Evidence of on-going transmission of Shiga toxin-producing Escherichia coli O157:H7 following a foodborne outbreak.

In August 2019, public health surveillance systems in Scotland and England identified seven, geographically dispersed cases infected with the same strain (defined as isolates that fell within the same five single nucleotide polymorphism single linage cluster) of Shiga toxin-producing Escherichia coli O157:H7. Epidemiological analysis of enhanced surveillance questionnaire data identified handling raw beef and shopping from the same national retailer (retailer A) as the common exposure. Concurrently, a microbiological survey of minced beef at retail identified the same strain in a sample of minced beef sold by retailer A, providing microbiological evidence of the link. Between September and November 2019, a further four primary and two secondary cases infected with the same strain were identified; two cases developed haemolytic uraemic syndrome. None of the four primary cases reported consumption of beef from retailer A and the transmission route of these subsequent cases was not identified, although all four primary cases visited the same petting farm. Generally, outbreaks of STEC O157:H7 in the UK appear to be distinct, short-lived events; however, on-going transmission linked to contaminated food, animals or environmental exposures and person-to-person contact do occur. Although outbreaks of STEC caused by contaminated fresh produce are increasingly common, undercooked meat products remain a risk of infection.

Measles cluster at a university in the United Kingdom.

BACKGROUND: Measles remains an infection of public health importance. We describe a cluster of measles in a university setting between April and May 2007. CASE PRESENTATION: The outbreak took place over a period of six weeks and involved nine students, eight of whom lived in halls of residence. Due to the potential for significant spread in an institutional setting, a public health investigation was initiated to identify the source of the outbreak. Follow up of cases was undertaken proactively with the university and local general practitioners. Salivary fluid test kits and questionnaires were sent to suspected cases. Seven salivary test kits were returned, but only one questionnaire was returned. Four cases were confirmed as measles. Although seven students had been previously immunised, immunity was only demonstrated in three. CONCLUSIONS: Public health investigations were hampered by the poor return rate of questionnaire and oral fluid sampling kits despite proactive follow up by public health staff, as well as the break for summer vacation. Nevertheless, our report highlights the public health effort in investigating such outbreaks and the importance of reinforcing immunisation to college and university students.