If There's A Raccoon in Your Bed, Call A Doctor

When I heard that a raccoon attacked a Massachusetts woman in her bed, I immediately assumed the raccoon to rabid--and it was. 

As a virus that infects the brain, rabies has the ability to change its host's behavior. As rabies is spread via saliva, it makes perfect sense, in evolutionary terms, for the virus to prompt some change in behavior in order to facilitate saliva exposure in potential new hosts. Hence, rabid animals "foam at the mouth" and become aggressive. See the book Rabid for a great history of the disease.

A raccoon's natural proclivity is to avoid human contact. For a raccoon, the most commonly reported wildlife reservoir for rabies in the US, to pounce into a bed and attack a woman is an unequivocal behavior change consistent with rabies. 

In the US, human deaths from rabies seldom occur given the ability of those exposed to access effective post-exposure prophylaxis which consists of the vaccine (thank you Louis Pasteur) and immune globulin. For those who develop symptoms, a fatal course is to be expected (unless the Milwaukee Protocol is initiated and is efficacious). 

Among the pantheon of infectious diseases, rabies has a special place in my heart as it was the children's book detailing Pasteur's work to develop the rabies vaccine that first captured my interest in the field.

Grave-robbers, No Need to Fear Smallpox

Since smallpox has been eradicated from the planet, thanks to DA Henderson, the human population has little to no immunity to this deadly pathogen. This fact is what prompts concern about its use as a bioweapon. 

In lectures, I often say that one case of smallpox represents a likely bioterror event. However, a recent paper published in Emerging Infectious Diseases details the ability of smallpox to persist in relics (corpses, scabs). 

The conclusion of this interesting paper is that historical relics do not pose a major threat of smallpox exposure as infectious viral particles have not been recovered from myriad samples, though viral DNA has been discovered. 

So grave-robbers are likely safe from this pathogen.

You're Never Too Cool for Pneumonia

One of the crucial interventions to undertake after a person suffers cardiac arrest is therapeutic hypothermia. This intervention cools the body temperature (by a few degrees Centigrade) in order to minimize damage to then brain that might have occurred during the period of time the person was deprived of oxygen and after circulation has been restored. 

There are several means to achieve a lowered body temperature and usually include either the insertion of a cooling catheter in a major vein or a special cooling blanket. 

One of the caveats to therapeutic hypothermia is that it increases the risk of infection. A recent systematic review and meta-analysis published in Critical Care Medicine, tries to asses the magnitude of this risk. 

Pooling the results of prior research, as was done in this paper, revealed that therapeutic hypothermia increases the risk of pneumonia and sepsis. This is not a surprising finding given the impact cold temperatures can  have on the immune system. Specifically, hypothermia blunts the ability of cells to employ specific cytokines thus rendering the individual in a net state of immunosupression. 

This finding illustrates the delicate balance physicians must strike in order to optimally treat a patient, continually weighing risks versus benefits. In the end, therapeutic hypothermia--for those who need it--confers too high of a  benefit to be jettisoned secondary to a heightened risk of infection. 

Legionairre's Disease: Three Rivers Nurture It

Today, the Department of Veterans Affairs conceded negligence in one of the fatal cases of hospital-acquired Legionnaire's Disease that have plagued the VA in Pittsburgh. In total 21 cases have been identified.

Irrespective of the issues regarding the VA, which likely resulted in the resignations of regional and local VA personnel, the fact remains that the Pittsburgh area is rife with Legionella. In fact, if taken as a state, the city of Pittsburgh would rank high as a state. Perhaps the confluence of our famed three rivers provide the perfect environment for Legionella.

In Pittsburgh, every case of pneumonia is considered a potential Legionella case. 

MRSA Probably Attends Every Super Bowl

As everyone was watching the Super Bowl today, I thought it appropriate to review an infection that is common in those who play football: MRSA skin and soft tissue infections.

One of the most famous associations of this organism with a football team was with the 2003 St. Louis Rams. In that incident, MRSA skin infections occurred in 9% of the Rams with--ominously--42% of players and  staff colonized in their nasal passages. 

More recent studies, have confirmed similarly high prevalence of infection with MRSA in high school football players as well.

Skin abrasions (i.e. turf burn) are thought to predispose to infections while the close contact amongst players coupled with suboptimal hygiene predisposes to colonization.

MRSA--another reason to prefer skateboarding (my favorite sport).