Originally published in the Spring 2006 Lincoln Park Zoo magazine

The flu happens. Every year, people across the country miss work, huddle
under the covers and drink plenty of fluids. Birds—particularly domestic species such as chickens, ducks and turkeys—are hit with their own flu strains as well. As with people, most bird strains run their course with bouts of runny nostrils and decreased energy; these strains are classified as low-pathogenic avian influenza. Occasionally, however, a more serious strain of highly pathogenic avian flu comes along, one that is highly transmissible, fast acting and likely fatal to the birds that contract it.

When a highly pathogenic strain appears, such as the H5N1 variant that is beginning to spread from Asia to Europe, zoo personnel, farmers and wildlife managers begin to worry about the health of their birds, while scientists and physicians worry about the prospect of bird-flu strains jumping the species barrier to sicken humans. Currently, H5N1’s rare leaps to humans have required close contact with infected birds. But as more people catch the virus, the probability of it mutating to a form that’s still virulent but easily transmissible between humans increases. Such a shift is thought to have been the stimulus for the 1918 influenza outbreak, estimated to have killed 50 million people worldwide.

There’s no need to stock up on surgical masks just yet, though. The H5N1 strain of avian influenza hasn’t even appeared in birds in the United States, much less crossed the species barrier to humans here. But while scientists hope that H5N1 and other highly pathogenic strains can be kept out of the United States, they also recognize the necessity of preparing for their possible arrival. Dr. Dominic Travis, head of the zoo’s Davee Center for Epidemiology and Endocrinology, says, “Nobody knows if or when H5N1 is going to enter the United States. The point is that people believe that it’s likely, and therefore we need to be prepared.”

Lincoln Park Zoo took a lead role by hosting the National Avian Flu Surveillance Planning Meeting for zoos from January 9–11. Organized and hosted by Travis on behalf of the American Zoo and Aquarium Association (AZA), the meeting gathered a variety of experts to craft a national surveillance plan for highly pathogenic bird flu in zoological institutions. Participants included representatives from the Centers for Disease Control and Prevention (CDC), the U.S. Department of Agriculture (USDA), the U.S. Department of the Interior, the AZA, state and local public health departments, zoo and university researchers, local wildlife experts and human-health professionals. The plan, still in draft stage, would provide participating AZA zoos with standardized guidelines for the collection and testing of samples as well as guide the distribution of data to researchers looking for signs of H5N1 in the United States.

Zoo-based disease monitoring is nothing new. In 2001, Lincoln Park Zoo, with funding from the CDC, helped establish a zoo-based monitoring program for West Nile virus. To track the spread of the disease, samples were collected from AZA zoos nationwide and sent to a testing laboratory at Cornell University’s College of Veterinary Medicine; the results were provided, anonymously, to federal, state and local public health representatives. The ongoing project, coordinated by Travis through the Davee Center, identifies vulnerable species and provides information about the spread of West Nile virus.

There are several reasons why zoos are effective partners for monitoring zoonotic diseases (those that can be passed from animals to humans). Zoos are located in close proximity to humans throughout the United States, in both urban and rural areas. They have diverse animal populations living in controlled conditions, many of which are vulnerable to the diseases in question. Most importantly, zoos constantly monitor the health of their collections. Travis says, “The reason zoos are good partners is that we already have the infrastructure in place. Zoos look at their animals every day and report anything that looks abnormal.”

Still, the proposed avian influenza surveillance program carries challenges beyond those faced with the West Nile project. Bird flu is potentially more dangerous; while West Nile requires a mosquito intermediate to spread to people, H5N1 and other highly pathogenic strains can pass directly from birds to humans in close contact with them. Due to this increased threat, more parties are involved, making the organization and distribution of information more complex. While one lab handled all of the West Nile testing, a network of regional labs will need to be established to screen for avian influenza. Finally, while the West Nile program was established with money from the CDC, the more ambitious avian influenza monitoring program is still seeking funding.

Ultimately, the funding will determine the project’s scope. Travis says, “With a small amount of funding, we can do surveillance for the scary stuff. With a large amount, we can actually try to learn about the ecology of avian flu and why it happens.” With one of the largest zoo scientific staffs in the country and the in-house expertise of the Davee Center, dedicated to analyzing issues of animal health and disease transmission, Lincoln Park Zoo is eager to contribute to any research efforts, as the knowledge gained could lessen the threat of future outbreaks.

Even if the program is dedicated solely to surveillance, there are good reasons for zoos to participate. At the most basic level, an avian influenza monitoring system helps zoos protect their animals, many of which are endangered. A careful watch is also beneficial for zoo staff, as they could be vulnerable to undetected zoonotic illnesses.

The surveillance plan is inspired by more than self-interest, however. It’s also rooted in zoos’ desire to give back to their communities. “Zoos are part of the community, and this is a way we can show that,” says Travis. After the surveillance meeting, Lincoln Park Zoo officials and other experts traveled to nearby Saint Joseph’s Hospital to discuss the potential public health impact of highly pathogenic avian influenza and the zoo’s role in monitoring the disease. As Travis reminds us, such collaboration with the community isn’t only a strategy for combating the disease; it’s an essential component of Lincoln Park Zoo’s mission as well.