NASA Looks to Advance Dengue Preparedness in Puerto Rico

Dengue remains a serious public health threat in Puerto Rico and a growing concern in parts of the mainland United States, including Florida and Texas. NASA is helping researchers tackle that challenge by tracking environmental conditions linked to transmission.

In 2024 and 2025, Puerto Rico reported more than 9,500 cases during a major outbreak, with more than half of reported cases in 2024 resulting in hospitalization. Locally acquired cases also were detected in Arizona, California, Hawaii, Florida, and Texas.

Aedes mosquitoes, which include the species that spread the dengue virus, thrive in warm, humid conditions and breed in lingering water. Forecasting dengue outbreaks depends on understanding how rainfall, temperature, the extent of standing water, and other factors shape mosquito habitats and help the virus spread. But traditional forecasting methods often struggle to predict those conditions weeks to months in advance, limiting how early public health officials can prepare.

A NASA-supported team led by Paul Block of the University of Wisconsin–Madison is using data from several tools and missions — including the Goddard Earth Observing System-S2S, IMERG (Integrated Multi-satellitE Retrievals for GPM), GRACE (Gravity Recovery and Climate Experiment), and VIIRS (Visible Infrared Imaging Radiometer Suite) — to improve longer-lead forecasts of dengue risk in Puerto Rico.

The researchers aim to develop an initial forecasting system this spring to predict environmental conditions linked to dengue risk across the island. Longer-lead forecasts could give officials more time to spray insecticide, strengthen public outreach, and prepare for rising outbreak risk.

Funded by NASA’s Health and Air Quality Applications team, part of NASA’s Earth Action program, the effort includes the Centers for Disease Control and Prevention Dengue Branch in San Juan and other local partners.

~ Emily DeMarco