Mosquitoes breed in standing water. As the hundreds of billions of gallons of water subside in dozens of Texas counties, mosquitoes become a pressing concern. However, the degree of the threat is not cut and dry.
After hurricanes have done their destruction, it’s not uncommon for large-scale mosquito control operations to take place to control the nuisance floodwater mosquitoes that hatch off in astronomical numbers. These mosquitoes are aggressive biters that target humans. Historically they significantly impede recovery efforts as crews try to salvage, repair and rebuild. The only bright spot is that these floodwater mosquitoes tend to be poor vectors for mosquito-borne disease.
But that doesn’t mean that the disease question is off the table. With Hurricane Harvey dumping so much water inland, it’s very difficult for that water to drain and dry. And when water with lots of organic material can’t drain, it becomes stagnant, and the perfect breeding spot for mosquitoes. Diseases like Zika, chikungunya and dengue are all vectored by container-breeding mosquitoes (Aedes aegypti and Aedes albopictus), and may not have an escalation of cases. But other diseases like West Nile Virus and St. Louis Encephalitis are spread primarily by mosquitoes in the genus Culex, which finds great opportunities in areas of standing water post-hurricanes.
With the record-setting rainfall, the pattern of drainage will have a large impact on whether mosquito-borne disease will amplify. Entomologists and state health officials will closely monitor traps and mosquito populations to determine the best course of public health mosquito control.