MIAMI (AP) — The waning of Zika outbreaks in the Caribbean and South America has helped slow the spread of the mosquito-borne virus in Florida this year, according to health officials.
Herd immunity, when enough people in an area are infected with a virus and develop resistance to it, likely has contributed to Zika’s decline outside the continental United States, Dr. Henry Walke, the U.S. Centers for Disease Control and Prevention’s incident manager for Zika response, said in a Miami Herald report .
“People that were infected before can’t be infected again. That’s our understanding,” Walke said. “So you don’t have as much of the virus circulating. That’s true not only in Puerto Rico but throughout the Caribbean and throughout South America.”
Excerpted from American Chemical Society newsletter August 23rd, 2017
“Conventional chemical insecticides used to control mosquitoes are used as cover sprays, frequently dispersed over wide areas. But this blanket spray approach exposes people and animals to potentially harmful compounds and can kill bees and other beneficial insects. In addition, residues of these sprays can contaminate soils and streams, as well as promote increased pesticide resistance. To overcome these issues, Mafra-Neto of ISCA Technologies and colleagues at several universities sought to create a more targeted approach using an insecticide potion spiked with a blend of semiochemicals, or chemical signals, that mosquitoes can’t resist.”
“The blend of chemicals that we use to attract mosquitoes is so powerful that they will ignore natural plant odors and attractants in order to get to our formulation,” says Agenor Mafra-Neto, Ph.D. “From a mosquito’s point of view, it’s like having an irresistible chocolate shop on every corner. The product is so seductive that they will feed on it almost exclusively, even when it contains lethal doses of insecticide.”
The resulting product, which is called Vectrax®, is a slow-release formula for use indoors or outdoors. It can be applied as a spray, which produces 1- to 5-millimeter dollops on vegetation or building eaves, or as a semi-solid, caulk-like gel on cracks or holes in outdoor structures. Because the mosquitoes visit and manipulate the dollops, they receive precise doses of the insecticide, and thus are more effectively controlled. Unlike with traditional blanket sprays, nearby surfaces can remain insecticide free.
The researchers are conducting field tests in Tanzania, an African nation where 93 percent of the population is at risk for malaria. In preliminary results, they found that mosquito populations plunged by two-thirds in just two weeks in Vetrax-treated communities compared to untreated ones.
“This summer, scientists in California are releasing 20 million mosquitoes in an effort to shrink the population of mosquitoes that can carry diseases.
It sounds counterintuitive. But the plan is to release millions of sterile male mosquitoes, which will then mate with wild female mosquitoes. The eggs the females lay won’t hatch, researchers say.
The project is called Debug Fresno and it’s being undertaken by Verily, a subsidiary of Alphabet, Google’s holding company. It’s the company’s first field study involving sterile mosquitoes in the U.S.
Scientists say the goal is to cut the population of Aedes aegypti mosquitoes — the species responsible for spreading Zika, dengue and chikungunya. A. aegypti have been present in California’s Central Valley since 2013 and have been a problem in Fresno County.”
“Each week for 20 weeks, the company plans to release 1 million of the sterile, non-biting male mosquitoes in two neighborhoods in Fresno County. The male mosquitoes are bred and infected with Wolbachia, a bacterium that is “naturally found in at least 40 percent of all insect species,” according to The Scientist magazine, though it’s normally not found in A. aegypti.”
The EPA has provided a couple new tools and graphics to assist the public in making an informed choice when picking an insect repellent to help prevent insect vectored diseases from mosquitos and ticks.
The first is a graphic that will appear on products that will show what insects it works against and how long until reapplication is needed called the Repellency Awareness Graphic:
The second is a selection tool where you enter your criteria on ingredients, time needs and potential insect exposure and it shows the products and ingredients available:
The Centers for Disease Control and Prevention(CDC) released the statistics for 2017 YTD:
Cumulative Zika Virus Disease Case Counts in the United States, 2015-2017
Provisional Data as of July 5, 2017
Zika virus disease became a nationally notifiable condition in 2016. Cases are reported to CDC by state, territorial, and local health departments using standard case definitions. This webpage contains cumulative provisional data reported to ArboNET for January 1, 2015 – July 5, 2017.