Buzzkill: The worrying rise in mosquito-borne diseases and how scientists are tackling them

Here in Washington, DC, it’s been an especially buggy summer, with more ticks, mosquitos, and even invasive lanternflies everywhere. In fact, we’re seeing a global rise in mosquito-borne diseases, as rising temperatures, shifting precipitation patterns, and increasing travel and migration bring these critters—and the viruses and parasites they carry—to new places and populations. For example, just last week, a potential case of locally acquired malaria was identified in Washington state, and West Nile virus, a disease transmitted by mosquitoes that was first isolated in Uganda, is now considered endemic in New York state in 2025. Last month, the World Health Organization issued an urgent call for action as chikungunya continues to spread globally again this year, prompting fear of a repeat of the 2004-2005 epidemic. Yellow fever is on the rise too—cases in the Americas during the first few months of 2025 alone more than tripled all cases the region saw last year. 2024 was also the worst year on record for dengue cases. The collective impact of these diseases is striking: globally, mosquito-borne diseases kill more than 1 million people and infect up to 700 million people each year.

As conventional vector control methods like insecticide-treated bed nets and indoor residual spraying increasingly face challenges from insecticide resistance and mosquito-borne diseases continue to enter new regions and communities, new and up-and-coming innovations, including in diagnostics, mosquito population modification, and vaccines, will be key to helping minimize the spread of these deadly and debilitating diseases.

New diagnostics can help ensure patients start treatment earlier

While effective tools exist to diagnose mosquito-borne diseases, next-generation tools now in the pipeline could help people receive an accurate diagnosis faster, earlier, at a lower cost, and closer to their home, as well as distinguish between different mosquito-borne infections with similar symptoms. These promising breakthroughs could improve detection and care, particularly in rural and remote areas worldwide.

A research team at Institut Pasteur is developing a new rapid diagnostic that can detect the presence of the Plasmodium vivax malaria parasite shortly after the initial mosquito bite—before symptoms arise—, helping patients receive appropriate treatment more quickly. Another team has developed a diagnostic device that uses strips of paper, which could serve as a more affordable, portable diagnostic alternative for detecting malaria infection in asymptomatic people in just 30 minutes.

Beyond malaria, a team of Brazilian researchers has developed a novel test that can rapidly identify exposure to all four serotypes of dengue virus, as well as the Zika virus, making it perfectly suitable for regions like Brazil that are endemic to both viruses, where the similarity between symptoms can make it hard to diagnose or assess immunity in patients. This test could also help health care providers and public health workers better pinpoint where treatment and preventive measures need to be implemented.

Another new tool developed by scientists at the National Institute of Allergy and Infectious Diseases could also aid surveillance and response. It uses blood samples to identify people who have been bitten by Aedes mosquitoes, which can spread diseases like dengue, Zika, and chikungunya, to identify geographic hot spots for the mosquitoes and monitor exposure in people, helping improve targeted public health interventions.

New and innovative tests like these can help identify and minimize the spread of mosquito-borne diseases by connecting people to treatment earlier, as well as informing public health efforts to implement larger-scale vector control measures.

Modifying mosquitoes can make it harder for insects to spread disease

Another approach to curb mosquito-borne diseases is to directly control the mosquito population by targeting the insect’s ability to transmit viruses or parasites to people through genetic modification or other means. One method establishes a bacterium called Wolbachia, which is commonly found in insects, in an Aedes aegypti mosquito population, blocking viruses like dengue, chikungunya, and Zika from growing inside the insects' bodies. This approach has helped protect more than 13.3 million people as of December 2024. Another research team has found a way to genetically engineer Anopheles stephensi mosquitoes by inserting a gene, which naturally occurs in some mosquitoes, that makes them poor hosts for malaria parasites.

Scientists are also exploring approaches that involve inhibiting the reproduction of mosquitoes to reduce population size, and thus, the spread of disease. A Spanish research team is releasing thousands of sterilized tiger mosquitoes, one of the species whose females transmit dengue, to reduce the spread of dengue and other vector-borne diseases. Similar sterilization techniques have been previously used to address other disease vectors, but the Spanish lab is pioneering its use on the tiger mosquito.

In an altogether different and novel approach, scientists in the Netherlands are looking into a way to modify mosquitoes so their bite can deliver a vaccine for malaria to humans, with continuous exposure through multiple bites prolonging immunity levels.

While some of these methods of targeting mosquito populations have proven effective already and new methods could offer even more precise mechanisms for vector control, the long-term implications on the ecosystem warrant further consideration, so science must move forward cautiously.

New vaccines could be game changers, but research has stalled for some diseases

Experts believe that vaccines are essential for drastically reducing the incidence of mosquito-borne diseases, and when used in combination with other prevention methods, could help turn the tide against this growing threat.

The world’s first malaria vaccine was approved in 2021, closely followed by a second vaccine in 2023, both of which have already had a huge impact, with 24 million doses delivered across 20 countries. Ongoing research aims to resolve some of the limitations of these first-generation vaccines. One innovative malaria vaccine candidate that is undergoing a clinical trial uses genetically engineered parasites that cannot cause disease but are potent enough to trigger a strong immune response. Preclinical data found that the vaccine could potentially offer higher efficacy at lower doses than current vaccines.

The first vaccine for dengue, which could only be used among people who had previous infections, was approved in 2019, but its production is being phased out due to limited use. It was trailed by additional vaccines, including the Qdenga vaccine, which targets all four types of the dengue virus and is safe for use in individuals with and without prior infection. However, it does not provide equal protection against all dengue subtypes and has not been studied enough in people over 16 years old. Researchers in Brazil have developed a single-dose vaccine targeting all dengue subtypes that demonstrated high efficacy in people across ages in recent Phase 3 trials. Its single dose would hopefully also make it easier to administer and scale up production.

While these vaccines hold tremendous promise, there are still gaps in the pipeline and a lack of availability of vaccines for certain mosquito-borne diseases. There are no human vaccines for West Nile virus, even though safe and highly effective West Nile vaccines for horses have been around for decades, with research and development efforts in the United States hindered by the sporadic and unpredictable nature of outbreaks. Zika vaccine research has also stalled since the 2015-2016 outbreak, attention dwindling along with cases as people forget the frightening and unexpected nature of the last rise in cases.

With trends like climate change, globalization, and migration showing no signs of slowing down, the world’s deadliest animal and the diseases it carries are only going to become a bigger risk to human health. We’ve made tremendous progress against these diseases, but further innovations will better prepare us to take on a buggier future.