Association between the ambient temperature and the occurrence of human Salmonella and Campylobacter infections.

Josef Yun,Ute Messelhäusser,Christiane Höller,Günter Klein,Matthias Greiner,Albert Rampp

doi:10.1038/srep28442

Abstract

Salmonella spp. and thermotolerant Campylobacter spp. are the most important causes of human bacterial diarrheal infections worldwide. These bacterial species are influenced by several factors like behaviour of the host, shedding, environment incl. directly or indirectly through ambient temperature, and the infections show seasonality. Therefore, the aim of our study was to investigate the association between the occurrence of human campylobacteriosis and salmonellosis and the ambient temperature. The number of campylobacteriosis and salmonellosis cases in two German metropolises, Munich and Berlin, and three rural regions was analysed with simultaneous consideration of the ambient temperature over a period of four years (2001 to 2004) using regression, time series, and cross-correlation analysis. The statistical analysis showed that an increase in the ambient temperature correlated positively with an increase in human Salmonella and Campylobacter cases. The correlation occurred with a delay of approximately five weeks. The seasonal rise in ambient temperature correlated with increased incidence of bacterial diarrheal infections.

Highlights

Salmonella spp. and thermotolerant Campylobacter spp. are the most important causes of human bacterial diarrheal infections worldwide
Information on the weekly frequency of human campylobacteriosis and salmonellosis cases was obtained from the reports of the Robert-Koch-Institut (RKI) from 2001 to 2004 for metropolitan (Berlin, Munich) and rural study sites located in North-Swabian counties (Dillingen, Donau-Ries und Augsburg-Land)[17]
We expressed the geographical variability of temperature using the between-location standard deviation (SD) of mean temperatures for each of the 212 weeks of the study

Summary

Introduction

Salmonella spp. and thermotolerant Campylobacter spp. are the most important causes of human bacterial diarrheal infections worldwide. These bacterial species are influenced by several factors like behaviour of the host, shedding, environment incl. The aim of our study was to investigate the association between the occurrence of human campylobacteriosis and salmonellosis and the ambient temperature. The seasonal rise in ambient temperature correlated with increased incidence of bacterial diarrheal infections. Salmonella spp. and thermophilic Campylobacter spp. are the most important causes of human bacterial diarrheal infections in Europe and worldwide. The hypothesis of our study was that there is an association between the occurrence of human campylobacteriosis and salmonellosis and the ambient temperature. We think that our study contributes to a better understanding of the association between the occurrence of clinical cases and the ambient temperature

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Conclusion