Public health agencies have reported an ongoing outbreak of foodborne Listeria monocytogenes infections in Ancona province in central Italy. The source of the outbreak has not yet been clearly identified.
In the first seven weeks of 2016, five Listeria monocytogenes serotype 1/2a strains were isolated from six patients with invasive listeriosis in Ancona province. Genetic comparison between these and six further serotype 1/2a strains isolated from patients in 2015 showed a clonal relationship, suggesting that they were part of the same outbreak. Most of those affected were elderly and suffering from underlying health problems.
It is suggested that the outbreak began in Ancona in 2015 and is ongoing. An investigation to identify the source of contamination and the food vehicle involved in the outbreak is under way. Initial findings suggest that a contaminated pork product could be associated with at least one of the reported cases, but this has not been confirmed and no clear link has been established.
A report of the outbreak is published in the journal Eurosurveillance and can be found here.