Bubonic plague - fever, nausea, vomiting and painful, swollen lymph nodes. Death occurs in over 50% of untreated cases.
Habitat and Transmission
- Yersinia pestis is carried in animals such as rodents, pigs, birds and other wild animals.
- The bacteria is spread to humans by fleas that first bite an infected animal and then an unlucky human.
Weapons and Defenses
- Survives well in animals and fleas
- Once blood from an infected animal is eaten by a flea, Yersinia pestis causes the blood meal to clot in the gastrointestinal tract of the flea. This allows the bacteria to reproduce and when the flea bites a human, it will vomit the blood to enable transmission of the bacteria to the unlucky human.
- Once in humans, the bacteria resist destruction by white blood cells and set up camp in lymph nodes.
- Once thriving in a lymph node, Yersinia pestis can spread to the entire body through the bloodstream, causing an overwhelming infection (sepsis).
- Susceptible to antibiotics such as gentamicin
- Vaccines have been used in the past for treating military members traveling overseas
Photo - Dark stained bipolar ends of Yersinia pestis can clearly be seen in this Wright's stain of blood from a plague victim. CDC. 1993. Used with permission.
Photo 2 - Xenopsylla cheopis, oriental rat flea, with a proventricular plague mass. CDC. Used with permission.
Last Updated (Monday, 22 June 2009 19:05)