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How veterinary medicine can save the world: Part 2, protecting the planet
According to one researcher, veterinarians' understanding of issues affecting global health is unmatched-which requires their involvement on the world stage.
Guy Palmer is not afraid to talk about social responsibility. He's not willing to write off the less-developed world as somebody else's problem. He's not afraid to discuss solutions to seemingly intractable problems.
He's not afraid to say these are his problems precisely because he's a veterinarian.
Palmer, DVM, PhD, anchors the Paul G. Allen School for Global Animal Health (named for Bill Gates' famous computing buddy and Microsoft cofounder, who donated $26 million toward the program and facility in 2010) at Washington State University College of Veterinary Medicine.
Tanzanian locals line up with their dogs for a village-based rabies vaccination program. At a typical village, 500 to 1,000 dogs may be vaccinated in a given day. Global animal health researcher Guy Palmer, DVM, PhD, says that with concentrated effort, rabies can actually be eradicated in sub-Saharan Africa.
The Allen School's core philosophy places its researchers squarely at center of "the animal-human interface." For Palmer, that's the place where emerging diseases incubate. It's the place where antimicrobial resistance mutates. It's the place where rabies kills children and desperately poor nutrition creates physical and cognitive stunting. And, he contends, it's a place where veterinarians belong.
"Veterinarians not only have a role to play in global health and the full development of people," he says, "but they have a role they must play. That is, there are some skill sets that need to be brought to the table and veterinarians have them; they're missing in other disciplines in global health. The situation literally requires veterinarians to take leadership roles."
Palmer's journey to the villages of sub-Saharan Africa and other remote corners of the globe began in the middle of the American landscape at Kansas State University in Manhattan, Kan. He was at K-State, two hours west of his boyhood home, to study private-practice veterinary medicine. But a series of mentors—Harry Anthony at K-State and Travis McGuire at Washington State—steered his interests into a broader world, especially Africa.
Palmer says a potential solution to the problem of stunting is to change the way animal protein is allocated in households-to make sure, for example, that pregnant and nursing women get eggs. (PHOTO COURTESY OF DR. GUY PALMER)
"I began to really appreciate the role of animals in people's daily lives and how they affect their education, their health, the stability of their communities," he says. "It brought home to me the importance of veterinary medicine. I feel quite strongly that veterinarians should not be afraid to talk about social justice or feeding the world. We have a very strong role to play and we shouldn't be shy about doing so."
The role of animals in the daily lives of people in sub-Saharan Africa isn't exactly like the human-animal bond most small animal practitioners understand so well. It's more about survival. Nutrition. Secondary education. Political stability.
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 resistance.
"Hereâs 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."
Stunting: As many as 50 percent of children can be affected
The second stream of Palmer's research agenda seeks physical, cultural and, ultimately, political answers to the problem of developmental stunting in sub-Saharan Africa. The United Nations Children's Fund (UNICEF) estimates that 800 million people in the world are stunted. In some villages of sub-Saharan Africa, nearly half the children are affected by the syndrome.
Why does a human ailment draw a veterinarian's attention? For one thing, Palmer says, humans become stunted because they don't get enough protein in the first 1,000 days of life—and malnutrition and protein production are areas veterinarians deeply understand. "These children never really get to their physical norms," Palmer says. "Their height shows up as reduced but their weight for height may actually look quite normal. The tragedy is that physical stunting is just the outward sign. There's also a good deal of cognitive stunting."
Cognitive stunting has far-reaching effects—Palmer has met with U.S. Rep. Adam Smith, the ranking member of the House Armed Services Committee, on the issue because Washington is seeing a connection between this disease and massive instability in parts of the world.
"People ask me, 'Why does this matter to us?'" Palmer says. "Well, this matters to us because young men who are cognitively stunted are not healthy for anybody." Cognitive stunting is associated with societal volatility when these unstable, underdeveloped, vulnerable children become boy soldiers, get involved with terrorist cells and so on. The U.S. government interest in stunting and its effects is keen, Palmer says.
But the condition is not always immediately recognizeable. Malnutrition has two faces, Palmer explains. One face is that of the starving child who is simply not getting enough calories. Those children are ravenous, he says. When relief workers put a high-energy supplement in front of them in the form of gruel, they devour it.
