Human Salmonella Isolates, 2016 No. 1, January

The number of isolates (n=128) confirmed this month showed a decrease in comparison to the number of isolates confirmed in January 2015 (n=160). Salmonella Typhimurium phage type 9 (2.5% in January 2015 vs 11.7% in January 2016) was the most common serotype confirmed this month. Uncommon serotypes confirmed this month included S. Eastbourne (14 human cases since it was first confirmed in New Zealand in 1990), S. Mana (1 human case since it was first confirmed in New Zealand in 2007), and S. Onderstepoort (3 human cases since it was first confirmed in New Zealand in 2008).

Increase in S. Typhimurium phage type 9 notifications November 2015 to Feb 2016 (Source: EpiSurv, ERL)

• From 01 November 2015 to 31 January 2016 there have been 18 notifications of S. Typhimurium phage type 9 in New Zealand. This is a significant increase when compared to the same period in previous years (7 in 2014/2015, 5 in 2013/2014).
• Cases have been reported from the following DHBs: Tairawhiti 6 (1 in 2014/2015 and 1 in 2013/2014), Southern 5 (0 in 2014/2015 and 2 in 2013/2014), Auckland and Hawkes Bay (2 cases each 2015/2016) Bay of Plenty, MidCentral and Capital and Coast (1 case each 2015/2016).
• 6 cases (37.5%) were hospitalised (16 had a known hospitalisation history).
• The most common risk factors recorded in EpiSurv (as at 1400 hours 02/02/2016) were consumption of untreated water (41.7%, 5/12 cases), contact with faecal matter (41.7%, 5/12), eating food from a food premise (38.5%, 5/13 cases), contact with farm animals (23.1%, 3/13 cases) and recreational water contact (25.0%, 3/12 cases).
  • The ERL has confirmed this phage type in isolates from bovine, ovine, food (not specified) and poultry environment sources previously.