Researchers Map Out Likely Spread of Zika Virus in U.S.

Zika virus carrying mosquitoes, the Aedes aegypti, are expected to increase abundantly across southern and eastern states this summer. According to a specialized computer simulation designed by researchers at the National Center for Atmospheric Research (NCAR) and NASA, the mosquitoes could spread as north as New York City and as far west as Los Angeles, due to favorable summer weather. The study noted that northern cities could become vulnerable if a related species of mosquito that is more tolerant of cold temperatures, Aedes albopictus, begins to carry the virus.

By analyzing travel patterns from countries and territories with Zika outbreaks, the research team further concluded that cities in southern Florida and impoverished areas in southern Texas may be particularly vulnerable to local virus transmission. The authors hope their paper can help guide mosquito control and public health preparedness. “Even if the virus is transmitted in the continental U.S., a quick response can reduce its impact,” said co-author Mary Hayden, a NCAR scientist. 

The long-term weather analysis so far predicts a 40-45% chance of a warmer than average summer in the U.S. this year, which would aid mosquito suitability. As well as meteorological factors, the authors also took travel and economic factors into account. They studied the number of passengers due to fly directly into the U.S. from the 22 Latin American countries listed on the CDC’s Zika travel advisory.

The virus has affected lower-income families in Latin America due to many lacking air-conditioning or secure screens, which aid easier access for the mosquitoes. The researchers hypothesized that this would factor when it came to border crossings between Mexico and the U.S., however, the virus has not been widely reported in northern Mexico. Conversely, the authors note how the prevalence of air-conditioning and largely sealed homes and work places in the U.S. make it unlikely that the virus will spread as widely has it has done in Latin America and the Caribbean.

“By integrating information on weather, travel patterns, mosquito biology, and human behavior, the project team has improved our ability to forecast, deal with, and possibly even prevent future outbreaks of Zika and other serious diseases,” said Sarah Ruth, of the National Science Foundation, which provides funding to NCAR.

The full findings are published in the PLOS Current Outbreaks journal.

For more information visit NCAR.edu.