WASHINGTON — An international coalition of governments and philanthropic organizations has donated $18 million to fight Zika and other mosquito-borne illnesses. The money will target the illnesses in Colombia and Brazil with a unique mosquito-control program.
The funds from the U.S. Agency for International Development and the British government, as well as Britain’s Wellcome Trust and the Bill and Melinda Gates Foundation, will be used to scale up the innovative, widely praised program being developed in Australia.
Use bacteria to fight virus
Over the years, the nonprofit Eliminate Dengue Program, in collaboration with Melbourne’s Monash University, has demonstrated a way to transfer a naturally occurring bacterium in the lab, called Wolbachia, into mosquitoes that carry the dengue virus.
Wolbachia is carried by 60 percent of all insect species worldwide, experts say, but not by Aedes aegypti, the type of mosquito that spreads dengue and can also transmit Zika virus, yellow fever and chikungunya.
Once infected with Wolbachia, the altered Aedes aegypti mosquitoes are unable to transmit dengue. When released into the wild, they mate with local mosquitoes, passing the bacteria to their offspring. Within a few months, the wild mosquitoes are unable to spread dengue to humans.
Wolbachia works by stopping the virus from growing inside the mosquito and thus spreading.
Researchers say the method of mosquito control is self-sustaining, having the potential to fight the life-threatening disease.
Trials to expand
Since 2011, the program has conducted field trials in Australia, Indonesia and Vietnam. The results show that when a high proportion of mosquitoes are infected, transmission of the virus stops. Small-scale field trials began in Rio de Janeiro, Brazil, in 2014, and last year in Bello, Colombia.
According to the World Health Organization, dengue infects almost 400 million people a year, mainly in tropical and subtropical countries.
Severe dengue can cause death, especially in children.
The newly announced donations will rapidly scale up Wolbachia deployments in Latin America, beginning in 2017, to see how well the intervention works on a broader scale and in urban settings, hopefully leading to a significant reduction in Zika, dengue and chikungunya.