John Elflein
Research expert covering health and health care
Mosquito-borne diseases in the U.S. - Statistics & Facts
Mosquitoes are the deadliest creatures in the world because of the many diseases they can transmit. Mosquito-borne diseases include the Zika virus, dengue, malaria, West Nile virus, chikungunya, yellow fever, and more. Different regions are impacted by different mosquito-borne diseases depending on climate, the types of mosquitoes common in the region, and access to preventative measures and medicine. However, the impact of such diseases remains widespread. In 2020, malaria alone was responsible for around 627,000 deaths worldwide.
Common mosquito-borne diseases in the United States
In 2019, malaria was the most common mosquito-borne disease in the United States by number of new cases, followed by dengue and West Nile virus. The number of annual cases of malaria in the U.S. has fluctuated over recent years, but reached over 2,000 for the first time in the past decade in 2016 and 2017. Similarly, cases of West Nile virus also fluctuate year-on-year. However, in contrast to malaria cases, the number of West Nile cases in the U.S. was lower in 2019 and 2020 than in recent years. In 2020, California was the state with the highest number of West Nile virus cases, accounting for 235 of the total 731 cases reported that year.Zika virus in the United States
The Zika virus gained international attention in 2015 when an outbreak occurred in Brazil. As a result, the U.S. saw increases in Zika cases and much attention was paid to the disease. However, in 2020 only around 34 percent of adults in the United States stated they were very or somewhat concerned about the Zika virus, with females reporting being slightly more concerned than males. This is most likely due to the fact that in 2020 there were only four cases of Zika virus in the United States a huge decrease from 5,168 cases in 2016. In 2019, only 13 U.S. states reported cases of Zika virus, with California reporting the highest number with five cases.Fighting mosquito-borne diseases
Measures to prevent mosquito-borne diseases include vaccination, wearing insect repellant, killing mosquitoes, and isolating infected people from mosquitoes to interrupt the transmission cycle. In 2022, vector-borne disease funding from the National Institutes for Health (NIH) was expected to be 752 million U.S. dollars, highlighting the importance of battling such diseases. This significance will possibly increase with time, as climate change spreads the distribution of disease-carrying mosquitoes in various parts of the world.
