Meningococcal disease epidemiology - United States, 2020-2023.

BACKGROUND: High quality surveillance data are important to monitor changes in incidence and better understand risk factors for meningococcal disease. This report summarizes meningococcal disease epidemiology from 2020 through 2023 in the U.S. METHODS: Epidemiologic information and isolates obtained through Enhanced Meningococcal Disease Surveillance for meningococcal disease cases reported through the National Notifiable Diseases Surveillance System (NNDSS) during 2020-2023 were included in the analysis. Isolates were characterized by serogrouping and molecular typing using whole genome sequencing. RESULTS: A total of 1,192 confirmed and probable meningococcal disease cases were reported through NNDSS during 2020-2023. Incidence was highest in 2023 (0.13 cases per 100,000) and lowest in 2021 (0.06 cases per 100,000). The proportion of cases that were serogroup Y increased over time, accounting for 56.8% of cases in 2023 compared to 16.0% in 2021. For serogroup Y, the most common clonal complex (CC) was CC23 in 2020-2021 and CC174 in 2022-2023. Prior to 2022, CC174 was rare in the U.S., accounting for less than 10% of serogroup Y cases, but in 2022-2023, CC174 accounted for more than 60% of serogroup Y cases. Nine outbreaks began in 2020-2023 and included 109 cases. The proportion of cases associated with outbreaks ranged from 0.9% in 2020 to 26.2% in 2022. CONCLUSIONS: Meningococcal disease incidence continued to decline during the COVID-19 pandemic but increased to above pre-COVID-19 pandemic incidence by 2023. It will be important to continue to monitor meningococcal disease incidence, especially of serogroup Y, over the next several years.