Multi‐country outbreak of Shiga toxin‐producing Escherichia coli infection associated with haemolytic uraemic syndrome

Abstract

A multi-country outbreak of Shiga toxin-producing Escherichia coli (STEC) infection associated with haemolytic uraemic syndrome (HUS) and affecting mostly young children has been reported in the last two months in Romania. Italy reported one related HUS case through the Early Warning and Response System (EWRS) on 21 March 2016. Overall, 25 cases were identified as associated with this outbreak, of which 19 developed HUS and three died. Twelve cases had microbiological and/or serological evidence of STEC O26 infection; 13 additional cases met the probable case definition by developing HUS, testing positive for another STEC O serogroup (O157) or by testing positive by PCR for stx1 and/or stx2 and eae genes. Information collected from patients pointed towards a milk processing establishment (the Romanian operator) as a possible source of infection. The implicated milk processing establishment exported a particular type of cheese to four EU countries (Belgium, Germany, Italy and Spain) and one Italian importer further distributed this product to France and Germany. In Romania, one fresh cheese product made of cow's milk produced by the Romanian operator tested positive for E. coli O26 not possessing stx virulence genes. Other dairy products produced by the Romanian operator tested positive for E. coli virulence genes stx1, stx2 and eae. In Italy, a STEC O26 strain (positive for stx1, stx2 and eae) was isolated from a sample of the cheese that had been produced by the Romanian operator, imported from Romania and consumed by the Italian child that later developed HUS (stool samples negative for STEC but serum samples positive for the presence of antibodies against the LPS of E.coli O26). The PFGE analysis suggests the potential involvement of multiple strains from a common source or from multiple sources. Multi-strain STEC outbreaks have been reported in the past [1]. Therefore, it cannot be excluded that the cases belong to a single outbreak associated with a source contaminated by different strains. The epidemiological evidence linking some of the Romanian cases and the Italian case to the Romanian operator, in addition to the microbiological findings, are consistent with the hypothesis of a multi-strain outbreak. The last Romanian case associated with this outbreak had onset of symptoms on 14 March. The cheese consumed by the Italian case was imported in Italy from Romania on 1 March and had been produced on 18 February 2016 with an expiry date of 18 April 2016. A recall of the company products was undertaken in Romania as of 5 March and in Italy as of 15 March. Other Member States subsequently undertook recalls. According to information available at the time of conducting this assessment, the withdrawal of potentially contaminated dairy products following a recall has been limited in Member States, with the exception of Romania. It is therefore possible that affected products are still present in households, and detection of new cases cannot be excluded. In order to minimise the spread of the infection and...

The European Union summary report on trends and sources of zoonoses, zoonotic agents and food‐borne outbreaks in 2016

“…STEC O26 (5.1% of the positive specimens) was the most commonly reported serogroup in food with a higher specific proportion than that of STEC O157 (3.2% of the positive specimens), when considering the samples tested with the ISO TS 13136:2012 method (ISO, 2012) as the denominator. Finally, among the 13 serogroups detected with a frequency between 0.7% and 13.2%, eight were included among those most commonly found as cause of human infections in the EU/EEA in 2015 and in the preceding years (EFSA and ECDC, 2016c).…”

“…STEC serogroup O8 was first reported in 2015 (0.43 per 1,000 samples analysed) and the reporting of this STEC serogroup continued in 2016 at a higher rate (0.58 per 1,000 samples analysed). Interestingly, this serogroup is one of the 20 most frequently isolated groups for human disease and reported to ECDC in 2015 (EFSA and ECDC, 2016c).…”

“…Moreover, a multicounty outbreak of STEC O26 infection with many cases of HUS, hospitalisations and deaths among young children was reported in Romania and Italy. A contaminated cheese was implicated in the transmission of infection to some but not all outbreak cases (EFSA and ECDC, 2016c).…”