Emerging Animal Diseases: Global Markets, Global Safety: Workshop Summary (2002)

Speakers noted that many types of systems are in place for early detection of emerging diseases, but these systems are, for the most part, not integrated or coordinated. Moreover, weaknesses in monitoring at the farm level make the system vulnerable to failure, they said.

A large number and variety of surveillance and monitoring systems are in place at the federal, state, and local levels, but “the effort to integrate them is sorely needed,” said Dr. Nora E. Wineland of the U.S. Department of Agriculture’s (USDA) Centers for Epidemiology and Animal Health. The chief barrier to integrating the various systems is a lack of resources, she said. Wineland described some of the many surveillance systems, pointing out the wide range of existing programs: active and passive, mandatory and voluntary, government and industry, formal and informal.

The first level of surveillance is at the farm or production level, where producers are the “first set of eyes and ears out there for the unusual event.” Producers can use networking (e.g., online listserves) to discuss any health issues that come up, or they can participate in federal or industry monitoring programs, she said. The next level of surveillance is the local veterinary practitioner, which is missing in cases where producers do not use the services of a veterinarian

routinely. In addition to advising producers, veterinarians can also participate in listserves and report diseases to state and federal officials. An additional emerging problem is the need for education at all levels on proper vigilance and reporting.

There are various surveillance programs at the state level, including the National Animal Health Reporting System (NAHRS), she noted. State veterinary diagnostic labs report on diseases they find, and state veterinarians also use telephone or online networks “to report the information they are seeing and talk about it and come up with recommendations for additional testing needs.”

Federal monitoring programs are both voluntary and mandatory, she said. Voluntary programs include the National Animal Health Monitoring System (NAHMS), which collects information on farm management, production, and diseases in order to create baseline data.

Monitoring is also done at feedlots and slaughter plants, where samples are taken and information on partial or whole condemnations is recorded. As an Office of International Epizootics member country, the United States participates in international awareness activities and information exchanges with experts in other countries and key trading partners. “That allows our vigilance at the border—be that air, sea, or land—to be appropriately enhanced based on what is going on around the world,” Wineland said.

Dr. Joan Arnoldi, Director of the Animal Industry Division, Michigan Department of Agriculture, said that the first line of defense in detecting and reporting emerging diseases—the farm owner and worker, local veterinary practitioner, and state laboratory technician—is also the “weakest link, and perhaps the most difficult to deal with.” Arnoldi stressed that more effort and resources should be directed to this first line of defense.

Arnoldi described two scenarios that illustrate the potential extremes of responding to an outbreak: In the first scenario, it takes weeks for a problem to come to the attention of officials with the expertise and authority to take action. The second is a best-case scenario where controls are put in place within 24 hours. The difference in response hinges on whether the first line of defense, which could be a minimum-wage worker, an absentee owner, or an overworked practitioner, has the adequate background, training, or awareness to recognize and report a problem. “The further up the chain or away from the disease problem you go, the more sophisticated the system becomes, whether you are speaking of molecular techniques in the lab or the very complex integrated control systems. The usefulness of these sophisticated systems may be dependent upon those unsophisticated and variable beginnings,” Arnoldi said.

Some of the barriers that states and localities face include declining resources, fewer staff, and insufficient training. “We have a lack of interest by local political bodies. We have a lack of good coordination of the resources that are available at times and poor or little rapport with producers, who view us as regulators or the government, neither of which are very popular in the

countryside,” she said. On the positive side, she noted that state and federal staff are “pretty good at applied epidemiology,” and states have broad quarantine authority and therefore are able to “stop movements, to gain immediate control over something we think is a foreign animal disease or something that appears to be spreading very rapidly.”

Arnoldi and Wineland said there is a need for a better animal identification and trace-back system, without which we cannot determine the origins of diseases. “We don’t really know, number one, where our producers are, how many there are, and where the animals are. We don’t know how they are identified, if they are identified in most instances, and we don’t have a good trace-back system in this country,” Arnoldi said. Concurring, Dr. Quentin Tonelli of IDEXX Laboratories, Inc., said the lack of such systems in the United States “will limit our ability to export to countries who have spent a lot of time and effort to eradicate many diseases.” Dr. David Swayne, Director of the USDA’s Southeast Poultry Research Laboratory noted that having specific information about farms, such as location, animal populations, and types of operation, in the public domain raises fears among producers that the information will be misused by various groups, including those seeking to sue over food-related problems.

Wineland noted that the USDA’s National Agricultural Statistics Service collects such data on producers and is the only federal agency with statutory protection to provide confidentiality to information from producers. She said the NAHMS national studies has the same statutory protection, which is crucial in assuaging the fears of producers when asked for sensitive information.

Dr. Michael Bunning of the Centers for Disease Control and Prevention (CDC) described a surveillance system the CDC is using to track the spread of the West Nile virus in the United States. West Nile is an arboviral disease that is transmitted between birds and mosquitoes and is spread to mammals by infected mosquitoes. It was first discovered in the United States in 1999. Bunning said the West Nile tracking system is designed to function as an early warning system that “would identify emerging, re-emerging disease patterns or situations as quickly as possible, in real time.”

As soon as a state or county has made a positive diagnosis, they will share that information with neighboring states and counties, and, 24 hours later, the information is made public by being published on the Internet. Anyone can then access up-to-date tallies of infections in humans, horses, sentinel chickens, birds, and mosquitoes on a U.S. Geological Survey website. The data is not comprehensive because not all states are testing or testing extensively for the disease, and data on pets and zoo animals is not yet collected consistently, he

said.

Bunning noted that surveillance and surveillance analysis could be better centralized. Various agencies could continue to collect the data, which would be funneled into one agency and put under a manageable scheme. When a veterinarian “is sitting out there at his desk and he wants to know something about foot-and-mouth, he doesn’t have to go to 27 different sites and miss the very site he wants. There ought to be a way to do it, and we have the technology,” he noted.