Protein malnutrition has a different face. These children aren't skin and bones; they're just stunted in terms of height and cognitive ability. Surprisingly, they aren't hungry. In fact, they generally refuse food. Even when they're put on an emergency feeding program, they improve temporarily and then relapse into protein malnutrition and chronic malabsorption syndromes, Palmer says.
This is not a battle veterinarians should be afraid to join, Palmer says. His words pick up strength as he wades into the issue. "Physicians are not afraid to jump into those kinds of problems," he says. "Yet veterinarians have often seemed reluctant."
Physicians, he continues, tend to look at stunting as a problem that begins with the food going into the mother. But they don't think about what happens before that. "Where does the food come from? What's the access? What's the availability? What's the affordability?"
Veterinarians, on the other hand, have tended to do the opposite, which is focus on animal productivity. "We're not afraid to look at those issues, but we want to stop when it gets to the household," he says.
And the household may be that critical interface between science and custom that goes well beyond the comfort zone of either physicians or veterinarians. The nagging question here relates to the distribution of food within the family. In a January lecture at the university, Palmer suggested that a partial solution to stunting could be as simple as families allocating eggs to pregnant mothers.
"Veterinarians cannot be afraid to talk about maternal child nutrition," he says. "We understand every aspect of that. There is really nothing very unique about a human mother versus a bitch or a cow or anything else. We understand the basic principle and we need to be willing to cross that divide."
But the relationship between livestock and human health in the parts of the world where Palmer works is not simply about nutrition. He suggests imagining a rural Kenyan suddenly transported to an American city. He'd look around and think everyone in America was wealthy. But if he stayed around awhile, he'd notice big differences in wealth. The same is true, Palmer says, for a visitor to Kenya. If the visitor looked around long enough, he'd see several strata of wealth. And looking around, of course, is what researchers do.
"If you walk onto a premises and you can see four head of cattle, I'll bet if you look at the questionnaire where we ask about malaria nets—the question is, 'Did you sleep under a bed net last night?'—that family will have answered 'yes,'" Palmer says.
Four head of healthy livestock makes a huge difference in quality of life for a family in the developing world, he says—the difference between being able to afford a malaria net and being exposed to disease, for example. Four head means the family's assets are higher, nutrition is better and children are more likely to attend secondary school. "There is very good economic data on this," he says. "You see this tremendous effect that correlates very strongly with the presence of healthy livestock."
A virus travels around the world in 24 hours—guess what: so does antimicrobial resistance
Keeping animals healthy creates a thorny problem that's the subject of Palmer's third research stream: antimicrobial resistance. Families with four head of livestock, or even 10 head, are not likely to use antibiotics on their animals. But as cities and populations grow, much of the world's demand for protein will generate huge pressure to protect livestock investments with antibiotics—often antibiotics that have been banned in the United States for more than three decades.
So even as the developing world craves more protein to feed its hungry, the method it uses to produce protein is a ticking time bomb. At the end of the fuse is the next dangerous microbe for which mankind has no remedy. Palmer says the idea that the developed world can protect itself from antimicrobial resistance by enacting strict antibiotic controls for meat production is simply "a fool's paradise."
"There's a lot of talk about how we need better inspection of animal products coming into the U.S.," he explains. "You get no argument from me on that. But we need to realize that inspections don't actually solve the problem, because people come and go."
People can pick up antibiotic resistance wherever they are, Palmer continues, especially in areas where antibiotics are used very heavily. "We find antibiotic residues in eggs in Nigeria, for example, without any problem," he says. "So the eggs I'm enjoying in the hotel in Nigeria, the resistance in them shows up in Kansas City 24 hours later. They say a pathogen can travel around the globe in 24 hours. So can antimicrobial resistance."
In fact, in a February article published by the Institute of Medicine of the National Academies, Palmer and WSU colleague Douglas R. Call cited a 2001 study suggesting that antibiotic-resistance traits travel the globe at exponentially higher levels than pathogens.
A good example of the complexity of the problem can be found in Denmark, Palmer wrote, where strict inspection and strict laws have dramatically reduced the levels of antibiotics in pork and poultry. Unfortunately, pork and poultry also enter Denmark from other far less careful parts of the world. The emerging question is whether people will be willing to pay a premium for strictly controlled livestock products. The problem is exacerbated in the poorest countries where the dangers of antimicrobial resistance are pitted against the dangers of starvation. "No one can argue this isn't a fantastic achievement for Denmark," Palmer says. "The problem is that the rest of the world doesn't look like Denmark. Only Denmark looks like Denmark. This is great for Denmark, but you can't apply it to India. It isn't going to work."
