BATON ROUGE, LA. – With more than 60 species of mosquitoes in Louisiana and mild temperatures most of the year anytime is a good time to be bitten, said LSU AgCenter entomologist Kristen Healy. But right now is an especially important time to be on the lookout for these pesky predators.
“July through September is when mosquitoes tend to be most active in the state,” Healy said.
With the first case of West Nile virus recently reported in Caddo Parish, precautions need to be taken to reduce the chance of being bitten, she said.
West Nile has been in Louisiana for about 12 years and is here to stay, Healy said.
Eastern equine encephalitis virus is another mosquito-transmitted disease. But it is a rare illness in humans, with only a few cases reported in the United States each year, according to the Centers for Disease Control and Prevention in Atlanta.
Most persons infected with EEEV suffer no symptoms, according the CDC website. However, severe cases involving encephalitis, an inflammation of the brain, begin with the sudden onset of headache, high fever, chills, and vomiting.
Also new to the U.S. this year is chikungunya, a disease transmitted by mosquitoes now being tracked in this country, Healy said.
“Chikungunya has been common in Asia and Africa for more than 60 years,” Healy said. “This past December, it showed up in the Caribbean for the first time. And it was recently found in Miami and Palm Beach counties in Florida.”
Normally about 20 imported cases of the disease are treated in the U. S. each year from people who have traveled to Asia or Africa and brought it back, she said.
This year so far, there have been over 250,000 cases in the Caribbean and 250 cases in the U.S., which is a 10-fold increase over past years, Healy said.
“We believe that this year someone returned with enough of the virus in their body for a mosquito to transmit it,” Healy said.
She said this disease is very unlikely to be fatal, but it is possible, especially in the elderly, those who are seriously ill and newborns of infected mothers.
“There is no antivirus available for chikungunya,” Healy said. “Really all that we can do right now is provide some relief for the symptoms.”
About 80 percent of people with the disease will show symptoms, which are similar to the flu, along with excruciating joint pain that can last from six months to a year.
Healy said East Baton Rouge Parish has a “really good” mosquito abatement program, but the public needs to do its part in controlling mosquitoes by making sure they are not providing a breeding ground for the pests.
LSU AgCenter entomologist Tim Schowalter said destroying mosquito breeding grounds will go a long way toward reducing their numbers and decreasing the spread of disease transmitted by them.
“Female mosquitoes require standing water to lay their eggs, and if we can deny this, there is a better chance of keeping their numbers low,” Schowalter said.
When standing water is available, the mosquito has all that it needs to reproduce.
“She has to have a blood meal or she will die before laying her eggs, but if humans or other animals are around and the standing water is available, the conditions are favorable for the increase in populations,” he said.
It normally takes about two weeks for mosquitoes to go through their breeding cycle in standing water, and then they become the biting pests that are both feared and hated.
“Other things we can do to lessen our chances of being bitten are to avoid being outside at dawn and dusk, wear light-colored clothing with long sleeves and double layers wouldn’t hurt,” Healy said. “Mosquitoes are attracted to our body odor, so wearing light colors lessens the amount of heat we produce, therefore decreasing body odor.”