Strange virus.

But unlike other mosquito-borne outbreaks, Zika doubles as a sexually transmitted infection, passing from person to person in bodily fluids. And that’s where things get complicated.

In a new paper, a team led by Santa Fe Institute Research Fellow Laurent Hébert-Dufresne asks under what conditions a Zika outbreak might be sustained where mosquitos play no role.

“Zika has a lot of unusual characteristics that have caused scientists a lot of confusion,” says Hébert-Dufresne. “Infected people rarely have symptoms, and typically only reproducing women get tested, so we know very little about the true extent of Zika’s sexual transmission.”