The West Nile virus has apparently claimed six more lives in Tennessee, Kentucky and Illinois. A seventh probable death was reported Monday in New York City.
If confirmed by the federal Centers for Disease Control and Prevention, the additional deaths will bring the national total to at least 37 this year.
Three men ages 72, 85 and 91 were among the first such deaths from the mosquito-borne virus ever recorded in Tennessee, according to state health officials.
The Illinois Department of Public Health on Tuesday reported the deaths of a 71-year-old man Sunday and a 79-year-old woman Aug. 29, bringing the total number of fatalities in that state to nine.
The two deaths were among 44 new human cases in Illinois announced Tuesday. The state has reported 165 cases of the mosquito-borne virus this year.
A second death in the state of Kentucky was attributed to infection by the West Nile virus. The victim was described as an 82-year-old woman.
And on Monday, New York City health officials said a 73-year-old Queens man had died from the virus.
The number of human cases of West Nile has been decreasing in the city since the virus was first detected in 1999, when there were seven deaths. Last year New York saw seven hospitalizations, none fatal.
Most people infected with the West Nile virus have no clinical symptoms of illness, but some might feel flulike symptoms such as fever, headache and body aches three to 14 days after a bite from an infected mosquito.
But especially in older people or those with weakened immune systems, the virus can lead to stupor, convulsions, paralysis and even death.
The Associated Press contributed to this report.