Deaths per year from rabies: 50,000, mostly children...
Palmer's work today at the Allen School follows three streams: zoonotic disease, developmental human stunting and antimicrobial
"Here’s a good example of the many inventive ways people bring their dogs [to be vaccinated]," Palmer says. (PHOTO COURTESY
OF DR. GUY PALMER)
One of the top zoonoses he studies is rabies—a disease, he says, that can actually be eradicated in communities in Africa
because it's strictly carried in the dog population. Without a reservoir of the disease in wildlife, vaccination programs
can successfully eliminate the deadly problem in areas isolated by natural barriers. That's the good news.
The bad news is that rabies still takes 50,000 lives a year, most of those deaths among children in sub-Saharan Africa and
South Asia. Dogs in rural Africa are mostly owned by boys, who are often bitten on the neck, face or head. "Those areas are
more highly innervated and they're also close to the cranial nerves, which is the way rabies uses to move up into the brain,"
he explains. "Children are at much higher risk."
Palmer and his colleagues have seen an almost linear correlation in Africa between a bitten child's distance from a clinic
where he could receive post-exposure prophylaxis and death. "When they're a distance away, their odds increase dramatically
of dying," he says. "There's no money for transport. They simply can't get there."
The challenge for Palmer and others is to build self-sustaining rabies vaccination programs in Africa. Today, most programs
are supported by nongovernmental organizations, which "go away when they can't fundraise or they get donor fatigue." So Palmer
is working with economists and epidemiologists in London and Glasgow to devise vaccination programs with lower costs and community
control. And the signs point to progress—last May, Kenya for the first time initiated its own rabies eradication program.
Veterinarians from the Allen School (Palmer is at left) discuss research addressing household welfare and health as related
to animal ownership in Asembo, Kenya. (PHOTO COURTESY OF DR. GUY PALMER)
Palmer says a vaccination level of 60 percent of the dog population in a community can eliminate rabies since it's not carried
in local wildlife—an important discovery he credits to researchers at the University of Glasgow. "If we can control it in
dogs," he says, "we can get to an elimination point where you would not have to continually vaccinate."
For comparison, consider human measles. Measles has a reproductive rate of about 15, which means a child who goes to school
with measles will likely infect 15 other children. For rabies, the rate is 1.2—an infected dog is likely to transmit the disease
to just one other dog. "So if you get that to drop below one, obviously the infection dies out on its own," Palmer explains.
"You don't have to vaccinate the full population. In fact, if there are three dogs out there and two are vaccinated, it's
just an odds ratio that our rabid dog is more likely to bite one of the vaccinated dogs."
Natural barriers also make rabies elimination possible. In Tanzania, where one of the Allen School's initiatives is located,
Lake Victoria is on one side and a mountain range on the other, so the community is "basically an island free of rabies,"
Palmer says. His goal is to knit together strings of rabies-free islands across the region.
This is important from a veterinary medical perspective but also from a psychological perspective. "It breaks down the overwhelmingness,"
he says, both for local community leaders and for folks at home who contribute financially.
"Veterinarians need to take the absolute lead in this area," Palmer says. "They need to say this is a controllable problem
responsible for 50,000 deaths a year and we can do something about it." He thinks private practitioners in the States can
promote rabies elimination among their clients—dog owners who "a priori love dogs and also have a social conscience."
"If we can bring the awareness to them—the idea that this isn't a one-off thing; this isn't hopeless; there's actually an
elimination goal—we can galvanize them," he says. A veterinarian might explain to potential supporters, for example, that
as developing countries get wealthier, they'll have the veterinary infrastructure and the finances for dog owners and private
veterinary practitioners to take responsibility. "As you can imagine, that's not in the foreseeable future. But by talking
about an elimination strategy, we've begun to change the way people look at the issue," Palmer says.
Plus, Palmer finds hope in the long lines of boys—and a few girls—who bring their dogs to ad hoc vaccination clinics for rechecks.
He says the dogs aren't feral; they all have owners. They help protect the compound, but mostly their role is companionship.
In a country where people have few documents, the children who come for rechecks always seem to have their vaccination papers
clutched in their hands, and they relish logging in their dogs' names.
"The dogs are mostly owned by little boys and they like tough-guy names," Palmer says. "There are a lot of Simbas and Chuis—a
name for leopards—and Rambos, Saddams and Osamas. These names really crack me up. And they're marvelous dogs. They're about
35 pounds, have fantastic dispositions and, as you can imagine, they're tough as nails."