Seven different brands of infant formula from Lactalis in France have been identified as the vehicles of Salmonella Agona infection.
It has affected 39 infants: 37 in France, one in Spain confirmed by whole genome sequencing (WGS) and one probable case in Greece based on the rare biochemical characteristic of the isolate.
The first case was retrospectively identified with illness onset in April and the last was in early December. Families of 36 infants have been interviewed and 18 were hospitalised but have now recovered.
Cases in other countries likely not part of outbreak
France found the outbreak strain had different biochemical characteristics and contrary to most Salmonella populations did not produce hydrogen sulfide (H2S) and gas after 18 hours incubation on Kligler-Hajna media.
Belgium (four), Germany (two), Greece (one), Norway (one), Spain (two) and Sweden (one) reported S. Agona in 2017 in infants or young children in response to a notice from France.
Scotland reported two infant cases of S. Agona with onset of symptoms in March and April but WGS comparative analysis showed they are not linked to the outbreak in France.
Public Health England (PHE) had a small increase in S. Agona in children up to one year during 2017. However, the nearest isolate in the PHE database is 39 single nucleotide polymorphisms (SNPs) away from the sequence provided by France.
No isolates from Belgium, Germany, Norway and Sweden had the biochemical trait.
ECDC said it was ‘very unlikely’ cases from these countries were part of the outbreak and no further analysis of the isolates is expected.
The ECDC and EFSA said most involved batches have not passed their expiry date.
“However, broad withdrawal and/or recall measures, export bans and a suspension of market distribution of these batches…are likely to significantly reduce the risk of human infection. The possibility remains, however, that new cases may be detected.”
Multi-country WGS analysis, including sequences of human isolates from France and other EU countries, is being done by the Institut Pasteur.
Comparison with 2005 incident
Lactalis was linked to a S. Agona outbreak in 2005 which sickened 141 people. However, unlike current outbreak strains, isolates from 2005 did produce H2S and gas after 18 hours of incubation.
Comparison of human and environmental isolates from 2005 with those from the current outbreak is ongoing and may confirm relatedness of the outbreaks and possibly help identify weaknesses in the production process, said ECDC and EFSA.
“The fact that the current outbreak involves the same serotype as the previous outbreak raises the question whether the organism has persisted in the facility for 12 years,” said Nathalie Jourdan-da Silva et al in Eurosurveillance.
During the 2005 outbreak, only one of 176 and four of 27 samples from the two implicated food products and six of 420 environmental samples tested positive suggesting low level contamination.
S. Agona is the tenth most commonly reported Salmonella serotype in the EU/EEA. In 2012-16, 26 countries reported an annual number of cases ranging from 400 to 581.
French recall system scrutiny
Meanwhile, Bruno Le Maire, French Minister for the Economy, has called on a group to draft plans by the end of April on how to reinforce effectiveness of withdrawal-recall procedures and help transfer of information to consumers.
The Conseil National de la Consommation (CNC) is within the Ministre chargé de la consummation for debate on matters relating to consumption between representatives of consumer protection associations and professional organizations.
Le Maire said it is important for all parts of the supply chain to take responsibility.
“The role of the state is to control. The role of manufacturers is to never put into circulation products that are not safe. The role of distributors and all those who market products is to remove them when there is a withdrawal or recall.”
French police raided the headquarters of Lactalis in Laval and its factory in Craon earlier this week, according to AFP.
It emerged last week that retailers had sold items that should have been removed from shelves.
The Direction générale de la concurrence, de la consommation et de la répression des fraudes (DGCCRF) made 2,500 checks in the distribution chain and found batches of infant milk that should have been withdrawn.
No Salmonella but Cronobacter found
Lactalis Nutrition Santé recalled over 600 batches (more than 7,000 tonnes) of products manufactured at a site in Craon from 15 February 2017.
The World Health Organization (WHO) has informed individually all affected countries with details of quantities, lot numbers and importers in each country.
More than 12 million boxes have been recalled in 83 countries including 13 in the EU: Belgium, Bulgaria, Cyprus, Czech Republic, France, Greece, Ireland, Netherlands, Romania, Slovenia, Slovakia, Spain and UK.
No positive results for Salmonella have been detected in the products but presence of Cronobacter spp. was found in the final product distributed to the Netherlands.
Eric Andrieu and Guillaume Balas (Social Democrat MEPs) asked the European Commission about potential economic consequences for the dairy sector and if it had received a request from France to provide support due to the market disturbance. The Commission has three weeks to reply.