Outbreak of Shiga toxin-producing Escherichia coli O157:H7 linked to raw drinking milk resolved by rapid application of advanced pathogen characterisation methods, England, August to October 2017

Abstract

An outbreak of Shiga toxin-producing Escherichia coli (STEC) O157:H7 occurred on the Isle of Wight between August and October 2017. Of the seven cases linked to the outbreak, five were identified through the statutory notification process and two were identified through national surveillance of whole genome sequencing data. Enhanced surveillance questionnaires established a common link to a farm, and link to the likely food vehicle, raw drinking milk (RDM). Microbiological investigations, including PCR, identified the presence of STEC O157:H7 in samples of RDM. Analysis of core genome single nucleotide polymorphism (SNP) data of STEC O157:H7 from human stool specimens, animal faecal samples and RDM demonstrated a one SNP difference between isolates, and therefore close genetic relatedness. Control measures that were put in place included suspension of sales and recall of RDM, as well as restrictions on public access to parts of the farm. Successful integration of traditional epidemiological surveillance and advanced laboratory methods for the detection and characterisation of STEC O157:H7 from human, animal and environmental samples enabled prompt identification of the outbreak vehicle and provided evidence to support the outbreak control team’s decision-making, leading to implementation of effective control measures in a timely manner.

Prevalence of Escherichia Coli O157:H7 and Associated Factors in Under-five Children in Eastern Ethiopia

“…Although the levels of contamination of the water sources are not well identi ed, drinking water treatment methods were not found associated with the occurrence of the organism. However, other researchers reported drinking contaminated water sources as a predictor for the occurrence of E. coli O157:H7 infection [36,[54][55][56][57].…”

A sensitive method for the recovery of Escherichia coli serogroup O55 including Shiga toxin‐producing variants for potential use in outbreaks

“…Fifty cattle faecal samples collected from a previous on‐farm investigation were screened for the presence of E. coli O55 (Treacy et al ). One gram of faeces was added to 9 ml BPW and grown for 2 h at 37°C.…”

Gastrointestinal infections caused by consumption of raw drinking milk in England & Wales, 1992–2017

“…Since 2015, the use of routine whole genome sequencing (WGS) at PHE has provided unprecedented sensitivity and accuracy in identifying microbiologically linked cases of infection [9, 10]. However, all RDM-associated STEC O157:H7 outbreaks reported to date have been detected through epidemiological links established by local health protection teams prior to the availability of the WGS results [9, 10]. At the time of the STEC O157:H7 RDM outbreak in 2014, human and RDM isolates were linked using multilocus variable number tandaem repeat analysis, although WGS was used retrospectively to definitively link cases to the outbreak strain [9].…”