A Pilot Study for Control of Hyperendemic Cystic Hydatid Disease in China

Gulnor Tulson,Baoxin Shi,Hong You,Donald P. McManus,Darren J. Gray,Jincheng Wang,Zhuangzhi Zhang,Jun Li,Wenbao Zhang,Turhong Yimit,Hasyeti Aili

doi:10.1371/journal.pntd.0000534

Gulnor Tulson, Baoxin Shi + Show 9 more

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https://doi.org/10.1371/journal.pntd.0000534

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Abstract

BackgroundCystic hydatid disease (CHD) is a global parasitic zoonosis caused by the dog tapeworm, Echinococcus granulosus. The disease is hyperendemic in western China because of poor economic development; limited community knowledge of CHD; widespread, small-scale household animal production; home killing of livestock; and the feeding of dogs with uncooked offal.Methodology/Principal FindingsA control program focusing on monthly praziquantel (PZQ) treatment of all registered dogs and culling unwanted and stray dogs has been designed to control CHD in hyperendemic areas in China. A pilot field control project in two counties (Hutubi and Wensu) in Xinjiang, China showed that after 4 years of treatment, the prevalence of dogs with E. granulosus was reduced from 14.7% and 18.6%, respectively, to 0%, and this caused a 90%–100% decrease of CHD in sheep born after commencement of the control program.Conclusions/SignificanceThe strategy aimed at preventing eggs being released from dogs into the environment by treating animals before adult tapeworms are patent can decrease E. granulosus transmission and considerably reduce hyperendemic CHD. Monthly treatment of dogs with PZQ and culling unwanted and stray dogs have been shown to be an efficient, highly cost-effective and practicable measure for implementation in rural communities. As a result, the Chinese Ministry of Health has launched an extensive CHD control program in 117 counties in western China using this control strategy.

Highlights

Cystic hydatid disease (CHD), caused by Echinococcus granulosus, is hyperendemic in China, especially in western areas
Baseline surveys showed that the two counties were hyperendemic for cystic echinococcus (CE)
In Hutubi County, the prevalence of echinococcosis in sheep was 88.8% (Table 2). 18.5% of dogs were infected with E. granulosus

Summary

Introduction

Cystic hydatid disease (CHD), caused by Echinococcus granulosus, is hyperendemic in China, especially in western areas. More recent surveys using ultrasound and X-ray analysis showed that 3%–12% of Tibetans had hydatidosis (both CHD and alveolar hydatid disease cases) in Ganzi, Sichuan Province [2], and 1%–10% in south Qinghai Province [3,4], Ningxia [5], and Gansu [6]. In these regions as well, more than 50% of 170 million domestic animals (58% being sheep) were infected with CHD [1]. The disease is hyperendemic in western China because of poor economic development; limited community knowledge of CHD; widespread, small-scale household animal production; home killing of livestock; and the feeding of dogs with uncooked offal

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Conclusion