A bulletin for the Australian Food Industry May 2002
Contents: Salmonella in chocolate | Hazards in international trade | Children and microbial foodborne illness | International spread of foodborne illness | Sanitizers and fresh produce | Supplement: Acrylamide detection in starchy foods
Hazards in international trade
The report above is an example of a diffuse outbreak of foodborne illness which affected consumers not only in the country in which the food was produced but also in countries to which the food was exported.
A number of districts in Germany reported cases caused by consumption of the particular batch of chocolate while Denmark, Sweden and The Netherlands have reported the same strain of S. oranienburg being associated with illness in consumers of chocolate purchased from a particular supermarket chain in their own country. Austria, Belgium and Finland may also have been affected as investigation of cases in those countries continues. Canadian authorities issued recall notices following the finding that chocolate from the implicated lots had been imported and subsequent laboratory investigation has revealed the presence of a S. oranienburg strain in the suspect chocolate.
Australia does not appear to have been affected in this particular outbreak.
The same, however, could not be said with respect to outbreaks of foodborne illness caused by Salmonella typhimurium DT104 in contaminated sesame seed products. This strain poses special problems because it is typically resistant to at least five commonly used antibiotics.
The product which appears to have caused most of the reported cases is halva (or helva) a confectionery common in Turkey and other Middle Eastern countries. It is manufactured from ground sesame seeds and honey, sometimes with other products added. In Australia it is usually sold through speciality delicatessens or restaurants.
In April - July of 2001 there were reports of cases of salmonellosis caused by S. typhimurium DT104 in Sweden, Germany and Australia (Eurosurveillance 33 16 August, 2001). Swedish authorities tentatively associated an outbreak of 27 cases to a particular brand of imported Turkish halva. Australian health officials investigating a cluster of 16 cases of infection with the same Salmonella strain were then able to establish a clear epidemiological link with the Australian outbreak and the consumption of halva under different brand names (Food Safety and Security, September 2001). Subsequent laboratory testing confirmed the contamination of the product.
Another country affected was Norway where 29 cases occurred in 24 apparently independent incidents. Twelve of the 29 cases were younger than 15 years. Samples of halva were also found positive for the same strain in the United Kingdom where recall notices were issued although it is not clear if any of the recent cases involving S. typhimurium DT104 in that country were due to the same product.
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