With summer on the horizon, the New Mexico Department of Health is once again asking residents to protect themselves against the threat of West Nile Virus. Mosquitoes thrive in wet and warm weather and residents should take precautions now to avoid contracting the virus, said Paul Ettestad, the state public health veterinarian at the New Mexico Department of Health.

According to Ettestad, mosquito populations will stay high until the first hard frost reduces their numbers significantly. West Nile Virus can be prevented by following a few safety tips such as staying indoors at dusk and dawn, when mosquito activity is at its peak, and using insect repellents such as DEET when you are outdoors. Standing water should be drained or cleaned up immediately as it can be a breeding ground for mosquitoes.

West Nile Virus can cause a mild illness with flu-like symptoms such as fever, nausea, headache and muscle aches, and it can also cause more severe illnesses such as meningitis and encephalitis. People older than 50 are at the highest risk for serious complications from West Nile Virus.

Meningitis and encephalitis can be fatal, especially in the elderly. However, most people who become infected have either no symptoms or mild symptoms. Less than 1 percent of all people infected, including those who have no symptoms and have not been tested, develop meningitis or encephalitis. Meningitis is an infection of the lining around the brain, while encephalitis is an infection of the brain itself.

There were 88 human cases of West Nile Virus in 2004 in New Mexico, with seven cases in Doña Ana County and one case in Grant County. In 2005, there were 33 human cases statewide, including 10 in Doña Ana County and one in Luna County. Four cases in 2004 and two in 2005 resulted in death.

The department also recommends that people take the following steps to reduce the risk of infection from West Nile or Western Equine Encephalitis:

Stay indoors at dawn, dusk and in the early evening.

• Wear long-sleeved shirts, long pants and socks whenever you are outdoors.
• Products containing DEET or Picaridin can provide longer lasting protection. Use insect repellent products with no more than 35 percent DEET for adults and follow the directions on the label for children from ages 2 to 12. Natural products containing soybean oil or lemon eucalyptus oil have also been shown to be effective but need to be applied more often.
• Keep windows and doors closed if not screened. If you leave your doors or windows open, make sure they have screens that fit tightly and have no holes.
• Do not allow water to stagnate in old tires, flowerpots, trash containers, swimming pools, birdbaths, pet bowls, etc.
• Horse owners should contact their veterinarian to have their horses vaccinated against West Nile Virus.

  Insect repellents should never be used on pets, according to the National Animal Poison Control Center, which is part of the University of Illinois College of Veterinary Medicine. Dogs and cats tend to lick themselves and can ingest toxins, which could harm them significantly more than the West Nile Virus. So far, both dogs and cats have been fairly resistant to the virus.

  Chris J. Minnick, who works with the New Mexico Department of Health, writes a weekly column for the Sun-News. He can be reached at christopher.minnick@state.nm.us