A bulletin for the Australian Food Industry March 2003
Contents: Integration of the NSW food safety system | HACCP and small businesses in the UK | Another study on HACCP and small business | Vegetables in oil and vinegar | Illness associated with minor fish species | The protective effect of alcoholic beverages in foodborne illness outbreaks | Seminar for noodle manufacturers
The protective effect of alcoholic beverages in foodborne illness outbreaks
Many readers will have heard anecdotal evidence of how consumption of alcohol during a meal has protected some diners from the worst effects of an associated foodborne illness outbreak. These stories are understandably greeted with a degree of skepticism.
A report by Spanish public health workers (Epidemiology 13 2002 228) indicates that, at least in some circumstances, the stories may have some firm basis. The Spanish workers report on an outbreak which followed a banquet attended by 120 people. One hundred and two of the party were interviewed, 59 of whom reported typical symptoms while 43 did not.
Seventy-eight people responded to a subsequent questionnaire which sought details of alcohol consumption during the meal. Of these, 58 had consumed at least one of the foods confirmed as being contaminated with Salmonella ohio (potato salad and tuna sandwiches).
Alcohol was considered in two ways: qualitative (yes/no) and by level (1-40 g, and more than 40 g) based on the estimated grams of alcohol per serving of beer, wine or spirits.
Further analysis was restricted to those who answered the alcohol questions and who had eaten the implicated food. Among these 51 people, a mean difference of 33.2 g of alcohol intake was present between the 40 ill people and the 11 others. A protective effect of alcohol was observed among those drinking more than 40 g of alcohol. Attack rates were 95 per cent, 78 per cent and 54 per cent respectively for those drinking 0, 1-40, and more than 40 g. The authors note that age could confound these results if children had different attack rates from non-drinking adults but excluding all subjects under 15 years old did not alter the analysis.
They conclude that the results of this study are consistent with an earlier study by them of an outbreak associated with Salmonella enteritidis. In addition, there is some supporting evidence from other studies involving hepatitis A virus (Epidemiology 3 1992 371).
The Spanish authors emphasise, however, that their findings do not mean that alcoholic beverages should be recommended as a protective factor against infectious foodborne diseases. The universal recommendation of sound practices among food handlers and correct food safety operations are the best way to prevent such outbreaks.
Food Science Australia
PO Box 52, North Ryde 1670. Tel +61 2 9490 8397 Fax +61 2 9490 8499
Email enquiries@csiro.au