CDC: Number of Reported U.S. Measles Cases Increased in First Quarter of 2024

THURSDAY, April 11, 2024 (HealthDay News) -- U.S. measles elimination status was maintained as of the end of 2023, but there was an increase in the number of measles cases reported in the first quarter of 2024, according to research published in the April 11 issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.

Adria D. Mathis, M.S.P.H., from the CDC in Atlanta, and colleagues analyzed epidemiologic and laboratory surveillance data and the performance of the U.S. measles surveillance system after the 2019 measles outbreaks.

The researchers found that the CDC was notified of 338 confirmed measles cases during Jan. 1, 2020, to March 28, 2024; 29 percent of these cases occurred during the first quarter of 2024, representing a more than 17-fold increase over the number of cases during the first quarter of 2020 to 2023. The median patient age was 3 years among the 338 reported cases; 91 percent of patients were unvaccinated or had unknown vaccination status. Information on ≥80 percent of critical surveillance indicators was included for 336 case investigations. The largest transmission chain during 2020 to 2023 lasted 63 days. As of the end of 2023, U.S. measles elimination status was maintained due to the absence of sustained measles virus transmission for 12 consecutive months in the presence of a well-performing surveillance system.

"Because of high population immunity, the risk of widespread measles transmission in the United States remains low; however, efforts are needed to increase routine measles, mumps, and rubella vaccination coverage," the authors write.

Abstract/Full Text