DALLAS -- Health officials say it's the worst year ever for West Nile in Texas, which has seen nearly half the country's deaths from the virus this year.

Texas Department of State Health Services Commissioner David Lakey said Wednesday that at least 40 people have died from the virus in Texas. The state has recorded at least 495 cases of neuroinvasive West Nile, the most serious form of the illness.

That's already worse than in all of 2003, when Texas had 439 neuroinvasive cases and 40 deaths.

Federal officials say there have been at least 87 deaths nationwide this year.

Lakey says numbers are expected to increase through mid-October. But he says there are indications August marked the peak, especially in the hard-hit North Texas area that includes Dallas and Fort Worth.