Molecular Epidemiology of Measles in California, United States—2019

Abstract

In 2019, the United States experienced the highest number of measles importations and cases in the post-elimination era. More than a quarter of imported cases entered the US through California. Measles surveillance efforts in California resulted in the identification of 26 importations, 6 outbreaks, and 72 cases in 2019. Only genotype B3 and D8 measles strains were detected. Genotype-specific differences were noted in the incidence of vaccine failures, hospitalizations, and severe complications among cases. A targeted whole genome sequencing (WGS) approach provided higher resolution discrimination between epidemiologically linked and sporadically introduced strains than conventional N450 sequencing. Our report underscores the importance of ensuring appropriate measles vaccination status, especially prior to international travel to measles endemic regions, and highlights the value of a strong measles surveillance system in minimizing outbreaks and preserving measles elimination status in the US.

Epidemiology of measles in southern Iran: trends, challenges, and vaccination insights

“…Despite the availability of a safe and effective measles vaccine, measles outbreaks continue to loom as a significant global public health concern 11 . In the period spanning from 2016 to 2019, a sharp upswing in measles cases was observed, with an alarming tally of over 500 000 confirmed cases reported to the WHO 12 .…”