Transmission dynamics of re-emerging rabies in domestic dogs of rural China.

Huaiyu Tian,Yunzhi Zhang,Yun Feng,Hailin Zhang,Philippe Lemey,Yuzhen Zhang,Mandev S Gill,Simon Dellicour,Bram Vrancken,Hua Tan,Weihong Yang,Oliver G Pybus,Qiqi Yang,Bernard Cazelles,Yidan Li,Nils Chr Stenseth

doi:10.1371/journal.ppat.1007392

Abstract

Despite ongoing efforts to control transmission, rabies prevention remains a challenge in many developing countries, especially in rural areas of China where re-emerging rabies is under-reported due to a lack of sustained animal surveillance. By taking advantage of detailed genomic and epidemiological data for the re-emerging rabies outbreak in Yunnan Province, China, collected between 1999 and 2015, we reconstruct the demographic and dispersal history of domestic dog rabies virus (RABV) as well as the dynamics of dog-to-dog and dog-to-human transmission. Phylogeographic analyses reveal a lower diffusion coefficient than previously estimated for dog RABV dissemination in northern Africa. Furthermore, epidemiological analyses reveal transmission rates between dogs, as well as between dogs and humans, lower than estimates for Africa. Finally, we show that reconstructed epidemic history of RABV among dogs and the dynamics of rabid dogs are consistent with the recorded human rabies cases. This work illustrates the benefits of combining phylogeographic and epidemic modelling approaches for uncovering the spatiotemporal dynamics of zoonotic diseases, with both approaches providing estimates of key epidemiological parameters.

Highlights

Rabies remains a significant threat to public health in the 21st century [1], causing around 60,000 human fatalities worldwide each year [2]
It is thought that the number of human deaths due to rabies virus (RABV) infections is underestimated, and that the dynamics of the virus in dog populations is poorly understood
Analyses of case records date the first documented rabies case in Yunnan Province back to 1956. These data indicate that an epidemic wave of rabies occurred in the 1980s and that, from the mid-1990s onwards, human rabies cases were reported only sporadically in the region

Summary

Introduction

Rabies remains a significant threat to public health in the 21st century [1], causing around 60,000 human fatalities worldwide each year [2]. Rabies control in the developing world is currently hindered by a lack of timely and accurate data about rabies cases in both humans and animals [3]. It is thought that the number of human deaths due to rabies virus (RABV) infections is underestimated, and that the dynamics of the virus in dog populations is poorly understood. These uncertainties inevitably hamper improvements in disease control strategies and the evaluation of control measures. More than 90% of human rabies cases in China occur in rural regions [6] where the proportion of vaccinated dogs is very low [7]. A better quantitative understanding of rabies epidemiology in dogs is needed to help predict future vaccine demand in China and other developing countries

Objectives

Methods

Results

Discussion

Conclusion