More states could be affected by Zika

Another tough mosquito can spread the Zika virus, increasing the number of U.S. regions that could be susceptible to the virus.

Mexican researchers discovered the virus, which spreads primarily through mosquito bites, in the Asian tiger mosquito. It is the first evidence of the virus in the mosquito, according to a report from the Pan American Health Organization, the Americas arm of the World Health Organization.

Zika causes a mild illness in most people, but the federal government has linked it to a birth defect called microcephaly and is studying a link to a neurological disorder called Guillain-Barre Syndrome that causes paralysis.

The finding is significant as it means that a third type of mosquito can carry the virus. For now, the only two types of mosquitoes that carry Zika are the Aedes aegypti and the tiger mosquito.