Topeka ? Reporting unconfirmed cases of West Nile virus detected by commercial labs will give a clearer picture of the spread of the illness in Kansas, state health officials said Friday. The Kansas Department of Health and Environment said in addition to the 61 confirmed cases of severe West Nile virus, there had been 423 cases where human tests have yielded presumptive positives for the illness.

KDHE also will begin reporting all unconfirmed deaths to West Nile virus, based on death certificates sent to its Division of Vital Statistics. KDHE only can confirm one death — an 83-year-old man in Butler County — but death certificates show three unconfirmed deaths.

The virus is transmitted by infected mosquitoes, whose bites lead to severe illness in one of every 150 people infected.

Dr. Gianfranco Pezzino, state epidemiologist, said states had been left to their own discretion by the Centers for Disease Control and Prevention on how West Nile virus had been reported. KDHE to date has only reported those cases confirmed as either leading to meningitis, encephalitis or acute paralysis.

Pezzino said the state’s numbers of confirmed and unverified cases “are really in line with a lot of other states in the Midwest.” The agency had faced some criticism for only reporting serious, confirmed cases.

According to the CDC, this year’s West Nile outbreak caused nearly 2,000 cases in Colorado, an additional 1,000 in Nebraska and more than 800 in South Dakota.

Commercial labs began this year to use new tests to detect West Nile virus. Still, Pezzino said, the tests are not 100 percent reliable and should not be interpreted as representing hundreds of confirmed cases of West Nile.

He said the results that had been shared with KDHE by the labs came with a disclaimer that the information could show a presumptive positive but not West Nile upon further testing. The KDHE does not know residence or age information for victims identified through private lab tests.

West Nile virus appeared in 2002 in Kansas, with 22 human cases confirmed with no fatalities. This year the virus was first detected in mosquito populations in Crawford County. The virus has also been found in birds and horses.

Dr. Gail Hansen, state veterinarian, said the changes in the reporting of West Nile cases should serve as a reminder to the public how serious they should take the disease. In addition, the numbers give the state health officials another piece of information to determine the severity of the outbreak and how to fight it.

“It’s still a pretty new kid on the block. The disease has only been in the U.S. since 1999,” Hansen said.

Although treatments and vaccines against the virus are being worked on, they are still years away from public use, officials said. CDC officials estimate the 2002 outbreak cost the country at least $200 million in medical services.

KDHE recommends minimizing contact with mosquitoes as the best way to avoid infection. Suggestions include using insect repellent containing DEET, remaining indoors at dusk and dawn, wearing long-sleeved shirts and pants outdoors whenever practical, eliminating stagnant pools of water and repairing screens or other places where mosquitoes can enter a home.

Most people who are infected with the virus won’t get sick. The CDC says about a fifth of those will develop a fever, headache, body aches and sometimes a rash and swollen lymph glands.