What This Program Does
Since West Nile Virus was first found in Manchester in 2000, the Manchester Health Department has monitored mosquitoes and worked to reduce the risk of mosquito-borne illness.
Our goals are to:
- Watch for mosquito-borne viruses in the city
- Respond quickly if risk increases
- Share information with the public so people can protect themselves
What Are Arboviruses?
“Arbovirus” means arthropod-borne virus – viruses spread by insects like mosquitoes and ticks.
In New Hampshire, the main mosquito-borne viruses we watch for are:
- West Nile Virus (WNV)
- Eastern Equine Encephalitis (EEE)
- Jamestown Canyon Virus (JCV)
These viruses can spread to people through the bite of an infected mosquito.
How We Monitor Mosquitoes and Illness
From July through mid-October, we survey mosquito populations:
- Set mosquito traps at locations around the city
- Collect and identify mosquitoes by species
- Send them to the NH State Public Health Lab to be tested for WNV, EEE, and JCV
If mosquitoes test positive, it may mean a higher risk for people in that area.
For human surveillance, we work with:
- Local healthcare providers
- The New Hampshire Department of Health and Human Services
to identify people who may be infected with WNV, EEE, or JCV and to better understand where infections may have occurred.
You can view weekly test results and the statewide Arboviral Risk Map on the NH Department of Health and Human Services Mosquito-Borne Illnesses webpage.
Preventing Mosquito Breeding on Your Property
Mosquitoes lay eggs in standing (stagnant) water. Getting rid of standing water is one of the best ways to reduce mosquitoes and protect your family and neighbors.
The City of Manchester has a local rule that requires property owners to keep their property free of conditions that allow mosquitoes to breed. In simple terms:
If water is collecting in containers on your property (barrels, tires, tubs, pools, etc.), you must remove the water or treat it so mosquitoes cannot breed there.
What you can do to Reduce Mosquito Breeding
Eliminate Standing Water
- Empty and scrub birdbaths, gutters, and pet water dishes regularly
- Turn over wheelbarrows, plastic wading pools, and other items when not in use
- Remove old tires, buckets, cans, and other containers that can hold water
- Drill holes in the bottom of outdoor containers so water drains out
Swimming Pools and Ponds
- Keep swimming pools clean, filtered, and properly chlorinated
- Cover pools when not in use and make sure the cover does not collect water
- Aerate ornamental ponds or add mosquito-eating fish (such as goldfish or guppies)
Yard and Landscaping
- Cut tall grass and trim bushes so air can move through vegetation
- Remove excess leaves, brush, and yard debris around wet areas
Rainwater Management
- Check that gutters and drainage systems are working and not backing up
- Use rain barrels with tight lids or fine mesh screens
- Fix areas where water pools after rain
Screens and Barriers
- Use window and door screens with fine mesh
- Repair tears or holes in screens
Regular Property Checks
- Walk around your property weekly to look for and dump standing water
- Make sure septic tanks are sealed and in good repair
Larvicides (for Water You Can’t Remove)
For standing water that cannot be drained (like some ponds or ditches), you can:
Preventing mosquito-borne illness is a community effort. Talk with your neighbors and encourage them to remove standing water too.