The Aedes albopictus mosquito, native to NYC, has been known to transmit Zika in other areas. (Wiki commons)

Five people have tested positive for the mosquito-borne Zika virus in New York City since the end of January, with all of the cases originating in the Latin American and Caribbean countries that are seeing a true outbreak of the virus. Today, Mayor Bill de Blasio said that while there is currently no risk of contracting the virus in the city, experts are concerned about what might happen with the onset of mosquito season this spring.

"We are very concerned about the onset of the mosquito season at the beginning of April," de Blasio said on Thursday. He added, "We have the most comprehensive response capacity anywhere in the nation. That was clearly on display during the Ebola crisis...New Yorkers should rest assured that the finest medical minds and scientific minds are being tapped to help us address the situation."

The Aedes aegypti mosquito, which has been spreading Zika left and right in countries such as Brazil, Guatemala, and Ecuador—among many others—is not native to New York. However, our region does have Aedes albopictus, also known as the Asian tiger mosquito, which has been known to carry the Zika virus in other areas.

Dr. Mary Bassett, Commissioner of the Department of Health and Mental Hygiene, said that transmission by this native mosquito is not inevitable, because the mosquito can transmit other viruses, such as chikungunya and dengue, but has not done so in New York City, possibly because the climate does not get quite warm enough.

In the meantime, the city is warning people who are pregnant or hope to become pregnant to avoid areas stricken by the Zika outbreak, as there is some evidence that the virus may cause babies to be born with microcephaly—abnormally small skulls and brains. Anyone who is pregnant or attempting to conceive is recommended to receive a blood test for the Zika virus if they ignore this advice and do travel to an affected region.

Bassett noted that no prenatal tests for pregnant women who contract Zika can absolutely confirm that the fetus will develop microcephaly.

The DOH has also released a list of recommendations for anyone returning from a Zika-affected region; precautions include using insect repellents to avoid transmitting the virus to NYC-native mosquitos, and using condoms during any sexual activity as there is a slight risk of the virus being transmitted sexually.

In the run-up to mosquito season, the city is working on a plan for mosquito control that will be similar to methods used to target the West Nile virus: surveilling and killing larvae, and, if necessary, spraying pesticides.

"We remain cautiously optimistic that we're not going to have to deal with local Zika transmission from mosquitoes," said Deputy Mayor for Health and Human Services Herminia Palacio. "But we've all been around long enough to know that Mother Nature may not share our optimism."