The Plague: Causes, Symptoms, and Treatment

Plague is still alive and well and a group of researchers recently expressed concern that the international community does not give enough attention to the disease. In a paper published January 15, 2008, (see the link at the end of this article), the researchers also asserted that plague could become a larger threat than it currently is. Climate changes will, potentially, increase cases and allow the disease to spread to regions in which it has not normally been present. In addition, some are concerned that the bacterium that causes plague could become resistant to antibiotics.

At this time, only a few thousand human cases of plague are reported across the globe each year. Most of these occur in Africa. Researchers believe that plague is under-reported, however, because many cases occur in areas without modern medical resources.

Even if the reported stats are true and plague only numbers a few thousand cases per year, the disease warrants more attention than it receives--for the reasons already mentioned and the following reasons, touched on in the researchers' paper: Plague has been used as a biological weapon before (even quite far back in history, when it is said that infected corpses were sometimes catapulted into enemy territory) and could be used as a weapon again. Plague spreads very rapidly and it kills rapidly. The incubation period is around 3-7 days (the CDC states 2-6 days) and if treatment is delayed, death quickly follows.

Medical personnel, and indeed all citizens, should know the causes and symptoms so that treatment is prompt.

The Cause and Symptoms:

All forms of plague are caused by a bacterium called Yersinia Pestis (Y-pestis). The differences between bubonic, pneumonic, and septicaemic plague are the following:
Bubonic plague is Yersinia Pestis infection of the lymph nodes. This infection causes painful, large swelling in the nodes -these swollen nodes are called "buboes." Other symptoms include flu-like chills and fever. Untreated, bubonic plague will spread to other areas of the body.

Pneumonic plague is Yersinia Pestis infection of the lungs. Symptoms include fever, fatigue, chest pain, cough, and pneumonia. The mortality rate for the pneumonic form is higher than for the bubonic form. Pneumonic plague is also the most dangerous variety because it is the most easily spread.

Septicaemic plague is a Yersinia Pestis infection of the blood. The blood infection can occur directly from the bite of an infected flea, but it also occurs in untreated cases of bubonic or pneumonic plague. Septicaemic plague causes bleeding under the skin. These areas of bleeding quickly darken, becoming black, and this symptom is why plague has at times been called the Black Death.

How plague is spread:

Bubonic plague is usually spread via flea bites from infected rodents. It can also be transmitted through contact with infected body fluids, infected meat, or through exposure to Yersinia Pestis in a lab.

Pneumonic plague can be spread easily through infected airborne droplets.

Common Carriers

Rats, mice, certain kinds of squirrels, chipmunks, and prairie dogs are among the animals that can harbor Y-pestis.

If you think you are safe from either bubonic plague or from pneumonic plague because you live in the United States, you are wrong (though the number of cases is very small). According to the World Health Organization (WHO) the U.S. reports between 10-20 cases of plague per year.

Plague cases have occurred in several states in the western half of the United States, including Colorado, New Mexico and Arizona.

Treatment

Antibiotics are effective against plague if they are given in time. Unfortunately, because the initial symptoms are similar to other illnesses, the sufferer might be misdiagnosed. That is what happened in the most recent human plague case in the United States. Eric York, a wildlife biologist, died of pneumonic plague just days after he was exposed to the bacteria (he was exposed to plague while autopsying an infected mountain lion. It was unknown that the mountain lion had contracted the disease). Mr. York sought treatment for a flu-like illness, but doctors did not suspect he had anything more serious until after he died.

Plague is certainly not on the current top-ten list of killer diseases. However, the potential for deadly outbreaks still exists. Global awareness and understanding of this disease can cut down on the mortality rate should another plague epidemic ever occur.

Sources:

*Researchers: Nils Chr. Stenseth*, Bakyt B. Atshabar, Mike Begon, Steven R. Belmain, Eric Bertherat, Elisabeth Carniel, Kenneth L. Gage, Herwig Leirs, Lila Rahalison. Published January 16, 2008 "Plague: Past, Present, and Future."

http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.0050003&ct=1

http://www.cdc.gov/ncidod/dvbid/plague/index.htm

http://www.medicalnewstoday.com/articles/88362.php