Eurosurveillance - Volume 28, Issue 36, 07 September 2023

We describe 10 cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant BA.2.86 detected in Denmark, including molecular characteristics and results from wastewater surveillance that indicate that the variant is circulating in the country at a low level. This new variant with many spike gene mutations was classified as a variant under monitoring by the World Health Organization on 17 August 2023. Further global monitoring of COVID-19, BA.2.86 and other SARS-CoV-2 variants is highly warranted.

Many European countries have recently reported upsurges in invasive group A Streptococcus (iGAS) infections, mainly caused by emm1 Streptococcus pyogenes, specifically the toxigenic M1UK lineage. We present the epidemiology of emm1 causing iGAS in Belgium during 2018–August 2023, and describe an emergence of the toxigenic M1UK lineage in Belgium in mid-2022 that was observed as an increase in bloodstream infections caused by emm1 S. pyogenes that continued into 2023.

Since autumn 2022, observed numbers of paediatric invasive group A Streptococcus infections in Portugal (n = 89) were higher than in pre-COVID-19 seasons. Between September 2022 and May 2023, the dominant diagnoses were pneumonia (25/79), mostly with empyema (20/25), and sepsis (22/79). A number of cases required admission to intensive care (27/79) and surgery (35/79), and the case fatality rate was 5.1% (4/79). Genomic sequencing (n = 55) revealed multiple genetic lineages, dominated by the M1UK sublineage (26/55) and more diverse emm12 isolates (12/55).

Several SARS-CoV-2 variants that evolved during the COVID-19 pandemic have appeared to differ in severity, based on analyses of single-country datasets. With decreased testing and sequencing, international collaborative studies will become increasingly important for timely assessment of the severity of new variants. Therefore, a joint WHO Regional Office for Europe and ECDC working group was formed to produce and pilot a standardised study protocol to estimate relative case-severity of SARS-CoV-2 variants during periods when two variants were co-circulating. The study protocol and its associated statistical analysis code was applied by investigators in Denmark, England, Luxembourg, Norway, Portugal and Scotland to assess the severity of cases with the Omicron BA.1 virus variant relative to Delta. After pooling estimates using meta-analysis methods (random effects estimates), the risk of hospital admission (adjusted hazard ratio (aHR) = 0.41; 95% confidence interval (CI): 0.31−0.54), admission to intensive care unit (aHR = 0.12; 95% CI: 0.05−0.27) and death (aHR = 0.31; 95% CI: 0.28−0.35) was lower for Omicron BA.1 compared with Delta cases. The aHRs varied by age group and vaccination status. In conclusion, this study demonstrates the feasibility of conducting variant severity analyses in a multinational collaborative framework and adds evidence for the reduced severity of the Omicron BA.1 variant.

In recent years, field epidemiologists have embraced rapidly evolving digital tools, data sources and technologies, and collaborated with an ever-growing field of scientific specialisms. The COVID-19 pandemic put field epidemiology under unprecedented demand and scrutiny. As the COVID-19 emergency recedes, it is timely to reflect on the core values of our profession and the unique challenges and opportunities that lie ahead. In November 2022, alumni of the European Programme for Intervention Epidemiology Training (EPIET) and the European Public Health Microbiology (EUPHEM) training programme celebrated 25 years of EPIET, and the present and future of field epidemiology was discussed. The output was recorded and qualitatively analysed. This Perspective reflects the authors’ interpretation of the discussion. We should reaffirm our commitment to field epidemiology’s core strengths: competence and rigour in epidemiology, surveillance, outbreak investigation and applied research, leading to timely and actionable evidence for public health. Our future success will be defined by an ability to adapt, collaborate, harness innovation, communicate and, ultimately, by our tangible impact on protecting and improving health.

We present the findings from the European Programme for Intervention Epidemiology Training (EPIET) Alumni Network (EAN) Member Survey conducted in October to December 2021. The EAN consists of field epidemiologists (EPIET) and public health microbiologists (European Public Health Microbiology Training Programme (EUPHEM)) who stay connected after their 2-year fellowship. This active alumni network provides opportunities for career development, mentorship, knowledge exchange and sharing of best practices for community members, affiliated professionals and public health organisations in Europe. Overall, 281 of 732 members participated in the survey. Of the 192 European fellowship alumni respondents, 173 (90%) indicated that skills and competencies acquired during their fellowship improved performance in their role compared with their abilities before the fellowship. Reported skills and competencies that could be further strengthened included data management/analysis, communication, mathematical modelling and leadership/team management. The EAN Member Survey provides valuable feedback to the EAN, as well as the fellowship programme offices at the European Centre for Disease Prevention and Control (ECDC) and affiliated field epidemiology programmes. The COVID-19 pandemic was a stark reminder of how essential cross-border collaborations are for continued European health security. Maintaining and increasing the professional, well-trained workforce remains crucial for optimal response to infectious diseases and protection of public health.