The San Antonio Metropolitan Well being District detected West Nile virus in a mosquito entice in early Could, months sooner than common. Town and county are urging residents to take precautions in opposition to mosquitoes as rainfall, excessive temperatures and humidity create the proper situations for the bugs.
The optimistic mosquito pool was situated close to the intersection of Hillcrest Drive and Bandera Highway in Northwest San Antonio. Metro Well being staff fogged and handled standing water within the space shortly afterwards, in response to the division’s web site.
There haven’t been any human circumstances of West Nile virus in Bexar County this 12 months, in response to the most recent knowledge from the Texas Division of State Well being Companies.
Though no extra mosquito samples have come again optimistic since Could, metropolis and county officers are ramping up efforts to tell the general public about the way to maintain themselves protected from mosquito-borne ailments this summer time.
“We now have the hotter temperatures, we now have the humidity, we now have the latest rainfall,” stated Joel Lara, senior environmental well being officer at Metro Well being. “These are very best situations for mosquito improvement.”
Mosquitoes and West Nile virus
The vast majority of pesky mosquitoes that trouble you within the hotter months are “nuisance mosquitoes.” Though they depart painful bites, they don’t pose a lot of a danger to people, defined Molly Keck, an entomologist with Texas A&M AgriLife Extension.
“They’re not recognized to be good carriers or vectors of assorted ailments,” Keck stated. “They’re simply annoying, however they’re not ones that your metropolis well being officers can be extremely involved about.”
Solely a handful of the over 80 species of mosquitoes in Texas, although, are recognized to be carriers of sicknesses like West Nile virus, the commonest mosquito-borne sickness within the U.S. These mosquitoes usually get the illness by feeding on contaminated birds after which transmit the virus to people and different animals by means of bites.
Most individuals contaminated with West Nile virus don’t expertise any signs or issues, however roughly 1 in 5 folks expertise flu-like signs, in response to the U.S. Facilities for Illness Management and Prevention. There are not any particular remedies for West Nile Virus.
In very uncommon circumstances (lower than 1% of infections), the virus impacts the central nervous system, inflicting irritation of the mind or spinal wire. Round 10% of people that develop neurological issues die. In Texas, there have been 881 circumstances of West Nile neuroinvasive illness reported to the state well being division from 2020 by means of 2025, although a few of the knowledge is provisional.
Native surveillance and management efforts
Metro Well being works to manage and monitor the mosquito inhabitants within the metropolis by means of traps, illness detection and remedy of water with pesticides. The efforts begin within the spring and final into the autumn. Mosquito traps positioned in 20 places across the metropolis are checked and examined on a weekly foundation for the presence of West Nile virus.
If a mosquito pool assessments optimistic for the virus, the town deploys insecticide from a truck on a longtime route, what’s known as “fogging,” and may deal with particular swimming pools of standing water. Bexar County’s Division of Public Works runs an identical vector management program for unincorporated areas.
Optimistic hits for West Nile virus usually don’t present up till mid to late summer time in San Antonio, in response to metropolis knowledge from latest years.
This 12 months could have been an outlier as a result of greater quantities of rainfall the realm has skilled this spring, however there’s a number of elements behind how populations drift, together with the migration of birds, which some researchers have theorized was a big contributor to the 2012 Texas West Nile virus outbreak.
Defending your self from mosquitoes this summer time
The only most necessary factor you are able to do to maintain mosquitoes away is eliminating stagnant water round your house, particularly soiled water, the place mosquitoes reproduce. It doesn’t take a lot water — even an overturned bottle cap crammed with water can breed mosquitoes, Keck stated.
Lara suggested checking rain gutters, animal meals bowls, chicken baths and the rest round your residence that may very well be a breeding floor for the bugs. For water that may’t be eradicated, like a heavy chicken tub, you possibly can deal with the water with insecticide, which is accessible at house enchancment shops.
Keck suggested not counting on broad pesticides in the long run since these may kill pure predators of mosquitoes like dragonflies. As a substitute, search for Bti merchandise, which goal mosquito larvae with out harming most different bugs, Keck stated.
If you must be exterior, particularly throughout peak mosquito exercise hours at daybreak and nightfall, put on lengthy sleeves and pants, or spray your self with insect repellent.
“Water is the massive factor,” Keck stated. “Keep indoors throughout daybreak and nightfall — that tends to be when the species of mosquito that extra seemingly is to hold West Nile is extra lively. Put on insect repellent. Cowl your self up, which is admittedly laborious in the summertime in Texas, or simply use any type of an insect repellent when you’re going to be exterior if you may be encountering mosquitoes.”
