## 2 Sampling of Poultry
### Seasonality of Sampling and Environmental Conditions  
The seasonality of sampling and the effect environmental conditions may have on the recovery of _Campylobacter_ spp. from broiler carcasses or chicken meat has been the subject of dozens of research papers, which present conflicting results as far as the effect of seasonality on _Campylobacter_ prevalence is concerned and fail to reach an agreement on the matter. In this context, a large number of studies have indicated a significant seasonal increase in the prevalence of _Campylobacter_ in broiler carcasses or in poultry meat during the hot summer  
Figure 2: Sampling sites of a broiler carcass with variations in _Campylobacter_ contamination depicted with the relative concentration of campylobacter (green curved bacteria). _Campylobacter_ concentration in descending order from the more heavily contaminated site to the less contaminated one, when sampled with skin, is as follows: (neck \(\geq\) wing \(\geq\) breast \(\geq\) leg) \(>\) (abdomen \(\geq\) back). Parentheses designate the sites that are highly correlated to each other in terms of _Campylobacter_ concentration. Created with BioRender.com. months [10; 57; 68; 82; 83; 84], even in tropical countries without marked seasons where other climatic conditions though, like increased rainfall and relative humidity, possibly reflect the pathogen's potential to colonize its host (e.g., chicken broilers) [85; 86]. The seasonal effect on _Campylobacter_ prevalence is inferred either by the increased number of reported campylobacteriosis cases during the summer months [10; 82] or the increased fly activity [87] and the presence of flies in the summer, which play the role of the bacterial vector (mechanical/transport host) in the warm months [83]. In addition, the aforementioned increase in prevalence could reflect the level of environmental contamination due to more regular ventilation of the poultry houses in summer, resulting in increased contact of birds with the external environment [88; 89]. To this end, higher wind speeds and the geographical location of the farm, surrounded by a more agricultural landscape, may also contribute to the extent of contamination in the poultry flock [57; 90]. Wind may introduce contaminated material (e.g., soil, dried fecal particles) to the poultry house, which is more likely to exist in the rural setting, exposing the flock to _Campylobacter_ spp. among other fecal pathogens, if birds have access to the external environment and come into contact with other wild birds and if contaminated particle matter gains access to air-inlets of poultry houses [91; 90; 92; 93]. Biosecurity measures at the farm level greatly contribute to the prevention of _Campylobacter_ colonization and reduce the prevalence of the pathogen in broiler flocks [89; 94]. On the other hand, several papers highlight the non-statistically significant effect of seasonality on _Campylobacter_ populations from broiler carcasses or chicken meat [61; 63; 89; 95], where especially in the warmer countries of southern Europe, like the Mediterranean countries, a higher prevalence of _Campylobacter_ spp. is reported in broiler flocks throughout the year compared to the colder northern European countries with the more pronounced and obvious seasonality in their bacterial recoveries of the pathogen [89; 94]. Moreover, many times the inability to ascertain the degree of influence of the seasonality on the recovery rate of _Campylobacter_ spp. is even related to the small number of samples analyzed which does not allow safe conclusions to be drawn [61; 63]. Regarding the distribution of different _Campylobacter_ species in poultry carcasses, [PERSON] et al. [59] reported higher recovery rates for _C. jejuni_ (75.2%) against _C. coli_ (24.8%) in winter (i.e., December-March) for chicken carcasses sampled from a single slaughterhouse in Italy, which were processed from broilers coming from a dozen of different chicken farms, compared to other seasons where _C.