Leanne Unicomb

Estimating Foodborne Gastroenteritis, Australia

An estimated 4.0–6.9 million episodes of foodborne gastroenteritis occur in Australia each year.

Population-Attributable Risk Estimates for Risk Factors Associated with Campylobacter Infection, Australia

One-sentence summary: Each year, an estimated 50,500 cases in persons >5 years of age can be directly attributed to consumption of chicken.

A multi-centre prospective case-control study of campylobacter infection in persons aged 5 years and older in Australia

There are an estimated 277,000 cases of campylobacteriosis in Australia each year, most of which are thought to be sporadically acquired. To explore causes for these infections, we conducted a multi-centre case-control study of patients and community controls across five Australian States during 2001-2002. A total of 881 campylobacter cases and 833 controls aged 5 years were recruited into the study. Crude logistic analyses were conducted within various food and non-food exposure groups. A final most parsimonious multivariable logistic regression model was developed and adjusted odds ratios (aOR), 95% confidence intervals (95% CI) were derived together with adjusted population attributable risks (PAR). Consumption of undercooked chicken (aOR 4.7, 95% CI 2.6-8.4) and offal (aOR 2.0, 95% CI 1.0-4.0), ownership of domestic chickens aged<6 months (aOR 12.4, 95% CI 2.6-59.3) and domestic dogs aged<6 months (aOR 2.1, 95% CI 1.1-4.2) were found to be independent risk factors for illness in the final model. The PAR proportions indicate that eating chicken meat, either cooked or undercooked may account for approximately 30% of campylobacter cases that occur each year in Australia. These results justify the continued need for education of consumers and foodhandlers about the risks associated with the handling of raw chicken and the potential for cross-contamination.

Sesame seed products contaminated with Salmonella: three outbreaks associated with tahini.

In November 2002, the first of three outbreaks of Salmonella Montevideo infection in Australia and New Zealand was identified in New South Wales, Australia. Affected persons were interviewed, and epidemiologically linked retail outlets inspected. Imported tahini was rapidly identified as the source of infection. The contaminated tahini was recalled and international alerts posted. A second outbreak was identified in Australia in June-July 2003 and another in New Zealand in August 2003. In a total of 68 S. Montevideo infections, 66 cases were contacted. Fifty-four (82%) reported consumption of sesame seed-based foods. Laboratory analyses demonstrated closely related PFGE patterns in the S. Montevideo isolates from human cases and sesame-based foods imported from two countries. On the basis of our investigations sesame-based products were sampled in other jurisdictions and three products in Canada and one in the United Kingdom were positive for Salmonella spp., demonstrating the value of international alerts when food products have a wide distribution and a long shelf life. A review of the controls for Salmonella spp. during the production of sesame-based products is recommended.

Foodborne Disease in Australia: The OzFoodNet Experience

In 2000, Australia improved national surveillance of gastrointestinal and foodborne illness by adapting the Centers for Disease Control and Prevention’s (CDC’s) FoodNet model of active surveillance. The OzFoodNet surveillance network applied concentrated effort at the national and local levels to investigate and understand foodborne disease, to describe more effectively its epidemiology, and to provide better evidence for minimizing the number of cases of foodborne illness in Australia. The Australian government funded each of Australia’s 6 states and 2 territories to employ 1 epidemiologist to enhance surveillance of foodborne disease, with a coordinating team based at the federal Department of Health and Ageing. OzFoodNet estimated that there are ∼5.4 million cases of foodborne disease per year, costing A

Fluoroquinolone Resistance in Campylobacter Absent from Isolates, Australia

1.2 billion annually. In Australia, contaminated food results in ∼100 outbreaks of illness each year, with the incidence of outbreaks of illness caused by fresh produce and internationally distributed food increasing. In addition, OzFoodNet showed the value of aggregating national-level outbreak data for policy development and conducted successful multijurisdictional investigations of outbreaks; these investigations implicated a variety of foods, including alfalfa sprouts, chicken meat, eggs, peanuts, baby corn, tahini, and oysters. Foodborne diseases are globally important because of their high incidence and the costs that they impose on society. There is a great potential for large outbreaks of foodborne illness in both developing and developed countries. More than 200 different diseases may be transmitted through contaminated food or water [1]. Most foodborne diseases result in gastroenteritis, but other nongastroenteric illnesses are common. Prevention of foodborne disease occurs through interventions aimed at the

