|Bureau of Epidemiology|
|Bureau of Epidemiology||April 2001||Utah Department of Health|
Nile Virus and Utah (Its not here...yet) The outbreak
of West Nile Encephalitis in the summer of 1999 received much attention. A brief history
of what is known of the related events follows. In June of 1999, a veterinarian in Queens
found birds suffering and dying from a central nervous system disease. The wildlife
pathologist at New York States Department of Environmental Conservation could not
identify a cause. In August, zoo vets at the Bronx and Queens zoos began to notice a
number of wild and caged birds dying. At about the same time, an infectious disease
physician in a Queens hospital noted that there were an unusual number of elderly patients
with suspect encephalitis or meningitis, and that several of the patients also had
profound muscle weakness. The physician called the New York Citys Bureau of
Communicable Disease to report this remarkable event. The New York State Department of
Health and the Centers for Disease Control and Prevention (CDC) were asked to help
investigate. At this point in time, the massive bird die-off and unusual human outbreak
were being treated as two separate incidents.
On September 3, 1999, the CDC announced that the cause of the human outbreak was the virus that causes St. Louis Encephalitis (SLE). On the same day, massive mosquito control efforts were started throughout New York City. However, the massive bird die-off was not explained by the diagnosis of SLE in humans. The zoo vets and the wildlife pathologist continued to look for an answer, working with the United States Department of Agriculture and the United States Geological Survey. Also, investigators of the human outbreak began to question the diagnosis of SLE because of inconsistencies. Some of their laboratory results were not wholly consistent with the diagnosis of SLE, and the profound muscle weakness suffered by many of the patients was not consistent with the typical clinical picture of SLE. The two groups discovered almost simultaneously the true cause of illness in both birds and humans, and on September 27, an official confirmation was made. Birds, humans and horses in the area were suffering from West Nile Encephalitis (WNE), a disease caused by West Nile Virus, a virus that had never been isolated in the western hemisphere. By the end of the 1999 mosquito season in New York City, 62 persons were confirmed as having WNE, and seven had died as a result. Twenty-five horses were diagnosed with WNE, and nine had died or were euthanised as a result. Thousands of wild birds, especially common crows and blue jays, had died of either suspect or confirmed WNE.
Early in the spring of 2000, mosquitoes in the New York City area were found to be carrying West Nile Virus (WNV). Over the summer, WNV continued to spread into the nearby states of Connecticut, Delaware, Maryland, Massachusetts, New Hampshire, New Jersey, North Carolina, Pennsylvania, Rhode Island, Vermont, and Virginia. There were 17 human cases of WNE, and there was only one death. A total of 63 horses were diagnosed with WNE. Bird die-offs were also reported, but these were not as extensive as in 1999.
This sudden appearance of WNV in the U.S. was quite unexpected, and provided valuable lessons in how to improve disease surveillance. The outbreak was initially brought to the attention of human public health authorities by the infection disease physician in the Queens hospital. Existing surveillance systems had not detected this unusual event. The many different agencies that became involved with surveillance and disease control efforts often did not know who to talk to in the other agencies, or how to reach them. Communication between agencies was not as smooth or as rapid as it could have been. Laboratory facilities were overwhelmed with either thousands of dead birds, or thousands of human specimens from suspected cases or from persons who were worried that they might be infected. The volume of work was far beyond what the laboratories could handle. An excellent review of the events associated with the WNV outbreak is available from the United States General Accounting Office. The title is West Nile Virus Oubreak: Lessons for Public Health Preparedness (GAO/HEHS-00-180). (A copy of this report can be obtained from the GAO web site: Use the HEHS-00-180 order number.)
In response to the threat of WNV, the CDC appropriated funding for states to set up surveillance for WNV and to enhance their existing arboviral surveillance programs. The Utah Department of Health (UDOH) was awarded funds in September of 2000 to set up enhanced surveillance for WNV and the other arboviruses that impact Utah (i.e., Western Equine Encephalitis and St. Louis Encephalitis). While surveillance for arboviral diseases is an ongoing part of communicable disease surveillance, this additional funding will allow UDOH to increase awareness about these diseases and their prevention. Nationwide surveillance is being promoted because many experts believe that, within the next few years, WNV will be distributed in a pattern similar to that of the virus that causes SLE (i.e., in most of the continental U.S., parts of Canada, and parts of Latin and South America).
