Time-series analysis of Campylobacter incidence in Switzerland.
Campylobacteriosis has been the most common food-associated notifiable infectious disease in Switzerland since 1995. Contact with and ingestion of raw or undercooked broilers are considered the dominant risk factors for infection. In this study, we investigated the temporal relationship between the disease incidence in humans and the prevalence of Campylobacter in broilers in Switzerland from 2008 to 2012. We use a time-series approach to describe the pattern of the disease by incorporating seasonal effects and autocorrelation. The analysis shows that prevalence of Campylobacter in broilers, with a 2-week lag, has a significant impact on disease incidence in humans. Therefore Campylobacter cases in humans can be partly explained by contagion through broiler meat. We also found a strong autoregressive effect in human illness, and a significant increase of illness during Christmas and New Year's holidays. In a final analysis, we corrected for the sampling error of prevalence in broilers and the results gave similar conclusions.
Department of Biostatistics,Epidemiology, Biostatistics and Prevention Institute, University of Zurich,Switzerland.
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W
Wei
Veterinary Public Health Institute, University of Bern,Switzerland.
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G
Schüpbach
Department of Biostatistics,Epidemiology, Biostatistics and Prevention Institute, University of Zurich,Switzerland.
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L
Held
D000818:Animals; D002167:Campylobacter / Q000302:isolation & purification*; D002169:Campylobacter Infections / Q000453:epidemiology* / Q000382:microbiology / Q000662:veterinary*; D002645:Chickens; D006801:Humans; D015994:Incidence; D008460:Meat / Q000382:microbiology; D011201:Poultry Diseases / Q000453:epidemiology* / Q000382:microbiology; D015995:Prevalence; D012189:Retrospective Studies; D012621:Seasons; D013557:Switzerland / Q000453:epidemiology
Incidence of Campylobacter in humans; prevalence of Campylobacter in broilers; time-series analysis