欧洲疾控中心-腮腺炎-2023年年度流行病学报告（英）-2025_11页_867kb

Mumps Annual Epidemiological Report for 2023

Core Content

The 2023 Annual Epidemiological Report on Mumps in the EU/EEA region highlights a continued decline in mumps notifications compared to pre-pandemic levels. A total of 2,963 cases were reported by 27 EU/EEA Member States, with an overall notification rate of 0.7 cases per 100,000 population. This rate is similar to 2022 but slightly higher than 2021 and significantly lower than 2019 and 2020. No data was reported by Austria, France, and Liechtenstein.

Key Findings

• Age Distribution: The highest age-specific notification rates were observed in children aged 1–4 years (4.4) and 5–9 years (4.05). However, the largest number of cases were in individuals aged 30 years and older (26.4% of total cases), with a median age of 21 years for all cases, up from 10 years in 2022.
• Gender Distribution: Males were slightly more affected than females, with a male-to-female ratio of 1.16:1. Notification rates were higher among males in younger age groups, but slightly lower among adult males compared to adult females.
• Vaccination Status: Data on vaccination status was available for 65% of cases. Of these, 29% were unvaccinated, 20% received one dose, and 32% received two doses. The majority of fully vaccinated cases were among children aged 5–14 years.
• Vaccination Coverage: The population-weighted average vaccination coverage for the first dose was 93%, and for the second dose, it was 89% across the EU/EEA in 2023. Nineteen countries reported a decrease in first-dose coverage, and eighteen reported a decrease in second-dose coverage, while four countries showed an increase in both doses.

Epidemiological Trends

• Seasonality: Mumps cases in 2023 showed no significant seasonal variation, unlike the previous years where there was a winter peak and summer low.
• Outbreaks: The majority of cases were reported by Poland, Spain, and Germany, accounting for 62% of total cases. Poland's notification rate was the highest at 2.6 per 100,000 population.
• Complications: Among 1,129 cases with known hospitalisation status, 108 were hospitalised. Complications included orchitis, pancreatitis, meningitis, and unspecified cases. Most complications were reported among children aged 1–4 years and adults over 30.

Discussion

• Impact of the Pandemic: The low notification rates in 2021–2023 may be attributed to the residual effects of the COVID-19 pandemic, including reduced transmission due to public health measures and decreased surveillance capacity.
• Vaccination Efficacy and Waning Immunity: The mumps component of the MMR vaccine provides lower and more rapidly waning protection compared to measles and rubella components. This may explain the observed shift in case distribution towards older age groups.
• Vaccination Coverage: While some countries achieved high coverage rates (≥95%), the majority faced challenges in maintaining these levels, particularly due to the indirect effects of the pandemic on immunisation programs. The need for continued surveillance and evaluation of vaccine effectiveness is highlighted.

Conclusion

The report underscores the importance of maintaining high vaccination coverage for the MMR vaccine to prevent mumps outbreaks and reduce disease severity. It also calls for addressing operational barriers and ensuring long-term immunisation success, especially in light of the observed waning immunity and the impact of the pandemic on surveillance and immunisation efforts.