martes, 12 de abril de 2016
Multi-country outbreak of Shiga toxin-producing E. coli infection
At least three children died due to hemolytic uremic syndrome
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. In addition, 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. The product was consumed by a 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 multiple strains from a common source or from multiple sources. Multi-strain STEC outbreaks have been reported in the past . Therefore, probably the outbreak is associated to a source contaminated by different strains. The last Romanian case associated with this outbreak had onset of symptoms on 14 March. Recalls were conducted in Romania in March 5 and in Italy in 15 March. Other Member States subsequently undertook recalls. 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 minimize the spread of the infection and investigate possible new cases in a timely manner, Romania, Italy and other Member States that are possibly involved could consider enhancing surveillance for STEC cases.
Further food and environmental studies in suspect premises to identify the vehicle of Multi-country outbreak of infection. Whole genome sequencing (WGS) on isolates will confirm about possible links between cases.