Reinfection studies of canine echinococcosis and role of dogs in transmission of Echinococcus multilocularis in Tibetan communities, Sichuan, China

J E Moss,P R Torgerson,A Ito,T Li,Q Wang,X Chen,P Giraudoux,P S Craig,J Qiu

doi:10.1017/s0031182013001200

Abstract

In the eastern Tibetan plateau both human cystic and alveolar echinococcosis (AE) caused by infection with Echincoccus granulosus or Echinococcus multilocularis, respectively are highly endemic. The domestic dog plays a key role in zoonotic transmission in this region. Our primary objective was to investigate the role of domestic dogs in maintaining transmission of E. multilocularis in Shiqu county, Sichuan. A cohort of 281 dogs was followed up over one year after a single treatment with praziquantel followed by re-infection surveillance at 2, 5 and 12 months post-treatment. Faecal samples were tested by an Echinococcus genus-specific coproantigen ELISA and two species-specific copro-PCR tests. Total Echinococcus coproantigen prevalence in Shiqu at baseline was 21% and 9·6% after 2 months. E. multilocularis copro-PCR was positive in 11·2% of dogs before treatment (vs 3·6% with E. granulosus copro-DNA), 2·9% at 2 months post-treatment, and 0% at 5 month and 12 months. The results suggest that dogs may have the potential to maintain E. multilocularis transmission within local pastoral communities, and thus dog dosing could be an effective strategy to reduce transmission of E. multilocularis as well as E. granulosus in these co-endemic Tibetan communities.

Highlights

Echinococcosis is a zoonosis that affects both domestic animals and wildlife populations, and is a severe public health concern in much of western China (Craig, 2006; Wang et al 2008a)
In Ganze Tibetan Autonomous Prefecture (Sichuan province), the predominant cycle for E. granulosus involves the domestic dog and livestock (Yang et al 2009), whilst for E. multilocularis the natural cycle appears to be between fox species and a number of small mammal hosts including microtines and lagomorphs (Raoul et al 2006; Wang et al 2008a)
Due to the high prevalence of both E. multilocularis and E. granulosus in Tibetan domestic dogs, for example purge rates of 12 and 8% respectively (Budke et al 2005a), it has been hypothesized that domestic dogs are responsible for zoonotic transmission of E. granulosus, and for E. multilocularis in this locality (Wang et al 2001a; Vaniscotte et al 2011)

Summary

Introduction

Echinococcosis is a zoonosis that affects both domestic animals and wildlife populations, and is a severe public health concern in much of western China (Craig, 2006; Wang et al 2008a). Due to the high prevalence of both E. multilocularis and E. granulosus in Tibetan domestic dogs, for example purge rates of 12 and 8% respectively (Budke et al 2005a), it has been hypothesized that domestic dogs are responsible for zoonotic transmission of E. granulosus, and for E. multilocularis in this locality (Wang et al 2001a; Vaniscotte et al 2011). It is not clear whether dogs could maintain E. multilocularis in an independent peri-domestic cycle involving dogs and small mammals, or merely act as a reservoir host

Results

Discussion

Conclusion