National borders effectively halt the spread of rabies: the current rabies epidemic in China is dislocated from cases in neighboring countries

PLoS Negl Trop Dis. 2013;7(1):e2039. doi: 10.1371/journal.pntd.0002039. Epub 2013 Jan 31.

Abstract

China has seen a massive resurgence of rabies cases in the last 15 years with more than 25,000 human fatalities. Initial cases were reported in the southwest but are now reported in almost every province. There have been several phylogenetic investigations into the origin and spread of the virus within China but few reports investigating the impact of the epidemic on neighboring countries. We therefore collected nucleoprotein sequences from China and South East Asia and investigated their phylogenetic and phylogeographic relationship. Our results indicate that within South East Asia, isolates mainly cluster according to their geographic origin. We found evidence of sporadic exchange of strains between neighboring countries, but it appears that the major strain responsible for the current Chinese epidemic has not been exported. This suggests that national geographical boundaries and border controls are effective at halting the spread of rabies from China into adjacent regions. We further investigated the geographic structure of Chinese sequences and found that the current epidemic is dominated by variant strains that were likely present at low levels in previous domestic epidemics. We also identified epidemiological linkages between high incidence provinces consistent with observations based on surveillance data from human rabies cases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Asia, Southeastern / epidemiology
  • China / epidemiology
  • Cluster Analysis
  • Dogs
  • Epidemics*
  • Genotype
  • Humans
  • Molecular Epidemiology
  • Phylogeography
  • Rabies / epidemiology*
  • Rabies / transmission*
  • Rabies / virology
  • Rabies virus / classification
  • Rabies virus / genetics
  • Rabies virus / isolation & purification*

Grant support

This work was supported by the funding from the National Department Public Benefit Research Foundation (201103032), the Pathogens Network Monitoring Technology Research Program (2008ZX10004-008) and the National Basic Research Program of China (2012CB721100). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.