Human salmonella isolates 2017

Annual summary 2017

The number of Salmonella isolates confirmed this year (n=1217) showed an increase in comparison with 2016 (n= 1150). Salmonella Typhimurium phage type 56 variant was the predominant serotype, representing 9.6% of total isolates (5.6% in 2015).

Significant outbreaks and clusters:

An outbreak of Typhoid fever in Auckland in March-April 2017 (Source: Health Intelligence Team, Auckland Regional Public Health Service, EpiSurv, ERL)

• Auckland Regional Public Health Service is currently managing a large typhoid outbreak. To date, all cases in this outbreak are connected to the same church group, the Mt Albert Samoan Assembly of God church which met at a school hall in Mt Roskill. As at 0900 hours 26 April 2017 there are 23 cases (22 confirmed and 1 probable) linked to the outbreak. No change from last week’s update.
• The most recent onset date is 01 April 2017 (no change).
• Cases range in age from 12 months to 78 years old and are evenly distributed by sex.
• 19 of the confirmed cases and the 1 probable case have been hospitalised at some time for this illness. There are no cases remaining in hospital. There has been one death.
• ARPHS is continuing to follow-up 67 contacts, 9 contacts were identified as high risk (8 are food handlers and 1 attends an ECEC). All high risk cases and contacts have been excluded from work / ECEC pending faecal clearance. All contacts are being asked to provide at least 1 faecal specimen for clearance (2 for high risk contacts). 7 high risk contacts have been cleared, to date. Since last week’s update no new contacts have tested positive for S. Typhi.
• ARPHS has established a landing page on its website where all media updates and information is located: http://www.arphs.govt.nz/typhoid-response

Outbreak of Salmonella Paratyphi A in Hawke’s Bay potentially linked to mussels collected from Napier Marina September-October 2017 (Source: Health Intelligence Team, EpiSurv, Hawke’s Bay DHB, Auckland Regional Public Health Service, ERL, ESR Public Health Laboratory)

• Hawke’s Bay PHU is investigating an outbreak of S. Paratyphi A (Ciprofloxacin sensitive) linked to non-commercially gathered shellfish from Napier/Ahuriri harbour.

• The number of confirmed cases remains at 10 (including one from Auckland), no change from last week. There are 4 probable cases and 3 are currently under investigation.
• The onset date for the most recent confirmed case is 25 September 2017.
• Mussels from 5 locations around Ahuriri harbour collected on the weekend of 23/24^th September showed faecal contamination (presence of E. coli, norovirus (GI and GII) and Salmonella Typhimurium). Further testing will be conducted on mussels and water from the affected areas to determine if there is an ongoing contamination issue in the area.