The news about Zika virus just got a bit worse: Researchers in Brazil have found that a more common mosquito than previously thought can carry the virus, which may hamper efforts to stop its spread. The primary transmitter of Zika, which has been linked to birth defects and other maladies, is a species called Aedes aegypti. Now, scientists in a lab have been able to infect the Culex quinquefasciatus mosquito—a more prevalent species, the Guardian reports. Whether or not Culex quinquefasciatus, which is 20 times more common in Brazil than the other species, can actually transmit the virus is still unclear. Scientists injected the mosquitoes with rabbit blood infected with Zika. The virus made its way to the insects' salivary glands, which means transmission to humans may be possible.
Zika has been linked to microcephaly, a birth defect resulting in abnormally small heads and brains. In Brazil, more than 5,600 cases have been reported since October. Last month, it was reported that two of nine American women who had tested positive for Zika have had abortions. Two of the women had miscarriages, and another birthed a child with microcephaly. The women had recently traveled to countries where the virus is rampant, according to reports. On Thursday, health authorities in San Francisco confirmed a case of the virus in a non-pregnant person, KRON reports. Earlier in the week a pregnant woman in Napa County, Calif., was diagnosed with Zika. Both had traveled to Central America at some point. (Read more Zika virus stories.)