The Estonian Health Board (Terviseamet) has detected a second strain of listeria bacteria, following an original strain which had been traced to the M.V.Wool fish plant. The latest strain is not related to the variety traced to M.V.Wool, it is reported.
According to a report on ETV current affairs show Aktuaalne kaamera (link in Estonian) the latest strain detected, termed ST87, has caused 40 cases of listeria and six deaths Europe-wide, along with the ST1247 strain already found, which caused nine cases and three more deaths. Two of the latter deaths were reportedly in Estonia.
An actual food product match for the ST87 strain is still being searched for, meaning it cannot be linked directly to M.V. Wool, according to the report.
"It is certain that this strain can be found nationwide in Estonia and not just at one factory or in one product," said Irja Lutsar, professor of medial microbiology at the University of Tartu.
"I believe that the factory (i.e. M.V.Wool-ed.) is now clear, but this does not mean that the strain has disappeared from Estonia as a whole," she continued.
"The S87 strain is not one which has existed before. In Spain and Germany, outbreaks of this type of sequence have also been found to possibly be common in the environment and occurring in several foods, and not necessarily in one location," Professor Lutsar continued.
Lutsar added that finding food matches is not easy, noting tha while the latest strain need not come from the M.V.Wool plant, the fact that a strain had been found there should not be minimized.
M.V.Wool wrong to minimize listeria strains risk
Mati and Meelis Vetevool, board members at M.V.Wool, said the report states that the listeria strain found at their plant belongs to a less dangerous category than the more virulent strains, a claim which they based on a report from the Institute of Genomics at the University of Tartu.
However, the institute itself says that the Vetevools had not given the most accurate interpretation of their report.
"It's still a rather arbitrary interpretation because actually both … strains are dangerous. In essence, it doesn't really make any difference as all strains are equally dangerous, especially the strains mentioned. You can't say that one is more or less dangerous than another," said Reedik Mägi, Senior Research Scientist in Bioinformatics at the institute.
Last week, the Estonian Veterinary and Food Board (VTA) made an injunction to M.V.Wool's production unit as well as to a company, OÜ Peetsman, following the detection of the original strain of listeria.
M.V.Wool also announced that its expiry dates for cold-smoked and salted fish products from 30 days, to 24 days, and the company also halted production at the Harku plant to fully sterilze its facilities.
*Please note an earlier version of this story stated erroneously that the recent strain found by the Health board, ST87, had been linked to M.V.Wool. In fact, no concrete link has been made to any food product or producer.
Editor: Andrew Whyte