SIKESTON -- Many health professionals across the state are bracing themselves, hoping a West Nile virus outbreak doesn't occur as widespread as it did last year around this time.
Already this summer, birds and horses in Missouri have tested positive for the potentially deadly virus, but so far, there haven't been any positive human cases.
"The two animals most commonly affected by West Nile are the horses and us -- outside of birds, which are also commonly infected," noted Taylor Woods, state veterinarian and director of the Division of Animal Health. "We're what you call the dead-end hosts."
West Nile virus, the mosquito-borne illness that can be fatal for birds, horses and even humans, causes brain inflammation. Mosquitoes contract the virus by feeding on infected birds, then spread the disease by biting humans, horses, birds and other host animals.
"We are expecting a really tough year," Woods said. "If you haven't vaccinated your horse, you need to. So far this year there have been two horse deaths from West Nile virus in Missouri -- one in Kansas City and the other in McDonald County."
The Missouri Department of Health and Senior Services reported 277 positive dead birds and 662 horses were diagnosed with West Nile in 2002.
"Most owners have been pretty religious about getting their horses vaccinated," said Jeff Lawrence of North Ridge Veterinary Hospital.
When the initial vaccination is completed, there should be a booster shot that follows, Lawrence said. After that, a shot once a year is sufficient, he said, adding that he thinks the vaccination has been helpful this year.
Woods suggested removing sources of stagnant water, such as containers and old tires. Modify low-lying areas where mosquitoes might breed and clean water troughs as often as possible or at least once a month, he said. Keep fans in the stalls, too, Lawrence recommended.
Nineteen positive dead birds have been confirmed in Missouri this year, according to Karen Yates, coordinator of the Vector-Borne Disease Program at the Missouri Department of Health and Senior Services. The only positive dead bird from Southeast Missouri was found in Bollinger County, she said.
"We're getting calls (from people inquiring about West Nile), but not near as many as last year," said Barry Cook, administrator of the Scott County Health Department. "Last year it was the general questions. 'Should I be concerned? What do I look for?' The few calls I've received this year have been about dead birds that people have found."
Scott County residents have turned in only dead starlings and finches, Cook said. The Center for Disease Control tests only the fresh carcasses of bluejays, crows and raptors so there have been no positive cases in Scott County (or other area counties), he pointed out.
The first positive dead bird this year was found June 11 in St. Charles and the first positive dead bird in 2002 was found June 28 in St. Louis City, Yates said.
"The virus is so pervasive in the bird population and it has great potential to spread over to the human population. So we like to encourage Missourians to notice the dead birds and get them tested if needed," Yates said.
Yates said another mosquito-borne illness residents should look out for is eastern equine encephalitis virus, which is just as serious as West Nile. Illinois is reporting positive cases of eastern equine this year and emus in the south have acquired eastern equine, she explained.
Despite the fact that no positive human cases of West Nile have been reported in Missouri, chances of cases popping up this summer look promising, officials said.
Missouri's first human case contracted West Nile at the end of July last year and the last case was reported in the second week of October.
"Obviously if people aren't taking the right precautions, they're more likely to contract West Nile," Yates noted.
Yates cautioned: Don't go out during the peak mosquito biting time periods of dusk and dawn, wear long sleeves and use the repellents. Cleaning out gutters and ditches, not leaving toys and tires outside can help cut down on the mosquito population.
"We want people to be prepared," Yates said. "Eighty percent of the people who are infected with West Nile don't know it. They don't notice symptoms because they're immune system kicks in and eliminates the virus. People over age 50 have a 70 percent increased risk of death from West Nile."
In addition to covering up with long sleeves and pants, when active outside, use an insect repellent with DEET, or N,N-diethyl-meta-toluamide. This works for both mosquitoes and ticks. Yates also said good, basic overall health is a great method of prevention.
Last year 168 human cases were reported in 29 Missouri counties, and seven human deaths in Missouri were linked to WNV infection, according to Missouri Department of Health and Senior Services. None of those cases were in Scott, New Madrid, Mississippi or Stoddard counties.
However, Cook said: "The public needs to be aware that sooner or later it will probably hit us and getting rid of mosquito populations is the key to prevention."