A team of investigators from the US Centers for Disease Control and Prevention (CDC) have published a report of their investigation into a multistate outbreak of Salmonella Newport infection that was identified in August 2014.
The outbreak affected at least 275 people in 29 states and the District of Columbia between May and September. A high proportion of cases (34%) required hospital treatment and one related death was also reported.
Characterisation of the outbreak strain of Salmonella Newport by pulsed-field gel electrophoresis (PFGE) showed it to be indistinguishable from a strain that had caused previous outbreaks. These earlier outbreaks were linked to consumption of tomatoes grown in the Delmarva region of the state of Virginia.
The investigation therefore focused on salad vegetables grown in this region, but epidemiological, microbiological and product traceback evidence suggested a link with cucumbers, rather than tomatoes, grown in Delmarva.
The authors of the report state that their investigation into the outbreak suggests an environmental reservoir for this strain of Salmonella in the Delmarva region, although faecal samples taken from wildlife in the area have tested negative. Identification of the reservoir could help to prevent future outbreaks.
The report is published in the CDC journal Morbidity and Mortality Weekly Report (MMWR) and can be found in full here.