Ocozocoautla de Espinosa virus and hemorrhagic fever, Mexico.
Article Type: Report
Subject: Hemorrhagic fever (Causes of)
Hemorrhagic fever (Diagnosis)
Hemorrhagic fever (Research)
Arenaviruses (Health aspects)
Arenaviruses (Research)
Arenaviruses (Genetic aspects)
RNA (Physiological aspects)
RNA (Research)
Authors: Cajimat, Maria N.B.
Milazzo, Mary Louise
Bradley, Robert D.
Fulhorst, Charles F.
Pub Date: 03/01/2012
Publication: Name: Emerging Infectious Diseases Publisher: U.S. National Center for Infectious Diseases Audience: Academic; Professional Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2012 U.S. National Center for Infectious Diseases ISSN: 1080-6040
Issue: Date: March, 2012 Source Volume: 18 Source Issue: 3
Topic: Event Code: 310 Science & research
Geographic: Geographic Scope: Mexico Geographic Code: 1MEX Mexico
Accession Number: 283455621
Full Text: Tacaribe serocomplex viruses (family Arenaviridae, genus Arenavirus) comprise Bear Canyon virus, Tamiami virus, and Whitewater Arroyo virus in the United States; Tacaribe virus (TCRV) on Trinidad; Chapare virus (CHPV) and Machupo virus (MACV) in Bolivia; Guanarito virus (GTOV) in Venezuela; Junin virus (JUNV) in Argentina; Sabia virus (SABV) in Brazil; and 9 other species (1). Provisional species in the Tacaribe serocomplex include Big Brushy Tank virus, Catarina virus, Skinner Tank virus, and Tonto Creek virus in the United States (2-4), and Real de Catorce virus in Mexico (5).

Five members of the Tacaribe serocomplex (CHPV, GTOV, JUNV, MACV, and SABV) cause hemorrhagic fever in humans (6,7). Diseases caused by these viruses are zoonoses. Specific members of the rodent family Cricetidae (8) are the principal hosts of the Tacaribe serocomplex viruses for which natural host relationships have been well characterized. For example, the short-tailed cane mouse (Zygodontomys brevicauda) in western Venezuela is the principal host of GTOV (9,10), and the drylands vesper mouse (Calomys musculinus) in central Argentina is the principal host of JUNV (11).

The history of human disease in North America includes large epidemics of highly lethal hemorrhagic fever during 1545-1815 in Mexico (12). These epidemics primarily affected native inhabitants of the highlands. Medical historians theorized that the hemorrhagic fever was caused by Tacaribe serocomplex virus(es) or other viruses associated with rodents native to Mexico (13).

A recently published study reported antibody against a Tacaribe serocomplex virus in 3 (25.0%) of 12 Mexican deer mice (Peromyscus mexicanus) and 0 of 29 other cricetid rodents captured in the municipality of Ocozocoautla de Espinosa, State of Chiapas, Mexico (14). Analyses of serologic data suggested that the 3 antibody-positive deer mice were infected with an arenavirus that is antigenically more closely related to the South American hemorrhagic fever arenaviruses than to other North American Tacaribe serocomplex viruses. The objective of this study was to determine the identity of the Tacaribe serocomplex virus associated with P. mexicanus deer mice in western Chiapas.

Materials and Methods

Kidney samples from the 3 antibody-positive Mexican deer mice, Mexican deer mouse TK93314 (15) and 8 other antibody-negative Mexican deer mice, 18 southern pygmy mice (Baiomys musculus), and 11 Jaliscan cotton rats (Sigmodon mascotensis) were tested for arenavirus by cultivation in monolayers of Vero E6 cells (16). The 3 antibody-positive deer mice (TK93319, TK93321, TK93325) and 38 antibody-negative rodents were captured on July 16, 2000, at a locality (Universal Transverse Mercator coordinates 15-451772E, 1864243N; elevation 1,021 m) in the municipality of Ocozocoautla de Espinosa (Figure 1).


