A clearer picture emerges in Dallas: mosquito surveillance key in fighting WNV epidemics
I remember being frustrated when WNV illness was surging in Alabama in 2002-2003. With such a complex transmission cycle, and so little known about the ecology of the virus in a naive part of the world, it was difficult to figure out how to have a real impact in controlling transmission to people in any given area of the state. It was even more difficult to communicate a clear strategy to community officials because testing and result turn-around time hampered our knowledge of what was happening. And if that was difficult, it was close to impossible to clearly communicate to the public the nuanced message about what might be happening and why. Even though government resources were given to us abundantly, expertise was stretched thin, and by the time a new crop of entomologists trained in mosquito identification emerged, funding to monitor WNV activity dried up.
The end of each surveillance season was an opportunity to tally cases, create graphs, and look in hindsight at a pattern that would have been so helpful to understand earlier in the year when mosquitoes were biting. Not having a background in public health myself, it struck me as so odd that this was the only way to intervene. And each year would bring a new set of variables that would reveal a different pattern the next winter at chart-making time.
Now, with a decade of hindsight behind us, a clear and concise picture has been assembled, at least for Dallas County, Texas (Texans do everything better. Didn’t y’all know that?). Thanks to the work of UT Southwestern Medical Center researchers, calculating a “vector index” based on mosquito population surveillance and mosquito infection rates, along with observing weather patterns, strongly indicated when to intervene with more-than-normal public health measures to prevent a serious outbreak. Don’t you just love applied science?
I’m linking to two articles written online about this research in the past few weeks. I’ve also requested permission to publish the study’s abstract here and am waiting for a response from the Journal of the American Medical Association.
If you are running a mosquito surveillance and control program in your community, this research identifies a way to potentially monitor and respond in real-time to prevent human WNV illness.