Third Reported Recovery From Clinical Rabies in the U.S.

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Rabies is a serious — almost always fatal — viral infection of the central nervous system. The virus is present in the saliva of infected mammals, and is most often spread via a bite wound. Raccoons, skunks, bats, foxes, and coyotes are the most common carriers of rabies in the United States, though any mammal, including domestic dogs and cats, can become infected and transmit the disease. The U.S. Centers for Disease Control and Prevention keeps statistics on rabies incidence in the U.S., and notes that cases are quite rare. Only one or two individuals a year become infected with the rabies virus, and prophylaxis (vaccination post-exposure, but prior to the development of symptoms) is almost always effective.

Bat


Despite the very good prognosis for exposed individuals who receive appropriate post-exposure prophylaxis, rabies is nearly universally fatal once symptoms begin to appear. After exposure to rabies, it generally takes a few weeks for early symptoms to develop. The earliest symptoms are flu-like, but resolve after several days to a week. Symptoms then become more specific, and include anxiety, hallucination, insomnia, and abnormal cognition and behavior. There have been fewer than 10 reported cases of survival from clinical rabies (that is to say, rabies that has developed to the point of being symptomatic). Until recently, there were only two documented cases of survival from clinical rabies without post-exposure prophylaxis.

The first documented survival of this type occurred in 2004 in Wisconsin [1]. A 15-year-old girl was exposed to rabies after picking up a bat, which subsequently bit her. The wound was cleaned, but there was no post-exposure prophylaxis administered. She developed symptoms approximately one month post-exposure. Following admission to the hospital, she was put into an induced coma for a week. Surprisingly, she recovered from the virus and was brought out of the coma.

A second case of survival from clinical rabies with no proper post-exposure prophylaxis occurred in 2009 [3]. A 17-year-old Texas girl who’d had contact with bats during a cave exploration — but who did not recall being bitten — developed symptoms approximately two months thereafter. She eventually recovered with supportive care.

Recently, a third case of survival from clinical rabies has been reported [3]. An 8-year-old California girl developed symptoms and was admitted to the hospital. After the rabies diagnosis was made, she was put into an induced coma. 52 days later, she was discharged from the hospital to continue therapy as an outpatient. It was eventually determined that she’d been exposed to rabies after coming into contact with feral cats.

It’s interesting to note that in all three cases of recovery from clinical rabies with no post-exposure prophylaxis, the patients were children. Whether this is clinically relevant or merely coincidence has not yet been established; there are simply insufficient numbers to derive robust conclusions. Nevertheless, a third such case of recovery begins to pique scientific interest, and it may be that in the coming years, researchers will be able to identify factors that make children more resilient in the face of clinical rabies infection.

The CDC warns that despite the third documented case of clinical rabies survival, there are no justified grounds for viewing rabies as treatable. The very slight possibility of recovery from clinical rabies notwithstanding, the CDC emphasizes the importance of rabies education in reducing the risk of exposure and obtaining proper post-exposure care. Any physical contact with a bat, regardless of evidence of a bite, is grounds for receiving post-exposure prophylaxis (unless the bat is obtained and tests negative for rabies). Any bite from a wild mammal, unless the animal can be obtained and tests negative for rabies, is grounds for post-exposure prophylaxis. Any bite from a domestic dog or cat, unless the animal tests negative for rabies or has a documented history of up-to-date rabies vaccination, is grounds for post-exposure prophylaxis.

One final note for those who are nervous about the nature of post-exposure rabies prophylaxis: while rabies shots were once given in the abdomen and quite painful, they’re now given in the arm (like a flu shot), and are no more painful than any other immunization.

References

  1. Centers for Disease Control and Prevention (CDC). Recovery of a patient from clinical rabies–Wisconsin, 2004. MMWR Morb Mortal Wkly Rep. 2004 Dec 24;53(50):1171-3.
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  2. Centers for Disease Control and Prevention (CDC). Presumptive abortive human rabies – Texas, 2009. MMWR Morb Mortal Wkly Rep. 2010 Feb 26;59(7):185-90.
    View abstract
  3. Centers for Disease Control and Prevention (CDC). Recovery of a Patient from Clinical Rabies — California, 2011. MMWR Morb Mortal Wkly Rep. 2012 Feb 3;61(4):61-5.
    View abstract