A meta-analysis of case-control studies examining sporadic campylobacteriosis in Australia and New Zealand from 1990 to 2016

Objective: We conducted a meta-analysis of case-control studies to identify locally relevant risk factors for sporadic campylobacteriosis in Australia and New Zealand. Methods: We searched Medline, Web of Science, ProQuest and Google Scholar using PRISMA guidelines. Reference lists and grey literature were hand-searched. Meta-analyses were conducted in the R package ‘metafor’ using published odds ratios and 95% confidence intervals. Results: We identified 325 articles, from which we included 10 that described case-control studies. Four risk factors were statistically significant in the meta-analysis: eating undercooked poultry (OR=4.28, 95%CI 3.09–5.93); eating poultry cooked outside the home (OR=2.13, 95%CI 1.66–2.72); having pet chickens (OR=3.29, 95%CI 2.12–5.10); and overseas travel (OR=5.55, 95%CI 3.20–9.63). Among children, having pet dogs showed elevated but not significant risk (OR=1.57, 95%CI 0.99–2.49). Conclusions: We identified consumption of chicken meat and contact with domestic chickens as important risk factors for campylobacteriosis in Australia and New Zealand. Implications for public health: While consumption of chicken meat is a well-known risk factor for campylobacteriosis, zoonotic transmission is often overlooked. This research indicates a greater need for public health awareness surrounding zoonotic campylobacteriosis, especially for young children.