BATON ROUGE The Louisiana Department of Health has reported the state’s first case of West Nile virus in a human in 2009.  The case was confirmed July 16 in St. Tammany Parish, and was a neuroinvasive illness.

 Health officials characterize West Nile infections in three ways: a neuroinvasive illness is severe and typically results in a swelling of the brain or spinal cord. People with this illness are at risk of brain damage or death. West Nile fever is less severe, with most people only suffering mild, flu-like symptoms. People who are asymptomatic were never ill and were only discovered to have the West Nile antibodies when blood work was done for some other reason (such as donating blood). 


About 90 percent of all cases are asymptomatic, while about 10 percent will develop West Nile fever.  Only a very small number of people who are infected with the virus will show the serious symptoms associated with the neuroinvasive disease.

 According to State Epidemiologist Dr. Raoult Ratard, the first human cases are reported around mid-July each year, so this case follows the usual seasonal pattern.  He also recommends that citizens take precautions to protect themselves.

 “West Nile virus is spread to humans through mosquito bites,” Dr. Ratard said.  “No matter what time of year it is, and no matter how active the season, try to keep the mosquito population down near and around homes and play areas, and try to avoid being bitten by mosquitoes.”

 To help control the mosquito population, eliminate standing water around your home, which is where mosquitoes breed.  Here are some tips:

  1. Dispose of tin cans, ceramic pots or any unneeded containers that have accumulated on your property.  Turn over any wheelbarrows, plastic wading pools or buckets that could collect water.
  2. Drill holes in the bottom of recycling containers that are left outside. Drainage holes that are located on the container sides collect enough water for mosquitoes to breed in.  
  3. Clean clogged roof gutters yearly, as they are easily overlooked but can produce millions of mosquitoes each season.
  4. Aerate ornamental pools or stock them with fish. Water gardens can become major mosquito producers if they are allowed to stagnate.
  5. 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.

To avoid being bitten by mosquitoes, follow these guidelines:

  1. If you will be outside, you should wear a mosquito repellent containing 20 - 30 percent DEET for adults and no more than 10 percent for children.
  2. Apply repellent on exposed skin and clothing.  Do not apply under your clothes or on broken skin.
  3. To apply repellent to your face, spray on your hands and then rub on your face.
  4. Adults should always apply repellent to children.
  5. Wear long-sleeved shirts and pants when outdoors for long periods of time.
  6. Avoid perfumes and colognes when outdoors for extended periods of time.
  7. You should also make sure that your house has tight-fitting windows and doors, and that all screens are free of holes.

The Louisiana Department of Health serves 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