State Health Officials Announce Confirmation of Four Human Cases of West Nile Virus in Middlesex and Hampden Counties
WNV threat level raised in numerous communities; residents urged to protect against mosquito bites
BOSTON — The Massachusetts Department of Public Health (DPH) today announced that West Nile virus (WNV) illness has been confirmed in three Middlesex County residents and one Hampden County resident. All four cases were listed as “probable” in a DPH news release earlier this week, and all patients are recovering.
“Confirmation of these four cases is a timely reminder that people need to take the threat of mosquito-borne illness seriously no matter where they live,” said DPH State Epidemiologist Dr. Al DeMaria. “Warm temperatures are forecast for Labor Day weekend, and it’s vitally important that people take steps to protect themselves against mosquito bites: use insect repellant, cover up, and avoid outdoor activities at dusk and after nightfall when mosquitoes are at their most active.”
As a result of the Middlesex County findings, the WNV threat level is being raised to “High” in Chelsea, Everett, Lexington, Malden, Medford, Melrose, Revere, Saugus, and Winthrop. The threat level is being raised to “Moderate” in Bedford, Burlington, Lincoln, Stoneham, Wakefield, Winchester, and Woburn. Based on the Hampden County findings, the WNV threat level is being raised to “High” in Chicopee, and to “Moderate” in Holyoke, South Hadley, and West Springfield.
“The news that a Chicopee resident has contracted WNV is another indication that mosquito-borne illness is present across the state, and residents should continue using personal preventive measures to avoid getting bit by mosquitoes,” said Chicopee Health Director Lisa Sanders.
WNV infected mosquitoes have been found in 97 communities from nine counties so far during 2012, and health officials predict that the state is on track to have the greatest number of WNV-positive mosquito pools since WNV was first seen in Massachusetts in 2000. There have been four human cases of WNV in Massachusetts prior to today’s announcement – three in Middlesex County and one in Berkshire County. There were six cases of WNV in Massachusetts residents and one in a horse last year.
While WNV can infect people of all ages, people over the age of 50 are at higher risk for severe disease. WNV is usually transmitted to humans through the bite of an infected mosquito. Most people infected with WNV will have no symptoms. When present, WNV symptoms tend to include fever and flu-like illness. In rare cases, more severe illness can occur.
People have an important role to play in protecting themselves and their loved ones from illnesses caused by mosquitoes:
Avoid Mosquito Bites
- Apply Insect Repellent when Outdoors. Use a repellent with DEET (N, N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), oil of lemon eucalyptus [p-methane 3, 8-diol (PMD)] or IR3535 according to the instructions on the product label. DEET products should not be used on infants under two months of age and should be used in concentrations of 30% or less on older children. Oil of lemon eucalyptus should not be used on children under three years of age.
- Be Aware of Peak Mosquito Hours. The hours from dusk to dawn are peak biting times for many mosquitoes. Consider rescheduling outdoor activities that occur during evening or early morning.
- Clothing Can Help Reduce Mosquito Bites. Wearing long-sleeves, long pants and socks when outdoors will help keep mosquitoes away from your skin.
Mosquito-Proof Your Home
- Drain Standing Water. Mosquitoes lay their eggs in standing water. Limit the number of places around your home for mosquitoes to breed by either draining or discarding items that hold water. Check rain gutters and drains. Empty any unused flowerpots and wading pools, and change water in birdbaths frequently.
- Install or Repair Screens. Keep mosquitoes outside by having tightly-fitting screens on all of your windows and doors.
Protect Your Animals
Animal owners should reduce potential mosquito breeding sites on their property by eliminating standing water from containers such as buckets, tires, and wading pools — especially after heavy rains. Water troughs provide excellent mosquito breeding habitats and should be flushed out at least once a week during the summer months to reduce mosquitoes near paddock areas. Horse owners should keep horses in indoor stalls at night to reduce their risk of exposure to mosquitoes. If an animal is diagnosed with WNV or EEE, owners are required to report to DAR, Division of Animal Health by calling 617-626-1795 and to the Department of Public Health (DPH) by calling 617-983-6800.
More information, including all WNV and EEE positive results from 2012, can be found on the Arbovirus Surveillance Information web page at www.mass.gov/dph/wnv or by calling the DPH Epidemiology Program at 617-983-6800. The findings of the DPH Eastern Equine Encephalitis Expert Panel can be found here:
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