as more human cases of West Nile virus emerge: one confirmed, six probable human cases in Essex, Hampden and Middlesex counties
BOSTON – The Massachusetts Department of Public Health (DPH) today announced that a fourth human case of West Nile virus (WNV) has been confirmed in the state. The patient, a Newton woman in her 50s, was briefly hospitalized and is recovering. As a result, the WNV threat level has been raised to “High” in Newton and to “Moderate” in Needham, Waltham, Wellesley and Weston. Health officials are also awaiting confirmation of an additional six probable human cases of WNV: four in Middlesex County, one in Hampden County and one in Essex County.
“With today’s announcement, it’s clear that the threat of mosquito-borne illness is present throughout the Commonwealth,” said DPH State Epidemiologist Dr. Al DeMaria. “It’s critically important that people across the state take steps to protect themselves against mosquito bites – especially with the warm temperatures and outdoor activities planned for this long Labor Day Weekend.”
“While we now have a confirmed WNV case in a Newton resident, we have known about positive mosquitoes in Newton since July,” said Dr. Dori Zaleznik, Commissioner of Health and Human Services for the City of Newton. “We continue to urge our residents to take common-sense precautions to prevent mosquito bites by using insect repellent – especially if you need to be out between dusk and dawn.”
WNV infected mosquitoes have been found in 93 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 three human cases of WNV in Massachusetts prior to today’s announcement – two 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. Owners should also speak with their veterinarian about mosquito repellents approved for use in animals and vaccinations to prevent WNV and EEE. 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.