West Nile Virus Outbreak in Massachusetts is Ongoing

Four additional cases of West Nile virus (WNV) were disclosed by the Massachusetts Department of Public Health (DPH) today.

These 4 new cases bring the total number of WNV cases in Massachusetts to 9.

In 2017, there were only 6 human cases of WNV infection identified in Massachusetts.

As of August 21, 2018, a total of 45 states have reported 231 cases of West Nile virus disease in people by the Centers for Disease Control and Prevention (CDC).

Of these cases, 133 (58%) were classified as neuroinvasive diseases, such as meningitis or encephalitis.

“The risk for additional people to get infected with WNV is ongoing,” said Public Health Commissioner Monica Bharel, MD, MPH.

WNV is usually transmitted to humans through the bite of an infected mosquito.

Unfortunately, there are no preventive vaccines or medications to treat WNV infections.

“It is extremely important for people to take steps to avoid mosquito bites including using repellents, wearing clothing to reduce exposed skin, dumping standing water, and moving indoors when mosquitoes are present.”

Most people infected with WNV will have no symptoms. When present, WNV symptoms tend to include fever and flu-like illness.

The CDC recommends that individuals protect themselves against mosquito bites by practicing the "Three Ds":

• DEET - Apply insect repellent containing DEET, picaridin, oil of lemon eucalyptus or IR3535 according to label instructions. Repellents keep the mosquitoes from biting you. Insect repellents should not be used on children under two months of age.
• DAWN AND DUSK - Mosquitoes that transmit WNV usually bite in the early morning and evening so it is important to wear proper clothing and repellent if outside during these times. Make sure that your doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens that have tears or holes.
• DRAIN - Mosquitoes lay their eggs on standing water. Eliminate all sources of standing water on your property by emptying flower pots, old car tires, buckets, and other containers. If you know of a swimming pool that is not being properly maintained, please contact your local mosquito and vector control agency.