A European court has ruled as part of a Dutch case involving Salmonella detection in poultry and when repeat testing can be undertaken.

The request for a preliminary ruling covered the interpretation of EU law around Salmonella, exceptional cases, and routine sampling. It was made in proceedings between L. Vof and the Minister for Agriculture, Nature, and Food Quality in the Netherlands.

L. Hof operates a poultry breeding farm in the Netherlands with a flock of 27,000 hens. On Feb. 10, 2020, Hof took samples from the five houses where that flock was located as part of routine sampling. On Feb. 17, an accredited laboratory detected Salmonella in samples of the left boot swabs of three of those houses.

Following the positive results, Dutch authorities declared the three houses infected with Salmonella and imposed control measures. Removing poultry, eggs, and poultry droppings from the infected houses and taking poultry and eggs into them was prohibited. The poultry and eggs in the houses had to be removed or destroyed in a manner set by the Dutch Food and Consumer Product Safety Authority (NVWA). Those measures were implemented on Feb. 28, 2020.

Testing process change
The initial decision was adopted without a confirmatory test being carried out since Dutch authorities considered there was no reasonable doubt in the accuracy of the result.

Until January 2020, after a positive result, a confirmation test based on which the flock was declared infected or not was always carried out.

However, in January 2020, the European Commission said the standard confirmatory test was contrary to EU law and would stop co-financing the Netherlands’ plan to combat Salmonella. Later that month, the Netherlands informed the Commission that it accepted this position and adapted its control policy. This means a confirmatory test can only be carried out where the positive result of the control sample is considered unreliable.

Following the rejection of the objection lodged by Hof against the initial decision, an action was brought before the referring court, the College van Beroep voor het bedrijfsleven (Supreme Administrative Court for Trade and Industry). The Dutch court asked the EU Court of Justice what constitutes an exceptional case in the regulation and what factors are relevant in defining such a case.

Hof claims there were reasons which enabled the authority to call into question the positives from routine sampling carried out in February 2020 and to carry out a confirmatory test before adopting the initial decision. Dutch authorities believe the incident does not represent an exceptional case.

Considerations for Exceptional Case
Hof cited several factors in support of this argument, including the negative result of several subsequent tests carried out on samples taken on Feb. 18, 2020, and the flock being young and vaccinated against Salmonella. Samples were also taken every two weeks in the holding concerned and no other positive was obtained either before or after the routine sampling.

The EU court said it was for the relevant authority to assess whether there are factors capable of casting doubt on test results. Such an assessment must be made on a case-by-case basis, taking into account the circumstances of each incident.

Negative results need to be sent to the authority before a decision has been adopted to be considered in the decision to declare an exceptional case.

The fact that only one of two samples taken in routine sampling was positive for Salmonella does not support the conclusion that there is a serious risk that the sampling or analysis was wrong. Also, according to the court, the finding that certain houses have a positive result and others are negative is not a relevant factor for showing sampling processes were incorrect. 

Vaccination status of the flock and history of Salmonella prevalence at the holding are relevant when considering if cases are exceptional. However, they do not mean the positive finding was wrong.

The case will now go back to the referring court in the Netherlands.

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