Manchester mosquitoes test positive for West Nile Virus

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MANCHESTER, NH – One batch of mosquitoes collected in Manchester on July 16, 2018 has tested positive for West Nile Virus (WNV).

According to Tim Soucy, MPH, Manchester’s Public Health Director, “Although the finding of WNV in the community is not unexpected, it is early in the season and a good time to remind residents to be vigilant in eliminating mosquito breeding areas and to take simple steps such as using effective mosquito repellent and wearing long pants and sleeves at dusk and dawn to prevent being bitten by mosquitoes.”

The city has three testing pools located throughout the city — two on the West Side and one located in the southeastern area, according to the city’s Senior Public Health Specialist, Aaron Krycki.

“We don’t like to pinpoint the testing pool locations because people have a tendency to look for them and vandalize them, unfortunately,” Krycki said.

But the presence of WNV at any one of the testing pools means infected mosquitoes could be anywhere.

“In an urbanized environment, so ‘container breeders’ are common, which means you have to be vigilant about removing standing water in unused swimming pools, buckets, old tires — any place that would provide a place for mosquitoes to breed,” Krycki said.

“We know mosquitoes are also testing positive for West Nile in New York, Massachusetts — we know the mosquito population is so diverse and they travel quite a distance searching for meals, which is another reason we don’t like to pinpoint the location when we get a positive test result. It’s not like they’re going to stop at the border,” Krycki said. “We want people across the city to protect themselves with repellent and take any precautions they can.”

Weekly mosquito pool testing in New Hampshire will continue through October, normally until the first hard frost, Krywcki said.

West Nile Virus is transmitted through the bite of an infected mosquito that has picked up the virus by feeding on an infected bird. For humans the risk of contracting the infection is low and in the overwhelming majority of cases, there are no symptoms or just mild flu-like symptoms. If illness does occur, it happens within four to 10 days after being bitten by an infected mosquito. If someone is experiencing flu-like symptoms including fever and headache, they should contact their local medical provider.

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Current NH 2018 Arboviral Risk map.

The Manchester Health Department has established an information line to assist citizens with concerns and questions about WNV and EEE. The phone number is 628-6003, Ext. #325 and is staffed during normal business hours. After normal business hours, citizens can leave a voice message that will be returned the next business day.

Prevention Guidelines for West Nile Virus and Eastern Equine Encephalitis

1. Eliminate standing water and other mosquito breeding locations around your property. Please do not attempt to drain or alter natural waterbodies for mosquito control, since the management of ponds and wetlands is regulated by the Department of Environmental Services and any planned alterations will require a permit before work may begin. In warm weather, mosquitoes can breed in any puddle that lasts more than 4 days!

  • Remove old tires from your property.
  • Dispose of tin cans, plastic containers, ceramic pots, or other containers. Don’t overlook containers that have become overgrown by aquatic vegetation.
  • Drill holes in the bottom of recycling containers that are left outside.
  • Make sure roof gutters are clean and draining properly.
  • Clean and chlorinate swimming pools and hot tubs. If not in use, keep empty and covered and keep covers free of standing water.
  • Aerate garden ponds or stock them with fish.
  • Turn over wheelbarrows and change water in birdbaths at least twice weekly.
  • Turn over plastic wading pools when not in use.
  • Remind or help neighbors to eliminate breeding sites on their properties.  

2. Be aware of where mosquitoes live and breed and keep them from entering your home.

Mosquitoes lay their eggs in standing water. Weeds, tall grass, and bushes provide an outdoor home for adult mosquitoes, including several species commonly associated with West Nile virus and Eastern Equine Encephalitis.

Mosquitoes can enter homes through unscreened windows or doors or broken screens. Make sure that doors and windows have tight-fitting screens. Repair or replace all screens in your home that have tears or holes.

Resting mosquitoes can often be flushed from indoor resting sites by using sweeping motions under beds, behind bedside tables etc. and once in flight, exterminated prior to sleeping at night.

 3. Protect yourself from mosquito bites.

If outside during evening, nighttime, and dawn hours when mosquitoes are most active and likely to bite, children and adults should wear protective clothing such as long pants, long-sleeved shirts, and socks.

Consider the use of an effective insect repellent, such as one containing DEET. A repellent containing 30 percent or less DEET (N,N-diethyl-methyl-meta-toluamide) for children and adults. Use DEET according to the manufacturer’s directions. Children should not apply DEET to themselves. Repellents that contain Picaridin, oil of lemon eucalyptus, or IR3535 have also been determined to be effective.

Vitamin B, ultrasonic devices, incense, and bug zappers have not been shown to be effective in preventing mosquito bites.

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Manchester Health Department