欧洲疾控中心-腮腺炎-2023年年度流行病学报告（英）-2025_11页_1mb

Mumps Surveillance Report Summary (2023)

Core Content

Mumps is a contagious viral infection caused by an RNA virus in the Paramyxoviridae family, primarily manifesting as acute parotitis. It can lead to complications such as orchitis, meningitis, and sensorineural hearing loss, with long-term consequences like subfertility and oligospermia in males. Transmission occurs through respiratory droplets or direct contact with saliva, with an incubation period of 14–25 days. The only effective preventive measure is immunisation via the MMR vaccine, which is included in all EU/EEA countries' routine childhood immunisation schedules.

Key Facts

• In 2023, 2963 cases were reported in 27 EU/EEA Member States, with an overall notification rate of 0.7 cases per 100,000 population.
• This rate is similar to 2022, slightly higher than 2021 (0.4), but significantly lower than 2020 (1.7) and 2019 (3.4).
• The most affected age groups were 1–4 years (4.4 cases per 100,000) and 5–9 years (4.05 cases per 100,000), but absolute case numbers were highest in the 30 years and older group (26.4% of total cases).
• The median age of cases in 2023 was 21 years, compared to 10 years in 2022.
• Mumps was slightly more common among males (53.7%) than females, with a male-to-female ratio of 1.16:1.
• Children aged 5–9 years accounted for 25.1% of all cases, with 34% being fully vaccinated (at least two doses of MMR).

Epidemiology

• Three countries (Poland, Spain, Germany) accounted for 62% of all mumps cases in 2023, with Poland reporting the highest rate at 2.8 cases per 100,000 population.
• Poland used a national case definition for possible cases, which did not include laboratory confirmation, leading to a discrepancy in data classification.
• Austria, France, and Liechtenstein reported no data for 2023.
• Notification rates varied widely across countries, ranging from 0.0 (Greece, Hungary, Iceland, Slovenia) to 2.46 (Poland) cases per 100,000 population.

Vaccination Status

• Vaccination data was available for 1938 cases (65% of total), with 564 unvaccinated cases (29%), 390 vaccinated with one dose (20%), 624 vaccinated with two doses (32%), and 12 vaccinated with three or more doses (0.6%).
• Unvaccinated cases were most common in children under one year (52%) and adults over 30 years (27%).
• Fully vaccinated cases were predominantly among children aged 5–14 years, with 5–9 years (41%) and 10–14 years (23%) being the most affected.
• Vaccination status was unknown in 18% of cases, especially in 15–19 years (43%), 20–29 years (52%), and 30 years and older (54%).

Vaccination Coverage

• In 2023, the population-weighted average vaccination coverage for MMR vaccines was 93% for the first dose and 89% for the second dose.
• 19 countries reported a decrease in first-dose coverage (range: -1 to -13%), and 18 countries reported a decrease in second-dose coverage (range: -1 to -18%).
• 4 countries reported an increase in first-dose coverage (1–3%), and 4 countries reported an increase in second-dose coverage (3–9%).
• 15 countries (50%) had ≥95% first-dose coverage, while only 4 countries (14%) had ≥95% second-dose coverage (Hungary, Malta, Portugal, and Slovakia).
• Only 3 countries (Hungary, Malta, and Portugal) had ≥95% coverage for both doses.

Outcomes

• 39% of cases had known outcomes, with no deaths reported in 2023.
• 38% of cases had known hospitalisation status, with 9.6% being hospitalised.
• Complications were reported in 26 cases of orchitis, 8 of pancreatitis, 4 of meningitis, and 8 unspecified complications.
• Most complications were observed in children aged 1–4 years (32%) and adults aged 30 years and older (30%).

Discussion

• Mumps notification rates in the EU/EEA have remained below pre-COVID-19 levels from 2019 to 2023, with a continued decreasing trend from 3.1 in 2019 to 0.7 in 2023.
• The notification rate in 2023 (0.7) is stable compared to 2022 but still lower than pre-pandemic levels.
• The rise in notifications in 2022 and stagnation in 2023 may be linked to the relaxation of public health measures and restoration of surveillance systems post-pandemic.
• The decline in cases from Spain and Ireland in 2023 had a dramatic impact on the overall notification rate.
• The shift in age groups affected by mumps in recent years suggests epidemiological changes and changes in the countries contributing to case numbers.
• Waning immunity after the MMR vaccine, with studies indicating that immunity may last 16–51 years, contributes to the susceptibility of adolescents and adults.
• Despite 32% of cases having received at least two doses, most were among children aged 5–19 years, highlighting the need for improved long-term vaccine effectiveness.
• High MMR coverage in the EU/EEA remains a positive factor, but post-pandemic disruptions may affect coverage stability.
• The priority should remain on reinforcing immunisation systems, closing immunity gaps, and addressing operational barriers to ensure the long-term success of the current two-dose strategy.