Mass. — The Massachusetts Department of Public Health (DPH) has announced another human case of West Nile virus (WNV), bringing the total number of confirmed cases in the state this season to nine.
The newly reported case involves a man in his 50s with exposure in Middlesex County.
According to DPH, no risk level increases are indicated at this time of year. At the end of October, municipalities at high risk for WNV will be reduced to moderate until there is a hard frost.
“This case is a reminder that WNV infections can occur even in the fall, and we should remain vigilant,” said Public Health Commissioner Robbie Goldstein, MD, PhD. “We are now past the peak season for West Nile virus in Massachusetts, but some risk will continue until the first hard frost, and we are still reminding everyone to continue to take steps to protect themselves from mosquito bites.”
The first WNV-positive mosquitoes in the state this year were announced on June 17.
There were a total of 451 mosquito samples that tested positive for WNV this season from Barnstable, Berkshire, Bristol, Dukes, Essex, Franklin, Hampden, Middlesex, Norfolk, Plymouth, Suffolk, and Worcester counties. There was also one animal case of WNV this year in a goat.
In addition to WNV, Eastern equine encephalitis (EEE) was detected in mosquitoes in Massachusetts this year. There were 23 EEE-positive mosquito samples and no human or animal cases.
State officials shared the following tips to help prevent mosquito bites and the transmission of the virus:
Avoid mosquito bites and 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 the evening, after 6 p.m. or early morning. Otherwise, take extra care to use repellent and protective clothing. Mosquitoes can be active during daylight hours when the temperatures are cool.
Clothing can help reduce mosquito bites. Although it may be difficult to do when it is hot, wearing long sleeves, long pants, and socks when outdoors will help keep mosquitoes away from your skin.
Apply insect repellent when you go outdoors. Use a repellent with DEET (N, N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), or oil of lemon eucalyptus [p-methane 3, 8-diol (PMD)] according to the instructions on the product label. DEET products should not be used on infants younger than 2 months of age and should be used in concentrations of 30 percent or less on older children. Oil of lemon eucalyptus should not be used on children younger than 3 years of age.
Mosquito-proof your Home and 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 getting rid of 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. Some mosquitoes like to come indoors. Keep them outside by having tightly fitted screens on all 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 suspected of having West Nile Virus or EEE, owners are required to report to the Department of Agricultural Resources, Division of Animal Health by calling 617-626-1795, and to the Department of Public Health by calling 617- 983-6800.
More information, including all West Nile Virus- and EEE-positive results can be found at this website or by calling the DPH Division of Epidemiology at 617-983-6800.
This is a developing story. Check back for updates as more information becomes available.
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