sunday times: mosquitoes and west nile virus

Effect Measure, the blog so effectively covering avian influenza, had an interesting post on the effectiveness of spraying pesticides to control adult mosquitoes to control West Nile virus (WNV). First, the post outlines results of studies concluding that this type of spraying is safe for humans, at least under the limited parameters of the studies.

More importantly, the post went on to explain that there is no proof that killing adult mosquitoes is effective at preventing human exposure to WNV. First, it only reduces mosquito populations temporarily, and we just don't know if this brings about any significant reduction in virus transmission to people. 

The part I found especially interesting and relevant is the outline of the fundamental shortcomings of the usual truck-mounted, urban-street-spraying pesticide delivery method, which may render this type of application fundamentally ineffective in killing WNV-carrying mosquitoes in the first place.

Add this to the fact that little is known about the long-term effects of widespread pesticide spraying on non-target organisms (in the short term, these are broad-spectrum pesticides that kill other insects including butterflies and dragonflies upon contact), and there is ample reason to use great caution when considering mosquito adulticide programs.

Comments

[Lene]

Thank you for posting this information. I'm glad to hear that people are questioning the effectiveness of adulticiding in reducing mosquito populations, as well as WNV risk.

I was living in south central Texas for the first three years of the WNV issue. I was amazed at how the fear of infection drove unsound policy. Aerial applications as well as "fogging" were seen as necessary, as well as spraying ditches with malathion and promoting back yard fogging machines for homeowners.