Massachusetts health officials say the state's fourth case of West Nile virus has been confirmed and there are six more probable cases.
The Department of Public Health said Wednesday the latest confirmed patient is a Newton woman in her 50s who was briefly hospitalized and is recovering. Four likely new cases have been reported in Middlesex County, and one each in Essex and Hampden counties.
There have been two West Nile cases in Middlesex County this summer and one in Berkshire County.
Last year, there were six human cases in Massachusetts.
The health department is urging people to take precautions against mosquito bites including avoiding nighttime outdoor activities and using insect repellent and protective clothing.
Mosquitoes infected with West Nile have been found in 93 communities in nine counties in the state this year.
Massachusetts health authorities say the state is on track to have more infected mosquitoes this year than since the virus was first seen here 12 years ago.
Federal health officials said Wednesday that West Nile cases around the country are up 40 percent last since last week and may approach the record years of 2002 and 2003, when almost 3,000 severe cases and more than 260 deaths occurred each year.
About 1,590 cases of West Nile have been reported to the Centers for Disease Control and Prevention this summer, and 66 deaths.
Officials say this year's early spring and hot summer may have contributed to the higher number of cases.
This program aired on August 29, 2012. The audio for this program is not available.