The Tick Surveillance Scheme (TSS) is a citizen science initiative which relies on public and professional submissions to monitor tick species distribution, seasonal exposure, and host associations across the United Kingdom (UK). During the period 2021-2024, 3182 tick records were received and 27 tick species were detected. The data confirm that Ixodes ricinus, the primary vector for Lyme disease and Tick-borne encephalitis, remains the most common tick in the UK. The TSS continues to detect imported tick species, underscoring the risk of novel pathogens entering the country, with new species like Hyalomma excavatum and Rhipicephalus pulchellus reported for the first time. The scheme also provides crucial evidence of non-endemic species like Hyalomma marginatum being found on hosts without history of foreign travel, although establishment risk is currently considered low. In addition to updated species distribution maps, a new tick-bite incidence metric has been developed and translated into a heat map for England and Wales. Updated regularly, this enables targeted public health interventions and awareness campaigns at the local authority level, providing a proxy for potential tick exposure. Tick submissions are likely underrepresented from Scotland and Northern Ireland, suggesting a need to strengthen outreach in these areas to improve data accuracy.

The rapid detection and containment of healthcare-associated infections (HCAIs) is critical in preventing and controlling infectious disease outbreaks within healthcare settings. Whole genome sequencing (WGS) has emerged as a powerful tool for tracking the transmission dynamics of pathogens and when used alongside traditional epidemiological methods it can better inform our understanding of the pathogen origin, pathway and extent of transmission. Additionally, WGS can aid in identifying previously unrecognized reservoirs of infection, allowing for more effective control strategies and targeted interventions. This article describes the incorporation of WGS into infectious disease management in Wales and explores it in the context of COVID-19 and Clostridioides difficile. We also describe the developments made to the workforce in Wales to enable the expansion of WGS and reflect on the resources, infrastructure and training frameworks still required.

BACKGROUND:Delayed discharge of patients considered medically fit for discharge places operational and economic strain on UK National Health Service hospitals, and it is unclear what harms may be experienced by patients who remain in hospital longer than clinically required. AIM:To describe the pattern of delayed hospital discharge, and the incidence of hospital-acquired infections and hospital-acquired pneumonia (HAP) in adult inpatients experiencing delayed discharge. METHODS:An observational study was performed where delayed discharge patient data (May to December 2022) from an acute district general hospital in Wales was mapped to a range of hospital and microbiology data systems to identify if, and when, an infection event occurred between the medically fit for discharge date and the actual discharge date. FINDINGS:During the study period, 1047 admissions resulted in delayed discharge, accounting for 5.6% of all admissions and occupying ∼17.9% of the estimated potential bed-days available. Several types of harms occurred in delayed discharge patients including HAP (0.4 per 100 bed-days of delayed discharge), respiratory infections (0.2 per 100 bed-days of delayed discharge), and positive blood culture infections (0.1 per 100 bed-days of delayed discharge). Among patients without HAP, mortality was 7% (95% confidence interval: 5-9); however, among patients with HAP it was 39% (27-51). CONCLUSION:The delay in discharge of medically fit patients causes a large reduction in hospital inpatient capacity. Additionally, this patient population experiences a considerable burden of infections, and of clinical cases of HAP which is of particular concern.

Shiga toxin-producing Escherichia coli (STEC) is a group of bacteria that causes gastrointestinal illness and occasionally causes large foodborne outbreaks. It represents a major public health concern due to its ability to cause severe illness which can sometimes be fatal. This study was undertaken as part of a rapid investigation into a national foodborne outbreak of STEC O145. On 22 May 2024, United Kingdom (UK) public health agencies and laboratories identified an increase in stool specimens submissions and patients testing positive for Shiga toxin-producing E. coli (STEC). Whole genome sequencing (WGS) identified serotype O145:H28 stx2a/eae belonging to the same five single nucleotide polymorphism (SNP) single linkage cluster as the causative agent. By 3 July 2024, 288 cases had been linked to the cluster. Most cases were adults (87%) and females (57%), 49% were hospitalized with a further 10% attending emergency care. Descriptive epidemiology and analytical studies were conducted which identified consumption of nationally distributed pre-packed sandwiches as a common food exposure. The implicated food business operators voluntarily recalled ready-to-eat sandwiches and wraps containing lettuce on 14 June 2024.

