Invasive Meningococcal Disease in the Post-COVID World: Patterns of Disease Rebound

Abstract

Invasive meningococcal disease (IMD) is a global health threat with an unpredictable epidemiology that varies regionally and over time. During the COVID-19 pandemic, the Invasive Respiratory Infection Surveillance Consortium reported widespread reductions in bacterial diseases transmitted via the respiratory route, including IMD, that were associated with the stringency of COVID-19 measures implemented in each country. Here, we report the epidemiology of IMD from the United States, England, France, Australia, and Chile during and after the COVID-19 pandemic. There was a consistent trend in which IMD incidence declined throughout 2020 and into 2021 but began to increase in 2021 (England and Chile) or 2022 (United States, France, and Australia). Case numbers of IMD in France and the United States surpassed pre-pandemic levels by December 2022 and 2023, respectively, whereas in other countries examined, overall cases in 2021/2022 or 2023 approached but did not exceed pre-pandemic levels. Except for the United States, meningococcal serogroup B was the prominent serogroup of post-pandemic re-emergence, although substantial increases in serogroup Y and W disease in France in 2022 and serogroup W disease in Chile in 2023 were also observed. In the United States, where meningococcal vaccination coverage did not decline during the pandemic, the rebound in cases was predominantly due to serogroups C, Y, and nongroupable serogroups. The data indicate that surveillance of IMD cases, associated serogroups, and vaccination uptake is essential for monitoring the effectiveness of disease prevention strategies and guiding future public health policy.

Keywords: epidemiology; invasive meningococcal disease; surveillance; vaccines.

Figure 1

Invasive meningococcal disease cumulative case numbers (A) and annual case numbers by serogroup reported by the National Notifiable Diseases Surveillance System (B) and the Enhanced Meningococcal Disease Surveillance (C) in the United States: 2016–2023 (Centers for Disease Control and Prevention [18,28,29,30,31,32,33,34]). MenACWY, meningococcal serogroups A, C, W, and Y; MenB, MenC, MenW, and MenY, meningococcal serogroups B, C, W, and Y, respectively. Cumulative year-to-date and yearly case numbers are determined from periods of time when the condition was reportable in the jurisdiction (i.e., may be incomplete year-to-date data or less than 52 weeks of data).

Figure 2

Quarterly invasive meningococcal disease case numbers by serogroup (A) and yearly incidence by age group (B) in England: 2018–2022 ([43,44,45,46,47,48,49,50,51,52,53,74,75]; contains public sector information licensed under the Open Government License v3.0). MenB, MenC, MenW, and MenY, meningococcal serogroups B, C, W, and Y, respectively; Other, serogroups A, X, E, Z, or ungroupable and ungrouped serogroups.

Figure 3

Yearly cases of invasive meningococcal disease by month (A), by proportion of each serogroup (B), and incidence by serogroup (C) in France: 2015–2023 [22].

Figure 4

Annual invasive meningococcal disease case numbers by serogroup (A) and age (B–D) in Australia through 2022 [23,58,59,60,61,62,63,64,65,66]. MenB, meningococcal serogroup B; MenC, meningococcal serogroup C; MenW, meningococcal serogroup W; MenY, meningococcal serogroup Y; Other, non-BCWY serogroups.

Figure 5

Number of cases (samples and strains) of confirmed IMD (A) and incidence of IMD by serogroup (B) and incidence of IMD in infants <1 year of age (C) in Chile: 2012–2023 [25]. IMD, invasive meningococcal disease; MenB, meningococcal serogroup B; MenC, meningococcal serogroup C; MenW, meningococcal serogroup W; MenY, meningococcal serogroup Y; Others, non-BCWY serogroups.