Substantial increase in listeriosis, Denmark 2009

Abstract

In 2009, 97 cases of listeriosis were reported in Denmark (1.8 per 100,000), a significant rise over the previous year. The increase was seen both in cases of bacteraemia and meningitis and affected mainly people aged 70 years and older. A foodborne outbreak of eight cases was identified by pulsed-field gel electrophoresis typing. No explanation has so far been found for the marked increase in incidence. An increasing trend has been observed since 2003 and possible explanations are discussed.