Local wisdom key to combating animal diseases

Flush with success over the unprecedented eradication of rinderpest, scientists are setting their sights on the next big livestock disease to rid from the world. Experts are aligning their crosshairs over foot and mouth disease, which affects every continent except Antarctica.

“In my opinion foot and mouth disease is by far the most important socio-economic disease of livestock worldwide,” said George Saperstein, a veterinary medicine professor at Tufts University. “It is highly contagious, affects multiple species, is difficult to control, has a major impact on international trade of animals and animal products, and causes dramatic reductions in livestock productivity for farmers on a global scale.”

“Foot and mouth disease could be the next big target for the international community at large,” said Kazuaki Miyagishima, deputy-director-general of the World Organization for Animal Health (OIE.) “There are still more than 100 countries suffering either endemically or periodically.”

The Food and Agriculture Organization (FAO) and the OIE plan to hold a pledging conference next summer to motivate international donors to provide more funding for vaccine research to combat the disease.

But experts agreed that eradicating it would be an especially tall order.

There are several strains of food and mouth disease, so one vaccine will not protect against all types. The vaccination has to be kept cold, one of the most daunting challenges in administering it in remote locations. And the immunity it provides does not last very long; animals have to be vaccinated over and over again to keep them safe.

Eradication the goal?

Not everyone is on board with making eradication the goal.

“We should move away from the focus on eradication, which has had its day,” said Andy Catley, a Research Director at Tufts University. “It took us 50 years, hundreds of millions of dollars, and a global effort [to eradicate rinderpest]. And it was a relatively simple disease.

“Eradication is easy for the public and donors to understand. The question is, do you really need to eradicate any other disease in these pastoral areas? Technically it’s incredibly difficult and economically it might not be needed to get the trade benefits.”

Instead, Catley suggested bringing epidemiologists, economists, and livelihoods experts together to take a closer look at how to control diseases with community involvement, instead of bounding off on an overly-ambitious, and uncertain global eradication campaign.

Catley believed one of the reasons the rinderpest eradication worked was that it did not just involve local collaboration, it was based on it. But a community-based, culturally-appropriate local effort to control disease can be a hard sell and a long haul. “It’s a more complex, less sexy message to sell to donors,” he said.

Rinderpest lessons

When the highly contagious rinderpest virus was inadvertently introduced to sub-Saharan Africa in the late 1800s, it ruined pastoral economies and social structures, and left 90-95 percent of cows in Africa dead.

“It swept across the whole continent and all previously known livestock diseases paled into insignificance beside the trail of destruction left in its wake,” wrote IRIN journalist Louise Tunbridge in a 2005 book on animal health care in Southern Sudan. “Historians describe it as the greatest natural calamity ever witnessed in Africa.”

Once a vaccine was developed that could survive the scorching African heat without a cold chain, it took another decade for it to be deployed effectively to the desolate locales where the virus still lurked. Success started with 20 local herdsmen in Cameroon who were trained to vaccinate their own cattle and quickly proved they were able to access more cows than government veterinarians.

“The pastoralists knew how to inject their animals. They were also at home in the harsh terrain, wading up to their waists in swamps, clambering up rocky mountainsides and walking with heavy loads for days at a time,” wrote Tunbridge. “How many town-based professional veterinarians would endure such discomforts?”

Juan Lubroth, FAO’s chief veterinary officer, agreed that local wisdom was key to recognizing where to go to vaccinate in Southern Sudan and Somalia. But he said Western biotechnology and science still had a big role to play in combating diseases.

PPR

While the vaccines for foot and mouth disease are technically and logistically problematic, another livestock disease called Peste des Petits Ruminants (PPR) already has a successful vaccine. An acute and highly contagious disease that affects mostly sheep and goats, it is caused by a virus similar to rinderpest, and according to OIE’s Miyagishima, could be a more promising target for eradication.

“We have a relatively good and cheap vaccine for PPR. The problem is that small ruminants have less economic importance so it’s harder to get countries and governments engaged,” he said. Since cows are traded on the global economy while poorer people keep small animals for household use, diseases that affect them are paid less heed by scientists, researches and donors.

“Small ruminants are usually held by the poorest of the poor; they don’t have the same value as cattle,” said FAO’s Lubroth. “For PPR, we have similar tools that we had for rinderpest; it’s related to it; we know a lot about it and we have diagnostics. What we don’t really have is the political support.

Miyagishima said foot and mouth disease would probably be prioritized despite its technical problems, because governments are more conscious of it and see more economic benefit in its eradication.

“Certain wealthy countries with sophisticated surveillance systems and favorable geography can keep [foot and mouth disease] out, but it is in everyone’s best interests to eradicate it worldwide rather than exclude it from individual countries - usually the wealthiest countries,” said Tufts University’s Saperstein.

Meanwhile, the InterAfrican Bureau for Animal Resources warned: “Unless coordinated action is taken to control the spread of the disease, small ruminant plague [PPR] is likely to spread to most of Africa, bringing with it untold losses of livestock and endangering the livelihoods of millions of African farmers and herders.”

“You can’t just be in a comfortable chair in the capital and know what’s going on on the ground,” said Miyagishima. Locals are essential in watching out for signs of the disease and reporting them to the authorities. “If they start hiding the disease, it will be propagated,” he said.

Animal owners often do want to hide evidence of an outbreak, since authorities respond to some diseases by killing animals, even healthy ones. Some developed countries have financial compensation schemes, or even private insurance. “But in most of the developing world, there’s no incentive to report disease,” said Miyagishima. “This is something that’s really important to address since early detection is key.”

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