Tangential to Mosquito Squad’s mantra of reducing water collection sources to reduce the mosquito population is this interesting view from Jonathan May, Harvard
“For months, experts predicted that local Zika transmission would hit the U.S. When mosquitos began transmitting the virus from infected to uninfected people, the threat of a major epidemic would rise significantly.
“Then it happened. The first cases were detected in Miami, with a large cluster found in a one-square-mile patch on the north side of the city, in a hip, artsy neighborhood called Wynwood.
“As expected, Zika appeared in a major city along the Gulf Coast, where the Aedes aegypti mosquito thrives. But why Wynwood?
“The neighborhood, long known as ‘Little San Juan’ for its large Puerto Rican community, has been quickly gentrifying over the last ten years (according to Wikipedia). Now it’s also known for its street art, including the Wynwood Walls, which has driven a hipster feel and growing fashion scene.
“But, as the New York Times reported, while bustling and visually appealing, Wynwood includes a ‘still-tattered section of run-down buildings where residents struggle in poverty.’ The Times noted that the mix of housing, businesses and warehouses made fighting mosquitos particularly tough.
“I ran my own analysis on data collected by the U.S. Postal Service to assess a possible link with vacant housing. Vacant and foreclosed homes have been identified as major potential breeding sites for mosquitos: as Sonia Shah wrote recently for the Washington Post, swimming pools in foreclosed homes were implicated in Florida’s 2009 dengue outbreak and Bakersfield, California’s 2007 West Nile virus outbreak.
“I found a strong link. Out of Miami-Dade County’s 517 census tracts (geographical groupings of roughly 1,200-8,000 people) the three highest rates of residential vacancy are tracts 28, 31 and 22.02. One of these tracts represents Wynwood’s southern half; the others lie directly adjacent to Wynwood’s north and south limits.
“In each of these areas, around 10% of homes (as represented by a USPS mailing address) had been vacant for at least 90 days, as of June 30. That’s far higher than the county average of 2.1% and median of 1.4%. These census tracts aren’t the biggest in Miami-Dade County, nor have they got the most vacancies, but they’ve got the steepest concentration of vacant homes:
“Each area has also got a business vacancy rate over 10%, placing them in the top quintile of Miami-Dade census tracts. On a quick look at Google Street View, you can hardly miss all the available commercial spaces, like this one:
“When nobody’s using a property, it’s a lot less likely to stay clean. That could mean more debris and standing water, where Ae. aegypti mosquitos like to breed. As health officials scramble to prepare cities all along the Gulf Coast, residential vacancy rates could prove a useful statistic for predicting neighborhood-level risk.”
Since the mosquitos don’t fly far—WHO says they travel about 400 meters in their lifetimes—and take 90% of their meals from human hosts, they also need environments with plenty of access to human residents and/or passersby. Wynwood’s active street life might have added fuel to the mix, especially since Ae. aegypti likes to bite during daylight hours.
Source: Harvard University