Inverse trends of Campylobacter and Salmonella in Swiss surveillance data, 1988–2013

Abstract

Clinical isolates of Campylobacter spp. and Salmonella spp. are notifiable in Switzerland. In 1995, Campylobacter replaced Salmonella as the most frequently reported food-borne pathogen. We analysed notification data (1988-2013) for these two bacterial, gastrointestinal pathogens of public health importance in Switzerland. Notification rates were calculated using data for the average resident population. Between 1988 and 2013, notified campylobacteriosis cases doubled from 3,127 to 7,499, while Salmonella case notifications decreased, from 4,291 to 1,267. Case notifications for both pathogens peaked during summer months. Campylobacter infections showed a distinct winter peak, particularly in the 2011/12, 2012/13 and 2013/14 winter seasons. Campylobacter case notifications showed more frequent infection in males than females in all but 20-24 year-olds. Among reported cases, patients' average age increased for campylobacteriosis but not for salmonellosis. The inverse trends observed in case notifications for the two pathogens indicate an increase in campylobacteriosis cases. It appears unlikely that changes in patients' health-seeking or physicians' testing behaviour would affect Campylobacter and Salmonella case notifications differently. The implementation of legal microbiological criteria for foodstuff was likely an effective means of controlling human salmonellosis. Such criteria should be decreed for Campylobacter, creating incentives for producers to lower Campylobacter prevalence in poultry.

Acute Gastroenteritis and Campylobacteriosis in Swiss Primary Care: The Viewpoint of General Practitioners

“…in the last 20 years. This is confirmed by the trends of campylobacteriosis and salmonellosis case numbers reported to the NNSID [11]. Similar trends in notification rates were observed in the EU [10] e.g.…”

“…[14, 17]. NNSID data also support GPs’ impressions that young adults and middle-aged people are more frequently affected [11]. More prevalent exposure risks among these groups, such as traveling abroad, eating out and preparing food themselves, as stated by GPs, could be responsible for increased case numbers.…”

“…Over the last decade notification rates for campylobacteriosis had not only steadily increased between 2005 and 2012 but also weekly notification rates peaked annually at the turn of the year. In 2011/2012 weekly notifications increased extraordinarily twofold compared to the previous and following weeks [11]. In concert with the general epidemiological trend this situation was categorised as an epidemic threat by the Federal Government.…”

“…Among these, the most frequently notified IID in Switzerland is campylobacteriosis. Since 2006, a dramatic increase in case notifications has been observed, with an all-time high of almost 8,500 notified cases in 2012 [11]. Increasing trends in case notifications were also observed in the European Union (EU) [10] e.g.…”

Dynamics of Salmonella Shedding and Welfare of Hens in Free-Range Egg Production Systems

“…Our previous study also indicated high Salmonella counts in feces in summer, with S. Typhimurium phage type 9 as a predominant serovar (18). Human gastrointestinal infections with Salmonella have been positively correlated with warmer temperatures (35,36), as warmer temperatures can enhance the replication of bacteria. In this study, S. Typhimurium was detected in environmental samples and egg shell wash.…”