Louisiana continues to see a rise in human West Nile virus infections, with the Louisiana Department of Health reporting 24 new cases this week. No additional deaths from West Nile have occurred, though six people this year have died after contracting the virus. LDH has detected 92 West Nile virus cases thus far for 2012, and more than half of these - 47 - are West Nile neuroinvasive disease, the more serious form of the virus that infects the brain and spinal cord and can cause brain damage or death. LDH issues a weekly Arbovirus Surveillance Report that details cases detected thus far by parish, which is published here.
The 24 new infections include 10 cases of neuroinvasive disease, with four being reported in Caddo Parish and one each reported from DeSoto, Orleans, Ouachita, St. Tammany, Tanigipahoa and Webster parishes. There were also new cases of West Nile fever, the milder form of the virus that causes flu-like symptoms, reported from Avoyelles (1), Bossier (3), Caddo (2), Iberville (1), Ouachita (1), Rapides (2) and St. Tammany (1) parishes. Three new asymptomatic cases, meaning the infected people had the virus but did not feel ill and only discovered the West Nile infection when they had blood work done for an unrelated reason such as blood donation, were reported from Caddo, Pointe Coupee and West Baton Rouge parishes.
"We continue to confirm additional cases each week, and as mosquitoes remain active, we can expect to see more," said Dr. Raoult Ratard, LDH State Epidemiologist. "People need to take this disease seriously and follow precautions to avoid mosquito bites."
St. Tammany Parish has reported Louisiana's most neuroinvasive disease cases so far with seven, Caddo Parish is reporting six neuroinvasive disease cases and East Baton Rouge and Tangipahoa parishes each have five neuroinvasive disease cases. But, infected mosquito pools that carry the virus have been detected in all parts of the state, so health officials remind residents that they must take precautions regardless of whether there are cases in their areas.
Most people who contract West Nile virus will have asymptomatic cases, and nearly 10 percent of all cases will develop West Nile fever. Only a very small percentage of infected people develop neuroinvasive disease, and the elderly are particularly at risk for this form of the virus. But, health officials urge individuals of every age to take precautions.
Local mosquito control partners and abatement districts remain vigilant in keeping the population of infected mosquitos under control, but everyone has a personal responsibility to prevent infection by avoiding mosquito bites.
- 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.
- People should be especially vigilant if they are outside at dusk. The mosquitoes that carry West Nile are most active at that time.
- 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.
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 or buckets 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.
- Clean clogged roof gutters yearly. 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 that goes on vacation 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.
West Nile virus has been active in Louisiana since 2002, when the state experienced 328 cases and 24 deaths from the disease. For 10 years, state health officials have conducted robust surveillance during mosquito season, which includes working with doctors, hospitals and health care providers around the state to track human cases and reminding people to be vigilant in avoiding mosquito bites.
The Louisiana Department of Health strives to protect and promote health statewide and to ensure access to medical, preventive and rehabilitative services for all state citizens. To learn more about LDH, visit http://www.dhh.louisiana.gov. For up-to-date health information, news and emergency updates, follow LDH's blog, Twitter account and Facebook.