West Nile virus detected in mosquitoes in New Orleans

New Orleans, La -  The City of New Orleans Mosquito and Termite Control Board is reporting the detection of West Nile virus in mosquitoes collected in Orleans Parish.

The Mosquito Control Board has increased aerial and truck applications targeting Culex quinquefasciatus, the "southern house mosquito". This mosquito is a known vector of West Nile virus.

The City says it will continue aggressive control measures by applying insecticides targeting mosquito larvae and adults. Adult mosquitoes are being treated by fog truck and airplane. The City will continue these operations throughout the summer.

While no human infections have been reported in Orleans Parish, according to the Louisiana Department of Health and Hospitals, the first WNV human case of 2012 season was recently reported in St. Bernard Parish.   The person determined to have the virus was asymptomatic, which means the individual had no sign of illness.

Health officials characterize West Nile infections three ways: neuroinvasive, West Nile fever and asymptomatic. 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. Asymptomatic individuals were never ill and were only discovered to have the West Nile virus in their blood when blood work was done for some other reason, such as blood donation.

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.

According to State Epidemiologist Dr. Raoul Ratard, the first human cases are typically reported around mid-July each year. 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, it is important for residents to take preventive steps to control the mosquito population near and around homes and play areas, and try to avoid being bitten by mosquitoes."

Protect Yourself

  • 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.
  • 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.

Mosquito Population Control

  • 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.

Louisiana Numbers 

Last year, Louisiana recorded 12 cases of West Nile virus, the lowest number over the 10 years the state has been tracking the disease. The highest number of cases came in 2002, the first year of tracking, with 328 cases