National Center for Biotechnology Information NCBI NLM MEDLINE humans pubmed abstract nih national institutes of health national library of medicine research support non-u.s. gov't u.s. gov't non-p.h.s. N.I.H. Extramural plague / epidemiology* DNA polymerase chain reaction Polymorphism madagascar / epidemiology analysis of variance bacterial / chemistry phylogeography cluster analysis plague / microbiology* yersinia pestis / genetics* amy j vogler paul keim molecular typing minisatellite repeats / genetics single nucleotide / genetics pmid:21931876 pmc3172189 doi:10.1371/journal.pntd.0001319 fabien chan molecular epidemiology / methods