2 humans ill; horse dies of mosquito-borne viral illness

Two people in New Hampshire (Newton and Newfields) have fallen ill with Eastern Equine Encephalitis (EEE) and a horse has died of the disease. EEE is a mosquito-spread, viral disease of birds that sometimes gets transmitted (via mosquito bite) to horses and people.

Only a handful of the 47 species of mosquitoes in New Hampshire can transmit EEE. Although the chances of getting it are very low, the consequences can be serious. Symptoms in people range from mild flu-like illness to inflammation of the brain, coma, and death. The human death rate is 35 percent, and about 35 percent of people who survive have lasting neurological effects of some type.

Infected humans can't pass the disease to others by coughing, sneezing or other means.

People most at risk for contracting EEE: those younger than 15 or older than 50.

The EEE season runs from late August until the arrival of hard frost, typically late September to mid-October. Southeast Rockingham County is at highest risk for EEE, although southern Merrimack, southern Strafford, and possibly eastern Hillsborough have a slightly elevated risk.

Protect yourself: Reduce your risk of getting bitten:

• Use insect repellent containing either DEET or picaridin when you are outdoors.
• Wear clothing that doesn't expose lots of skin. Consider wearing net-like clothing that is stiff enough to stay away from your skin, such as Bug Baffler.
• Try to limit time spent outdoors within an hour or so of dusk or dawn, especially in areas with lots of mosquitoes.
• Mosquitoes that transmit EEE aren't very active in mid-day. An exception is if you walk through thick brush or woods. You disturb the vegetation on which they rest, so they will then fly to you and bite.
• Be sure that sleeping quarters have tight-fitting screens on doors and windows. This includes tents and other camping quarters.
• Limit your activity in areas near freshwater marshes with permanent vegetation, especially cattails.

For more on the subject, read our 13-page fact sheet, which contains links to much more information.

You may also want to check the latest information from the N.H. Department of Health and Human Services.

By Dr. Alan T. Eaton, UNH Cooperative Extension entomology specialist