This is a big week for creatures of all kinds: Horses are due for another protective injection. Birds of the corvid or raptor groups could begin to die at any time. And the mosquitoes that carry West Nile virus, primarily the night-biting Culex tarsalis, are already testing positive in some states, meaning they could reach Utah soon.
It's time for people to pay attention to protecting themselves.
Today, the Division of Wildlife Resources will issue a plea for people to report certain kinds of dead birds, including jays, magpies, crows and small raptors such as hawks that might have been felled by West Nile virus. In three weeks, the state Department of Health will start checking its sentinel chickens. They've already begun an ad campaign aimed at getting people to wear DEET mosquito repellent.
And mosquito abatement pros have been in the field for weeks, identifying areas where mosquitoes have over-wintered and laid eggs, so they can be destroyed before they start biting birds, horses and people.
The virus is carried by mosquitoes and spread to birds, humans and horses through biting. People can also, on rare occasion, receive the virus from a blood transfusion or transplant, mother to baby in the womb or by a needle stick.
It has deadly potential, though very few of those bitten by an infected mosquito will show even mild symptoms. Fully 80 percent of those bitten by an infected mosquito will have absolutely no symptoms. Nearly 20 percent will have symptoms of West Nile Fever: headache, fever, muscle aches, nausea, vomiting, eye pain, but will usually recover completely within a week. About 1 in 150 people who are infected will show neurological symptoms such as meningitis, encephalitis or acute flaccid paralysis from spinal cord damage. And 10 percent of those few about 1 in 1,000 infected people will die, according to state epidemiologist Dr. Robert Rolfs.
The virus first appeared in Utah last year. Historically, the second year is the worst for human infection. So a consortium that includes health, wildlife, agriculture, mosquito abatement, environmental quality, the Bureau of Land Management and other officials is taking it very seriously
The first new generation of Culex tarsalis mosquitoes has already been born, according to Sam Dickson, manager of the Salt Lake City Mosquito Abatement District, which began seeing "lots of larvae" last month. Because of the weather, the pesky biters are actually three or four weeks ahead of schedule. Abatement staffers are busy destroying breeding grounds something they hope people will do in their own yards, as well.
State veterinarian Mike Marshall hopes that owners gave their horses the first inoculation around April 1. It's now time for the second dose, with another due in August, if it's the first year a horse has been inoculated. Otherwise, it needs one in spring and one around Aug. 1. That has to be done every year.
Like people, not all horses bitten by an infected mosquito will become sick. Some might be just a "little logy, off-color." But, he added, "the ones that get really sick might be sick for two weeks and they're deathly ill. Last year, almost half the ones that were noticeably sick died" of an encephalitis illness. In 2001, nationally, 18,000 horses showed clinical signs of the disease, though many more had likely been infected without any outward sign. Of those with noticeable effects, 4,000 died.
Even those that recover "often are not correct mentally," with heads that tilt, brain damage, stumbling, eyes that don't track together, "not something you'd trust your son getting on. There are some permanent changes," said Marshall, who will update a legislative interim committee on preparations to prevent the illness during a meeting Wednesday.
There simply isn't enough virus in infected horse blood to transmit it, even to another horse, making equines a "dead-end" host.
The Department of Agriculture is trying to spread the message for mosquito control, DEET use and the importance of a product to put in ponds that stops larvae from hatching. They're telling Utahns to use fly wipes on horses or put them in enclosed barns between dusk and dawn, when the infected mosquitoes bite. And they're trying to teach farmers and their families (others should learn, too) that although it's going to be warm, it's important to wear long-sleeved and -legged clothes, a hat and put DEET on hands, neck and face.
The overarching message is "don't just spray at the last minute, do all the preventive things including vaccination of horses to prevent it," Marshall said.
The multi-agency team is also keeping track of where the virus has been to determine where it's going to go. They know there's a "direct correlation" with major waterways in Utah and where the disease has occurred, he said.
Even the Legislature has gotten into the virus-busting act, providing a half-million dollars to help with mosquito control, with the focus on counties that don't have a mosquito-abatement system.
The first human infections are most likely to occur in Utah around July 1 but now is the time to prevent it completely, said Jana Kettering, Health Department spokeswoman.
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