BACKGROUND:The role of the hospital environment in the spread of COVID-19 is unclear.AIM:To measure associations between ward characteristics and outbreak size to inform mitigations.METHODS:Wards with large (case wards) and small (control wards) outbreaks in three acute hospitals were compared. Cases were healthcare-associated COVID-19 inpatients (positive polymerase chain reaction test ≥8 days post admission). Case wards were adult medical/surgical wards with ≥10 cases within rolling 14-day periods, between April 1st, 2020 and April 30th, 2022. Control wards were equivalents with 2-9 cases. Demographic and laboratory data were extracted from routine surveillance systems. Continuous data were aggregated fortnightly and analysed as binary variables according to median values. Each case ward was compared with two control wards matched on outbreak start date (±14 days) to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) using univariable and conditional multivariable logistic regression.FINDINGS:From 170 outbreaks (median: 5 cases; interquartile range: 2-9), 35 case wards were identified. Community admissions were lower in case wards vs control wards (5 vs 10 median admissions; P<0.01, respectively), whereas transfers between wards within the same hospital were higher (58 vs 29 median transfers; P<0.01, respectively). Wards with more transfers in the preceding fortnight were significantly more likely to experience a large outbreak (≥35 vs <35 transfers; adjusted OR: 9.08; 95% CI: 2.5-33).CONCLUSION:We recommend safely minimizing patient movements, such as by asking clinicians to record the rationale for transfer, to reduce the likelihood of disease transmission.

Following an outbreak of Salmonella Typhimurium in Wales in July 2021 associated with sheep meat and offal, further genetically related cases were detected across the UK. Cases were UK residents with laboratory-confirmed Salmonella Typhimurium in the same 5-single-nucleotide polymorphism (SNP) single-linkage cluster with specimen date between 01/08/2021-2031/12/2022. We described cases using routine (UK) and enhanced (Wales only) surveillance data. Exposures in cases in Wales were compared with non-Typhimurium Salmonella case-controls. Environmental Health Practitioners and the Food Standards Agency investigated supply chains of food premises reported by >= 2 cases. Animal, carcass, and environmental samples taken for diagnostic or monitoring purposes for gastrointestinal pathogens were included in microbiological investigations. We identified 142 cases: 75% in England, 23% in Wales and 3% in Scotland. Median age was 32 years, and 59% were male. Direct contact with sheep was associated with becoming a case (aOR: 14, 95%CI: 1.4-145) but reported by few (6/32 cases). No single food item, premises, or supplier linked all cases. Multi-agency collaboration enabled the identification of isolates in the same 5-SNP single-linkage cluster from a sheep carcass at an English abattoir and in ruminant, wildlife, poultry, and environmental samples, suggesting multiple vehicles and pathways of infection.

Routine laboratory surveillance has identified an unprecedented and ongoing exceedance of Cryptosporidium spp. across the United Kingdom, notably driven by C. hominis transmission, since 14 August 2023. Information from 477 reported cases in England and Wales, followed up with a standardised exposure questionnaire as of 25 September 2023, identified foreign travel in 250 (54%) of 463 respondents and swimming in 234 (66%) of 353 cases. A significant, common exposure has not yet been identified in first analyses.

Objective To identify ethnic differences in proportion positive for SARS-CoV-2, and proportion hospitalised, proportion admitted to intensive care and proportion died in hospital with COVID-19 during the first epidemic wave in Wales. Design Descriptive analysis of 76 503 SARS-CoV-2 tests carried out in Wales to 31 May 2020. Cohort study of 4046 individuals hospitalised with confirmed COVID-19 between 1 March and 31 May. In both analyses, ethnicity was assigned using a name-based classifier. Setting Wales (UK). Primary and secondary outcomes Admission to an intensive care unit following hospitalisation with a positive SARS-CoV-2 PCR test. Death within 28 days of a positive SARS-CoV-2 PCR test. Results Using a name-based ethnicity classifier, we found a higher proportion of black, Asian and ethnic minority people tested for SARS-CoV-2 by PCR tested positive, compared with those classified as white. Hospitalised black, Asian and minority ethnic cases were younger (median age 53 compared with 76 years; p<0.01) and more likely to be admitted to intensive care. Bangladeshi (adjusted OR (aOR): 9.80, 95% CI 1.21 to 79.40) and ‘white – other than British or Irish’ (aOR: 1.99, 95% CI 1.15 to 3.44) ethnic groups were most likely to be admitted to intensive care unit. In Wales, older age (aOR for over 70 years: 10.29, 95% CI 6.78 to 15.64) and male gender (aOR: 1.38, 95% CI 1.19 to 1.59), but not ethnicity, were associated with death in hospitalised patients. Conclusions This study adds to the growing evidence that ethnic minorities are disproportionately affected by COVID-19. During the first COVID-19 epidemic wave in Wales, although ethnic minority populations were less likely to be tested and less likely to be hospitalised, those that did attend hospital were younger and more likely to be admitted to intensive care. Primary, secondary and tertiary COVID-19 prevention should target ethnic minority communities in Wales.

