DALLAS – Health officers in Texas shall be on watch in coming weeks for any will increase in mosquito-borne illnesses together with the West Nile and Zika viruses after Harvey’s heavy rains and flooding introduced water that stuffed ponds and ditches and crept into trash and particles that piled up.
“We’re not out of the woods. I nonetheless assume we don’t actually know what we’re going to see, in order that’s why we’ve acquired to observe it,” mentioned Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston. “The subsequent month goes to be the crucial time,” he added.
Officials are hopeful, although, that aerial and floor spraying achieved after Hurricane Harvey made landfall on Aug. 25 will assist be sure that populations don’t swell. The Texas Department of State Health Services mentioned greater than 7 million acres (2.eight million hectares) have been sprayed by aircraft throughout areas inundated from Harvey.”
Of explicit concern is West Nile. Texas trails solely California this 12 months within the variety of instances of the virus, which is transmitted from contaminated birds to people by the widespread Culex mosquito. Most folks don’t develop any signs, however those that do might have fever, headache, vomiting and diarrhea. In uncommon instances, folks develop extreme diseases corresponding to encephalitis and meningitis, which may be lethal. Texas has had no less than 100 human instances this 12 months, together with three deaths. That may occur if somebody who had traveled to a spot with energetic instances acquired the illness, returned to Texas and was bitten by a mosquito that in flip bites and infects another person.
Van Deusen mentioned that after a quick reprieve as heavy rains and floods from Harvey washed away mosquito eggs, “nuisance” mosquitoes emerged. Those don’t sometimes carry illness however can have an effect on restoration efforts by swarming folks as they clear up and restore. Any remaining standing water is a matter as a result of Culex mosquitoes have a tendency to put eggs in bigger areas of nonetheless water like ponds and ditches, whereas the Aedes often breeds in small water-filled containers close to properties.
“So all of that particles and trash that you just see round Houston because the floodwaters recede, there’s going to be pockets of water in there -old discarded TV units, previous discarded tires – and that might simply led to a rise in Aedes aegypti,” Hotez mentioned.
As anticipated within the Houston space, a rise in mosquitoes took place two weeks after the storm. But Dr. Umair Shah, government director of Harris County Public Health, mentioned officers have been capable of get these numbers down with aerial and floor spraying.
“We’re fairly assured that the mix of all the things we’ve achieved has decreased the danger of mosquito-borne illness in our neighborhood, particularly for West Nile virus. But we don’t know if that danger will return if we now have a rise in mosquitoes over the subsequent a number of weeks and that’s one thing that we’re going to proceed to observe,” Shah mentioned.
Sven Rodenbeck, chief science officer of the Centers for Disease Control and Prevention’s hurricane response, mentioned there’s a possible for upticks in mosquito-borne illnesses after hurricanes, so “that’s why you usually do monitoring and as acceptable do mosquito management actions.”
In the U.S. mainland, Florida and Texas are the one two states which have seen native transmission of Zika, which might trigger mind injury in infants whose moms are contaminated when pregnant.
Officials in Florida, the place Hurricane Irma hit two weeks after Harvey, are additionally carefully monitoring for mosquito-borne illnesses and have elevated spraying in a number of areas. Florida additionally at present has no ongoing transmission of Zika, chikungunya or dengue, and this 12 months has solely had one regionally acquired case of West Nile.