RESUMO
BACKGROUND: In the conjugate vaccine era, viruses are the most common cause of meningitis. Here, we evaluated epidemiological trends in laboratory-confirmed viral meningitis across all age-groups over an 11-year period in England. METHODS: In England, hospital laboratories routinely report laboratory-confirmed infections electronically to the UK Health Security Agency. Records of positive viral detections in cerebrospinal fluid during 2013-2023 were extracted. Incidence rates with confidence intervals were calculated using mid-year resident population estimates. RESULTS: There were 22,114 laboratory-confirmed viral meningitis cases, including 15,299 cases during 2013-19 (pre COVID-19), with a gradual increase in incidence from 3.5/100,00 (95%CI, 3.3-3.6) to 3.9/100,000 (95%CI, 3.6-4.1). During 2020-21 when pandemic restrictions were in place, there were 2,061 cases (1.8/100,000; 1.7 - 1.9), which increased to 4,754 (4.2/100,000; 4.0-4.3) during 2022-23 (post pandemic restrictions). Infants aged <3 months accounted for 39.4% (8,702/22,048) of all cases, with a stable incidence 2013-19 (504/100,000, 95%CI: 491-517), followed by a significant decline during 2020-21 (204/100,000; 188-221) and then an increase during 2022-23 (780/100,000; 749-812), with enteroviruses being the commonest cause (84.9%, 7387/8,702; 424.74/100,000; 95%CI, 415.12-434.51), followed by parechoviruses (9.1%, 792/8702; 45.54/100,000; 95%CI, 42.42-48.82) and herpes simplex virus (4.4%, 380/8702; 21.85/100,000; 95%CI, 19.71-24.16). Pandemic restrictions were associated with significant declines in the incidence of enterovirus (77.7%) and parechoviruses (64% lower), with rebounds after societal restrictions lifted. CONCLUSIONS: Rates of viral meningitis have returned to pre-pandemic levels since societal restrictions were lifted. The highest incidence of viral meningitis remains in infants aged <3 months and most commonly due to enteroviral infection.
RESUMO
BACKGROUND: The UK transition from a 2 + 1 to a 1 + 1 infant immunisation schedule with the 13-valent pneumococcal conjugate vaccine (PCV13) on Jan 1, 2020, coincided with the start of the COVID-19 pandemic. We describe the epidemiology of invasive pneumococcal disease (IPD) in England over 6 financial years (April 1 to March 31) between 2017-18 and 2022-23. METHODS: We used prospective national surveillance data, including serotyping and whole-genome sequencing of invasive isolates, to analyse IPD trends in England by age and financial year. We compared breakthrough infections and vaccine failure rates in 2022-23 among children eligible for the 1 + 1 schedule with rates in cohorts of children eligible for the 2 + 1 schedule between 2017-18 and 2019-20. We assessed genomic changes over time by comparing Global Pneumococcal Sequencing Clusters and multilocus sequence types among PCV13 serotypes causing IPD. FINDINGS: There were 4598 laboratory-confirmed IPD cases in 2022-23, 3025 in 2021-22, 1240 in 2020-21, and 5316 in 2019-20. IPD incidence in 2022-23 was 14% lower than in 2019-20 (incidence rate ratio [IRR] 0·86, 95% CI 0·81-0·91; p<0·001). IPD incidence in 2022-23 compared with 2019-20 was 34% higher in children (aged <15 years) (378 cases vs 292 cases; IRR 1·34, 95% CI 1·08-1·68; p=0·009) and 17% lower in adults (aged 15 years and older; 4220 vs 5024; 0·83, 0·78-0·88; p<0·001). The proportion of PCV13-type IPD increased from 19·4% (95% CI 18·2-20·4; 957 of 4947) in 2019-20 to 29·7% (28·3-31·0; 1283 of 4326) in 2022-23, mainly due to serotype 3, but also serotypes 19F, 19A, and 4, alongside a decrease in non-PCV13 serotypes 8, 12F, and 9N. The increase in IPD incidence due to serotypes 3, 19A, and 19F was driven by clonal expansion of previously circulating strains, whereas serotype 4 expansion was driven by newer strains (ie, sequence types 801 and 15603). Breakthrough infections and vaccine failure rates were similar in children eligible for the 1 + 1 (1·08 per 100 000 person-years) and 2 + 1 (0·76 per 100 000 person-years; IRR 1·42, 95% CI 0·78-2·49; p=0·20) PCV13 schedules. INTERPRETATION: Overall, IPD incidence in England was lower in 2022-23, 2 years after removal of pandemic restrictions, than in 2019-20. Breakthrough and vaccine failure rates were not significantly different between children who received the 1 + 1 compared with the 2 + 1 PCV13 immunisation schedule. The post-pandemic increase in childhood IPD incidence and especially PCV13-type IPD will require close monitoring. FUNDING: None.
