Seasonality and the effects of weather on Campylobacter infections

Abstract

BackgroundCampylobacteriosis is a major public health concern. The weather factors that influence spatial and seasonal distributions are not fully understood.MethodsTo investigate the impacts of temperature and rainfall on Campylobacter infections in England and Wales, cases of Campylobacter were linked to local temperature and rainfall at laboratory postcodes in the 30 days before the specimen date. Methods for investigation included a comparative conditional incidence, wavelet, clustering, and time series analyses.ResultsThe increase of Campylobacter infections in the late spring was significantly linked to temperature two weeks before, with an increase in conditional incidence of 0.175 cases per 100,000 per week for weeks 17 to 24; the relationship to temperature was not linear. Generalized structural time series model revealed that changes in temperature accounted for 33.3% of the expected cases of Campylobacteriosis, with an indication of the direction and relevant temperature range. Wavelet analysis showed a strong annual cycle with additional harmonics at four and six months. Cluster analysis showed three clusters of seasonality with geographic similarities representing metropolitan, rural, and other areas.ConclusionsThe association of Campylobacteriosis with temperature is likely to be indirect. High-resolution spatial temporal linkage of weather parameters and cases is important in improving weather associations with infectious diseases. The primary driver of Campylobacter incidence remains to be determined; other avenues, such as insect contamination of chicken flocks through poor biosecurity should be explored.Electronic supplementary materialThe online version of this article (10.1186/s12879-019-3840-7) contains supplementary material, which is available to authorized users.

An analecta of visualizations for foodborne illness trends and seasonality

“…We applied the negative binomial harmonic regression NBHR models, commonly used in the time series analysis of counts and cases. While the use of NBHR models, specifically the inclusion of trigonometric harmonic oscillations, is similar to existing works on foodborne illnesses, these studies often incorporate harmonic oscillators only to adjust for or remove seasonal oscillations [47][48][49][50][51][52][53][54][55] . We have extended the use of harmonic terms and develop the tools to estimate peak timing and amplitude 8,29,30 .…”

Campylobacter infections expected to increase due to climate change in Northern Europe

“…Only few published studies have analysed the association between climate and Campylobacter cases-and some with conflicting results. Generally, it appears that Campylobacter in chicken flocks fluctuates with temperature and humidity 9,44 while incidences in humans may be linked to fluctuations in both temperature and rainfall and especially heavy precipitation events 21,24,25,28,[45][46][47][48] . Heat waves have been linked to reduced incidences of Campylobacter 21,22 .…”

Can good broiler flock welfare prevent colonization byCampylobacter?

“…The copyright holder for this preprint this version posted March 30, 2021. ; https://doi.org/10.1101/2021.03.30.437710 doi: bioRxiv preprint BROILER WELFARE AND CAMPYLOBACTER with the warmer, summer months seeing flocks test positive for Campylobacter more frequently (Djennad et al, 2019;Nylen et al, 2002).…”

“…Previous studies have suggested that the seasonal increase of flies (Hald et al, 2004(Hald et al, , 2007, rodents (Meerburg and Kijlstra, 2007), and wild birds (Colles et al, 2008) as vectors of Campylobacter transmission may be responsible, while seasonal patterns in country-wide clonal complex incidence potentially point to genetic adaptation to seasonal trends (Jorgensen et al, 2011). Investigating this trend in human incidence of campylobacteriosis, Djennad et al (2019) conducted a rigorous statistical assessment of spatial and weather factors, concluding that the correlation between incidence and temperature was " likely to be indirect". Our above results reach the same conclusion for broiler colonization.…”