The Louisiana Department of Health has confirmed one new human case of West Nile Virus, bringing this year's total to four. The new case comes from East Baton Rouge Parish. This case is reported in LDH's weekly Louisiana Arbovirus Surveillance Summary which can be found in the Surveillance Reports Section of the LDH website.
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.
The new case is asymptomatic. This is the second asymptomatic case; the other is from St. Tammany Parish. There have been two cases of West Nile fever, both from Livingston Parish. There has not been a case of the more serious neuroinvasive disease this year. At this time last year, Louisiana had six cases of neuroinvasive disease, six cases of West Nile fever and seven asymptomatic cases.
At this pace, Louisiana is on track to have a record low year of West Nile Virus infections. In 2009, Louisiana recorded its lowest number with 29 West Nile virus infections, of that 11 cases were neuroinvasive disease. Louisiana's record high came in 2002 when the state reported 328 West Nile virus infections, of that 204 cases were neuroinvasive disease.
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.
West Nile Virus is spread to humans through mosquito bites. LDH encourages residents to take the following precautions to protect themselves:
- 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.
Residents can also help control the mosquito population by eliminating standing water around their home, which is where mosquitoes breed. Louisianians are encouraged to follow these tips:
- 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.
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.