At least 13 people have been poisoned by salmonella in Spain after consuming domestically produced eggs that were part of a batch also distributed in Portugal and which has already been withdrawn from the market. Spanish authorities communicated this in an alert issued last Thursday, October 8th, to the European Union’s Rapid Alert System for Food and Feed (RASFF).
The bacterium causing the outbreak is Salmonella Enteritidis, and the European food safety network has classified the incident as “grave”, the most significant of the four categories into which an alert on the RASFF network can be classified. The other three are “not grave”, “indeterminate” and “no risk”.
The Spanish Agency for Food Safety and Nutrition (AESAN) has not offered further details about the case for now. The severity of the affected individuals, the quantity of eggs withdrawn and the areas where they were distributed have not been made public either. In fact, the food poisoning does not even appear on the agency’s alert page, which occurs when the agency considers that the product causing the poisoning no longer poses a risk to the public because the measures adopted — in this case, the withdrawal of the affected batch from the market — are sufficient to prevent new cases.
Salmonellosis, which is the name of the infection caused by this pathogen, presents with clinical symptoms that begin suddenly after an incubation period ranging from six to 72 hours. It causes diarrhoea, abdominal pain, nausea and repeated vomiting, in addition to fever and intense malaise. In the vast majority of healthy individuals, the process resolves without major complications in a few days, although in elderly people or those with underlying pathologies, complications can be serious and even fatal.
Salmonella outbreaks are a recurring problem in the food chain in both Europe and the United States, where authorities withdrew some 19 million eggs last July following the salmonella poisoning of around a hundred people, about thirty of whom required hospitalisation. The last major outbreak experienced in the EU occurred in Belgium in May and affected 200 people.
The complexity of preventing these outbreaks for the food industry lies in the very biology of the bacterium and the concentration of animals on farms. Laying hens can become infected with the pathogen via various routes — feed, water, wildlife — and then be asymptomatic carriers, contaminating eggs through vertical transmission (the bacterium infects the bird’s ovary and infects the egg before the shell forms) or horizontal transmission, which occurs when their own faeces contaminate the egg during laying.
Although biosecurity measures, hygienic control and the vaccination of birds have significantly reduced the number of outbreaks in Europe and the developed world, the high density of birds in farming operations and the high environmental resistance of Salmonella Enteritidis bacteria mean that community poisonings still continue to occur.
