Epidemiological trends in viral meningitis in England: Prospective national surveillance, 2013–2023

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 2061 cases (1.8/100,000; 1.7–1.9), which increased to 4754 (4.2/100,000; 4.0–4.3) during 2022–23 (post pandemic restrictions). Infants aged <3 months accounted for 39.4% (8702/22,048) 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%, 7387/8702; 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 were 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.