a case of hps was diagnosed at the uruguayan department of maldonado in february 2005 . the patient worked and lived in a greenhouse near punta ballena ( 3455s , 553w ) . to determine the source of the patient s infection , during march 1215 and december 1011 , 2005 , small mammals were trapped near where the patient had lived or worked during the 6 weeks before the onset of symptoms and in nearby habitats . taxonomic identification of seropositive rodents was corroborated by analyzing skull characteristics and by comparing mitochondrial dna sequences with sequences available in genbank . voucher specimens were deposited at the mammal collection of the facultad de ciencias , universidad de la repblica , montevideo , uruguay . in march 2005 , during 1,100 trap nights , 133 rodents belonging to the subfamilies sigmodontinae ( family cricetidae ) and murinae ( family muridae ) were collected ( trap success rate 12.1% ) . nine months later , in december , 45 rodents belonging to the same subfamilies were collected ( trap success rate 8.2% ) ( table 1 ) . immunoglobulin g antibodies to maciel hantavirus were detected by elisa ( 6 ) in 5 rodents ( collected in march ) : 4 long - nosed mice ( genus oxymycterus ) , 6% seroprevalence , and 1 black - footed pigmy rice rat ( oligoryzomys nigripes ) , 3.2% seroprevalence . ( maciel antigen for the elisas was kindly provided by s. levis , instituto nacional de enfermedades virales humanas , argentina . ) a serum dilution was considered positive if optical density was > 0.2 u after adjustment . a serum titer > 400 was considered positive . molecular methods corroborated the field identification of the 1 black - footed pygmy rice rat and assigned the 4 long - nosed mice to 1 of the 2 species of oxymycterus inhabiting uruguay : o. nasutus . all 5 specimens ( 3 male , 2 female ) were captured in areas of human disturbance : road borders , shrublands , and artificial pine woods ( acacia spp . or eucalyptus spp . ) . total rna was extracted from lung tissue of seropositive rodents and from serum of the hps patient ( 6 ) . nested or seminested pcrs ( rt - pcrs ) were performed for partial small ( s ) and medium ( m ) segments ( 8,9 ) . viral rna was detected in 4 of 5 rodents that were seropositive for m or s segments ; material was not available for viral rna testing for 1 o. nasutus mouse . m segment amplicons ( g2 glycoprotein  encoding region ) were 735 bp ; s segment amplicons were 416 bp . similarly , the sequence of the m segment from sample pb981 was not long enough to be included in the phylogenetic analyses . for sequence comparison and phylogenetic analyses , sequences of representative new and old world hantaviruses were obtained from genbank . phylogenetic analyses were conducted by using bayesian inference and maximum parsimony ( figures 1 , 2 ) . majority - rule consensus tree obtained in the bayesian analysis of sequences of the medium segment of juquitiba - like hantavirus isolated from 2 nonrelated rodent species . alignment and editing of nucleotide sequences were conducted by using bioedit v7.0.9.0 ( www.mbio.ncsu.edu/bioedit/bioedit.html ) . estimation of the suitable model of nucleotide substitution and phylogenetic analyses were carried out by using modelgenerator ( http://bioinf.may.ie/software/modelgenerator ) , mrbayes v3.1.2 ( bayesian analysis ; http://mrbayes.csit.fsu.edu ) , and paup * 4.0b10 ( maximum - parsimony analysis ; http://paup.csit.fsu.edu ) . bayesian analyses were conducted under the general time reversible + gamma + proportion invariant model . two runs of 4 chains each ( 1 cold , 3 heated , temperature 0.20 ) were run for 3 million generations ; trees were sampled every 100 generations . convergence was assessed by using the average standard deviation in partition frequency values across independent analyses with a threshold value of 0.01 ; burn - in was set to 25% . seropositive specimens from uruguay are as follows : pb1033 ( black - footed pigmy rice rat , oligoryzomys nigripes ) and pb1002 ( long - nosed mouse , oxymycterus nasutus ) , genbank accession nos . eu564726 and eu564725 , respectively . analyzed hantavirus sequences are hantaan , ( dq371905 ) , seoul ( sa7716 ) , juquitiba ( ay963900 , on10386 , on15691 , on15827 , hu206776 , hu238063 , hu193256 ) , maporal ( ay363179 ) , andes central plata ( ay204678 , ay204677 , ay204679 , ay204680 , eu564721 ) , lechiguanas ( af028022 , af283897 ) , bermejo ( af028025 ) , hu39694 ( af028023 ) , orn ( af028024 ) , andes ( af291703 , af324901 , af028026 , ay228238 ) , castelo dos sonhos ( af307326 ) , maciel ( af028051 ) , araraquara ( af307327 , ay970821 ) , pergamino ( af028028 ) , laguna negra ( af005728 ) , sin nombre  like ( l37903 , af030552 , af030551 ) , puumala ( u14136 , u22418 ) , and muju ( ef198413 ) . majority - rule consensus tree obtained in the bayesian analysis of sequences of the small segment of juquitiba - like hantavirus isolated from 2 nonrelated rodent species . seropositive specimens from uruguay are as follows : pb1033 ( black - footed pigmy rice rat , oligoryzomys nigripes ) , pb981 and pb1002 ( long - nosed mouse , oxymycterus nasutus ) , genbank accession nos . eu564724 , eu564722 , eu564723 , respectively . analyzed hantavirus sequences are seoul ( nc0052361 ) , hantaan ( ab1279981 ) , laguna negra ( af005727 ) , rio mamore ( u52136 ) , alto paraguay ( dq345762 ) , andes central plata ( eu564711 , eu564717 , eu564718 , eu564719 , eu564716 , eu564720 , eu564715 ) , lechiguanas ( eu564713 , af482714 ) , bermejo ( af482713 ) , eembucu ( dq345763 ) , hu39694 ( af482711 ) , orn ( af482715 , af325966 ) , araucaria ( ay740627 , ay712944 , ay740631 , ay740633 , ay740625 , ay740628 , ay740632 , ay7406261 , ay7406221 , ay7406241 , ay740630 , ay740629 , ay740623 ) , juquitiba ( hu063 , ef446280 , hu256 , eu373729 , eu373731 ) , itapa ( dq345766 , dq345765 ) , andes ( af291702 , af482712 , af324902 , ay228237 ) , maciel ( af482716 ) , araraquara ( af307325 ) , paranoa ( ef576661 ) , pergamino ( af482717 ) , sin nombre  like ( u47135 , u29210 , l37904 , l25784 ) , calabazo ( af395443 ) ; el moro canyon ( u11427 ) , limestone canyon ( af307322 ) , bayou ( l36929 ) , catacamas ( dq256126 ) , muleshoe ( u54575 ) , puumala ( ab010731 , af294652 ) , and prospect hill ( m34011 , u47136 ) . scale bar indicates expected changes per site . bayesian analysis based on partial m segment sequences ( figure 1 ) showed that the sequences retrieved from 1 black - footed pygmy rice rat ( pb1033 ) and 1 long - nosed mouse ( pb1002 ) form a strongly supported clade ( posterior probability [ pp ] 0.97 ) . the uruguay clade is sister to a clade ( pp 1.00 ) formed by juquitiba ( juq ) hantaviruses retrieved from black - footed pigmy rice rats ( prefix on and ay963900 ) in brazil and human hps case - patients ( hu ) in brazil . we refer to this strongly supported ( pp 1.00 ) clade formed by brazil and uruguay sequences as the juq - like clade . maximum - parsimony analysis ( available from a. delfraro upon request ) also recovers the juq - like clade ( bootstrap support 100% ) . phylogenetic analysis of s - segment sequences showed a broader taxonomic coverage than that of the m segment ( figure 2 ) . the clade containing the viruses from uruguay is part of a larger and strongly supported ( pp 1.00 ) clade also formed by juq hantaviruses from argentina ( eu373731 from an hps case - patient ; eu373729 from a black - footed pygmy rice rat ) and brazil ( hu256 and hu063 from hps case - patients ; ef446280 from a black - footed pygmy rice rat ) , as well as by araucaria viruses ( from hps case - patients from brazil ) and itapa viruses from southern paraguay , a viral lineage also detected in black - footed pygmy rice rats ( dq345765 - 66 ) . ( sequences from brazil juq hantaviruses , isolated from o. nigripes and hps case - patients , were kindly provided by s. levis , instituto nacional de enfermedades virales humanas , argentina . ) remarkably , juq and araucaria viruses do not form monophyletic groups . the juq - like clade is sister to a clade formed by hu39694 , eembucu , bermejo , andes central plata , lechiguanas , and oran ; however , this relationship is weakly supported . maximum - parsimony analysis ( not shown ) also recovers a strongly supported juq - like clade ( bootstrap support 100% ) . sequence comparison for m and s segments showed that hantaviruses that cluster in the juq - like clade , including the uruguay samples , form a homogeneous group that shows a high identity percentage at the nucleotide and amino acid levels . under the general time reversible + gamma + proportion invariant model , the most similar lineages to the juq - like viruses are hu39694 for the m segment and oran for the s segment ( table 2 ) . * parameters used in the analyses were medium segment , gamma shape 0.29 , proportion of invariable sites 0.18 ; small segment , gamma shape 0.59 , proportion of invariable sites 0.38 . sequence comparisons were conducted by using mega version 4.0 ( www.megasoftware.net ) and modelgenerator ( http://bioinf.may.ie/software/modelgenerator ) . distance between the juq - like clade and several south american hantavirus lineages , under the general time reversible + gamma + proportion invariant model . genetic and phylogenetic analyses showed that in maldonado , o. nigripes and o. nasutus carried the same type of hantavirus . moreover , the viruses from uruguay form a well - supported clade with juq , araucaria , and itapa viruses from hps case - patients and black - footed pigmy rice rats ( o. nigripes ) from argentina , brazil , and paraguay . in view of the high sequence similarity and the well - supported phylogenetic relationship , we propose that all of these viruses should be considered as juq - like hantaviruses . additional studies will clarify whether all the viruses in the juq - like clade represent 1 viral type . antibodies to hantavirus in uruguay oxymycterus spp . may be interpreted as a secondary infection ( spillover ) ( 10 ) . interestingly , in the trapping area , the long - nosed mice are the most abundant rodent species , and the seroprevalence of hantavirus among them ( 6% ) is higher than that previously reported in uruguay ( 6 ) . black - footed pygmy rice rats are the second most abundant rodent captured ; however , the seroprevalence of hantavirus among them ( 3.2% ) is lower . the presence of the same or similar hantavirus in 2 different rodent species may represent an event of host switching ( 5,1114 ) . hantaviruses detected in maldonado are similar , although not identical , and are carried by 2 distantly related rodent species that belong to different tribes , akodontini ( oxymycterus ) and oryzomyini ( oligoryzomys ) . derived hantaviruses is needed to elucidate whether long - nosed mice are true reservoirs or only incidental hosts . clarification may come from complete sequencing of m and s segments , viral isolation attempts , and new capture expeditions to look for more seropositive long - nosed mice in different areas of uruguay .
serologic and genetic analyses indicate that a juquitiba - like hantavirus circulates in maldonado , uruguay . 
 this virus is carried by 2 rodent species , oligoryzomys nigripes and oxymycterus nasutus . 
 the same hantavirus in 2 nonrelated species can be explained by a spillover infection or a host - switching event .