On Thursday, Dallas County Health and Human Services (DCHHS) announced a Mesquite resident became the 50th case of West Nile infection in Dallas County in 2016. This is a milestone moment, and one we'll commemorate with a roundup of news from this season of the mosquito-borne disease.
The Zika virus captures lots of headlines but West Nile is deadly. In August, a Carrollton resident became the first person in Dallas County to die from the West Nile virus in 2016. "As far as we're concerned, the West Nile virus is still public enemy No. 1," according to DCHHS director Zach Thompson. In September, the county confirmed a second fatality.
West Nile Neuroinvasive Disease is transmitted to mosquitoes and then humans through infected birds, and the county takes aggressive action when West Nile is detected in bug traps. In "Inside a Spray Truck During a Night of Mosquito Spraying," the Observer rode with a spray crew to examine the front line of the fight: "When mosquito traps test positive for West Nile virus in any neighborhood within city limits, one of these trucks is dispatched to drive around and spray a mosquito-killing fog in the form of the chemical compound Aqualuer 20-20. Each neighborhood takes about an hour and a half to spray, though sometimes the crews can be out all night depending on how many they have to hit and how many trucks are available from other cities."
Preparations for this season's war on mosquitoes begin far in advance of the actual outbreak season. According to a presentation made by John Carlo, Dallas County's former medical director, to the Dallas Bar Association in May, only four active ingredients will help keep mosquitoes from biting — DEET (diethyltoluamide), IR3535 (Ethyl butylacetylaminopropionate), picaridin and the oil of lemon eucalyptus. Nothing else, not citronella nor any of the other myriad natural repellents that don't contain oil of lemon eucalyptus, will do much to keep mosquitoes away for more than a half hour.
Dallas has not conducted aerial spraying since 2012, when an unprecedented West Nile outbreak infected more than 1,000 and killed 36 in North Texas. It is considered a last resort, and one not adopted this season. Still, Dallas County Commissioners authorized the use of aerial spraying to combat mosquitoes carrying West Nile Virus in July, leaving cities across the county to decide whether or not they want to use the option. So, as the Observer reported, the debate over aerial spraying returned.
Zika fears prompted the Dallas City Council in September to pre-approve aerial spraying, if the need arises.