Between 1 June 2016 and 31 May 2017, 17 European Union (EU) and European Economic Area countries reported 4,096 cases associated with a multi-country hepatitis A (HA) outbreak. Molecular analysis identified three co-circulating hepatitis A virus (HAV) strains of genotype IA: VRD_521_2016, V16–25801 and RIVM-HAV16–090. We categorised cases as confirmed, probable or possible, according to the EU outbreak case definitions. Confirmed cases were infected with one of the three outbreak strains. We investigated case characteristics and strain-specific risk factors for transmission. A total of 1,400 (34%) cases were confirmed; VRD_521_2016 and RIVM-HAV16–090 accounted for 92% of these. Among confirmed cases with available epidemiological data, 92% (361/393) were unvaccinated, 43% (83/195) travelled to Spain during the incubation period and 84% (565/676) identified as men who have sex with men (MSM). Results depict an HA outbreak of multiple HAV strains, within a cross-European population, that was particularly driven by transmission between non-immune MSM engaging in high-risk sexual behaviour. The most effective preventive measure to curb this outbreak is HAV vaccination of MSM, supplemented by primary prevention campaigns that target the MSM population and promote protective sexual behaviour.

A nanopore DNA sequencer is used for real-time genomic surveillance of the Ebola virus epidemic in the field in Guinea; the authors demonstrate that it is possible to pack a genomic surveillance laboratory in a suitcase and transport it to the field for on-site virus sequencing, generating results within 24 hours of sample collection. This paper reports the use of nanopore DNA sequencers (known as MinIONs) for real-time genomic surveillance of the Ebola virus epidemic, in the field in Guinea. The authors demonstrate that it is possible to pack a genomic surveillance laboratory in a suitcase and transport it to the field for on-site virus sequencing, generating results within 24 hours of sample collection. The Ebola virus disease epidemic in West Africa is the largest on record, responsible for over 28,599 cases and more than 11,299 deaths1. Genome sequencing in viral outbreaks is desirable to characterize the infectious agent and determine its evolutionary rate. Genome sequencing also allows the identification of signatures of host adaptation, identification and monitoring of diagnostic targets, and characterization of responses to vaccines and treatments. The Ebola virus (EBOV) genome substitution rate in the Makona strain has been estimated at between 0.87 × 10−3 and 1.42 × 10−3 mutations per site per year. This is equivalent to 16–27 mutations in each genome, meaning that sequences diverge rapidly enough to identify distinct sub-lineages during a prolonged epidemic2,3,4,5,6,7. Genome sequencing provides a high-resolution view of pathogen evolution and is increasingly sought after for outbreak surveillance. Sequence data may be used to guide control measures, but only if the results are generated quickly enough to inform interventions8. Genomic surveillance during the epidemic has been sporadic owing to a lack of local sequencing capacity coupled with practical difficulties transporting samples to remote sequencing facilities9. To address this problem, here we devise a genomic surveillance system that utilizes a novel nanopore DNA sequencing instrument. In April 2015 this system was transported in standard airline luggage to Guinea and used for real-time genomic surveillance of the ongoing epidemic. We present sequence data and analysis of 142 EBOV samples collected during the period March to October 2015. We were able to generate results less than 24 h after receiving an Ebola-positive sample, with the sequencing process taking as little as 15–60 min. We show that real-time genomic surveillance is possible in resource-limited settings and can be established rapidly to monitor outbreaks.