Benign bacteria, a new weapon against Zika, chikungunya viruses

A team of researchers has confirmed that a benign bacterium, called Wolbachia pipientis, can completely block transmission of Zika virus in Aedes aegypti, the mosquito species responsible for passing the virus to humans.

First author Matthew Aliota of the University of Wisconsin-Madison said that the bacteria could present a "novel biological control mechanism," aiding efforts to stop the spread of Zika virus.

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.

There are not yet any approved Zika virus vaccines or antiviral medications, and ongoing mosquito control strategies have not been adequate to contain the spread of the virus.

Researchers led by Jorge Osorio and Scott O'Neill are already releasing mosquitoes harboring the Wolbachia bacterium in pilot studies in Colombia, Brazil, Australia, Vietnam and Indonesia to help control the spread of dengue virus.

An important feature of Wolbachia is that it is self-sustainable, making it a very low-cost approach for controlling mosquito-borne viral diseases that are affecting many tropical countries around the world.

Wolbachia can be found in up to 60 percent of insects around the world, including butterflies and bees. While not typically found in the Aedes aegypti mosquito, the species that also transmits dengue, chikungunya and yellow fever viruses, O'Neill discovered in the early 1990s that Wolbachia could be introduced to the mosquito in the lab and would prevent the mosquitoes from transmitting dengue virus.

The study appears in journal Scientific Reports.