Saturday, September 28th, is World Rabies Day. Scientists estimate that 60,000 people die every year from the animal-transmitted disease. Many of the victims are children bitten by rabid dogs.
The risk of rabies depends on where in the world you live, says Professor Neil Dyer, director of the Veterinary Diagnostic Laboratory at North Dakota State University in Fargo. In the United States rabies is generally not a big problem, but in Asia and Africa, where there are more stray animals and fewer vaccination programs, rabies is a much more serious problem.
Rabies in the United States, says Dr. Dyer, is mostly limited to the wild animal population, but in “[o]ther parts of the world, there still is rabies in the dog population. Some parts of Asia would be wolves or foxes. The virus has the ability to go in different directions, which is part of the reason why it’s been able to be as successful as it has been.”
Bats are known to transmit rabies in South America, for example.
Rabies, a virus, has been around for thousands of years. The World Health Organization says it is present in 150 countries and territories. About the only place where rabies has not penetrated is Antarctica, the icy continent on the South Pole.
Because Africa and Asia see greater prevalence of rabies among domestic animals, that is where most of the 60,000 annual rabies fatalities occur. Dyer says that historically, rabies in developing countries is nearly always fatal once contracted. Today, however, health officials stress that rabies is a preventable disease.
The Infection Is Slow…
Professor Dyer says rabies usually infects more slowly than other viruses because it travels along nerves, not in the bloodstream.
“(L)et’s say you got bitten on the finger,” Dr. Dyer explains. “The virus would have to travel up your peripheral nerves, eventually get to your spinal cord and then go up to your brain and ultimately would travel to a salivary gland because that’s how the virus is transmitted: through saliva.” It is contact with infected saliva that spreads the virus to new hosts.
Only when the virus reaches the spinal cord and brain do hosts start to show clinical signs of infection, including paralysis and behavioral abnormalities.
But the Response Must Be Fast
Dr. Dyer emphasizes that rabies infections can be prevented, but only if steps are taken immediately after being bitten by an animal infected with rabies.
“(T)horoughly wash out the spot where you’d been bitten because the virus tends to hang around the bite site for a little while,” says Dr. Dyer, “and then you would get a shot, which is essentially antibody against the virus. So that would be kind of immediate passive immunity given to you. And then you would get a series of three shots after that that would essentially vaccinate you for rabies, as well.”
The U.N. Food and Agriculture Organization, the WHO and the World Organization for Animal Health say vaccinating at least 70 percent of dog populations “breaks the cycle of transmission” from dogs to humans. Vaccination efforts should include “free roaming and street” dogs.
The agencies say livestock can be infected with rabies from both dogs and wildlife. Rabies infections can affect both livelihoods and food security.
This is why the Global Alliance for Rabies Control launched the first World Rabies Day in 2007, to encourage communities to focus on rabies prevention.
Dyer says, “Getting [the] vaccine out into the smaller communities [is important] because…that’s where the interface between wildlife and domestic animals is. And as long as you have that potential, the virus can leak back into the domestic animal population and then by extension into the human population.”
To break the cycle, Dyer warns, the entire community must be engaged must be part of any vaccination program.