The Louisiana Department of Health today confirms 31 new human cases of West Nile virus, reaching 176 reported infections from West Nile in the State so far in 2012. LDH also confirms a new death from this disease, which is the 10th West Nile death in Louisiana this year. The State is experiencing the highest number of West Nile cases and deaths it has seen in the past several years.

State health officials caution residents that these reported cases are not related to Hurricane Isaac because there is a two-week period between when people are infected with West Nile through mosquito bites and when symptoms appear. This week's new cases were infected before the hurricane. Also, many health care facilities closed because of weather last week, and the State public health laboratory staff were engaged in hurricane response activities, so there was a delay in the reporting cycle. But, people should be aware of West Nile virus as they recover from the storm, and should take appropriate precautions.

"During a hurricane, floodwater washes out stagnant water and disrupts mosquito breeding. It's the coming weeks that pose a health threat, as standing water collects and more people head outside to clean up after the storm," said LDH Secretary Bruce D. Greenstein. "Also, as people resume their daily activities and the weather gets cooler, they will start spending more time outside for tailgating, football games and cookouts. This makes them more at risk for mosquito bites and West Nile. Take the steps to protect yourself and your family from this disease." 

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.

Of the new West Nile cases reported this week, 10 have neuroinvasive disease, from Ascension (1), Bossier (1), Caddo (2), East Baton Rouge (2), Jefferson (1), Madison (1), Rapides (1) and Webster (1) parishes; 16 have West Nile Fever, from Ascension (1), Bossier (1), Caddo (4), Calcasieu (4), East Baton Rouge (4), Iberville (1) and Webster (1) parishes; and five have asymptomatic cases, from Caddo (2), Catahoula (1), Jefferson (1) and West Baton Rouge (1) parishes.

LDH issues a weekly Arbovirus Surveillance Report that details cases detected thus far by parish, which is published here.

The most active year for West Nile cases in Louisiana was 2002, when the state experienced 328 cases and 24 deaths. For 10 years, state health officials have conducted robust surveillance year-round, 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 elderly and people who have weakened immune systems are most at risk for developing neuroinvasive disease, but anyone bitten by a mosquito can contract West Nile and develop neuroinvasive disease.

"We know from 10 years of tracking West Nile that this virus is in every corner of our state," Greenstein said. "Don't let your guard down. Even if you live in a parish that didn't get rain and flooding during Hurricane Isaac, you are still at risk for this disease. Everyone, regardless of their age or where they live, needs to Fight the Bite. "

Fight the Bite

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 avoid mosquito bites. Health officials recommend:

  • 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 dawn and dusk. The mosquitoes that carry West Nile are most active at that time. But, people should take precautions against mosquitoes if they are outside at any time of day.
  • 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.

Another effective way to prevent mosquito bites is to drain stagnant water from around homes and property to prevent mosquitoes from breeding and swarming, which will be especially important after Hurricane Isaac: 

  • 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. An unattended swimming pool 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.

For more information on West Nile activity in Louisiana and prevention tips, visit

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 For up-to-date health information, news and emergency updates, follow LDH's blog, Twitter account and Facebook.