Last week, the Centers for Disease Control and Prevention or the CDC Center issued an emergency alert about dengue, a common pain and sometimes fatal mosquito-borne disease in tropical and subtropical areas around the world. According to the CDC, about 3,500 travelers from the United States signed contracts for dengue abroad in 2024, an increase of 84% from 2023. “This trend is expected to continue,” the agency noted, noting that Florida, California and New York may see the biggest surfing of the year under the order.
On Thursday, the UK Health Security Agency issued a similar warning, noting that there were 900 travel-related dengue cases in the UK in 2024, 300 more than the previous year. The two reports convey similar statistics on dengue fever, symptoms and cases. But the UK Health Security Agency included key information omitted by the CDC: It points out Why The case is breaking records. “The rise is driven by climate change, rising temperatures and flooding,” it said.
In the past, the Centers for Disease Control and Prevention (CDC) has easily acknowledged the role of climate change in spreading dengue fever – but in the months since President Donald Trump took office, the political conditions that affect American scientific research and federal public health transmission have undergone seismic changes. The new government has cleared the mention of equity and climate change on the federal agency website and is trying to remove the scientific infrastructure agencies such as the CDC use to understand and deal with a range of health risks, including risks posed by global warming.
Last week, Propublica reported that the National Institutes of Health (NIH) is the largest funding source for medical research worldwide – which will close all future funding opportunities for climate and health research. Whether ongoing research grants to allow for research at this intersection remains to be seen. A few days later, U.S. Secretary of Health and Human Services Robert F. Kennedy Jr.
To sum up, the directive suite will prevent scientists in the U.S. and other countries from relying on NIH funds to prepare and respond to dengue at the exact moment when climate change has caused cases of the disease to soar. As climate change can lead to sudden subversion of people and institutions responsible for the threat to dengue cadavers as mosquitoes, fungi and ticks expand their historical scope and penetrate new areas of disease vectors.
“The disease stress in the past few years is very compelling, and it is moving in one direction,” said Scott O'Neill, founder of the nonprofit World Mosquito Program. For example, Brazil (the country that has always recorded the largest number of dengue cases) recorded a historic 10 million cases last year. The country reported 1.7 million cases in 2023.
In warm, humid conditions, dengue fever is most commonly used, Egypt and the Aedes Albino plant infected two types of mosquitoes in humans, which makes the rise in atmospheric temperatures caused by the combustion of fossil fuels, making people more common. The vast majority of annual dengue cases are asymptomatic, but about 25% of people are infected, depending on the population, and symptoms such as fever, headaches and joint pain can occur. A small percentage of these cases lead to severe illness, hospitalization and even death.
The number of severe dengue infections roughly corresponds to the size of the population infected each year. In 2023, when a total of 6 million dengue infections were present, 6,000 people died. In 2024, more than 13 million cases were registered worldwide in one year, with more than 8,000 deaths.
There is no cure for dengue fever. Patients in wealthier countries generally perform better than those in developing areas, which have received medical interventions such as blood transfusions and a wave of dengue patients with overwhelmed health care systems. There are two dengue vaccines available in some countries, but there are serious restrictions on efficacy and how long they impart immunity.
NIH began taking climate change and health research seriously in 2021, with the institutes funding dozens of studies that have since explored all aspects of climate registration connections. NIH-funded researchers are trying to understand how higher temperatures change the geographical range of the Aides mosquitoes, which is a factor predicting dengue outbreaks and how communities can protect themselves from dengue after extreme weather events.
These studies occur in the southeastern United States, where dengue is becoming increasingly common, internationally, in countries such as Peru and Brazil, where dengue is an almost constant threat. NIH also funded research that brings the world closer to finding medical and technical interventions: more effective vaccines and genetically engineered mosquitoes that cannot develop dengue fever, among others.
“Diseases have no national borders,” said American vector biologists who have received funding from NIH in the past. Fearing about the Trump administration’s retaliation, she demanded that her name or affiliated academic institution be mentioned in the story. “I’m worried that if we don’t learn it, we will continue to watch it continue to happen and we won’t be ready.”
Americans not only bring dengue fever home, but also from travel abroad. The disease is also spread locally in warmer areas of the country and its territory. Last March, Puerto Rico declared a public health emergency when a case exploded on the island. By the end of 2024, Puerto Rico had registered more than 6,000 cases – officially becoming the threshold for the epidemic through outbreaks. More than half of known infections result in hospitalization. Nearly 1,000 cases have been reported so far this year, an increase of 113% from the same period in 2024. California and Florida reported 18 and 91 locally obtained dengue cases last year, respectively. California registered its first locally-acquired dengue case in 2023.
“Dengue fever has been found in many places in the United States where this disease has never been seen before,” said Renzo Guinto, a physician and director of the Planetary Health Program at Duke-Nas Medical College in Singapore. “To address this emerging climate-related health threat, American scientists must work with others working overseas. How will this collaboration happen without the resources and capabilities?”
For climate and health research, non-government funding sources are limited. Funds available to U.S. researchers are primarily provided by private foundations such as the Gates Foundation and Wellcome Trust. Compared to the $40 million Congressional offering annually through the NIH in the two years before Trump took office, the $40 million Congressional offering annually is compared with the grants available for climate and health research. Over the next few years, researchers will be forced to compete for a small portion of the funding, which may lead to less research and innovation in the coming years. “The end result will reduce this work – we will all tell you that the interests of Americans are harmed for a long time,” said a vector biologist.
As dengue spreads in countries that are already widespread and spreads across areas where disease remains relatively rare in North America, it is clear that countries need to expand their weapons against disease. But the United States seems to be leading in the opposite direction, with thousands of lives under threat.
“We are at a time when we need to accelerate innovation and solutions to accelerate global problems,” O’Neal said, who has received funding from governments around the world, including the United States, and “it’s not the time to let ideology push science rather than let science push itself.”
Originally published by Grist, the story is part of Climate Now, a global news collaboration that enhances the reporting of climate stories.
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