Distribution of Marburg virus in Africa: An evolutionary approach.
The aim of this study was to investigate the origin and geographical dispersion of Marburg virus, the first member of the Filoviridae family to be discovered. Seventy-three complete genome sequences of Marburg virus isolated from animals and humans were retrieved from public databases and analysed using a Bayesian phylogeographical framework. The phylogenetic tree of the Marburg virus data set showed two significant evolutionary lineages: Ravn virus (RAVV) and Marburg virus (MARV). MARV divided into two main clades; clade A included isolates from Uganda (five from the European epidemic in 1967), Kenya (1980) and Angola (from the epidemic of 2004-2005); clade B included most of the isolates obtained during the 1999-2000 epidemic in the Democratic Republic of the Congo (DRC) and a group of Ugandan isolates obtained in 2007-2009. The estimated mean evolutionary rate of the whole genome was 3.3×10(-4) substitutions/site/year (credibility interval 2.0-4.8). The MARV strain had a mean root time of the most recent common ancestor of 177.9years ago (YA) (95% highest posterior density 87-284), thus indicating that it probably originated in the mid-XIX century, whereas the RAVV strain had a later origin dating back to a mean 33.8 YA. The most probable location of the MARV ancestor was Uganda (state posterior probability, spp=0.41), whereas that of the RAVV ancestor was Kenya (spp=0.71). There were significant migration rates from Uganda to the DRC (Bayes Factor, BF=42.0) and in the opposite direction (BF=5.7). Our data suggest that Uganda may have been the cradle of Marburg virus in Africa.
Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy. Electronic address: gianguglielmo.zehender@unimi.it.
Gianguglielmo
G
Zehender
Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy.
Chiara
C
Sorrentino
Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy.
Carla
C
Veo
Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy.
Lisa
L
Fiaschi
Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy.
Sonia
S
Gioffrè
Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy.
Erika
E
Ebranati
Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
Elisabetta
E
Tanzi
Department of Infectious Parasitic and Immunomediated Diseases, National Institute of Health, Rome, Italy.
Massimo
M
Ciccozzi
Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy.
Alessia
A
Lai
Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy.
Massimo
M
Galli
D000349:Africa / Q000453:epidemiology; D000818:Animals; D001499:Bayes Theorem; D005075:Biological Evolution; D051456:Gene Flow; D006801:Humans; D016013:Likelihood Functions; D008379:Marburg Virus Disease / Q000453:epidemiology; D029024:Marburgvirus / Q000235:genetics / Q000472:pathogenicity; D010802:Phylogeny; D058974:Phylogeography; D012641:Selection, Genetic
Geographic dispersion; Marburg virus; Phylodynamics; Ravn virus