Two Utah County children have been tentatively identified as suffering the more serious, neuro-invasive form of West Nile virus, according to a county health official. If a state lab test confirms the diagnosis, it will bring to eight the number of human cases so far in the state this year, half of them in Utah County.

The two, identified only as 18 or under to comply with federal privacy laws, were both exposed in southern Utah County, where mosquito pools, horses and sentinel chickens have all tested positive for the virus.

The children were both hospitalized with meningitis, a severe form of the disease that only occurs in 1 of 150 people infected with West Nile. But they are getting better and have been released from the hospital, according to Utah County Health spokesman Eric Edwards.

West Nile numbers statewide are starting to climb, with almost one-third of Utah's counties reporting some West Nile virus activity — either in humans, sentinel chickens, horses, birds, mosquito pools or a combination. Affected counties so far include Weber, Davis, Tooele, Salt Lake, Utah, Duchesne, Uintah, Grand and Washington counties.

The human cases are in Duchesne, Uintah and Utah counties, with one case in Salt Lake County also being counted, although it's slightly different. In that case, the individual showed no symptoms of illness. But the individual was a blood donor, and evidence of the virus was detected during routine screening of blood, says Stephen McDonald, Utah Department of Health spokesman.

Cases are tentatively diagnosed through lab tests, but the state's public health lab runs a confirmatory test before a West Nile virus diagnosis is considered official. Typically, each year, the number of cases are considered an undercount because many people do not experience symptoms severe enough to send them to a doctor and even those who see a doctor may not have a lab test done.

Nationally, 42 states are reporting West Nile virus activity, including 25 states with a total so far of 501 human infections. There have been 12 published West Nile virus fatalities in 2005. So far, the average age nationally of those infected has been 50 years old, and 58 percent of those infected are male. Forty-three percent have been neuro-invasive cases (last year 37 percent were neuro-invasive). The average age of those who died from infection is 77.

The mosquitoes responsible for spreading West Nile virus in Utah, Culex tarsalis, fly and bite between dusk and dawn, a time when health experts counsel people to stay indoors and to use products containing DEET and wear long sleeves and pants if they must be outdoors. The best treatment of the virus is prevention, avoiding being bitten altogether.

The number of West Nile virus cases typically starts climbing in August, health officials say. Although they begin to taper off sometime in September, some activity remains until the first hard frost stops the mosquitoes.

The Utah Department of Health posts information on the virus, updated each Wednesday afternoon, on its Web site, www.health.utah.gov. The Deseret Morning News will be printing an updated count each week, as well.

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