January 28, 2020

Warren, Markey Request Updates from CDC on Efforts to Study and Address Rise of EEE Virus

Commonwealth was the Hardest-Hit State in 2019, With 12 Reported Cases and 3 Deaths

Text of Letter (PDF)

Boston, MA - United States Senators Elizabeth Warren (D-MA) and Edward J. Markey (D-MA) wrote to the Centers for Disease Control and Prevention (CDC) seeking an update on the agency's efforts to study the epidemiology of Eastern Equine Encephalitis (EEE) and prepare for the upcoming mosquito season. The senators' letter follows a record number of EEE cases reported nationwide in 2019, with 12 confirmed cases in Massachusetts and 3 deaths.

EEE, a rare virus that causes swelling in the brain, is one of the most deadly mosquito-borne diseases in the United States. Nearly one-third of individuals infected with EEE die, and those who recover often live with severe and devastating neurological complications. In 2019, the CDC received reports of 38 confirmed cases of EEE, including 15 deaths, and Massachusetts was the hardest-hit state, with 12 confirmed cases and 3 deaths. Massachusetts has historically seen a disproportionately high number of cases, and the 12 confirmed Massachusetts cases in 2019 marked a disturbing spike of EEE incidence: there were only ten cases in Massachusetts in the decade prior to 2019. 

In their letter to CDC, Senators Warren and Markey noted that the risk of EEE could increase during future mosquito seasons, and that experts believe that warmer temperatures spurred by climate change may be a contributing factor in the rise of EEE and other vector-borne viruses. However, current information on the life cycle of the EEE virus is based on decades-old studies, and more research is needed on the effects of climate change on public health.

"We urge the CDC to explore every opportunity and tool available to work with state and local governments and other federal agencies on ways to address the threat of EEE and other vector-borne viruses," the senators wrote in their letter. "We encourage the CDC to collaborate with the National Institutes of Health, the Environmental Protection Agency, and the Department of Defense to fill the gap in our knowledge about EEE and the role of climate change on public health."

To address their concerns, the senators asked the CDC to answer a series of questions about the actions the agency has taken to understand the epidemiology of EEE, assess the risk of another outbreak in 2020, and support vector control and other activities in Massachusetts and other states. 

In September 2019, Senators Markey and Warren sent a letter to the National Institute of Allergy and Infectious Diseases within the National Institutes of Health to seek information on research efforts on the EEE virus.