Ecology, genetic diversity, and phylogeographic structure of andes virus in humans and rodents in Chile.
Andes virus (ANDV) is the predominant etiologic agent of hantavirus cardiopulmonary syndrome (HCPS) in southern South America. In Chile, serologically confirmed human hantavirus infections have occurred throughout a wide latitudinal distribution extending from the regions of Valparaíso (32 to 33 degrees S) to Aysén (46 degrees S) in southern Patagonia. In this study, we found seropositive rodents further north in the Coquimbo region (30 degrees S) in Chile. Rodent seroprevalence was 1.4%, with Oligoryzomys longicaudatus displaying the highest seroprevalence (5.9%), followed by Abrothrix longipilis (1.9%) and other species exhibiting </=0.6% seropositivity. We sequenced partial ANDV small (S) segment RNA from 6 HCPS patients and 32 rodents of four different species collected throughout the known range of hantavirus infection in Chile. Phylogenetic analyses showed two major ANDV South (ANDV Sout) clades, congruent with two major Chilean ecoregions, Mediterranean (Chilean matorral [shrubland]) and Valdivian temperate forest. Human and rodent samples grouped according to geographic location. Phylogenetic comparative analyses of portions of S and medium segments (encoding glycoproteins Gn and Gc) from a subset of rodent specimens exhibited similar topologies, corroborating two major ANDV Sout clades in Chile and suggesting that yet unknown factors influence viral gene flow and persistence throughout the two Chilean ecoregions. Genetic algorithms for recombination detection identified recombination events within the S segment. Molecular demographic analyses showed that the virus is undergoing purifying selection and demonstrated a recent exponential growth in the effective number of ANDV Sout infections in Chile that correlates with the increased number of human cases reported. Although we determined virus sequences from four rodent species, our results confirmed O. longicaudatus as the primary ANDV Sout reservoir in Chile. While evidence of geographic differentiation exists, a single cosmopolitan lineage of ANDV Sout remains the sole etiologic agent for HCPS in Chile.
Medina
Rafael A
RA
Center for Infectious Diseases and Immunity, Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131, USA.
Torres-Perez
Fernando
F
Galeno
Hector
H
Navarrete
Maritza
M
Vial
Pablo A
PA
Palma
R Eduardo
RE
Ferres
Marcela
M
Cook
Joseph A
JA
Hjelle
Brian
B
D000818:Animals; D002677:Chile / Q000453:epidemiology; D005260:Female; D014644:Genetic Variation; D005843:Geography; D006476:Orthohantavirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D018778:Hantavirus Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology*; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D011995:Recombination, Genetic; D012377:Rodentia; D017422:Sequence Analysis, DNA; D016036:Seroepidemiologic Studies
D012367:RNA, Viral