Wednesday, June 13, 2012

A Pathogen That Still Plagues Mankind

 

 

 

# 6382

 

 

In 1975, after completing my paramedic training in Florida, I was offered an ALS (Advance Life Support) ambulance job in Phoenix, Arizona.

 

On my first day there, I was given an orientation, which included information about threats I hadn't dealt with in my home state of Florida: Scorpion stings, Gila Monster bites, and bubonic plague.

 

Albeit rarely, bubonic plague still occurs in the United States. This map, from the CDC, shows areas of the world where plague is endemic, mostly in rodents.

 

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The last major urban outbreak of plague in the United States occurred in 1924-25 in Los Angeles.  Since then, only scattered cases have been reported, with about 10-15 cases each year.

 

Globally, the World Health Organization reports between 1,000 and 3,000 cases occur each year.

 

Today the Associated Press is reporting on an Oregon man who is hospitalized in critical condition with what appears to be septicemic plague.

 

Plague: Central Ore. man contracts rare disease

PRINEVILLE, Ore. (AP) — A central Oregon man in his 50s is in critical condition at a Bend hospital after a form of plague infected his blood, according to a Crook County health official.

 

The disease can spread through contact with a sick animal or a bite from an infected flea. The man, who has not been identified, had contact with a sick cat.

(Continue . . . )

 

 

Plague is caused by a gram negative bacteria called Yersinia pestis. There are three types of plague (all caused by the same pathogen); bubonic, septicemic & pneumonic.

 

From the CDC’s brochure Protect Yourself From Plague, we get the following definitions:

  • Bubonic plague is the most common form of the disease and typically occurs after the bite of an infected lea. The hallmark of bubonic plague is a swollen, painful lymph gland, called a “bubo,” usually in the groin, armpit, or neck. Other symptoms include fever, chills, headache, and extreme exhaustion. A person usually becomes ill with bubonic plague 2 to 7 days after being infected. If not treated early, the bacteria can spread from the bubo to other parts of the body.
  • Septicemic plague occurs when bacteria multiply within the bloodstream. This may occur if bubonic plague is left untreated, but it can also occur in patients without a bubo. Symptoms include high fever, exhaustion, light-headedness and abdominal pain. Septicemic plague can rapidly result in shock and organ failure.
  • Pneumonic plague occurs when the plague bacterium infects the lungs. This happens when bacteria spread through the bloodstream to the lungs or, less often, when bacteria are inhaled directly into the lungs. Symptoms include high fever, chills, cough, breathing difficulty, and bloody sputum. Pneumonic plague is almost always fatal if not treated rapidly.

 

 

Although most people are aware that plague is transmitted by the bites of infected fleas (who obtain the plague bacteria from rodents), it can also on rare occasions be transmitted from human-to-human (via droplet or saliva), and and can be contracted from contact with an infected animal, such as a mouse or squirrel. 

 

While it is uncommon, people can sometimes contract plague from their pets. Cats, which may have contact with infected rodents while roaming, can either bring back infected fleas, or become infected themselves.

 

 

The CDC offers the following advice on avoiding plague:

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The good news is - that if diagnosed and treated early - plague responds well to several common antibiotics. 

 

My interest in plague began at the tender age of 11 when I read James Leasor’s  The Plague and The Fire.

 

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I’ve no doubt that this account of two incredible years in London’s history (1665-1666) - which began with the Great plague, and ended with the Fire of London – have unduly influenced my life, and interests, over the past 45 years.

 

A cautionary note, I suppose, regarding what one ought to read at an impressionable age.

 

 


While Yersinia Pestis is assumed by most scientists to have been the cause of the Black Death of the Middle ages, there remains some controversy on that topic (see EID Journal: A Scholarly Debate).

 

Last year, Ed Yong, writing for Discover Magazine took a fresh look at the debate in The lost plague – London graveyards suggest that Black Death strain may be extinct.

 


While not a common disease in the United States, there have been some concerns that climate change could exacerbate the spread of Yersinia infected rodents, and increase the risks of infection (see Climate Change Eyed As Spreading Diseases).

 

For more on Plague, the CDC’s  DVBID (Division of Vector-Borne Diseases) maintains an extensive website on the pathgoen at:

 

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