Rabies Alert

Don’t let your curiosity for the exotic come back to bite you

Vampire bats do exactly what you think they do—feed off animal blood. Native to Latin and South America—where they hide out in caves, old wells and trees, especially in rainforests—they’re a major reservoir for rabies, a deadly virus transmitted through saliva. Since rabies can be fatal to humans if left untreated, people travelling to places with vampire bat habitats should be vaccinated, says Dr. Terill Udenberg, a Vernon, B.C., veterinarian and volunteer with the Canadian Animal Assistance Team (CAAT), an organization that helps domestic 
animals in underdeveloped regions. “Certainly if you are sleeping in a hammock with your toes sticking out, you are going to be exposed to rabies.”

Yet perhaps the greater threat is how bats can infect other animals, like dogs and cats, which are rarely immunized for rabies in the developing world. It’s quite possible this is how a dog Udenberg encountered in Guyana became rabid. “The family brought the dog to us because she’d been acting abnormal and threatening to bite. You just needed to look at it to know—her lips peeled over, [she showed] the salivation typical of rabid dogs, she was uncoordinated.” Etch this picture in your brain, Udenberg told his team—this is what rabies looks like.

Each year about 55,000 people die from rabies, says the World Health Organization (WHO). As a disease of nature that can infect almost any mammal, it’s considered prevalent worldwide—though the less developed the country, the higher the incidence—and is highly endemic in China, India, Pakistan, the Philippines and sub-Saharan Africa. In Canada, five people have died from rabies since 1985—one of them a traveller bitten by a rabid dog while in the Dominican Republic. And just last year, an elderly man from Alberta died nine months after being bitten by a bat—the third bat bite victim since 2000. In North America and Europe, pet immunization has rendered rabies a low-risk disease. Even still, the Canadian Food Inspection Agency reports that between the years 2000 and 2006, there were 2,467 laboratory-confirmed cases of animal rabies in the country.

According to Dr. Charles Rupprecht of the Centers for Disease Control and Prevention (CDC), all bat species pose a threat for rabies since they don’t respond to the vaccine-laced bait-drop programs done in many regions to immunize animals in the wild. Compounding the containment problem, people often don’t realize they’ve been bitten and the incubation period (the time before symptoms manifest) can run from 20 to 60 days, up to months and even years. If you’re ever bitten or even scratched by a bat anywhere in the world, immediately contact a doctor or public health authority, who may prescribe post-exposure treatment.

Rabies is a horrific way to die. As an acute, progressive encephalitis (inflammation of the brain), it begins when the virus attacks the central nervous system and travels along the spinal cord to the brain. (It ends up in saliva looking for an exit route.) It literally drives its victims mad—causing hallucinations, delirium, convulsions, paralysis and difficulty swallowing, and a peculiar fear of water (hydrophobia). There’s no cure, no medicine that can kill the virus once symptoms appear. For travellers, rabies is both a rural and an urban hazard, since dogs and farm animals often roam free, and our sense of curiosity can get the best of us. Human cases have definitely resulted, says Rupprecht, from people interacting with the exotic. And western travellers can attract dogs, says Udenberg, since they may look or smell differently.

Fortunately, travellers can get a pre-exposure vaccine and there’s an effective (if taken in time) post-exposure treatment. The not-so-great news is that pre-exposure doesn’t confer total immunity. You absolutely need post-bite (or scratch, or lick) treatment if there’s any chance you’ve been exposed to the virus because the chance you take with rabies is not whether you end up sick, but whether you end up dead.

This entry was posted on Wednesday, July 30th, 2008 at 3:23 pm and is filed under Health. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a comment, or trackback from your own site. Add to del.icio.us.