even if this vaccine becomes available, it does not prevent the pneumonic form of plague.