In 2016, HPS received reports of 836 isolates of non-typhoidal Salmonella from people in Scotland – an increase of around 4% on the 803 reported in 2015. This further compares to 717 and 814 reports in 2014 and 2013 respectively (Figure 1).
There were 362 reports of Salmonella Enteritidis in 2016 compared to 315 in 2015. The most commonly reported phage type of S. Enteritidis was PT8, with 138 reports (compared to 102 in 2015). PT8 has remained the most commonly reported phage type in recent years. Reports of PT1 decreased in 2016, with 25 reports compared to 51 reported in the previous year. Reports of PT4 decreased slightly from 21 reports in 2015 to 16 in 2016.
Reports of Salmonella Typhimurium decreased slightly with 128 reports compared to 133 reports in 2015. Reports of Definitive Type 104 decreased (six reports compared to ten in 2015). DT193 remains the most commonly reported type, with numbers again remaining relatively stable (45 reports compared to 50 in 2015 and 45 in 2014).
The rate of Salmonella infection in Scotland was 15.6 per 100,000 population, a slight increase on the rate observed in 2015 (15.0 per 100,000 population) (Map 1). Seven NHS boards observed a decrease in the rate of infection while six NHS boards observed an increase. In most boards however, the fluctuation was slight. The rates and changes in rates in the island NHS boards should be viewed with caution due to the effect of their small population size.
In 2016 there were seven general outbreaks of Salmonella reported to ObSurv (the surveillance system for all general outbreaks of infectious intestinal disease in Scotland).This compares with six in 2015. Five of the outbreaks reported in 2016 were part of UK outbreaks, while one was a continuation of cases associated with contact with reptiles. Information on reducing the risk of Salmonella associated with contact with reptiles is available at https://www.gov.uk/government/publications/salmonella-reducing-infection-from-reptiles. Further information on general outbreaks of infectious intestinal disease will be published in issue 51/25 (27 June 2017).
During 2016, 5296 laboratory reports of Campylobacter were received by HPS. This was a decrease of 968 (15.5%) compared to 2015 when 6262 isolates were reported (Figure 2). This is the second consecutive year in which there has been a decline in reports of Campylobacter, with the reports in 2016 representing a decline of 1340 (20.2%) on the peak of 6636 reports in 2014.
In Scotland the overall rate of Campylobacter was 99.0 per 100,000, compared to 117.1 in 2015 (Map 2). Among the mainland NHS boards rates in 2016 ranged from 69.8 per 100,000 to 135.6 per 100,000. The decline in Campylobacter was observed in all mainland NHS boards compared to the rates in 2015, and in two of the three island NHS boards. Rates and changes in rates in the island boards should to be viewed with caution due to the effect of their small population size.
The incidence of reported Campylobacter infection is not uniform across the population. Rates are higher in children under one year of age compared with older children and young adults and then increase with the highest rates among those 50 years and older (Figure 3). Overall rates are higher among males, with 108.7 per 100,000 compared to 88.9 per 100,000 for females. This higher rate among males was observed in all apart from one age band (35-39 yrs). The greatest difference of 56 per 100,000 was observed among those in the under one year age group where the rates in males was 115 per 100,000 compared to 59 per 100,000 females. The reasons for the higher rates among males are unknown.
Most cases of Campylobacter infection are apparently sporadic with few identified outbreaks. In 2016, no general outbreaks of Campylobacter were reported to ObSurv (the surveillance system for all general outbreaks of infectious intestinal disease in Scotland). Likewise no general outbreaks had been reported in 2015 and one small general outbreak in 2014. Since ObSurv was established in 1996 there have been a total of 35 general outbreaks of Campylobacter reported.