West Nile Virus Management
Mosquito DUNKS available to control West Nile Virus
The Township, through an Oakland
County Health Division Program, is offering Mosquito DUNKS for
the biological control of mosquito populations which may
transmit West Nile Virus. DUNKS are doughnut shaped and each
DUNK treats up to 100 square feet of standing water for a
period of 30 days. Visit the Clerk’s office or the Public
Services Building for more information.
Frequently Asked Questions
What is West Nile Virus (WNV)?
West Nile Virus is classified as an emerging infectious
disease that is spread by a mosquito-borne virus. Historically
found in Africa, Asia and the Middle East, the first cases of
WNV within the United States occurred in the New York City
area in 1991. Since that time, WNV has been detected in birds
and mosquitoes in Michigan (2001) and human cases were
confirmed in 2002 and every year there after. The virus has
since spread across the United States to the Pacific Ocean,
into several Canadian Provinces and Mexico. The continued
expansion of the WNV indicates that it has been permanently
established in the Western Hemisphere.
Is the West Nile Virus in Oakland County?
This chart depicts the WNV activities in Oakland County for
the past few years. Federal, state, and local officials
continue to closely monitor the distribution of WNV cases
within the United States.
Table 1: WNV Case Total Comparison
Table 2: WNV Death Total Comparison
What is Bloomfield Township doing about West Nile Virus?
Bloomfield Township has been proactively working to protect
our residents against the WNV since 2003. Currently, the
Township West Nile Virus Management Program addresses the WNV
problem through an integrated pest management program that
consists of identifying and prioritizing approximately 1900
breeding sites (e.g. catch basins), then sampling and treating
those public areas of the Bloomfield Township found to be high
The most important step in controlling the virus is to
prevent the mosquitoes from becoming adults. In order to kill
the pre-adult larvae, we treat prioritized catch basins, which
have been identified as the principle breeding sites for
mosquitoes in urban and suburban environments, with a natural
insecticide called Bacillus sphaericus (BS). BS, known
by the trade name Vectolex, only affects mosquito and black
fly larvae. It is approved by the EPA and has been shown to be
highly effective in killing mosquito larvae. The
Township program begins in June and continues through late
September to early October, depending on weather conditions.
It is not likely that the wetlands in the Township, which
are natural environments, will breed large numbers of
mosquitoes. These natural environments contain not only
mosquito larvae, but also their predators, who are more than
happy to eat a mosquito lunch!
Additionally, mosquitoes need very specific requirements to
breed: wetlands seldom meet these requirements. The most
common mosquito in Michigan to be associated with WNV is the
Culex species. Culex mosquitoes prefer still, temporary
water sources and containers typically found around man-made
structures. Remember to regularly inspect all containers
in your yard for standing water and dump the water out.
Public education and community outreach activities include Township newsletter articles, printed
materials, website updates and cable programs. This
information highlights the modes of virus transmission; means
of prevention; and how to reduce the risk of exposure.
How is the West Nile Virus spread?
WNV is spread to humans by the bite of an infected
mosquito. The transmission cycle below illustrates that
a bird becomes infected after being bitten by a mosquito
carrying the virus. Several suspected mosquito species are
involved in the transmission of WNV. Horses and other
animals bitten by infected mosquitoes can also become
infected. A human or horse that has the disease cannot
spread the virus.
Whenever mosquitoes are active there is a risk of getting
WNV, therefore the highest probability of acquiring the virus
exists during the months from late July through September.
Although a vaccine is available for horses, there is currently
no vaccine for humans.
* Graphic courtesy of the CDC
What are the signs of West Nile virus?
Most people (80%) who become infected with the West Nile
virus suffer little more than flu-like symptoms or suffer no
symptoms at all. Approximately 20% of those infected may
develop West Nile fever, which may include the following
symptoms: fever, headaches, swollen lymph gland, muscle
weakness, body aches and skin rash. A very small percentage of
severe cases may experience headaches, high fever, stiff neck,
confusion, coma, tremors, paralysis and death. The risk of
severe illness is highest for people over 50 years of age.
What can we do to avoid contracting West Nile virus?
It’s important to remember that YOU are the most
important first line of defense in protecting yourself from
and preventing the spread of WNV. You can minimize your
contact with mosquitoes by following these three actions:
1. REDUCE AREAS WHERE MOSQUITOES BREED
Without proper areas to breed, mosquitoes cannot lay
their eggs. Throughout the season empty standing water from
containers, such as, flowerpots, buckets, toys, pet bowls,
clogged rain gutters, boats and discarded tires. Wash
birdbaths on a weekly basis to prevent the build-up of algae
and dead leaves. Keep swimming pools clean and
chlorinated and drain water that collects on top of pool
covers. Drain unused pools. Aerate ornamental pools or
stock them with surface feeding minnows. Mow your lawn
on a regular basis, cutting tall grass and weeds next to
foundations and fence lines.
2. REPEL AGAINST MOSQUITOES
Maintain window and door screening to keep mosquitoes out
of buildings. Always wear long sleeved shirts, pants and
socks outdoors, particularly from dusk to dawn. Avoid shaded
and wooded areas where mosquitoes may be present. Follow the
Centers of Disease Control and Prevention (CDC) current
recommendations for using insect repellent containing DEET,
especially on infants and young children.
3. REPORT POTENTIAL MOSQUITO BREEDING SITES AND DEAD
A connection had been made between an outbreak of human
WNV infection and disease in birds. Please report any dead
birds and potential mosquito breeding areas to the
Engineering and Environmental Department by calling
When calling to report a dead bird, please leave your
phone number, state the species of bird (if known), and an
address or location of where the bird was found. This data
is relayed monthly to the Oakland County Health Department
in order to monitor the incidence of WNV. While there is no
evidence that a person can get the virus from handling live
or dead infected birds, a person should avoid barehanded
contact when handling any dead animal. Please use gloves and
double plastic bags when handling the bird, then place in
your trash container.
documents are available in PDF format.
2012 Michigan West Nile Virus Surveillance Report
Township's West Nile Virus Management and Mosquito Smarts
Mosquito Smarts: Cat & Dogs Fact Sheet
Mosquito Smarts: Horses
Friends of the
For more information on how you can protect yourself
against the West Nile Virus, please visit the following
website links below:
Centers for Disease Control
Michigan Department of Agriculture
Mosquito Control Association
Oakland County Health Division
Updated March 2013
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Township of Bloomfield
4200 Telegraph Road
P.O. Box 489
Bloomfield Township, MI 48303-0489
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Bloomfield Township, Michigan
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