Louisiana has a good supply of the two known mosquitoes that transmit the Zika virus that’s causing concern in South and Central America, but it remains unlikely Louisiana will experience a large outbreak.
Dr. Raoult Ratard, state epidemiologist, said Louisiana could see some cases from people who have traveled to countries with outbreaks, but there are conditions in place that make it less likely that the state will have an outbreak.
Most Louisiana residents live in air-conditioned homes, their windows have screens, and there are robust municipal mosquito control programs or bug sprays that help keep down the population of the insect.
“It’s going to remain true until one day it doesn’t and we find we are wrong,” Ratard said. “You never know. It may happen one day. So far, we have been fairly lucky.”
Much like it does for dengue and chikungunya, the state Department of Health and Hospitals is in communications with emergency rooms and physicians and has a network of ways to detect if anything resembling Zika arrives in the state.
Rebecca Christofferson, assistant professor at the LSU School of Veterinary Medicine who expects a research paper on the virus and its spread to be published soon, said the reasons Louisiana likely won’t see a large outbreak are similar to those that have prevented the spread of dengue and chikungunya so far.
It’s possible, like with dengue, there could be small groups of two or three local outbreaks as the virus continues to spread. Places where dengue fever has appeared is where you’re going to see Zika as well, she said.
“On the border of Texas, there have been dengue outbreaks,” Christofferson said, adding that the outbreaks have been small and contained to two or three people in each instance.
There also are other areas in Florida, including Key West, where people spend more time outdoors and small outbreaks have occurred.
Identified in the 1940s in Uganda, the Zika virus sporadically showed up in Africa, Southeast Asia and around the Indian Ocean. As the virus made its way to South America, the impact on the population without any prior contact made for the right atmosphere for outbreaks and prompted the Pan American Health Organization to issue an alert about the virus in May.
Even in places where the outbreak is occurring, not every mosquito carries the virus. In addition, person-to-person transmission is difficult because there is a small window within which an infected person’s blood can be sucked by a mosquito and passed on to someone else. That’s part of the reason why the virus spreads faster in dense urban environments with poor mosquito control and open-air living conditions.
This week, the U.S. Centers for Disease Control and Prevention issued travel notices advising people to take more advanced precautions against mosquitoes when traveling to a variety of countries experiencing an outbreak. Included in those advisories are special recommendations for pregnant women to be cautious until more is known about a possible link between Zika and birth defects.
For the rest of the population, the CDC expects only about 1 in 5 people infected with the virus to become sick with flu-like symptoms. It’s uncommon for the virus to progress to a severe enough form to require hospital care.
Follow Amy Wold on Twitter, @awold10.