An assessment by two European agencies of a Salmonella outbreak with more than 30 cases has found the common source is three rice-based infant formula products from one brand.

The European Food Safety Authority (EFSA) and European Centre for Disease Prevention and Control (ECDC) report said products were made in a factory in Spain between August and October 2018 and marketed by a French company.

While the EU agencies did not name the companies involved, Food Safety News has  reported the products were made at the Industrias Lacteas Asturianas SA (ILAS) factory in Anleo, a municipality in the Spanish province of Asturias. The company previously sent us a statement on the incident.

The implicated factory is the same one that was linked in 2010 and 2011 to an outbreak of Salmonella Poona in Spain that sickened almost 300 infants who drank powdered milk. Strains in the two outbreaks are genetically related.

Cases in three countries; product sent to more than 20

Modilac brand milk formula is the outbreak source. Sodilac markets these items and issued a recall in late January. Products were distributed to French wholesalers, retailers and pharmacies who sold them to several other countries through wholesalers, online shops or Amazon. They were sent to more than 20 countries.

Information from interviews was available for 30 patients. All consumed one of three Modilac rice-based infant formula products before onset of symptoms. French patients live in at least 11 different regions. For the 30 cases wher information is available, 14 were hospitalized.

A total of 32 confirmed cases have been reported: 30 in France and one each in Belgium and Luxembourg. All patients experienced symptoms between August 2018 and February 2019.

One suspected case was identified in Belgium but it has not been possible to confirm through sequencing that it was a part of the same outbreak. Sequencing results are pending from the Czech Republic but cases are not known to have consumed the implicated infant formula.

Andorra, Denmark, Ecuador, Germany, Italy, Libya, Mexico, Morocco, Netherlands, Norway, Peru, Portugal, Romania, Saudi Arabia, Switzerland, Syria, Tunisia, United Arab Emirates, United Kingdom and Vietnam also received the infant formula but have not reported illnesses.

All tests on samples of implicated batches have been negative for Salmonella Poona. The pathogen has not been detected in the production environment of ILAS or in any other product dehydrated in the same drying tower since 2017.

This may be because Salmonella is typically difficult to detect in dried products and requires sampling and testing methods with a high degree of sensitivity, according to EFSA and ECDC. They added sensitivity of the sampling procedures and analytical method for this food warrants further evaluation.

ECDC is funding whole genome sequencing (WGS) analysis of human Salmonella Poona isolates from cases related to the outbreak in countries that do not routinely perform WGS.

Cases of salmonellosis in infants should be notified to national health authorities for serotyping. Salmonella Poona isolates should be sequenced to identify if they are associated with the outbreak, added the agency.

The European unio Reference Laboratory for Salmonella is supporting member states that do not have capacity to perform WGS analysis of non-human isolates possibly related to the outbreak strain.

Negative product and environmental results

The EFSA and ECDC assessment revealed Sodilac receives products from ILAS and they do not undergo any processing. The French company gets finished products at their logistics service center ready to be placed on the market.

“based on a commercial agreement preceding the current event between [Sodilac] and [ILAS], final products undergo testing for Salmonella in both companies (i.e. 30 cans from each batch are sampled in respective labs). At [Sodilac] no positive results for Salmonella were detected in the tests performed on the seven incriminated batches before their release to the market.

“The analyses were performed within a week of the production date of each batch on sealed packages of final products received from [ILAS]. From 11 Jan. to 4 Feb. 2019, [Sodilac] commissioned additional analyses for Salmonella on open and sealed cans from the seven incriminated batches: the results of all tests were negative.”

Between 22 Jan. and 11 Feb. this year, French authorities analyzed multiple samples of infant formula from opened and/or sealed cans, provided by parents of the infants but results were negative for Salmonella. The official laboratory of Asturias also analyzed product samples with negative results.

The manufacturing lines on which ILAS processed infant formula include three drying towers with different capacities, two can packaging lines for processing of different can sizes and one packaging line for bags. The two can packaging lines have a sanitization system using UV. Production lines are washed once per month.

In January, ILAS ceased operations in drying tower 2 wher suspected products had been dehydrated. This is the same tower that was involved in the 2010-11 outbreak. ILAS performed tests to detect Salmonella on 498 environmental samples taken at the premises of tower 2 and 336 samples from the packaging facilities with negative results.

In February, the Spanish Agency for Consumer Affairs, Food Safety and Nutrition (AECOSAN) issued a public warning concerning all infant formula products based on rice dried in tower 2 at ILAS since the start of 2017 with Laboratorios Ordesa S.A. recalling rice milk formula.