By K.D. Norris
It has long been known that dead birds can be a sign of West Nile virus infected mosquitoes in the area, and there has been reports in Kent County of dead birds with no obvious injury. But today the Kent County Health Department confirmed that West Nile virus has been detected in tested mosquitoes — not in an infected human — in the county.
According to an health department announcement July 22, the confirmation was made “during ongoing surveillance and testing” conducted by the Kent County Health Department (KCHD) The discovery comes after testing pools of mosquitoes that were trapped by the health department in the 49506 ZIP code (East Grand Rapids and area).
Brendan Earl, Kent County Parks’ supervising sanitarian, discussed with WKTV the relationship between dead birds and West Nile virus, and why the county is focused on testing live mosquitoes rather than dead birds.
“Generally it (the virus) goes from mosquitoes to birds, and then (mosquitoes) to humans,” Earl said to WKTV. “It used to be you brought in a dead bird and you tested the bird, because finding a dead bird is pretty obvious, right, and concerning for most people.
“Here at the health department, we like to look at the mosquito because it is a step before the bird. It is more preventive, it allows us to realize that West Nile is in the environment, in our county, so we can get the word out and take proper precautions to prevent the transmission into humans.”
Additionally, Earl said, finding positive tests in dead birds is a delayed indicator of the virus’ presence.
“When a mosquito bites and transfers the virus into a bird, they act as a host. Now any mosquito that bites the bird will now, itself, become infected. So that will amplify the number of mosquitoes the are positive. Unlike humans, who are dead-end hosts — so if we have West Nile virus and a mosquito bites us, we are not going to transmit the virus to the mosquito.”
(Earl further discussed the relationship between dead birds and the virus, and what to do if people find dead birds, in the video above. This is a link to to report dead birds to the state.)
West Nile and human infection
Humans may be ‘dead-end’ hosts, as Earl said, and rarely have severe consequences from infection unless the person is already immune compromised, according to the Centers for Disease Control. But that does not mean precautions are not advised.
“This discovery is important because it lets us know that this season’s mosquitoes are now carrying the virus and it could spread to humans,” Paul Bellamy, KCHD public health epidemiologist. “It is important for people to take precautions to prevent mosquito bites as much as possible.”
West Nile virus is spread primarily by infected Culex mosquitoes, according to KCHD. Only about 20 percent of the people infected will notice symptoms that may include headache, body aches, joint pains, and fatigue.
Most people with West Nile virus completely recover, but fatigue may linger. About 1 in 150 people infected develop severe illness that can affect the central nervous system. Recovery from West Nile virus may take several months. Some damage to the central nervous system can be permanent. In rare instances the disease can lead to death.
Since there is no vaccine or cure for West Nile virus, the best treatment is prevention. KCHD recommends the following measures:
Wear a mosquito repellant that contains 10 to 35 percent DEET.
Wear light colored clothing and stay indoors during dusk to reduce your risk of being bitten.
Remove or refresh water in bird baths, children’s wading pools, water bowls for your pets, and empty other small containers that can collect water in your yard.
More information about prevention can be found at accesskent.com.
