Assessing Interventions to Reduce the Risk of Campylobacter Prevalence in Broilers

Abstract

As part of a comprehensive risk assessment on the Campylobacter prevalence in the chicken production chain (from young born chicken till chicken fillet) in the Netherlands, we formulated a quantitative model on the transmission dynamics of Campylobacter at Dutch broiler farms. This model is used to quantify the risk of Campylobacter prevalence in broilers at the time that flocks leave the farm for processing. To this end, we assumed that the Campylobacter prevalence is primarily determined by two parameters, that is, the within- and between-flock transmission. The within-flock transmission was assessed fitting experimental data to a logistic growth model and the between-flock transmission was assessed fitting field data to a generalized linear model (GLM), which included three possible infection routes: (1) via an infected flock in the previous cycle, (2) via other infected flocks present on the farm, and (3) from other sources. This model was applied to assess the efficacy of three control scenarios; (1) a ban on other livestock on broiler farms, (2) a ban on thinning, and (3) a reduction of the between-flock transmission. In contrast to the other scenarios, the third one was shown to be most effective. Theoretically, this is accomplished by improved biosecurity. However, the impact of improved biosecurity cannot be specified into specific control measures, and therefore it is not clear what investments are needed. Finally, we also assessed the efficacy of scheduled treatment, that is, fresh meat production solely from test-negative flocks. We found that the reliability of negative test results, which is crucial, strongly depends on the length of time between testing and slaughter. The sensitivity and specificity of the test appeared to be of minor importance.

A Systematic Review Characterizing On-Farm Sources of Campylobacter spp. for Broiler Chickens

“…This SR-MA identified adjacent broiler flocks (n = 8 studies) as a source of flock-matching genotypes (8/8 studies) and the MA (OR = 124.78) suggests that the presence of adjacent broilers may pose a significant risk for Campylobacter transmission to a new flock in agreement with other synthesis papers [16], [21]. The same was not seen for other animals (e.g., cattle) on the farm, despite high prevalence and the detection of flock-matching genotypes in 66% (8/12) of studies.…”

“…There have been many investigations into potential biological mechanisms related to the survival of Campylobacter from egg to post-hatch stages [18], but more research is required to investigate this potentially under-recognized transmission route. It appears that any of these sources could result in an infected broiler flock as only a few susceptible birds are sufficient to result in flock-level colonization by the end of grow out [21], [92].…”

“…The potential for transmission of Campylobacter via other infected animals or pests highlights the importance of biosecurity, including hygiene barriers between animal production units. A number of biosecurity measures have been highlighted in previous reviews [12], [13], [16] including restrictions of other animals on the farm [21] and the use of pest control methods such as fly screens or insecticides [57], however the effectiveness of these interventions still needs to be evaluated for Canadian broiler farms.…”

Biosecurity-Based Interventions and Strategies To Reduce Campylobacter spp. on Poultry Farms

“…However, this seems to be a relatively rare event (46), and surprisingly, the majority of the strains in adjacent livestock are not recovered subsequently from broilers. Moreover, models from the Netherlands (49) indicate that removal of other livestock from a poultry farm would reduce infection only from 44% to 41%.…”

Retention of Campylobacter (Campylobacterales: Campylobacteraceae) in the House Fly (Diptera: Muscidae)

“…According to several risk analyses the main source of human Campylobacter infections in the industrialized world come from contaminated food, and most importantly poultry meat (Craven et al 2000, Katsma et al 2007, Nauta et al 2007). The incidence of Campylobacter infections of both poultry and humans peak every summer in Northern temperate climates (Nylen et al 2002, Patrick et al 2004.…”