It’s that time of year. No, not for snow (although it is snowing here at the moment). It’s time for the annual US rabies surveillance report in the Journal of the American Veterinary Medical Association (Dyer et al. Rabies surveillance in the United States during 2013).
- Over 5800 rabid animals were identified in the US. 92% of those were wildlife. That’s going to be a profound underestimation since most rabid wildlife aren’t caught and tested, but it shows that rabies is still alive and well in the US.
- Rabies was most commonly diagnosed in raccoons, followed by bats, skunks and foxes.
- Among domestic animals, there were 247 cats, 89 dogs, 86 cattle, 31 horses/mules, 9 sheep/goats, 3 pigs, 2 llamas, and a partridge in a pear tree. (Obviously the last one’s my lame attempt at early winter humour. Birds aren’t a rabies concern).
- Other species affected included mongooses (38; as always, just from Puerto Rico), groundhogs (37), bobcats (16), coyotes (5), deer (5), otters (3), opossums (2), wolves (2), marmots (2), a rabbit and a fisher. Most of those are fairly typical, both in terms of the species affected and the numbers.
- Pennsylvania had the most rabid cats, while Texas won for most rabid dogs.
- Vaccination history was not usually available for rabid dogs and cats. None of the rabid cats had been properly vaccinated against rabies. One of the rabid dogs had been vaccinated, a 10-month-old dog that developed rabies 7 months after receiving its first dose. This one’s a bit concerning, though. By being vaccinated at 3 months of age, it would have been considered "up-to-date" on rabies vaccination and this would therefore be a vaccine failure. No vaccine is 100% effective (although rabies vaccine is considered very effective as vaccines go) and the dog having only received only one dose because of its age was probably a key factor.
- The dominant rabies virus variants had a typical geographic distribution (see map above).
Three people were diagnosed with rabies during the year.
- The first was a person who died of raccoon rabies. There was no history of animal exposure, but he had received a kidney transplant 17 months earlier. The donor had been diagnosed with severe gastroenteritis, but also had some neurological abnormalities and when banked samples from the donor were tested, rabies virus was found. Three other organ recipients were then given post-exposure prophylaxis.
- The second person was a man from Guatemala who was detained trying to enter the US. While in custody, he developed neurological disease and died. Central American canine rabies variant was identified.
- I assume the third reported case was the organ donor from the first case, since the case was diagnosed in 2013 (even though the person died in a different year).
As per usual, there’s a little information about Canada and Mexico in the paper.
- 116 rabid animals were identified in Canada, 88% of those being wildlife. There were also 12 cats and dogs (combined) and 2 horses.
- In Mexico, an important finding was the fact that, for the first time since 1938, no people died of rabies. Eleven rabid dogs were identified. However, care must be taken in comparing data from different countries because of potential differences in testing (if you don’t look too hard, you don’t find).