Quantifying Transmission of
            <i>Campylobacter</i>
            spp. among Broilers

Gerwe, T. J. W. M. van; Bouma, A.; Jacobs-Reitsma, W.F.; Broek, J. van den; Klinkenberg, Don; Stegeman, Jan Arend; Heesterbeek, J.A.P.

doi:10.1128/aem.71.10.5765-5770.2005

Cited by 60 publications

(65 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Given the public health and commercial importance of C. jejuni as a zoonotic pathogen, it is somewhat surprising how little is known concerning the routes and dynamics of colonization in chickens. Few studies have attempted to quantify transmission rates (Shanker et al 1990;Stern et al 2001b) and only two studies which we are aware of in the literature have attempted to estimate (Van Gerwe et al 2005) and describe (Hartnett et al 2001) colonization dynamics within a commercial broiler house. Both studies chose, in the face of the multiple possible routes of introduction and transmission previously discussed, to describe colonization as a simple epidemic and attempt to estimate a single epidemiological parameter, the most basic parameter determining the rate of spread of an infectious agent-the transmission rate.…”

Section: Dynamics Of Transmissionmentioning

confidence: 99%

Campylobacter jejuni colonization and transmission in broiler chickens: a modelling perspective

Conlan¹,

Coward

Grant

et al. 2007

J. R. Soc. Interface.

View full text Add to dashboard Cite

Campylobacter jejuni is one of the most common causes of acute enteritis in the developed world. The consumption of contaminated poultry, where C. jejuni is believed to be a commensal organism, is a major risk factor. However, the dynamics of this colonization process in commercially reared chickens is still poorly understood. Quantification of these dynamics of infection at an individual level is vital to understand transmission within populations and formulate new control strategies. There are multiple potential routes of introduction of C. jejuni into a commercial flock. Introduction is followed by a rapid increase in environmental levels of C. jejuni and the level of colonization of individual broilers. Recent experimental and epidemiological evidence suggest that the celerity of this process could be masking a complex pattern of colonization and extinction of bacterial strains within individual hosts. Despite the rapidity of colonization, experimental transmission studies exhibit a highly variable and unexplained delay time in the initial stages of the process. We review past models of transmission of C. jejuni in broilers and consider simple modifications, motivated by the plausible biological mechanisms of clearance and latency, which could account for this delay. We show how simple mathematical models can be used to guide the focus of experimental studies by providing testable predications based on our hypotheses. We conclude by suggesting that competition experiments could be used to further understand the dynamics and mechanisms underlying the colonization process. The population models for such competition processes have been extensively studied in other ecological and evolutionary contexts. However, C. jejuni can potentially adapt phenotypically through phase variation in gene expression, leading to unification of ecological and evolutionary time-scales. For a theoretician, the colonization dynamics of C. jejuni offer an experimental system to explore these ‘phylodynamics’, the synthesis of population dynamics and evolutionary biology.

show abstract

Section: Dynamics Of Transmissionmentioning

confidence: 99%

Campylobacter jejuni colonization and transmission in broiler chickens: a modelling perspective

Conlan¹,

Coward

Grant

et al. 2007

J. R. Soc. Interface.

View full text Add to dashboard Cite

show abstract

“…It is generally assumed that following the onset of Campylobacter colonization of the gut, broilers shed these bacteria for the rest of their lives (1). Therefore, we assumed that birds were either susceptible (noncolonized) or infectious (colonized) and that an increase in prevalence could be described by a susceptible-infectious type of mathematical model (12,17). In this model, susceptible chicks can be colonized upon contact with an infectious chick, which occurs at rate ␤i(t), where i(t) is the proportion of infectious chicks in the shed.…”

Section: Data Setmentioning

confidence: 99%

“…It can be used to determine the moment of introduction from field data for increasing Campylobacter prevalence over time. The estimates for ␤ that have been obtained in experimental studies (15,17) are 1.04 to 1.13 per day. However, experimental conditions differ substantially from the field situation, which implies that the ␤ in commercial flocks should also be estimated.…”

mentioning

confidence: 99%

Quantifying Transmission of Campylobacter jejuni in Commercial Broiler Flocks

Gerwe

Miflin²,

Templeton³

et al. 2009

Appl Environ Microbiol

View full text Add to dashboard Cite

Since meat from poultry colonized with Campylobacter spp. is a major cause of bacterial gastroenteritis, human exposure should be reduced by, among other things, prevention of colonization of broiler flocks. To obtain more insight into possible sources of introduction of Campylobacter into broiler flocks, it is essential to estimate the moment that the first bird in a flock is colonized. If the rate of transmission within a flock were known, such an estimate could be determined from the change in the prevalence of colonized birds in a flock over time. The aim of this study was to determine the rate of transmission of Campylobacter using field data gathered for 5 years for Australian broiler flocks. We used unique sampling data for 42 Campylobacter jejuni-colonized flocks and estimated the transmission rate, which is defined as the number of secondary infections caused by one colonized bird per day. The estimate was 2.37 ؎ 0.295 infections per infectious bird per day, which implies that in our study population colonized flocks consisting of 20,000 broilers would have an increase in within-flock prevalence to 95% within 4.4 to 7.2 days after colonization of the first broiler. Using Bayesian analysis, the moment of colonization of the first bird in a flock was estimated to be from 21 days of age onward in all flocks in the study. This study provides an important quantitative estimate of the rate of transmission of Campylobacter in broiler flocks, which could be helpful in future studies on the epidemiology of Campylobacter in the field.

show abstract

“…That is, in each infected subpopulation prevalence rises predictably and rapidly to $90%. Other examples, where the prevalence of an infection rises rapidly within a week, are the spreading of campylobacter in broiler flocks (Van Gerwe et al, 2005) and the spreading of highly pathogenic avian influenza in chicken flocks (Tiensin et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

A fully coupled, mechanistic model for infectious disease dynamics in a metapopulation: Movement and epidemic duration

Jesse

Ezanno

Davis

et al. 2008

Journal of Theoretical Biology

View full text Add to dashboard Cite

a b s t r a c tThe drive to understand the invasion, spread and fade out of infectious disease in structured populations has produced a variety of mathematical models for pathogen dynamics in metapopulations. Very rarely are these models fully coupled, by which we mean that the spread of an infection within a subpopulation affects the transmission between subpopulations and vice versa. It is also rare that these models are accessible to biologists, in the sense that all parameters have a clear biological meaning and the biological assumptions are explained. Here we present an accessible model that is fully coupled without being an individual-based model. We use the model to show that the duration of an epidemic has a highly non-linear relationship with the movement rate between subpopulations, with a peak in epidemic duration appearing at small movement rates and a global maximum at large movement rates. Intuitively, the first peak is due to asynchrony in the dynamics of infection between subpopulations; we confirm this intuition and also show the peak coincides with successful invasion of the infection into most subpopulations. The global maximum at relatively large movement rates occurs because then the infectious agent perceives the metapopulation as if it is a single well-mixed population wherein the effective population size is greater than the critical community size.

show abstract

Quantifying Transmission of Campylobacter spp. among Broilers

Cited by 60 publications

References 30 publications

Campylobacter jejuni colonization and transmission in broiler chickens: a modelling perspective

Campylobacter jejuni colonization and transmission in broiler chickens: a modelling perspective

Quantifying Transmission of Campylobacter jejuni in Commercial Broiler Flocks

A fully coupled, mechanistic model for infectious disease dynamics in a metapopulation: Movement and epidemic duration

Contact Info

Product

Resources

About