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MRSA versus the plague

Posted Aug 26 2008 4:08pm


While we are in the midst of a political and public relations panic, there is a story flying just under the radar that would be worthy of a real run-in-the-streets-screaming panic.



A wildlife biologist from Massachusetts working in the Grand Canyon died of the plague. The story from a TV news outlet [for God's sake!] is more thoroughly reported and researched than much of what I see in the NYT.



Forty nine people were given prophylactic antibiotics because pneumonic plague is so highly infectious, even casual contact justifies treatment. In general, anyone who has come within 6 1/2 feet of an infected person should take preventive antibiotics. Yersinia Pestis is classified as a Category A Select Agent, which means it can be weaponized or used for bioterror, but it can be handled in a biosafety level 2 lab. Most of this information is from the CDC .



There are three forms of the disease, bubonic plague which affects predominantly the lymph nodes, septicemic plague where the bacteria break through initial structural barriers and find their way into the blood stream and pneumonic plague , affecting the lung, which has a 50% mortality, even with treatment. If treatment is delayed more than 18 hours, survival is unlikely. I find it troubling that there are no useful clinical clues to the presence of pneumonic plague. Bubonic plague present with a violent febrile illness with marked lymph node enlargement, but there is no guarantee that the pneumonic form of the disease produces those kind of lymph nodes.



Yersinia pestis is usually contracted from the bite of an infected flea. The major repository is wildlife, as our biologist discovered; he contracted the disease after doing an autopsy on a mountain lion.



A little history lesson is provided via JAMA :

In AD 541, the first recorded plague pandemic began in Egypt and swept across Europe with attributable population losses of between 50% and 60% in North Africa, Europe, and central and southern Asia. The second plague pandemic, also known as the black death or great pestilence , began in 1346 and eventually killed 20 to 30 million people in Europe, one third of the European population. Plague spread slowly and inexorably from village to village by infected rats and humans or more quickly from country to country by ships. The pandemic lasted more than 130 years and had major political, cultural, and religious ramifications. The third pandemic began in China in 1855, spread to all inhabited continents, and ultimately killed more than 12 million people in India and China alone.
Lest you think I am taking my turn at panic-mongering, there have been no cases of the plague in the Southwest for several years, but increased activity has been noted in Arizona and new Mexico. We are only talking about an average of 13 cases a year and about 15% case fatality, but it is worthy of watching. There is as yet no sign of an increase in incidence, despite the endemicity of Plague in the Western reaches of the continent.



It is unclear to me if this biologist was careless or slipped up. For example, we don't know if he was supposed to be using personal protection like a mask. Even if he took painstaking precautions, his occupational risk was working with animals that represent the reservoir of plague in an area where the disease is endemic. Fortunately no resistance has been described, unlike MRSA. Personally I think it's only a matter of time before someone on Fox blames the plague on illegals coming across the border from Mexico!



While we're on the topic of foreigners and disease panics [this is intended as biting sarcasm], has anyone noticed that bird flu has claimed it's 91st victim in Indonesia , bringing the international death toll to 205? We're going into the winter and the UN is concerned this may be the year we start to get human-to-human transmission.
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