Eurosurveillance - Volume 31, Issue 6, 12 February 2026

The Meningitis and Encephalitis Registry in Lower Saxony (MERIN), introduced in 2003, monitors circulating neurotropic pathogens in Lower Saxony and Bremen and offers free laboratory diagnostics for patients hospitalised with aseptic meningitis, encephalitis and polio-like symptoms.

We aimed to present set-up and operation of MERIN in detail and provide results of the collected data.

Data (work-flow, demographics, sample materials, detected pathogens including non-polio enterovirus (NPEV) genotypes), collected between 2003 and 2023 were extracted from the MERIN database and presented descriptively. Seasonal patterns of detected pathogens were analysed using a Poisson regression model.

During 21 years of MERIN’s operation, 34,688 samples from 13,813 patients were analysed, 54.6% (7,548/13,813) of which were male. The majority of patients were children, with 58.8% (8,127/13,813) under the age of 10 years. Twenty different pathogens were identified; NPEV infections constituted 56.9% (2,372/4,172) of all diagnoses and were found in 17.2% of patients (2,372/13,813). Borrelia burgdorferi sensu lato, adenovirus and varicella-zoster virus were identified in 7.3% (1,004/13,813), 2.1% (286/13,813) and 1.4% (190/13,813) of patients, respectively. Most frequently occurring NPEV genotypes were echovirus 30 (n = 437), echovirus 6 (n = 223) and coxsackie B virus (n = 103). Polioviruses were not detected. Increased numbers of patients and detected pathogens during summer months resulted in seasonal peaks.

MERIN elucidates the spectrum of circulating pathogens, mostly NPEV, causing symptoms of aseptic meningitis, encephalitis and polio-like symptoms and demonstrates seasonal occurrence of pathogens. MERIN contributes to the German national enterovirus surveillance and documents the polio-free status of Lower-Saxony and Bremen.

The World Health Organization aims to eliminate hepatitis B virus (HBV) by 2030 through reducing incidence and mortality. Accurate prevalence estimates are crucial to guide policies and monitor progress towards HBV elimination. However, HBV prevalence can be overestimated when relying solely on hepatitis B surface antigen (HBsAg) because of unconfirmed or false-positive results. Robust screening algorithms to improve diagnostic accuracy and minimise false positives are required.

We conducted a nationwide, population-based serosurvey to estimate HBV prevalence in Belgium by using HBsAg alone or combined with hepatitis B core antibody (anti-HBc) positivity as infection criterion.

We analysed HBsAg and anti-HBc in a total of 4,955 left-over serum samples from severe acute respiratory syndrome coronavirus 2 sero-epidemiology studies in 2020. Samples were stratified per region, 10-year age band and sex. A confirmatory anti-HBc neutralisation assay was performed in discordant samples.

We detected HBsAg in 0.75% (37/4,955) of samples, of which 62.2% (23/37) were anti-HBc-negative and showed no specific anti-HBc signal in the neutralisation assay. None of the samples from ≤ 5-year-olds (n = 87) were double-positive. Weighted analysis estimated HBsAg seroprevalence at 0.74% (95% confidence interval (CI): 0.50–1.04). However, considering double HBsAg and anti-HBc positivity, an HBV prevalence of 0.25% (95% CI: 0.13–0.42) was retained. The HBsAg/anti-HBc prevalence in ≤ 33-year-olds was lower than in older adults (0.079% vs 0.36%; p = 0.015), consistent with Belgium’s vaccination policy.

This serosurvey reinforces the importance of confirmatory anti-HBc testing in HBsAg-positive samples, particularly in low-endemic countries. Incorporating anti-HBc testing improves the correctness of prevalence estimates.

Chagas disease (CD), a tropical parasitic disease caused by Trypanosoma cruzi, is increasingly recognised as a public health concern among Latin American migrants living in non-endemic settings. In London, United Kingdom (UK), home to over 160,000 people from endemic countries, no formal population-level CD screening programmes exist.

To investigate the seroepidemiology of CD infection in Latin American adults living in London, UK.

A cross-sectional, observational study utilising questionnaires and serological (T. cruzi) screening was performed between August 2023 and January 2025. Adults born in South America, Central America or Mexico (or whose mothers were born there) were eligible to participate. Screening was offered in primary care sites and by point-of-care serological testing at community events. Outcomes were seroprevalence, screening yield, positive predictive value of screening tests and linkage to care.

In primary care, of 2,739 eligible individuals offered screening, 276 (10.1%) accepted. At community events, 247 were screened. Of the 523 screened, 20 (3.8%) participants had positive screening tests, and CD was confirmed in 14 (2.7%), all born in Bolivia. Seroprevalence was lower in those screened in primary care (1.1%) than at community events (4.5%). The number needed to screen to detect one confirmed case (linked into care) was 37 overall, 92 in primary care and 22 at community events.

Screening for CD through primary care in the UK is highly challenging, with both low uptake and low yield amongst those tested. Targeted community-based outreach approaches result in higher screening yield and linkage to care.