Measles isn't only a childhood disease; outbreaks can have lingering effects

PAHO issued an epidemiological alert after a sharp rise in measles cases in the Americas, and it will meet in April to decide whether the U.S. should lose its measles elimination status.

Measles cases have increased recently across parts of the Americas, prompting the Pan American Health Organization (PAHO) to issue an epidemiological alert on Feb. 3. Experts point to falling measles vaccination coverage since 2019 and localized pockets of low uptake as the main drivers of current outbreaks. Measles infections can lead to serious complications and longer-term effects on immune memory. Key points: - PAHO issued an epidemiological alert for the Americas after a sharp increase in measles cases. - Public health experts say declining vaccine coverage since 2019 and communities with low coverage are driving current transmission. - PAHO has scheduled a meeting in April to determine whether the United States should lose its measles elimination status; the decision will be based on whether there has been continuous transmission for 12 months or independent outbreaks. - Measles infection can cause complications such as encephalitis, hearing or vision loss, and "immune amnesia" that reduces previously acquired antibody protection for months to years. Summary: If PAHO finds sustained transmission, the U.S. could lose its measles elimination status, a designation tied to continued absence of endemic spread; that outcome would be associated with a higher risk of ongoing transmission and increased demands on clinical and public health resources. The next formal step is the PAHO meeting in April to review the situation and make a determination.