Eggs from Bavaria linked to a Salmonella outbreak that has sickened hundreds of people are believed to be no longer on the market, according to a joint EU report.

The contaminated product has led to illnesses in Austria, France, Germany, Luxembourg and the UK.

Despite strict regulations applying to eggs for human consumption and the success in reducing infections, Salmonella Enteritidis-contaminated eggs have been able to reach the market, said the European Centre for Disease Prevention and Control (ECDC) and European Food Safety Authority (EFSA
).

The eggs found to be contaminated are supposedly no longer on the market and their shelf life has probably expired.

However, due to the delay in case reporting, it is possible that more cases will be notified.

Linked between cases

Sporadic or outbreak cases of S. Enteritidis reported by Austria, France, Germany and the UK, in addition to one case reported in Luxembourg in a patient residing in France, appear to be linked by time of symptom onset and microbiological characteristics of isolates, said the report.

Cases in Austria, France and Germany share an epidemiological link to the same egg packaging centre in southern Germany.

Isolates from contaminated eggs identified in France originating from the implicated German egg packaging centre share similar molecular characteristics to the human cases.

Isolates from a sample of a Salmonella-contaminated strawberry cake, found in Germany through an investigation unrelated to this outbreak, also share similar molecular characteristics.

To date it is unclear whether eggs from the implicated Bavarian packaging centre were used for the preparation.

Outbreak reporting

The French Institute for Public Health Surveillance (INVS) reported six outbreaks of S. Enteritidis involving 45 cases (16 confirmed) in eastern France, between 23 June and 21 July.

The Federal Ministry of Health in Austria revaled a cluster of S. Enteritidis phage type (PT) 14b illnesses occurring since 14 June in the province of Tyrol involving 61 cases (27 confirmed).

The National Reference Centre at the Robert Koch Institute (RKI) in Germany reported 24 human isolates of S. Enteritidis PT14b since June, 17 of which have come from the state of Bavaria.

Public Health England (PHE) told local and regional outbreaks of S. Enteritidis PT14b, primarily linked to restaurants and takeaways at different locations, with 247 notified cases
.

Additional microbiological and environmental investigations could strengthen evidence to support or discard the hypothesis of all cases being part of the same outbreak, and being infected after eating the same food.

This is particularly unclear with regard to the outbreak cases in the UK, said the report.

ECDC said it will continue to closely monitor the occurrence of human cases through the Epidemic Intelligence Information System for Food- and Waterborne Diseases and Zoonoses (EPIS-FWD) and Member States could consider enhancing surveillance activities for this Salmonella serovar and specifically for the phage type 14b.

S. Enteritidis accounted for 179 outbreaks and 2,177 human cases (37.6% of all cases in Salmonella outbreaks) in 2012.

Most of these S. Enteritidis outbreaks were attributed to eggs and egg products.

In the same year, egg and egg products were implicated in 168 outbreaks (22%) out of 763 reported at EU level, of which 93.5 % were caused by Salmonella spp.