Low-Level Fluoroquinolone Resistance among Campylobacter jejuni Isolates in Australia

Fluoroquinolone resistance was detected in 12 of 370 Australian human Campylobacter isolates; 10 of these were travel-associated, and for 2 isolates travel status was unknown. No resistance was found in isolates known to be locally acquired. In Australia, fluoroquinolones have not been licensed for use in food production animals, a policy that may have relevance for countries with fluoroquinolone-resistant Campylobacter.

Multilocus sequence typing of Campylobacter jejuni isolates from New South Wales, Australia

BACKGROUND Ciprofloxacin-resistant Campylobacter jejuni isolates obtained from infected patients in Australia have not been detected in studies of isolates from specific geographic areas. The Australian government has prohibited the use of fluoroquinolone in food-producing animals. To assess the impact of this policy, we have examined the antimicrobial susceptibility of isolates from 5 Australian states. METHODS We conducted a period-prevalence survey of the susceptibility of C. jejuni isolates to 10 antimicrobial agents. C. jejuni isolates obtained from 585 patients from 5 Australian states (Queensland, South Australia, Tasmania, Victoria, and Western Australia) were identified by means of notifiable disease databases and were systematically selected from September 2001 to August 2002. RESULTS Among locally acquired infections, only 2% of isolates (range, 0%-8% in different states) were resistant to ciprofloxacin. The locally acquired isolates also exhibited resistance to sulfisoxazole (55%), ampicillin (46%), roxithromycin (38%), tetracycline (7%), nalidixic acid (6%), chloramphenicol (3%), erythromycin (3%), gentamicin (2%), and kanamycin (0.2%). Treatment with antimicrobial agents in the 4 weeks before onset was not associated with ciprofloxacin resistance. CONCLUSIONS The very low level of ciprofloxacin resistance in C. jejuni isolates likely reflects the success of Australias policy of restricting use of fluoroquinolones in food-producing animals.

Clonal Complexes of Campylobacter jejuni Identified by Multilocus Sequence Typing Are Reliably Predicted by Restriction Fragment Length Polymorphism Analyses of the flaA Gene

Aims:  Multilocus sequence typing (MLST) was used to examine the diversity and population structure of Campylobacter jejuni isolates associated with sporadic cases of gastroenteritis in Australia, and to compare these isolates with those from elsewhere.

Outbreaks of campylobacteriosis in Australia, 2001 to 2006.

ABSTRACT Multilocus sequence typing (MLST) has provided important new insights into the population structure of Campylobacter jejuni and is rapidly becoming the gold standard for typing this species. However, the methodology is comparatively costly and slow to perform for the routine surveillance testing of large numbers of isolates required by public health laboratories. Restriction fragment length polymorphism analysis of the flaA gene (RFLP-flaA) and sequencing of the variable region in the fla locus (SVR-fla) were compared to MLST to determine if a low cost alternative could be found that reliably predicts clonal lineage (as determined by MLST). An isolate of C. jejuni from each of 153 patients from New South Wales, Australia, collected sequentially over a period of 30 months from 1999 to 2001 and comprising 40 sequence types (ST) from 15 clonal complexes (CC) was examined. Of 15 CC, 12 were represented by more than one isolate and a predominant RFLP-flaA type was found for 10 (83%). Of these, seven (70%) correctly predicted the predominant MLST CC with a probability of >0.8. Of 40 STs detected, 19 were reported for the first time, 9 of which were represented by more than one isolate. Eight of these were represented by a single RFLP-flaA type. Only two of eight major SVR-fla types were able to predict CC with a probability of >0.8, indicating that flaA-RFLP is a more reliable predictor of CC than SVR-fla and thus offers an alternative to MLST for use in routine surveillance.