Human Salmonella Isolates, 2016 No. 4, April

The number of isolates (n=123) confirmed this month showed an increase in comparison to the number of isolates confirmed in April 2015 (n=112). Salmonella Stanley (0.0% in April 2015 vs 12.2% in April 2016) was the most common serotype confirmed this month. Uncommon serotypes confirmed this month included S. Typhimurium phage type 179 (1 human case since it was first confirmed in New Zealand in 2013).

Ongoing Increase in Salmonella Stanley in Tairawhiti DHB (Source: EpiSurv, Tairawhiti DHB)
· A further 14 cases of S. Stanley (including one case from Bay of Plenty who had travelled to Gisborne) linked to the outbreak were confirmed this month, bringing the total of cases confirmed since February 2016 to 25.
· Ten cases were known to have consumed food from the same food business.
· Pulsed-Field Gel Electrophoresis (PFGE) was performed on isolates from recent cases. The results showed the cases to have an indistinguishable PFGE profile.