Agencies outside of UDOH are frequently involved in communicable disease surveillance, and especially in arboviral disease surveillance. WNV may first be detected in Utah through bird die-offs, in mosquito pools, in a horse, or in a human. Participation of the Utah Department of Wildlife Resources, the local Mosquito Abatement districts, the Utah Department of Agriculture and Food, and all of the local health departments is essential for effective arboviral disease surveillance. A meeting of representatives from all of these agencies and UDOH was held on March 28, 2000 to discuss issues involved with WNV and arboviral surveillance. The objectives of the meeting were to: 1) provide information about the status of WNV surveillance in the United States; 2) provide information about the status of WNV surveillance in Utah; and, 3) provide an opportunity for agencies involved with WNV surveillance to meet and discuss current needs and issues. The meeting provided an opportunity for all agencies to describe what they do and how their activities impact arboviral surveillance. UDOH and the local health departments would receive reports of WNE in humans. The Utah Public Health Laboratory would conduct testing of specimens for WNV. The Utah Department of Agriculture and Food would receive reports of WNE in horses, and they may receive reports about dead birds. The Utah Veterinary Diagnostic Laboratory would receive dead birds (and perhaps other dead animals) for testing. The local Mosquito Abatement districts will continue to use chickens as sentinel animals for arboviral infections, will monitor and control mosquito populations as usual, and, in a few districts, will collect mosquitoes for testing. The Utah Department of Wildlife Resources would observe and report bird die-offs, and will send in selected dead birds for testing. All agencies would receive and respond to questions or concerns about WNV or arboviral diseases from Utahs citizens. To enhance communication between the agencies involved, a listserver is being established to allow all agencies to rapidly share information with each other. Fact sheets about WNV, one for the general public and one for health care providers, will soon be made available through the Bureau of Epidemiologys web site (look for these in May athealth.utah.gov/els/and look at the fact sheets). Brochures describing WNV and how to prevent it are available for concerned individuals through UDOH and the other participating agencies.
A final lesson from the General Accounting Offices review of the WNV outbreak is to expect the unexpected. Utah is fortunate in that it, along with the rest of the country, can learn from New York Citys experience. Enhanced surveillance for WNV and other arboviral diseases, combined with a renewed commitment to cooperation between all the agencies involved, will be useful should WNV, or other similar diseases, come to Utah.
Choose foods carefully
Select foods based on available resources and facilities. If one is planning on a day hike and taking sandwiches for lunch, he or she would be better off taking a peanut butter and jelly sandwich rather than one needing refrigeration. The availability of hand washing facilities should also play a role in deciding which foods to prepare for summers activities. If no such facilities are available, one should avoid handling raw chicken or beef.Prepare food carefully
One of the most effective ways to prevent summer food hazards includes washing hands thoroughly before any food handling. It is also wise to prepare as much food as possible at home. Many summer excursions include spots where food preparation facilities are less than adequate.
To avoid cross-contamination, clean cutting boards and utensils used for raw meats with hot, soapy water prior to their use with ready-to-eat foods. Contamination may also be avoided if one washes his or her hands frequently during food preparation. In addition, always use clean, treated water for washing hands, utensils, or dishes since lake, river, or stream water may contain harmful pathogens.
Food handlers need to cook meats thoroughly as well. Cook raw hamburger and chicken until the meat is no longer pink in the middle and the juices run clear.Store food appropriately
Remember one simple rule: keep hot foods hot and cold foods cold. Keep hot foods on the grill, fire, coals, or warming pan and keep cold foods in the shade, in a cooler, or sitting on ice until serving time.
Protect food from insects such as flies, which can spread bacteria, and store food so that it is inaccessible to animals like rodents. It is not only important to keep food away from animals, but to keep some items away from each other too. Store uncooked meats and ready-to-eat foods in separate containers to avoid cross-contamination.Eat food promptly
Eat food as soon as it is served and put it away as soon as possible following the meal. Do not allow it to sit for prolonged periods of time. Avoid eating food that should be refrigerated if it has been sitting at room temperature for more than two hours. Less time is needed if it is warmer than room temperature (such as sitting out on a picnic table).
Improper food-handling can ruin the most carefully planned summer activity. Fortunately, by implementing these simple precautions, summer food hazards can easily be prevented.
Utah Department of Health, Bureau of Epidemiology
Monthly Morbidity Summary - April 2001 - Provisional Data
The Epidemiology Newsletter is published monthly by the Utah Department of Health, Division of Epidemiology and Laboratory Services, Bureau of Epidemiology, to disseminate epidemiologic information to the health care professional and the general public.
Send comments to: The Bureau of Epidemiology, Box 142104, Salt Lake City, UT 84114-2104, or call (801) 538-6191
Approval 8000008: Appropriation 3705
Rod Betit, Executive Director, Utah Department of Health