Measles resurgence in England: challenges in maintaining elimination, 2023 to 2024

BACKGROUNDBetween October 2023 and September 2024, England experienced the largest measles outbreak in decades.AIMWe describe the epidemiology of the outbreak, burden on secondary care services and the factors that led to this resurgence.METHODSThe UK Health Security Agency (UKHSA) conducts enhanced surveillance of all suspected measles cases in England. A measles line list was established using routinely collected notification, laboratory, demographic and vaccination information. Laboratory-confirmed cases were defined using serology and PCR. Incidence rates were calculated using mid-2024 population estimates. Severity was assessed through linkage with emergency department attendances, hospital admissions and length of stay.RESULTSMost of the 2,821 laboratory-confirmed cases resided in London (n = 1,283; 45.5%) and in the West Midlands (n = 710; 25.2%). Incidence was highest in London (14.1/100,000 population). Children under 10 years represented 58.6% (n = 1,653) of cases. Most cases (n = 2,609; 92.5%) were not vaccinated, and 63.0% (n = 1,776) lived in areas belonging to the two most deprived quintiles. Of the 2,788 cases that could be linked to hospitalisation data, 76.3% (n = 2,127) attended emergency care and 38.2% (n = 1,066) were admitted. Median length of stay was 2.0 days, seven cases received intensive care; one death was reported. Admissions were highest among infants aged < 1 year (51.6%, 165/320) and adults ≥ 30 years (47.2%, 195/413).CONCLUSIONThis outbreak reflects a shift towards endemic measles transmission in areas of high deprivation and low vaccine uptake in England. It underscores the importance of achieving 95% uptake with measles vaccine in all areas and communities to achieve and maintain elimination.