Public Health England was informed of multiple European clusters of illness last year including Listeria and Salmonella in the Czech Republic, according to a recent report.
The report summarizes activities of the United Kingdom’s national reference laboratory (NRL) for food microbiology from April 2018 to March 2019. Public Health England (PHE) provides this NRL for the Food Standards Agency (FSA). It covers Listeria monocytogenes, coagulase-positive staphylococci, E. coli including Shiga toxin-producing E. coli (STEC), Campylobacter, Salmonella, and antimicrobial resistance.
PHE was informed of nine Listeria and six Salmonella clusters. In one Listeria outbreak, whole-genome sequencing data linked illnesses to strains found in a processing plant in the Czech Republic. PHE was also told of an increase in Salmonella Bareilly cases in the same country. A total of 325 probable salmonellosis cases were found in the Czech Republic from July 2017 to Oct. 2018. Eggs were identified as the probable vehicle of infection with contaminated egg drying equipment at a processing plant likely to blame.
The NRL attended European Reference Laboratory (EURL) training for the detection and characterization of STEC from food by ISO TS 13136 and is a member of a CEN expert working group for the revision of this standard, involving PCR detection of STEC.
Thirteen Official Control Laboratories (OCLs) took part in the European food microbiology legislation external quality assessment test. It was the first time that Campylobacter enumeration was included, as this is a new EU process hygiene criteria. Overall, results were satisfactory despite an increase from two to seven in labs producing one or more results below the 70 percent threshold but only two had an unsatisfactory result two or more times.
In July 2018, the EURL forwarded an EFSA and ECDC outbreak assessment and technical reports from the investigation into a multi-country outbreak of Listeria monocytogenes sequence type 6 (ST6) linked to frozen sweetcorn; which were sent on to the OCLs.
Between April 2018 and March 2019, there were nine EURL communications for eight Epidemic Intelligence Information System (EPIS) inquiries of Listeria clusters. EPIS is a web-based communication platform that allows certain public health experts to assess whether current and emerging threats have a potential impact on the European Union.
One was related to the sweetcorn incident, in which the U.K. had clinical and food isolates, and sent two clinical ones to the EURL for PFGE typing. Another caused a multi-country outbreak of listeriosis and was associated with gravid salmon but the U.K. had no non-human isolates in the database at the time of response.
In February 2019, the EURL announced changes to the retail temperatures in technical guidance because shelf-life testing had been accepted by the Standing Committee of the Food Chain and Animal Health section Biological Safety of the Food Chain. They have been lowered from 12 degrees C (53 degrees F) to 7 degrees C (44 degrees F), to reflect EU data.
A report was sent in March on the EURL’s assistance to the Czech Republic in investigating plant contamination with Listeria. WGS data linked illnesses to strains found at the processing plant.
A product alert was received in March 2019 from BioMerieux about a shortage of API Listeria kits. The availability of this confirmation test may affect other labs and the alert was sent to all OCLs.
In the external quality assessment, there was an improvement in categorizing ice creams for Listeria monocytogenes where labs understood this sample does not support growth — but does not kill the organism — due to it being frozen. A dried milk powder sample was less easy to class because regulations are unclear as to how these foods fit into the different categories for such testing when sampled at the food business.
Salmonella Bareilly and Coeln
Between April 2018 and March 2019, there were six EURL correspondences, four on EPIS and two NRL inquiries of Salmonella clusters.
Examples include a rise in Salmonella Bareilly cases in the Czech Republic and the U.K. sent data for 200 isolates to the EURL for comparison and when Salmonella Coeln caused multi-country cases; the U.K. observed no non-human isolates at the time of response.
Most labs in the quality assessment failed to identify the need for serotype strains for Salmonella Typhimurium and Salmonella Enteritidis. The requirement to test for absence applies to broilers after chilling, as they will be placed on the market. Only two labs identified the correct food category for this examination and one also rightly stated they would refer strains for further testing, according to the report.
Requests to the NRL between April 2018 and March 2019 included a query from a hospital for fungal testing in a food sample; advice sought from Campden BRI on measuring the risk of Clostridium botulinum in challenge testing; growth of an organism or toxin detection; and inquires from a person regarding suspected poisoning from eating supermarket pancakes.
Two came from the FSA, one seeking advice on differences of aerobic colony counts performed on raw milk samples at two different labs (dairy OCL and food business lab). The agency asked for further advice regarding testing methods for examining raw drinking milk. The other was about environmental swabbing in slaughterhouses and if there are existing ISO standards to do such work.
Planned PHE NRL activities on the April 2019 to March 2020 calendar include working with FSA on implementation of the new Official Controls Regulation 2017/625; produce a poor performance protocol for OCL participation in EFL proficiency tests, and assist in disseminating EPIS and other alerts.
The EURL shared information with NRLs including three E. coli outbreaks involving the United States.
One was updates of a multistate outbreak of STEC O157 linked to romaine lettuce, the other was an O157 outbreak from last year in Utah, thought to be transmitted from animal manure and the final one was two clusters of E. coli from two sources, unpasteurized cow’s milk and a daycare center associated with goat exposure, in Tennessee.
Other information included the Health Service Executive reporting an increase in E. coli infections in Ireland and an E. coli O26 outbreak in France, where unpasteurized cheese was implicated.
(To sign up for a free subscription to Food Safety News, click here.)