BOSTON - Massachusetts and Pennsylvania reported their first deaths this year on Friday from West Nile virus, as the mosquito-borne illness, which has claimed dozens of victims across the United States, spread.

An 87-year-old Boston woman and an 81-year-old man from the Boston suburb of Weymouth became the first West Nile fatalities in Massachusetts this year, according to the state Department of Public Health.

In Pennsylvania, Physician General Rob Muscalus reported the death from West Nile of an 87-year-old man from Allegheny County, the Pittsburgh area.

The U.S. Centers for Disease Control and Prevention, which has yet to confirm some of the cases, has blamed West Nile for at least 54 deaths this year in the United States.

At least 42 states, from Maine to California, and the District of Columbia have reported some West Nile activity this year. The virus has also been detected in parts of Canada.

Illinois authorities reported two more deaths on Friday, for a total of 16, the highest single-state toll in the West Nile outbreak.

Separately, a U.S. senator's office said he had no plans to press for an investigation of a possible terror link to the virus, which is common in Africa and Asia but did not appear in the United States until a 1999 outbreak that killed seven people in New York.

Sen. Patrick Leahy, a Democrat from Vermont, said in a radio interview broadcast in his home state this week that the government should look at whether the disease is "a biological weapon" being tested on unwary U.S. citizens.

But a spokeswoman for the senator said on Friday that it had been a casual remark in the context of a discussion of anthrax attacks.

She confirmed that Leahy, the target of an anthrax attack in 2001, had no plans to press for any formal investigation.

The U.S. government said on Friday it was providing an additional $6.3 million to 25 states, three cities and the U.S. capital, Washington, to help fight West Nile.

The CDC has awarded about $35 million total to states and cities so far this year for West Nile virus, according to a statement from the Department of Health and Human Services.

This year's outbreak of West Nile began in the southern United States and has been slowly spreading north and west.

Officials emphasized that the risk of becoming ill from a mosquito bite is very low, noting less than 1 percent of bites from mosquitoes infected with West Nile cause severe disease.

Most people bitten by a West Nile-carrying mosquito have no symptoms and those who do normally suffer little more than flu-like illness, the virus can cause fatal brain inflammations in the elderly and people with weak immune systems.