By BOB ANDERSON banderson@theadvocate.com Florida parishes bureau

Six new human cases of West Nile virus were confirmed during the past week, but state health officials said a couple of things concern them.

One concern is the huge number of mosquitoes that have hatched since a pair of storms hit Louisiana in recent weeks.

Another is the possibility of birds migrating to Louisiana from areas where the virus is still active.

"It's not over yet," said Dr. Raoult Ratard, the state epidemiologist, on Thursday afternoon.

"If people are optimistic that the outbreak is ending and are thinking about stopping their use of repellent, the massive number of mosquitoes that we are seeing should convince them to continue the preventive measure," said David Hood, secretary of the Department of Health and Human Services.

Some breeds of mosquitoes that have been hatching in recent days can carry the virus, said Matt Yates, director of the East Baton Rouge Mosquito and Rodent Control Program.

Before those mosquitoes can transmit the disease, they have to feed on an infected bird, he said.

The number of birds carrying the virus should have been reduced by the inactivity of mosquitoes during the recent storms, said Dennis Wallette, a medical entomologist with DHH.

The infection cycle can get broken by things like the storms or cold weather causing mosquitoes to become dormant for a week or so, Ratard said.

After birds have had the virus for about a week they either die or develop an immunity, the epidemiologist said.

The cycle gets broken unless new birds bring the virus back to the area, Ratard said.

Yates said one of his concerns is that the virus is still going strong in some states to the north of Louisiana, and migrating birds could bring it back to Louisiana, even if the cycle has been broken here.

Ratard agreed that is a possibility.

"There's not much we can do," to prevent that from happening, he said.

Ratard said he thinks the more likely scenario is that the number of new virus cases will remain relatively low over the next few weeks and dwindle or stop, at least for this year, after a prolonged period of cold weather.

Wallette and Ratard both said they are working with theories and will have to wait and see what happens.

The total number of confirmed human cases of the virus in Louisiana stands at 299, health officials said Thursday.

Those numbers include 15 deaths, including a 70-year-old Baton Rouge man who died from the virus last week.

-- Anonymous, October 11, 2002