Mosquitoes carrying West Nile virus detected in Picton

A “pool of mosquitoes” carrying the West Nile virus has been detected in the Picton area, according to regional health care authorities.

Hastings and Prince Edward Public Health (HPEPH) announced on Wednesday, Aug. 31, 2022 that the pool of West Nile infected mosquitoes had been found by the Health Unit, calling it “the first direct evidence of West Nile activity in our area this summer.”

West Nile virus (WNV), a viral infection found in birds and carried by mosquitoes that feed on infected birds, is spread when infected mosquitoes bite humans or other animals. HPEPH said it conducts an adult mosquito surveillance program using carbon dioxide baited light traps at 17 different locations throughout Hastings and Prince Edward Counties. The mosquitoes that are trapped at those locations are then taken to a laboratory where they are tested for WNV, the regional Health Unit explained.

According to Kingston, Frontenac, Lennox and Addington (KFL&A) Public Health, WNV has not been detected in the KFL&A region this year. In fact, the virus has not been detected in KFL&A for five years, according to Sarah Ryding, KFL&A Public Health’s Manager of Environmental Health.

“According to our surveillance results for 2022, WNV has not been detected in any of the mosquito pools we have tested. The last time WNV was detected in a mosquito pool in our region was 2017,” Ryding said in an email response to inquiries from Kingstonist about the presence of the virus locally.

Ryding explained that, like HPEPH, KFL&A Public Health conducts annual WNV surveillance for 12 weeks during June, July, and August, the months when mosquitoes are most active. The local Health Unit sets mosquito traps for 24 hours at seven sites across KFL&A, and all mosquitoes captured in the traps are sent for lab analysis to check for the presence of WNV, Ryding said.

“Mosquitoes can become infected with West Nile virus by biting an infected bird. It is not spread directly from birds to humans. The virus is not spread by person-to-person contact,” she clarified.

Both HPEPH and KFL&A Public Health said that, of those who become infected with WNV, few have severe reactions – if they have any reaction at all. Eight out of 10 people who contract the virus do not develop symptoms, Ryding stated.

“The risk of becoming seriously ill because of infection from West Nile virus is very low, and most people who become infected experience no symptoms or have a very mild illness,” Ryding continued. “Older adults and people with weakened immune systems are at higher risk for more serious illness.”

Symptoms of WNV usually appear within two to 14 days after being bitten, and approximately one in five people who are infected will develop a fever, along with other symptoms such as headache, body aches, joint pain, swollen glands, vomiting, diarrhea, or rash, said Ryding. HPEPH also noted that “in severe cases, West Nile virus can cause an inflammation of the brain known as encephalitis.”

While there is no specific treatment or vaccination available for WNV, supportive therapy is provided by health care professionals in severe cases of the virus.

Protecting against West Nile virus

Both HPEPH and KFL&A Public Health shared the following tips on how to protect yourself and your family members against West Nile virus:

• Apply  approved insect repellent containing DEET or Icaridin to exposed skin and clothing, and consider wearing permethrin-treated clothing.
• Wear long pants, a long-sleeved shirt, shoes, and socks to protect exposed skin.
• Wear light coloured, tightly woven, loose fitting clothing. “Mosquitoes are attracted to dark colours and can bite through thin clothing.” (KFL&A Public Health)
•  Make sure that screens for doors and windows have no holes and fit tightly.
• Stay out of wooded areas during dawn and dusk. “Mosquitoes are most active at dawn (first light) and dusk (just before dark).” (HPEPH)

“Mosquitoes lay their eggs in standing water (water that does not move/flow). It is advisable to get rid of any standing water around your home,” HPEPH said in a press release.

Both Health Units shared tips on how residents can help eliminate mosquito populations around their properties, mainly focused on getting rid of areas or objects that can accumulate or retain water for the reasons above:

• Routinely drain standing water from items like recycle bins, garbage cans, buckets, planters, toys, and flowerpot saucers.
•  Remove unused items (for example, old tires) from around your property that may collect water.
• Change the water in bird baths, pet bowls, children’s wading pools, and livestock watering tanks frequently.
•  Keep swimming pools clean and properly chlorinated; remove standing water from pool covers.
• Clean out eavestroughs regularly; remove leaves and debris that may prevent the drainage of rainwater.
•  Cover rain barrels with mesh screens.
• Keep bushes and shrubs clear of overgrowth and debris, as “adult mosquitoes like to rest in dense shrubbery,” Ryding said.

For more information on WNV from HPEPH, visit their website. For more information on WNV from KFL&A Public Health, visit their website, which includes a variety of links on the subject.