NCPA - National Center for Policy Analysis

Black Death Is The Original Biological Weapon

October 5, 2001

Bubonic plague is the original biological weapon blamed for the Black Death of medieval Europe. Tartars laying siege to the Black Sea port of Caffa, hurled the bodies of their plague victims over the city walls. When infected sailors returned to Italy, the Black Death killed one third of Europe's population between 1347 and 1351. There are concerns that governments or terrorists could spread plague again. Scientists defecting from the former Soviet Union claimed to have developed an antibiotic-resistant strain of Y. pestis, for example.

Although historically caused by bites from infected fleas, the bacteria sometimes invade the lungs of patients.

  • When this happens they cough, infecting nearby people with a nearly always fatal "pneumonic" plague.
  • Pneumonic plague is the form feared as a potential biological weapon.
  • The Soviet Union developed such a plague weapon.

Experts have sequenced the genome of plague strains and found the genes readily re-arranging themselves and picking up new genes from other microbes. That could mean that more virulent strains of plague might emerge, and enhanced strains might be relatively easy to develop as weapons.

Numerous genes have been copied backwards and have swapped positions within the genome, sometimes creating different variants in the same population.

These recombinations could mean differences in virulence in a single batch of plague. That could also mean that the bacteria -- or bioweapons developers -- have the genes at their disposal for new and potentially nastier strains of disease.

Sources: J. Parkhill et al., "Genome sequence of Yerisina pestis, the causative agent of plague," Nature, 413, 523 - 527, (2001). Nature (vol 413, p 523) and John Whitfield "Black Death's DNA," Nature Science Update, 4 October 2001; Debora MacKenzie "Bubonic plague genome is 'unusually fluid'", New Scientist, October 03, 2001.

For text 


Browse more articles on Government Issues