The National Center for Atmospheric Research, this morning, released an analysis of the potential spread of Zika viral illnesses in the continental United States. The study combines analysis of mosquito habitat with visitors from areas where Zika is already occurring to produce a map displaying the risk of a Zika outbreak. Cities from New York to Los Angeles are included and the abundance of the vector mosquito in July, Aedes aegypti, is measured from low to high.
Miami has both the greatest chance of an abundance of mosquitoes and the greatest number of visitors from Zika stricken countries. Local outbreaks of mosquito borne illnesses can only happen when local mosquitoes become infected by biting a human who contracted an illness outside the U.S. Miami has both the vector and the imported cases of Zika. As of March 14, Florida reports that Miami-Dade has reported 30 of the 62 travel associated Zika viral illnesses in the state.
Florida reports the countries of origin for imported arboviral illnesses in its weekly surveillance report. Colombia, Venezuela and Haiti top the list of countries where these illnesses were contracted thus far in 2016.
Aedes aegypti is called the Yellow Fever mosquito. It can transmit yellow fever, all of the dengue viral fevers, chikungunya and Zika. The risk of a local outbreak of any of these illnesses exists where there are Ae. aegypti and visitors from countries where the illnesses are endemic.
Alex Wild, Curator of Entomology at the University of Texas / Austin, has confirmed to the Examiner that Ae. aegypti are active in the Austin, Texas, area. Chuck Palmisano, from the St. Tammany Parish Mosquito Abatement District in Louisiana, has told us that his area expects activity to begin in April and be sustained from May through the summer. The mosquito is also active in southern Florida at this time.
The greatest abundance of Yellow Fever mosquitoes is expected from a line between New Orleans and Charleston, South Carolina and south to include all of Florida. A line from Houston to Atlanta and up the coast to New York City has risks of a moderate abundance of the vector mosquitoes. California, Dallas and Denver are among the regions with projected low abundance.
There have been no reports of locally contracted Zika illnesses at this time in the continental United States. A local outbreak of Zika or any of the other viral illnesses carried by the Yellow Fever mosquito could happen at any time and the risk increases with the warmer weather.