ECDC Surveillance Report on Salmonellosis Highlights SE from Polish Flocks


The Annual Surveillance Report for 2016 prepared by the European Center for Disease Prevention and Control (ECDC) documents data from 30 EU and EA nations.  A total of 95,326 cases of salmonellosis were confirmed during 2016 yielding an incidence rate of 20.4 cases per 100,000 population.  The rate varied widely among reporting nations with the highest from the Czech Republic at 110 per 100,000. Within the EU, the Southern European nations, Portugal (3.6 per 100,000), Italy and Greece (both 7.0 per 100,000) apparently were the lowest in incidence rate. This may not represent a low rate of exposure but rather indicates deficiencies in diagnosis, reporting and maintaining accurate databases.  Nordic countries reported that a high proportion of their cases were acquired during travel to Southern Europe, Thailand, Turkey and India. 


Among the thirty reporting nations, salmonellosis was clearly related to improved diagnosis applying both PCR and more recently multiple-locus variable-number tandem repeat analysis (MLVA) introduced in 2016. 



Subsequent to the recognition that eggs from Poland were a source of infection, epidemiologic surveys demonstrated that 1.4 percent of breeding flocks were infected and that 7.2 percent of laying flocks comprising 169 farms were infected with S. Enteritidis.  Following control measures applied by authorities in Poland and restricting distribution of potentially contaminated eggs, the incidence rate in the EU declined within months.


Salmonella Enteritidis Phage Type 8 was identified in 2016 associated with exposure to pet reptiles and feeder mice. Over 275 cases were identified in the UK and the outbreak apparently persisted for a number of years prior to surveillance in 2016.


The annual Epidemiologic Report concluded that egg and egg products persist as high risk factor for Salmonella outbreaks.  Premature relaxation of control measures against SE especially in Poland were cited as possible reason for the upsurge in a previously controlled disease.  The report stressed the need for vaccination and biosecurity presuming that commercial chicks are hatched from flock free of vertically transmission infection. The need to cook eggs to 165F is a meaningful preventive measure given that consumption of raw and under-cooked eggs is more prevalent in the EU compared to the U.S.

ECDCP in Solna, Sweden