Tuesday, January 15, 2008

Bringing Bubonic Back

The plague is back and moving to Africa.


The World Health Organization reports that between 1,000 and 3,000 people are infected with the plague each year in the Democratic Republic of Congo, Madagascar, Malawi, Mozambique, Tanzania and Uganda.

There are only 10 to 20 cases reported in the US each year.

The plague comes in three flavors: bubonic, septicemic and pneumonic. All are caused by the bacteria Yersinia Pestis and spread to humans by fleas in the following horrific manner:

"Bubonic plague is mainly a disease in rodents and fleas. Infection in a human occurs when a person is bitten by a flea that has been infected by biting a rodent that itself has been infected by the bite of a flea carrying the disease. The bacteria multiply inside the flea, sticking together to form a plug that blocks its stomach and causes it to begin to starve. The flea then voraciously bites a host and continues to feed, even though it cannot quell its hunger, and consequently the flea vomits blood tainted with the bacteria back into the bite wound. The bubonic plague bacterium then infects a new victim, and the flea eventually dies from starvation. Serious outbreaks of plague are usually started by other disease outbreaks in rodents, or a rise in the rodent population."

If you're bitten by a plague-vomiting flea, the bacteria will enter your tissue, and then probably travel through your lymphatic system and settle in your lymph nodes, which enlargen. Thus, bubonic plague ("bubo" means swelling of the lymph nodes in Greek).

Or, the bacteria will enter the bloodstream (septicemic plague) or the lungs (pneumonic plague). Septicemic plague and pneumonic plague have a much higher mortality rate than bubonic plague: 90% of those infected with septicemic or pneumonic plague die, compared to 60% of those infected with bubonic plague. Pneumonic plague is especially problematic because it can be spread by coughing or sneezing.

The plague killed 25 million people in Europe in the 14th century - one third of the continent's population.

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