The Louisiana Department of Health (DHH) has confirmed five new West Nile virus cases this week, bringing this year's total number of cases to 39. This week's new infections include three cases of neuroinvasive disease, with one case each from Caldwell, Lafayette and Rapides parishes, one case of West Nile fever from Ouchita Parish and one asymptomatic case from Lafayette Parish.
Humans contract West Nile when they are bitten by mosquitoes infected with the virus. When people are infected with West Nile, the virus will affect them one of three ways. West Nile neuroinvasive disease is the most serious type, infecting the brain and spinal cord. Neuroinvasive disease can lead to death, paralysis and brain damage. The milder viral infection is West Nile fever, in which people experience flu-like symptoms. The majority of people who contract West Nile will be asymptomatic, which means they show no symptoms. These cases are typically detected through blood donations or in the course of other routine medical tests.
About 90 percent of all cases are asymptomatic, while about 10 percent will develop West Nile fever. Only a very small number of infected individuals will show the serious symptoms associated with the neuroinvasive disease. Residents who are 65 years old and older are at higher risk for complications, but everyone is at risk for infection.
Last year, Louisiana reported 160 cases of West Nile virus neuroinvasive disease in the state, which is down from 2002's high of 204 cases of West Nile virus neuroinvasive disease. LDH has been tracking West Nile virus for more than a decade, and statistics about its occurrence in Louisiana can be found in LDH's weekly Arbovirus Surveillance Report, found on line at www.dhh.louisiana.gov/fightthebite.
This year, Ouachita Parish has reported 10 cases of neuroinvasive disease, one of which was previously reported as West Nile fever and has been upgraded to neuroinvasive disease. Lafayette Parish has five cases, two of which were previously reported as West Nile fever and have been upgraded to neuroinvasive disease. Caldwell and Rapides parishes each have three neuroinvasive disease cases, and Calcasieu, Livingston and St. Tammany parishes each have one case of neuroinvasive disease. The state has reported one West Nile virus death so far this year.
Dr. Raoult Ratard, LDH State Epidemiologist, recommends that all citizens take these precautions to protect yourself:
- If you will be outside, you should wear a mosquito repellent containing DEET. The American Academy of Pediatrics (AAP) recommends that repellents should contain no more than 30% DEET when used on children. Insect repellents also are not recommended for children younger than 2 months. CDC recommends that you always follow the recommendations appearing on the product label when using repellent.
- Apply repellent on exposed skin and clothing. Do not apply under your clothes or on broken skin.
- To apply repellent to your face, spray on your hands and then rub on your face.
- Adults should always apply repellent to children.
- Wear long-sleeved shirts and pants when outdoors for long periods of time.
- Avoid perfumes and colognes when outdoors for extended periods of time.
- Make sure that your house has tight-fitting windows and doors, and that all screens are free of holes.
Protecting Your Home
- Reduce the mosquito population by eliminating standing water around your home, which is where mosquitoes breed.
- Dispose of tin cans, ceramic pots and other unnecessary containers that have accumulated on your property. Turn over wheelbarrows, plastic wading pools, buckets, trash cans, children's toys or anything that could collect water.
- Drill holes in the bottom of outdoor recycling containers. Drainage holes that are located on the container sides collect enough water for mosquitoes to breed.
- Check and clean roof gutters routinely. They are often overlooked, but can produce millions of mosquitoes each season.
- Aerate ornamental pools or stock them with fish. Water gardens can become major mosquito producers if they are allowed to stagnate.
Clean and chlorinate swimming pools that are not being used. A swimming pool that is left untended by a family for a month can produce enough mosquitoes to result in neighborhood-wide complaints. Be aware that mosquitoes may even breed in the water that collects on swimming pool covers.