Human Salmonella isolates, 2017 No.4, April

The number of isolates (n=122) confirmed this month showed an increase in comparison to the number of isolates confirmed in April 2016 (n=123). Salmonella Typhi phage type E1a (2.4% in April 2016 vs 16.4% in April 2017) was the most common serotype confirmed this month. Uncommon serotypes confirmed this month included S Typhimurium phage type 99 (4 human cases since it was first confirmed in New Zealand in 2011).

An outbreak of Typhoid fever in Auckland (Source: Auckland Regional Public Health Service (ARPHS), 1350 hours 19 April 2017)

· 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 1350 hours 19 April 2017 there are 23 cases (22 confirmed and 1 probable) linked to the outbreak.

· The most recent onset date is 01 April 2017.

· 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 72 contacts, 9 of whom are high risk contacts (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). 6 high risk contacts have been cleared, to date. Since last week’s update 3 asymptomatic contacts have tested positive for S. Typhi. 1 of these 3 contacts is considered to be high risk. Asymptomatic positive contacts are currently being counted as confirmed cases.

· ARPHS has some general media messaging underway across Pacific radios to distribute some general messages about typhoid. Translated information was also sent to Pacific churches last Sunday.

· ARPHS has established a landing page on its website where all media updates and information is located: http://www.arphs.govt.nz/typhoid-response