Spring is fast approaching, and the mosquitoes are not far behind!
Michigan saw an increase in West Nile virus (WNV) activity last year, and many of you may be wondering if you should be taking special precautions to combat it this year.
From what we know, WNV is probably here to stay. Michigan and Washtenaw County have experienced human, horse, or bird cases every year since 2001, although the area with the largest number of cases in the United States has tended to move west each year. There are varying theories as to the cause of this westward trend, including weather patterns, the spread of immunity in the bird population, and effective prevention and awareness efforts. However, at this point we are not aware of any definitive studies that would indicate the virus will not return to our area in large numbers.
For that reason we are recommending continued vigilance, with an emphasis on personal responsibility. Residents should use personal protection during outdoor activities, eliminate standing water, repair broken screens, and take other actions to prevent infection. We are further recommending that municipalities begin or continue larviciding activities where budgets allow. We do know that larviciding of catch basins has been effective in reducing the Culex species of mosquitoes, believed to be the primary vector for WNV.
The County is taking a number of steps to help in the detection and prevention of WNV:
§ West Nile Virus Hotline: The hotline (734-544-6750) will be available to answer questions regarding WNV and to accept reports of dead birds. The hotline went live April 24th, and will run through the end of October.
§ Dead Bird Surveillance and Testing: Corvids (crows, ravens, and blue jays) are particularly sensitive to WNV. Public Health will perform throat swabs of dead corvids and forward the swabs to the State laboratory for testing. Citizens are encouraged to report dead birds to the local hotline, or to the State of Michigan website: www.michigan.gov/emergingdiseases.
§ Mapping: Since studies suggest dead birds are valuable in predicting the onset of human WNV cases, the County will be mapping reports of dead birds and looking for clusters. We will notify Local Units of Government when these clusters occur, and will assist in making recommendations for targeting educational information and/or initiating additional mosquito control measures.
§ Human and Horse Surveillance: The results of continued surveillance of equine and human cases will be posted on our website. Any confirmed cases will be reported to the Local Units of Government.
§ Educational Outreach: Our website (http://westnile.ewashtenaw.org) will have information on WNV as well as links to state and national websites. In addition, educational materials will be available through the hotline and our website. Feel free to copy and distribute these materials as you see fit.
With a large focus of our attention on testing birds for WNV, many people may be concerned about Avian Influenza. The birds that are tested for WNV will not be tested for Avian Influenza, as the target species are not the same (corvids vs. waterbirds). The United States and Michigan have surveillance plans in place, as well as plans to address Avian Influenza if or when it spreads to this country. For questions about Avian Influenza, feel free to refer residents to the State of Michigan Emerging Diseases website at www.michigan.gov/emergingdiseases or the WNV hotline (734-544-6750).
Please feel free to contact either one of us, or our hotline with any questions you may have. The hotline number again is 734-544-6750.
Richard M. Fleece, R.S.
Director of Environmental Services
Department of Planning & Environment
Washtenaw County
(734) 222-3875
Stan Reedy, M.D.
Medical Director
Department of Public Health
Washtenaw County
(734) 544-3058
