LANSING, MI -- With the first West Nile virus activity for Michigan in 2015 identified in crows collected in Ingham County, Michiganders should take the precautionary steps of applying repellents during peak mosquito biting periods such as dusk and dawn and to drain standing water around their homes to remove mosquito breeding sites.
West Nile virus can cause serious neurological illnesses, such as meningitis and encephalitis. Symptoms include a high fever, confusion, muscles weakness, and a severe headache, according to the Michigan Department of Health and Human Services. In 2014, nationally 2,205 human cases of the virus and 97 deaths were reported to the Centers for Disease Control and Prevention.
"While everyone should take steps to protect themselves, adults who are 50 and older have the highest risk of illness caused by West Nile virus," said Dr. Eden Wells, chief medical executive for the MDHHS. "Additionally, people who work in outdoor occupations like construction and landscaping are at increased risk of getting bitten by an infected mosquito. One bite from an infected mosquito can lead to a severe and possibly life-altering illness. Prevention is the key to protection."
During the week of June 7, three nestling crows from Ingham County tested positive for the virus at Michigan State University. The birds were found dead in early June and submitted by the public to the Michigan Department of Natural Resources. Birds are the natural animal reservoir for the virus and carry it in their blood. Mosquitoes become infected when they bite an infected bird.
Most birds show no symptoms of infection, but certain bird species, such as crows, blue jays and ravens, are more sensitive to the virus and are more likely to become sick and die when they become infected with the virus.
"As with many wildlife diseases, vigilant observation and reporting from the public are critical in helping health and wildlife experts better understand and contain the transmission of West Nile Virus," said Steve Schmitt, veterinarian-in-charge at the DNR Wildlife Disease Lab. "We ask residents to contact us if they find sick or dead crows, blackbirds, owls or hawks, or any other bird exhibiting signs of illness."
The mosquitoes that transmit West Nile virus are often referred to as the 'house mosquito' and may breed near people's homes in storm drains, shallow ditches, retention ponds, and unused pools. As summer temperatures rise, mosquitoes and the virus develop more quickly so it is important to protect yourself from mosquito bites.
"Recent heavy rains, combined with warm weather, have led to a lot of mosquito activity, and this can mean an increase in the use of insect repellents as we enjoy sports, backyard barbecues, camping and other outdoor summer activities," said Gina Alessandri, MDARD's Pesticide and Plant Pest Management Division Director. "Safe use of insect repellents is possible if you follow the directions listed on the bottle, especially when applying repellents on children."
According to MDARD, people can stay healthy by using simple, effective strategies to protect themselves and their families. In particular, residents are advised to use mosquito repellent products containing EPA-approved active ingredients, such as DEET, picaridin, or oil of lemon eucalyptus. Draining standing water, and making sure door and window screens are in good repair will also help keep mosquitoes out of the home. Also, consider using biological controls for small lakes and ponds you own, such as Bacillus thuringiensis israelensis (Bti), which is available at many stores.
When applying insect repellents, it's important to keep the following guidelines in mind:
• Before applying repellent, read all label directions; not all repellents are intended to be applied to the skin.
• Repellents with low concentrations (10 percent or below) are effective and may be preferred in most situations. Start with a low-concentration product and re-apply if necessary.
• If applying repellents over a long period of time, alternate the repellent with one having another active ingredient.
For information about West Nile virus activity in Michigan and to report sick or dead birds, visit www.michigan.gov/westnile. Additional information can be found at www.cdc.gov/westnile.