The world doesn't just want cheap food; it needs cheap food, Palmer says. In particular, it needs cheap protein sources. "It's very easy to say, 'Well, Nigeria should really crack down and regulate their antimicrobial use in animals,'" he says. "They should. But that's probably not their highest priority."
In rural sub-Saharan Africa, the typical livestock-producing family owns an average of 10 chickens. They don't use antibiotics to protect their investment. If they lose a chicken, they get another from a neighbor and they're back in business. Tyson Foods, on the other hand, has an enormous investment to protect, so the company spends heavily on the latest biosecurity techniques. A slip-up would cost it millions. But in the developing world, midlevel producers are emerging with flocks of 500 or 1,000 birds, and that's where the most frightening problem lies, Palmer says. "Biocontainment is now replaced by antibiotics," he explains. "The danger is not only amounts, but which antibiotics they use. Specifically, chloramphenicol is used in Nigeria. It's sold on the street. You can find it in the eggs. And it's been banned for any use in food animals in the U.S. for 30 years."
This challenge, Palmer says, will confront veterinarians who work on the world stage for decades. Global population is expected to peak around 2050, he says, so enormous pressure will build worldwide for animal protein production. If better systems aren't developed, if new ideas aren't brought to bear on the problem, if political will isn't strengthened, Palmer says, much of that animal protein "will be covered in antibiotics."
Taking the world stage
Marguerite Pappaioanou, DVM, MPVM, PhD, a retired captain in the U.S. Public Health Service, sounded the same alarm 11 years ago when she spoke to veterinary students at University of California-Davis in a talk titled "Improving Global Health in the 21st Century: Veterinary Medicine Steps Up to the Plate to Protect and Promote Human Health and Well-Being." Her topics in that address mirror Palmer's today—zoonotic disease, antimicrobial resistance, the delicate but dangerous balance between public health and the developing world's need for animal protein.
Today, Pappaioanou says the global challenges are no less onerous. It's a battle Pappaioanou has been fighting for decades. She joined the Centers for Disease Control in 1983 and has conducted research in Bolivia, Mexico, Cameroon, Cyprus and the Philippines. She now serves as the CDC liaison to the Food and Drug Administration for food safety. In February she moderated a panel in Bangkok, Thailand, telling the audience that outbreaks of zoonotic disease could be stopped if authorities would just cooperate across borders.
Forging cooperation and political will are also roles veterinarians need to play on the world stage, she says. While making a case for the strengths veterinarians bring to the table, she has charged the profession in the past with being reluctant to provide leadership on controversial issues and risk speaking out—waiting to be invited by others to participate fully on the global front.
"I spent many years working with other professions and and you just didn't see them hanging back," she says. "They'd just do it. They'd see a need and they didn't wait to be asked."
However, she says, the veterinary profession is making progress, particularly in veterinary schools where alliances with public health and human medical schools are more prevalent and among recent graduates who are opting for the sort of work Palmer does.
Obviously, Palmer didn't need to be cajoled to get involved. He thinks, as Pappaioanou does, that veterinarians should be part of the global think tank addressing these daunting problems. Their biomedical training is precisely the expertise needed in Kenya and Nigeria and elsewhere, he says, to help improve human health and to search for novel solutions to problems like rabies, developmental stunting and antimicrobial resistance.
And he thinks many younger students entering veterinary colleges just need nurturing to break outside the norm of clinical practice and devote their careers to these broader issues. But he's not so hopeful about the way many veterinarians have been reluctant to take their talents to the dance.
In fact, he uses the same metaphor as Pappaioanou to describe the role veterinarians have been reluctant to play.
"If you are a professional," Palmer asks, "are you going to stand at the corner of the dance hall and wait for somebody to ask you to dance? If you do, you're not getting the job done. You've got to actually step out there and make these things happen. I think we need to do a better job of taking the talents of our profession and encouraging veterinarians to push beyond those limits and not be afraid to use not only their biomedical training but their full understanding of the issues, of political systems and economics, across the board."
In fact, he emphasizes, the health and future of the planet require nothing less than that.