UF study shows how to prevent deadly dengue disease in the Galapagos

Sadie J. Ryan sits with team members to interview a resident of the Galápagos Islands to collect data for her study about dengue fevers effects on the people who live there. 


A potentially life threatening disease may no longer be a risk in the Galapagos Islands thanks to UF researchers.

A new study, led by UF medical geographer Sadie J. Ryan, examined the socio-ecological factors, or indicators of how humans respond to their environment, in the Galapagos Islands.

These factors lead to mosquito presence in the area and dengue fever, a disease from mosquito bites that causes high fevers, rashes, liver failure, and potentially death, Ryan said.

The study, which started in 2014 and was published Feb. 26 in MDPI, is the first of its kind to be conducted in the Galapagos and was funded by a grant from the University of Ecuador for $5,000, Ryan said.

“When we think of Galapagos, we think of wildlife and we think of tourism,” Ryan said. “But we should also be thinking about people and disease.”

The results showed that water storage is one of the biggest risk factors for island residents. With very little fresh water available, residents store water in containers, which attracts mosquitoes to settle and breed there, Ryan said.

The study also found that people traveling between the islands and other locations were exposed to the virus. This meant they were bringing the disease back to their local communities, Ryan said.

Residents’ attitudes and knowledge of the disease also contributed to the spread of dengue, Ryan said. People who were aware of and took preventative measures like using chemicals to treat their water, installing mosquito netting in their house and closing their doors and windows were less likely to contract the virus.

Mosquitos pose a large threat to the 30,000 people who live in the Galapagos because of the newly emerging diseases they carry like dengue, zika and chikungunya, Ryan said.

Dengue is found throughout South America, Ryan said. Cases in the Galapagos Islands started appearing in the early 2000s and an average of 25,000 deaths annually worldwide.

The study started in 2014 and took place on the two most populated islands, Santa Cruz Island and San Cristobal Island, where 100 households were surveyed, Ryan said.

Residents were asked about water storage, travel from the mainland and disease prevention knowledge, Ryan said. This was alongside the water samples researchers had collected to estimate mosquito population numbers.

The data points to the issues of a lack of government funding to create a healthy city, Ryan said.

“But if we can encourage people to do these at-home prevention practices, we will be able to start reducing dengue exposure,” he said.

Ryan collaborated with the Biosecurity Agency of the Galapagos, Universidad San Francisco de Quito, the Escuela Superior Politécnica del Litoral, and SUNY Upstate Medical University to identify the risk factors for contracting dengue, she said.

Ana Stewart, the director of the Latin America and Caribbean research program within the Institute for Global Health and Translational Science, worked with the team of 10 people on the study, including Ryan, by helping conduct the household surveys.

She said she hopes this study will raise awareness about mosquito borne diseases that pose a threat to both residents and for the thousands of tourists who visit the Galapagos Islands each year.

Increasing the piped water access and water storage will help protect those who dwell the area, she said.

“Most of the focus has been on the wildlife without taking into consideration the health needs of people who are living on the island.” Stewart said. “We need better solutions.”