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One hundred and two cases of Salmonella Oranienburg infection were notified to the Communicable Disease Control Branch (CDCB), South Australia, from March to June 1998. Food history questionnaires indicated that Italian food, in particular pasta, pizza and gelato featured highly in the food frequency analysis. A case-control study established an association between illness and the consumption of gelato.

Further to the epidemiological evidence, laboratory results identified Salmonella Oranienburg in gelato manufactured by a South Australian company. This was also supported by an environmental investigation conducted by the food unit of the South Australian Department of Human Services. Cases notified to the CDCB after the product was recalled had onset dates prior to the recall.

Editorial comment

Salmonella Oranienburg in Australia

Adapted from: National Enteric Pathogens Surveillance Scheme. Know your serovars. NEPSS Human Fourth Quarter Report Vol 2; 1998:10

Background

Salmonella Oranienburg was first isolated in 1929 from a child with gastroenteritis, a resident of a Children's Home in Oranienburg near Berlin. The find was first described in Germany in 1930.

The presence of this serovar has been documented in Australia at least since 1950 and has been most commonly isolated in the far north-west of Western Australia from the human populations of the aboriginal communities and the wild animals, particularly the reptiles (lizards, snakes and crocodiles) which form part of their diet. It is also found in water supplies and other native animals in these tropical areas. Between 1950 and 1976 in Western Australia 191 of the 216 human cases notified were from the Pilbara (43) and Kimberley (148) regions.^1,2

There were 54 cases in Victoria from September to November 1975, with all isolates from persons returning from overseas on two airline flights in September.

Since 1986 the number of cases notified from all states and territories has averaged 61 cases per year and ranged from 37 to 106, the latter recorded in 1989 when elevated case numbers were recorded in New South Wales (Broken Hill and Moree), Western Australia (Perth and Kimberley region) and the Northern Territory where there was an outbreak among visitors to an outback homestead resort near Alice Springs.

The majority of nonhuman isolates since 1990 have been from meat meals, beef meat, raw egg pulp (special survey, Queensland), buffaloes (Northern Territory), reptiles both captive and wild, sewage sludge samples from New South Wales (special survey) and, in low numbers, various companion and farm animals in all States. Isolates of interest prior to 1990 were from imported gum tragacanth (1978), dried yeast (1979, 1980), cinnamon powder (1980) and sesame seeds (1988, ex Mexico).

Situation in 1998

In the first half of 1998 there have been 92 cases notified to the National Enteric Pathogens Surveillance Scheme, 75 of these from South Australia. Initial notifications were from young adults between 20 and 30 years (15), teenagers (11) and children (25, only 3 infants) with a higher proportion of females (65%); there were five males of 30 years and over but no females in this age group.

References

1. Ivenson JB and Bamford VW. Enteric pathogens isolated in Western Australia 1950-1980. Report Part 1. Public Health Department, Western Australia, 1984.

2. Ivenson JB, Bamford VW, Wyner V et al. Salmonella and Edwardsiella isolations from humans, animals, waters and effluents in tropical and temperate latitudes of Australia. The Occasional Report Paper 42. State Health Laboratory Services, Perth, Western Australia, 1991.

This article was published in Communicable Diseases Intelligence Vol 22 No 8, 6 August 1998.