Date: Wed 25 Sep 2019
Source: Food Safety News (FSN) [edited]
A _Salmonella_ outbreak that sickened almost 200 people at a Belgian school was likely caused by eggs used to make a tartar sauce, according to authorities. The Agency for Care and Health (Zorg en Gezondheid) and Federal Agency for the Safety of the Food Chain (FASFC) investigation detected _Salmonella_ in the freshly prepared tartar sauce. Findings from an online survey of students and teachers also reached the same conclusion on the source.
The Agency for Care and Health had previously received information about a number of students from the school complaining of gastrointestinal illness. Since 14 Sep 2019, no new cases of illness have been reported so the Spermalie Hotel and Tourism School in Bruges [West Flanders] has been allowed to resume normal operation. About 200 students and teachers from the school became ill from 6 Sep 2019 onward. Laboratory analyses of stool samples revealed students and teachers had been affected by _Salmonella_.
The Agency for Care and Health handled the online survey part of the investigation, FASFC took samples of meals served on Tuesdays, Wednesdays, and Thursdays at the school restaurant. The samples were sent to the lab of Sciensano, the Belgian Institute for Health. The online survey showed the tartar sauce was the most likely source of the outbreak.
A total of 65 samples were sent to Sciensano and after analysis of the different dishes, _Salmonella_ was detected in the freshly prepared tartar sauce. Bacteria present in the food appeared to be the same as in the stool samples from patients.
Staff and students were asked to pay particular attention to hand hygiene and those sick were encouraged to stay at home. The kitchen of the school restaurant and all kitchens and related equipment have been cleaned and disinfected. The sale of any raw food was also suspended. Control measures have been verified by environmental sampling and no _Salmonella_ has been detected in lab analysis of these samples.
Belgium reported 2698 confirmed salmonellosis cases in 2016 compared to 3050 the year before.
[Tartar sauce (<https://en.m.wikipedia.org/wiki/Tartar_sauce
>) is based on either mayonnaise (egg yolk, mustard or vinegar, bitartrate, oil) or aioli (olive oil, garlic), with certain other ingredients added. In the UK, recipes typically add to the base capers, gherkins, lemon juice, and dill. US recipes may include chopped pickles or prepared green sweet relish, capers, onions (or chives), and fresh parsley. Chopped hard-boiled eggs or olives are sometimes added, as may be Dijon mustard and cocktail onions.
Salmonellosis is often thought to be associated with cracked eggs or eggs dirty with fecal matter, a problem controlled by cleaning procedures implemented in the egg industry. It is clearly the case, however, that most of the salmonellosis outbreaks linked to eggs were associated with uncracked, disinfected grade A eggs, or foods containing such eggs. The undamaged eggs become contaminated during ovulation, and thus were contaminated with the bacteria before the eggshell was formed. To avoid this, uncooked eggs should only be used as an ingredient, if pasteurized. - ProMED Mod.LL]
[HealthMap/ProMED-mail map of Belgium: