Gulf of America's Overlapping Chikungunya, Dengue, Malaria and Zika Risk

Over the last few decades, the continental United States has seen an unprecedented rise in local transmission of infectious diseases previously considered to be associated only with international travel.

These mosquito-transmitted diseases include malaria, dengue, chikungunya, and Zika.

Scientific models recently predicted that the risk of mosquito-transmitted diseases will continue to increase, particularly in the southern states along the Gulf of America, such as Florida and Texas.

These disease outbreaks may be influenced by changes in climate conditions and the geographic expansion of virus-carrying mosquitoes.

A study published in Nature Communications in April 2025 stated that Arboviruses, transmitted mainly by Aedes (Stegomyia) aegypti and Ae. albopictus poses an escalating threat in the United States.

Existing risk maps may underestimate or misrepresent the actual distribution of these diseases and do not incorporate epidemiological similarities despite shared vector species.

For example, Mexico reported over 500,00 dengue cases in 2024, but just across the Rio Grande River in Texas, only 43 travel-related cases were confirmed.

These researchers addressed this situation by generating new global environmental suitability maps for Aedes-borne arboviruses using a multi-disease ecological niche model with a nested surveillance model fit to a dataset of over 21,000 occurrence points.

This reveals a convergence in suitability around a common global distribution, with the recent spread of chikungunya and Zika closely aligning with areas suitable for dengue.

They assembled 58,361 occurrence records for dengue, chikungunya, Zika, and yellow fever between 1927 and March 2024.

They estimated that 5.66 (95% confidence interval 5.64-5.68) billion people live in areas suitable for dengue, chikungunya, and Zika.

They found significant national and subnational differences in surveillance capabilities, with higher-income, more accessible areas likely to detect, diagnose, and report viral diseases.

However, in remote rural areas, these diseases may go undetected.

When combined with estimates of uncertainty, these suitability maps can be used by ministries of health to target limited surveillance and intervention resources in new strategies against these emerging threats.

Without approved vaccines for dengue, malaria, and Zika, the U.S. CDC says the best way to avoid disease is not to be bitten by an infected mosquito.

However, there are U.S. FDA-approved chikungunya vaccines available in the U.S. in 2025.