A high-resolution genetic signature of demographic and spatial expansion in epizootic rabies virus

doi:10.1073/pnas.0700741104

A high-resolution genetic signature of demographic and spatial expansion in epizootic rabies virus

^†Department of Biology and Center for Disease Ecology, Emory University, 1510 Clifton Road, Atlanta, GA 30322;
^§Rabies Section, Centers for Disease Control and Prevention, 1600 Clifton Road, Mail-stop G33, Atlanta, GA 30333; and
^¶Department of Biostatistics, Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, GA 30322

Edited by John C. Avise, University of California, Irvine, CA, and approved March 26, 2007 (received for review January 26, 2007)

Abstract

Emerging pathogens potentially undergo rapid evolution while expanding in population size and geographic range during the course of invasion, yet it is generally difficult to demonstrate how these processes interact. Our analysis of a 30-yr data set covering a large-scale rabies virus outbreak among North American raccoons reveals the long lasting effect of the initial infection wave in determining how viral populations are genetically structured in space. We further find that coalescent-based estimates derived from the genetic data yielded an amazingly accurate reconstruction of the known spatial and demographic dynamics of the virus over time. Our study demonstrates the combined evolutionary and population dynamic processes characterizing the spread of pathogen after its introduction into a fully susceptible host population. Furthermore, the results provide important insights regarding the spatial scale of rabies persistence and validate the use of coalescent approaches for uncovering even relatively complex population histories. Such approaches will be of increasing relevance for understanding the epidemiology of emerging zoonotic diseases in a landscape context.

Footnotes

^‡To whom correspondence should be addressed. E-mail: rbiek{at}emory.edu
Author contributions: R.B. and L.A.R. designed research; R.B. and J.C.H. performed research; L.A.W. and C.E.R. contributed new reagents/analytic tools; R.B. and L.A.W. analyzed data; and R.B., C.E.R., and L.A.R. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. DQ886039–DQ886076, DQ888332–DQ888369, and EF508133–EF508144).
This article contains supporting information online at www.pnas.org/cgi/content/full/0700741104/DC1.
Abbreviations:

HPD,

highest posterior density;

Re,

effective reproductive number;

RRV,

raccoon rabies virus.