Biting Back Against West Nile Virus
August 23, 2012
With confirmation this week of the first human case of West Nile Virus (WNV) in New Hampshire in 2012, state health authorities and infectious-disease specialists at Dartmouth-Hitchcock are reminding Granite Staters of ways to prevent and identify the mosquito-borne malady.
The New Hampshire Department of Health and Human Services (DHHS) and the Manchester Health Department reported on August 22 that an adult resident of Manchester was admitted to a New Hampshire hospital this month the fifth confirmed case in the state since WNV first appeared here in 2000 and the first since September 2010.
"Fortunately, this individual has recovered from his infection," said Jose Montero, MD, the states Public Health Director. "However, there have been 41 deaths associated with West Nile Virus this year in other parts of the country. This is yet another reminder to us all that the illness is here in New Hampshire, and we should all be taking steps to prevent mosquito bites on ourselves and our loved ones."
So far this year, health officials have detected the virus in 29 batches of mosquitoes collected in Manchester; the city began spraying insecticide on August 22. Elsewhere in the state, a total of seven batches have tested positive in the southern-tier communities of Brentwood, Nashua, North Hampton, Salem, and Seabrook.
The West Nile Virus spreads through the bite of an infected mosquito, and can be transmitted to horses, other animals, and, in rare cases, people.
"The risk to humans is low and in the majority of cases there are no symptoms, or just mild, flu-like symptoms," explained Jodie Dionne-Odom, MD, an infectious-disease specialist at Dartmouth-Hitchcock and Deputy State Epidemiologist, who is working through the New Hampshire Health Alert Network to advise physicians and health care providers across the state on ways to test for, report and treat the virus.
Diagnosis comes from tests of blood or spinal fluid, and symptoms usually appear four to 10 days after an infected mosquito bites, according to Dionne-Odom. "People over the age of 50 are considered to be at higher risk of becoming ill," she said. "Symptoms can include severe headache, high fever, stiff neck, confusion, loss of consciousness, and muscle weakness."
Epidemiologists first described the disease in the United States in 1999. In 2012 to date, 38 states reported a total of more than 1,000 cases of WNV in humans, out of which 41 died. This year marks the highest activity noted for WNV at this point in the season. Why is it more prevalent in 2012?
"Some people think that its related to changes in the weather, but there are no conclusive reasons why one year is different than another," Dionne-Odom said.
When it comes to WNV, the best option is prevention according to DHHS. Steps include: using effective mosquito repellant, wearing long sleeves and pants at dawn and dusk (when mosquitoes are most active), removing standing water from around your house to deny mosquitoes a breeding ground and by checking doors and windows for secure screens.
For more information about West Nile Virus
- Prevention Guidelines for West Nile Virus and Eastern Equine Encephalitis
- West Nile Virus Fact Sheet (PDF)
- Information for Health Care Providers
Dartmouth-Hitchcock is a national leader in patient-centered health care and building a sustainable health system. Founded in 1893, the system includes New Hampshire's only Level 1 trauma center and its only air ambulance service, as well as the Norris Cotton Cancer Center, one of only 40 National Cancer Institute-designated Comprehensive Cancer Centers in the nation, and the Children's Hospital at Dartmouth-Hitchcock, the state's only Children's Hospital Association-approved, comprehensive, full-service children's hospital. As an academic medical center, Dartmouth-Hitchcock provides access to nearly 1,000 primary care doctors and specialists in almost every area of medicine, as well as world-class research at the Audrey and Theodor Geisel School of Medicine at Dartmouth.