NH DHHS - Mosquito Precautions

Health Department Encourages New Hampshire Residents to Take Precautions

against Mosquito-Borne Diseases

Concord, NH - The New Hampshire Department of Health and Human Services

(DHHS) Division of Public Health Services (DPHS) is encouraging residents

and visitors to the State to take precautions against mosquito bites this

season to prevent West Nile Virus (WNV) and Eastern Equine Encephalitis

(EEE). Mosquitoes are already out and the most likely time for them to

spread disease is June through September.

During the 2012 season, 9 batches of mosquitoes tested positive for EEE and

41 batches tested positive for WNV. There were 4 veterinary cases of EEE (2

horses and 2 emus) but none detected for WNV. There was also a human case

of WNV but no EEE cases.

During 2011, 9 batches of mosquitoes tested positive for WNV and no samples

tested positive for EEE. In 2010, 1animal and 1 person tested positive for

WNV and 1 animal tested positive for EEE.

“These numbers illustrate the unpredictability of these viruses,” said Dr.

José Montero, Director of Public Health at DHHS. “The weather plays a role

as do environmental factors so we just don’t know from year to year what

will happen. Therefore, it is important that we remind residents that these

diseases are preventable. It is essential that people follow precautionary

steps, most importantly using an insect repellent, to avoid becoming

infected by one of these diseases.”

Eastern Equine Encephalitis and West Nile Virus are transmitted through the

bite of an infected mosquito that has picked up the virus by feeding on an

infected bird. EEE is a serious disease that carries a high mortality rate

for those who contract the serious encephalitis form of the illness.

Symptoms may include high fever, severe headache, and a sore throat. A

stiff neck is also a symptom of the severe form of the disease, which can

lead to seizures and coma. Symptoms usually occur 4 to 10 days after

someone is bitten.

For individuals who are bitten by a mosquito carrying West Nile Virus, 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. At times,

West Nile Virus can cause meningitis and can be a serious threat to

seniors, young children, and those with compromised immune systems. If

illness does occur, it typically happens within 3 to 15 days after being

bitten by an infected mosquito.

Precautionary steps everyone should take to prevent being bitten by

mosquitoes include:

Using an insect repellent containing DEET, picaridin, oil of lemon

eucalyptus, or IR3535 against mosquitoes

Wearing long-sleeved shirts and pants when outdoors when mosquitoes

are biting

Make sure to remove standing water around your home where mosquitoes

can breed, such as in tires, flower pots, or pool covers

Make sure screens on windows and doors fit tightly and do not have


Monitor yourself if you are bitten by mosquitoes and tell your

healthcare provider if you develop any symptoms of WNV or EEE

For more information about WNV, EEE, or Lyme disease, visit the DHHS

website at www.dhhs.nh.gov , the Centers for Disease Control and Prevention

website at www.cdc.gov , or call the DHHS Bureau of Infectious Disease

Control at 1-800-852-3345 x4496.