Scientists at the Oswaldo Cruz Foundation in Recife, Brazil say that they suspect the Zika virus, which was previously thought to be spread only by the tropical Aedes aegypti mosquito, may have spread to the much more common Culex mosquito.
The virus, which the World Health Organization has said is spreading "explosively" with the potential to infect 4 million people in the Americas, has been causing a public health crisis in Brazil. Zika causes a mild illness in most people, but pregnant women infected with the virus can give birth to babies with microcephaly, an abnormal smallness of the head which is linked to vision and hearing problems, as well as lifelong mental disabilities and a shortened lifespan. In Brazil, Zika has been linked to thousands of cases of babies born with microcephaly.
Zika has also been seen in the U.S. There has been at least one reported case of a baby born with microcephaly related to Zika in Hawaii, and three cases of the virus related to travel to Zika-infected countries reported in New York state.
At Oswaldo Cruz Foundation, the scientists say that they could be a month away from confirming that Zika is being spread not only by the Aedes aegypti, which only exists in tropical climates, but also by the Culex mosquito, Sky News reports. The Culex is 20 times as numerous as the Aedes aegypti, and exists in the Americas, Africa and Asia.
"It means much more combined efforts from a lot of other countries are going to be needed to combat this virus," said Constancia Ayres, lead research scientist at Oswaldo Cruz.
WHO director general Margaret Chan has said that "the level of alarm is extremely high," when speaking about the spread of Zika. She noted that while a causal relationship between Zika virus and microcephaly has not yet been established, it is highly suspected.
"The possible links [to microcephaly] have rapidly changed the risk profile of Zika from a mild threat to one of alarming proportions. The increased incidence of microcephaly is particularly alarming as it places a heartbreaking burden on families and communities," Chan said.
At this time, there is no cure and no vaccines for Zika.