Tracey McNamara

It may still be winter, but the United States is already girding for a resurgence of human West Nile virus infections. This year, the sentinels for the advent of West Nile season will be not only dead crows on city streets or in suburban backyards, but animals at zoos nationwide, thanks to a program that is the brainchild of veterinary pathologist Tracey McNamara of the Wildlife Conservation Society, Bronx, NY. McNamara, who, in 1999, first realized that the dead birds found on the grounds of the Bronx and Queens Zoos were related to the encephalitis reported in patients in New York City hospitals—and that both were caused by a virus never before seen in the United States—wants zoos and aquariums to work together with public health departments. Zoos have joined together as part of the National Zoological West Nile Virus Surveillance Working Group, funded by the U.S. Centers for Disease Control and Prevention (CDC). Participating are more than 35 zoos, the New York State Diagnostic Laboratory at the Cornell University College of Veterinary Medicine in Ithaca, and public health departments. Samples from ill or dead outdoor zoo animals, dead wildlife found on zoo grounds, and outdoor zoo collection animals that are being shipped, are sent to Cornell to be tested for West Nile virus. This may give an early warning to public health departments about the presence of the virus in their regions. "From a public health point of view, it seems that zoos are vigilant about looking for diseases that might threaten their valuable collections. That's why we pursued a diagnosis in the crows in 1999. We do active health surveillance 365 days a year," says McNamara. "It seemed logical that the nation would benefit by tapping into that information. But due to fiscal constraints, most health departments could only test crows, excluding zoos from their surveillance programs." So, after a West Nile planning meeting in Charlotte, NC, in February of last year, McNamara was concerned that the current means of surveillance "had some drawbacks." She recalls that she said to Duane Gubler, director of the CDC's Division of Vector-Borne Infectious Diseases in Fort Collins, Colo., "Listen Duane, I think we need to do lunch." At lunch, "I suggested that now might be a good time to revisit the concept of working with zoos to accomplish active West Nile surveillance." The plan for the surveillance network began to hatch. McNamara saw this as a natural fit: "Zoos monitor the health of the animals in their care closely. They maintain serum banks, tissue banks, and computerized medical records, all of which make for an excellent surveillance system. What we lack are funding and technology, both of which are available to the public health community." If the CDC funded the program—offering free testing—McNamara was sure zoos would join in the effort. The CDC funded a meeting at Chicago's Lincoln Park Zoo in June 2001, where, "we crafted a plan for doing West Nile surveillance in zoological institutions," explains McNamara. What she and her new and old colleagues accomplished would have been unthinkable before the 1999 West Nile epidemic. McNamara points out that wildlife scientists, zoo scientists, and public health officials have "different mindsets." In setting up this surveillance at zoos, McNamara accomplished the same thing she did in 1999 after making the first West Nile diagnosis in birds. "She served a central role as a unifying force, molding and sometimes forcing interrelationships between local and federal government agencies and private enterprises, enabling progress toward the common goal of monitoring a newly emerging disease in the United States," says George V. Ludwig, chief of the Applied Diagnostics Branch, Diagnostic Systems Division of the US Army Medical Research Institute of Infectious Diseases, Frederick, Md. Ludwig's lab was the first to identify West Nile virus in samples sent by McNamara. What makes zoos such good sentinels for emerging infectious diseases? Veterinary pathologists, McNamara says, "take an unusual approach" to their work. "We systematically consider and rule out all the known differential diagnoses of domestic animals when we see disease in zoo species; however, we also consider the possibility that we may be dealing with something new." McNamara, a student of Eastern philosophy, calls this the "Zen of zoo pathology," which, she says, can be translated into challenging perceptions and questioning assumptions. McNamara notes that first there was West Nile, and now anthrax and the threats of other emerging diseases and bioterrorism to come. "These are strange times, and they've resulted in the formation of some unusual partnerships," she says. Included among these are joint projects between those interested in human health and those interested in animal health. And meetings about the virus have brought together "people from so many disciplines." "No one really knew who to call in 1999," McNamara recalls. Now, she knows exactly who to call if she detects anything unusual in zoo animals or wild animals that come into the zoo. Former Rockefeller University president Joshua Lederberg, chair of The Scientist's Editorial Advisory Board, knows McNamara from her briefings at National Academy of Sciences/Institute of Medicine committee meetings. "Dr. McNamara has played a key role in showing the necessity of good communication between the veterinary and public health communities and taking note of the role of animal health at zoos as an indicator of public health," he says. McNamara notes that the West Nile surveillance is but a first step. "What I'm hoping to see," says McNamara, "is that the program will be expanded to other infectious disease threats common to animals and man." She adds, "After all, these days, we are all potential canaries in the coal mine. But you know what they say about 'a bird in the hand.'" Myrna E. Watanabe is a freelance science writer in Patterson, NY.

Tracey McNamara

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