What do rabies, Ebola and West Nile virus all have in common? They're among a range of zoonotic diseases - jumping from animals to humans. And West Nile was first noted here in the USA not by the CDC nor an MD, but by a veterinarian, who was blown off by CDC because she was "only" a veterinarian.
"The veterinarian cracked the case, and no one was interested in talking with her because she was a veterinarian," says Laura H. Kahn, a physician and biodefense researcher at Princeton. They should have listened: McNamara identified the first outbreak of West Nile virus in North America.
And zoonoses are a critical but often overlooked issue in medicine today:
Seventy-five percent of newly emerging diseases are zoonotic, meaning they can be spread between animals and humans. And they wreak havoc: People fall ill having no natural defenses, and there is often no medicine to fill the gap. It's estimated that between 1997 and 2009, the cost of these diseases amounted to $80 billion worldwide. Every year, there are 2.5 billion cases of zoonotic illnesses in humans, resulting in 2.7 million deaths.
The importance of stopping transmission cannot be overstated; rabies, for example is spread from infected bats, which transmit the disease to other animals - such as a local dog - which subsequently bites a human, infecting her. Veterinary intervention in the chain is essential, which is why most counties here in the USA require rabies vaccines for dogs.
UC Davis, which produces many of the veterinarians in the USA, now sends teams of vets into Africa, South America, and elsewhere in a USAID-funded effort to detect outbreaks in animal populations - and ideally, get them under some degree of control - before they begin to impact humans:
In 2012, the U.C. Davis group encountered five dead howler monkeys in Boliva. The team immediately collected samples, ran diagnostics, and discovered a deadly strain of zoonotic yellow fever in the necropsies. That triggered a comprehensive response from the Bolivian government. "Before any human cases could develop, [the Bolivian government] implemented a vaccination campaign, public outreach to talk about the situation so that people knew to avoid mosquitos, and a mosquito-control effort," Johnson says. "There were zero human cases."
For its part, CDC now has a national Center for Emerging and Zoonotic Infectious Diseases, and they're taking veterinary sciences a lot more seriously than they did fifteen years ago. That's a good first step, but funding for animal health research needs to be seriously stepped up, and the current Ebola outbreak is sending us an unmistakeable warning in that regard.