False salmonella test result at organic chicken farm in Kuorttinen confirmed as laboratory error

An incident involving a false salmonella test result at the organic chicken farm in Kuorttinen, Lappeenranta, has been clarified. According to local news outlet MTV Uutiset, the farm was informed last May that salmonella bacteria were found in a sample taken for internal control. However, it has been confirmed that no salmonella was present; the issue was a laboratory error.

The farm reported suffering millions in losses as over 4,000 chickens had to be unnecessarily culled due to the erroneous test result. The contamination originated from a salmonella reference sample at Eurofins Scientific Finland oy’s laboratory in Helsinki, which polluted the farm’s sample during processing.

Eurofins has submitted a report to the Finnish Food Agency outlining the sequence of events. The investigation revealed that the salmonella bacteria from the reference sample mixed with the organic farm’s sample while they were being handled within the same biosafety cabinet. The contamination could have occurred through droplets, an employee’s hands, or the work surface.

The laboratory suspects that contamination happened when the reference sample bag was opened or during the simultaneous handling of both samples. The reference sample was pipetted into test tubes within the biosafety cabinet, where droplets may have been released into the environment. Later that same day, as the chicken farm’s sample was opened in the same cabinet, it may have become contaminated. The organic farm’s sample was also stored in the cabinet alongside the salmonella reference sample.

In light of this event, Eurofins Scientific Finland oy plans to revise its testing protocols for reference studies.