More than 130 people died due to Salmonella infection in Europe in 2016, according to a report from the European Centre for Disease Prevention and Control (ECDC).
Salmonellosis is the second most commonly reported gastrointestinal infection and 95,326 laboratory-confirmed cases were reported in 2016 and 134 were fatal. Notification rates have stabilized in the last five years after a long period marked by a declining trend.
For 2016, 30 countries reported 96,835 cases, of which 95,326 were confirmed. Of 52,878 cases with known outcome, 134 were reported to have died, giving a case fatality of 0.25 percent. In Cyprus, Greece, Portugal, and Romania, the proportion of hospitalized cases were very high at 74 to 88 percent.
The highest notification rates were in the Czech Republic and Slovakia, followed by Hungary and Lithuania while the lowest was in Portugal. The largest increase from 2015 to 2016 was in Estonia and Greece. The rise in Estonia could be attributed to two outbreaks, one of which was due to person-to-person transmission. Greece has been trying to increase the reporting of cases in recent years.
The largest proportion of travel-related cases were recorded by Finland, Norway, and Sweden. Among the 8,337 travel-associated cases with information on probable country of infection, Thailand, Turkey, and India were most frequently noted followed by Spain and Greece.
Numbers of reported cases were fairly constant from 2012 to 2016. Statistically significant increasing trends were observed in Greece, Malta, Poland, Portugal, Romania, Slovakia, and Spain, with decreasing trends in Denmark, Finland, Germany, Norway, and Sweden.
The highest notification rate was among young children aged 0 to four years. This was almost three times higher than in older children and seven times as high as adults 25 to 64 years. In some countries, the rate among young children was much higher than that for adults 25 to 44 years: Bulgaria (28 times), Cyprus (62 times), Greece (34 times), Italy (29 times), Latvia (34 times) and Portugal (34 times).
“The fact that the salmonellosis rate in young children is seven times higher compared with adults may be explained by a higher proportion of symptomatic infections among young children, an increased likelihood for parents to take children to see a doctor and for doctors to take samples,” according to the report.
Salmonella was the most common cause of foodborne outbreaks, accounting for 22 percent of all reported outbreaks (1,067). Eggs and egg products continued to be the most commonly identified vehicles and were also the source in a large multi-country outbreak linked to Poland.
An outbreak of Salmonella Enteritidis involving 14 countries associated with contaminated eggs from Poland was confirmed by epidemiological, microbiological and whole genome sequencing analysis in 2016. A total of 218 cases were confirmed by WGS and 252 probable infections by multiple-locus variable-number tandem repeat analysis (MLVA). Cases increased again after February 2017, with a peak in September 2017.
In 2016, Poland had 26 breeding flocks of Gallus gallus (1.4 percent) and 169 laying hen flocks (7.2 percent) positive for Salmonella Enteritidis, which was the highest proportion of positive flocks in the EU.
“Proper Salmonella control measures at the primary production level and sufficient laboratory capacity is a prerequisite to reducing Salmonella prevalence in food-producing animals,” said ECDC.
“As stated by EFSA, premature relaxation of effective control measures implemented to date in laying hen farms, in particular, the implementation of vaccination programs and the application of strict farm hygiene controls, should be avoided.”
Salmonella Typhi and Paratyphi stats
Meanwhile, from 2014 to 2018, Salmonella Typhi and Salmonella Paratyphi remained stable and only a few people became infected in Denmark, according to the Statens Serum Institut.
A total of 119 cases of typhoid and paratyphoid fever were recorded and the annual number remained below 30. Infection with both bacteria is mainly due to ingestion of food or water contaminated with feces from people who are Salmonella Typhi or Salmonella Paratyphi carriers.
The share of patients who became infected during travels abroad is 95 percent and less than 10 people were presumably infected in Denmark. Between one third and up to half of those infected abroad had presumably been to Pakistan or India. An increase in Paratyphi B infections in 2017 was due to patients with closely related types who had traveled to Bolivia.
Among recorded Salmonella Typhi and Salmonella Paratyphi A and B cases, 55 percent were women and the frequency of notifications was higher among young persons, particularly 16 to 20-year-olds.
Introduction in 2017 of whole-genome sequencing for samples submitted to the National Salmonella Laboratory Monitoring Initiative made it possible to identify patients who became infected with the same type of bacteria, and presumably the same source and probably in the same country.
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