Rabies: Disease in the shadows recognized Sunday

By Linda Weiford, WSU News 

dogPULLMAN, WASH. – It is a disease spread by a virus that strikes mostly in faraway places. Without quick treatment, an infection delivers agonizing symptoms leading to death.

It is not Ebola; it’s rabies. And though these two zoonotic diseases share some characteristics – and both ruthlessly exploit feeble health-care systems – a crucial difference is this: As the deadly Ebola outbreak continues to rage across West Africa, no proven vaccine exists to combat it. But a rabies vaccine has long existed, created by French scientist Louis Pasteur in 1885.

Which is why it is especially disturbing that each year rabies kills an estimated 69,000 people worldwide – that’s 189 each day. Most deaths occur in Asia and Africa, and 40 percent are children, according to the World Health Organization.

rabies-team
Annual dog vaccination clinics in Tanzania have reduced the number of human rabies cases to zero. Left to right: Machunde Bigambo, assistant project manager; Guy Palmer, Allen School director; Imam Mzimbiri, project manager and veterinarian; Paulo Tembo, field assistant and mechanic; Felix Lankester, Allen School East Africa-based researcher.

With this in mind, agencies and individuals around the globe have banded together to recognize Sept. 28 as World Rabies Day. Sunday marks the 119th anniversary of Pasteur’s death.

The virus – shaped like a bullet – could be eliminated among humans and yet it persists, partly due to political complacency and also a lack of international commitment, said veterinary infectious disease expert Guy Palmer, who directs Washington State University’s Paul G. Allen School for Global Animal Health based in the College of Veterinary Medicine.

“Once a person develops symptoms of rabies, the chance that he or she will die is nearly 100 percent,” he said. “The irony is that rabies is 100 percent preventable. People shouldn’t be dying at all.”

The rabies virus is spread to humans through the saliva of infected animals, mostly dogs. Unlike Ebola, which was identified just 38 years ago, rabies is one of the oldest diseases known to humankind.

“We’ve had plenty of time to acquire the know-how and tools to deal with it,” said Palmer.

Solution: protect dogs

To stop the disease among humans, it must be stopped among dogs, the biggest source of transmission. Dog immunization programs are the most viable way to do that, said Palmer.

Working with WSU veterinary colleague Felix Lankester and the Serengeti Health Initiative, Palmer runs dog vaccination clinics in 180 villages in East Africa’s Tanzania. In a region the size of Hawaii, “the number of human rabies cases has dropped to almost zero,” he said.

Taylor
Taylor

Vaccinating dogs is not only effective, but it’s also far less costly than trying to treat victims after they get infected, said Louise Taylor, a biologist with the Global Alliance for Rabies Control. With Palmer, Lankester and three other researchers, Taylor co-wrote the article, “Implementing Pasteur’s vison for rabies elimination,” published in the current issue of Science magazine. (See https://s3.wp.wsu.edu/uploads/sites/609/2014/09/Science-Polcy-Rabies-Elimination-092615.pdf)

Post-exposure treatment for humans – if available at all in impoverished and remote areas – generally requires four shots given over two weeks, Taylor said, adding that, “it’s expensive and time-consuming, especially compared to vaccinating dogs.”

One world, one health

Governments and political leaders can be complacent about rabies, often because they underestimate its threat and the suffering it can inflict upon its victims, she explained: “But without vaccinations, one rabid dog can quickly turn into many.”

A prime example is the arrival of a single infected dog to the Indonesian island of Bali in 2008. That animal bit another dog, which bit another and so on, according to studies done on the outbreak. A fast-growing population of rabid dogs went on to bite humans, resulting in 130 deaths.

“The outbreak is a tragic reminder of what can happen in countries that don’t respond appropriately and quickly to the threat of rabies,” said Taylor.

Though human rabies is rarely seen in developed nations that conduct mass vaccination programs, the disease should be viewed as a global public health problem, said Palmer. What’s more, because infections occur as a result of interactions between animals and people, a “One Health” approach is necessary where veterinary, medical and public health professionals work together to eliminate it.

“I think people tend to lose sight of why we vaccinate our pets, thinking that we do it to protect them from rabies,” he said. “But ultimately, we do it to protect ourselves.”

Learn more about the rabies program at the WSU Allen School at http://globalhealth.wsu.edu/research-intervention/control-of-disease-transmission/Rabies-Vaccination-Program.

 

Contact:
Guy Palmer, Paul G. Allen School for Global Animal Health, 509-335-6030, gpalmer@wsu.edu