HealthSponsoredByResearchers at the University of Wisconsin-Madison say they’ve found a benign bacterium that can completely block transmission of Zika virus in the mosquito species responsible for passing the virus to humans.

The bacteria, called Wolbachia pipientis, could present a “novel biological control mechanism,” aiding efforts to stop the spread of Zika virus, UW-Madison School of Veterinary Medicine scientist Matthew Aliota said.

Thirty-nine countries and territories in the Americas have been affected by the Zika epidemic, and it is expected that at least 4 million people will be infected by the end of the year. Scientists believe the virus is responsible for a host of brain defects in developing fetuses, including microcephaly, and has contributed to an uptick in cases of a neurological disorder called Guillain-Barre syndrome.

UW-Madison pathobiological sciences professor Jorge Osorio is one in a group of researchers leading an effort to release mosquitoes with the Wolbachia bacterium in pilot studies in Colombia, Brazil, Australia, Vietnam and Indonesia to help control the spread of dengue virus.

Researchers said the Wolbachia bacterium is self-sustainable, making it a very low-cost approach for controlling mosquito-borne viral diseases that are affecting tropical countries.

The study was published Friday in the journal Scientific Reports.