Second West Nile case reported in Massachusetts

By Stephen Smith, Globe Staff

A 54-year-old Boston man has been diagnosed with West Nile virus, which health authorities said today they believe he contracted while visiting Montana.

The man, who was not identified because of patient confidentiality laws, is recovering, said Donna Rheaume, a spokeswoman for the state Department of Public Health. This is the second human case of West Nile reported in Massachusetts this year.

Last month, a man vacationing on Martha's Vineyard tested positive for the mosquito-borne illness, although disease investigators said he most likely was exposed in Missouri before coming to Massachusetts.

So far this summer, 741 cases of West Nile have been reported nationally, with the majority of illnesses happening west of the Mississippi River. Montana, where the Boston man visited, has reported 37 cases.

In the most severe cases, West Nile virus can cause a high fever, headache, neck stiffness, stupor, coma, tremors, convulsions, muscle weakness, and paralysis. The US Centers for Disease Control and Prevention estimates that one of every 150 people infected with West Nile develops severe symptoms.

To avoid contact with infected mosquitoes, the Massachusetts Department of Public Health recommends limiting outdoor activities from dusk to dawn, peak biting times for mosquitoes. Otherwise, wear as much clothing as comfortable and apply insect repellents such as DEET, permethrin, picaridin, or oil of lemon eucalyptus.

DEET should not be used on infants under the age of 2 months and should be used in concentrations of 30 percent or less on older children. Oil of lemon eucalyptus should not be used on children under 3 years old.