Molecular and spatial epidemiology of human campylobacteriosis - source association and genotype-related risk factors
Mullner, P., Shadbolt, T., Collins-Emerson, J. M., Midwinter, A. C., Spencer, S. E. F., Marshall, J., Carter, P. E., Campbell, D. M., Wilson, D. J., Hathaway, S., Pirie, R. and N. P. French (2009)
Epidemiology and Infection 138: 1384-1390. (pdf)
The epidemiology of human campylobacteriosis is complex and poorly understood. Despite being a major public health concern in many countries, the presence of multiple hosts, genotypes and transmission pathways has made it difficult to identify and quantify the determinants of human infection and disease. This has delayed the development of successful intervention programs for this disease in many countries including New Zealand, a country with a comparatively high, yet until recently poorly understood, rate of notified disease. In this study the epidemiology of Campylobacter jejuni was investigated at the genotype-level over a three year period between 2005 and 2008 using multi locus sequence typing. By combining epidemiological surveillance and population genetics, a dominant, internationally-rare strain of C. jejuni (ST - 474) was identified, and the majority of human cases (65.7 %) were found to be caused by only seven different genotypes. Source association of STs was used to identify risk factors at the genotype-level through multivariable logistic regression and a spatial model. Poultry-associated cases were more likely to be found in urban areas compared to rural areas. In particular young children in rural areas had a higher risk of infection with ruminant strains than their urban counterparts. These findings provide important information for the implementation of pathway specific control strategies.