Risk factors for Echinococcus coproantigen positivity in dogs from the Alay valley, Kyrgyzstan.

A Mastin,T Tursunov,B Mytynova,P.S Craig,M.T Rogan,P.R Torgerson,I Ziadinov,F Van Kesteren

doi:10.1017/s0022149x15000590

A Mastin, T Tursunov + Show 6 more

Open Access

https://doi.org/10.1017/s0022149x15000590

Copy DOI

Abstract

Echinococcosis, caused by the zoonotic cestodes Echinococcus granulosus (sensu lato) and Echinococcus multilocularis, is highly endemic in the Central Asian Republic of Kyrgyzstan, and is being identified increasingly as a public health problem, especially amongst pastoral communities. As domestic dogs are considered to be the main source of human infection, the identification of potential transmission pathways is of relevance when considering implementing an echinococcosis control scheme. The current report describes the results of an analytical study of canine Echinococcus coproantigen enzyme-linked immunosorbent assay (ELISA) prevalence in the Alay valley of southern Kyrgyzstan prior to the commencement of regular praziquantel dosing of dogs. A logistic regression model using a form of Bayes modal estimation was used to identify possible risk factors for coproantigen positivity, and the output was interpreted in a Bayesian context (posterior distributions of the coefficients of interest). The study found that sheepdogs had lower odds of coproantigen positivity, as did dogs in households with donkeys, where owners had knowledge of echinococcosis, and households which engaged in home slaughtering. Surprisingly, there was no evidence of an association between free roaming or previous praziquantel dosing and coproantigen positivity, as has been found in previous studies. Possible reasons for these findings are discussed in the context of the epidemiology of echinococcosis and potential intervention approaches.

Highlights

Human echinococcosis, caused by infection with the metacestode stage of cestodes of the genus Echinococcus, is an important public health concern in various parts of the world
Potential risk factors for infection can be classified according to a number of general transmission processes: factors associated with access to infected material; factors associated with variability in infection after ingestion of infectious material; and factors associated with removal of infection, such as a history of anthelmintic treatment
The current study investigates risk factors for canine Echinococcus spp. coproantigen positivity in the Alay valley in the Osh Oblast of Kyrgyzstan – an area of known high endemicity of human alveolar echinococcosis (Usubalieva et al, 2013)

Summary

Introduction

Human echinococcosis, caused by infection with the metacestode stage of cestodes of the genus Echinococcus, is an important public health concern in various parts of the world. As the transmission cycle of Echinococcus spp. may vary between locations, it is useful to identify risk factors specific to the particular transmission system in question. It is useful to evaluate commonly identified risk factors from the wide range of studies that have been conducted worldwide (Otero-Abad & Torgerson, 2013). – classifying samples as coproantigen ‘negative’ or ‘positive’, according to their enzyme-linked immunosorbent assay (ELISA) optical density (OD) value in relation to a defined cut-off value. This will lead to some misclassification, which has been addressed in some studies by combining the results of purgation and coproPCR (Ziadinov et al, 2008). The most commonly identified risk factors are those relating to access to infected material, including access to offal or infected rodents (Bchir et al, 1987; Parada et al, 1995; Moro et al, 1999; Y.H. Wang et al, 2001; Shaikenov et al, 2003; Budke et al, 2005; Buishi et al, 2005b, 2006; Q. Wang et al, 2007, 2010; Dyachenko et al, 2008; Guzel et al, 2008; Huang et al, 2008; Ziadinov et al, 2008; Antolovaet al., 2009; AcostaJamett et al, 2010; Mastin et al, 2011; Reyes et al, 2012)

Objectives

Methods

Results

Conclusion