Kidney samples from the 3 antibody-positive animals also were tested for arenavirus nucleocapsid (N) protein gene RNA. First-strand cDNA was synthesized by using SuperScript III Reverse Transcriptase (Invitrogen Corp., Carlsbad, CA, USA) and oligont 19C-cons (18). The first-round PCR used MasterTaq Kit (5 PRIME, Inc., Gaithersburg, MD, USA) and 19C-cons and either AVNP42 (5 '-GCCGCGGACTGGGAGGGCA-3') or AVNP122 (5 '-GCCGCGGACTGGGGAGGCACTG-3'). The second-round (heminested) PCR used Master Taq Kit and either AVNP42 and oligont 1010C (19), AVNP122 and 1010C, or AVNP115 (5'-CCAATATA AGGCCAACCATCG-3') and AVNP149 (5'-CGCACA GTGGATCCTAGGCATAGTGTC-3'). The nucleotide sequence of a 3,380-nt fragment of the small genomic segment of arenavirus AV B1030026 (GenBank accession no. JN897398) was then determined from the first-strand cDNA from antibody-positive deer mouse TK93325 by using a series of 3 heminested PCRs. The 3,380-nt fragment extended from within the 5' noncoding region, through the glycoprotein precursor (GPC) gene, intergenic region, and N protein gene, and into the 3' noncoding region.

Analyses of GPC sequences, N protein sequences, and nucleotide sequences included AV B1030026, 8 other viruses from North America, and 15 viruses from South America (Figure 2). Sequences in each amino acid sequence dataset were aligned by using ClustalW version 2.0.12 (21). The sequences in each nucleotide sequence dataset were aligned manually, and alignment was guided by the corresponding computer-generated amino acid sequence alignment. Sequence nonidentities were equivalent to uncorrected (p) distances.

Phylogenetic analyses of nucleotide sequences were conducted by using MRBAYES version 3.1.2 (22) and programs in PAUP* (23). Bayesian analyses used the general time reversible + proportion invariant + [GAMMA] model with a site-specific gamma distribution and the following options in MRBAYES version 3.1.2: two simultaneous runs of 4 Markov chains, 10 million generations, and sample frequency every 1,000th generation. The first 1,000 trees were discarded after review of the likelihood scores, convergence statistics, and potential scale reduction factors. A consensus tree (50% majority rule) was constructed from the remaining trees. Probability values in support of the clades were calculated a posteriori, and clades with probability values [greater than or equal to] 0.95 were considered supported by the data (20).


Arenavirus was not isolated from any kidney samples. However, N protein gene RNA of arenavirus AV B1030022 and N protein gene RNA of arenavirus AV B1030026 were detected in samples of kidney from Mexican deer mice TK93321 and TK93325, respectively. The sequence of a 746-nt fragment of the N protein gene of AV B1030022 (GenBank accession no. JN897399) was 96.4% identical to the nucleotide sequence of the homologous region of the N protein gene of AV B1030026.

Bayesian analyses of complete GPC gene sequences (Figure 2, panel A) and complete N protein gene sequences (Figure 2, panel B) separated the Tacaribe serocomplex viruses into 4 groups (A, B, C, D). Arenavirus AV B1030026 was included in group B with Amapari virus (AMAV), Cupixi virus (CPXV), TCRV, and the 5 viruses from South America known to cause hemorrhagic fever in humans. Group D is exclusively North American, groups A and C are exclusively South American, and probability values calculated a posteriori indicate strong support for monophyly of viruses in each group and strong support for the sister relationship between AV B1030026 and TCRV.

Nonidentities between amino acid sequences of the GPC and N protein of AV B1030026 and amino acid sequences of homologous sequences of the 8 other viruses from North America ranged from 47.8% to 52.1% and from 44.3% to 45.4%, respectively. Similarly, nonidentities between the amino acid sequences of the GPC and N protein of AV B1030026 and homologous sequences of the 8 other members of group B ranged from 24.7% to 46.8% and from 16.1% to 32.3%, respectively (Table). Nonidentity between the GPC amino acid sequences of AV B1030026 and TCRV was greater than the nonidentity between the GPC amino acid sequences of CHPV and SABV (Table), among the GPC amino acid sequences of the 5 viruses in group A (range 15.8%-23.7%), and between the GPC amino acid sequences of Latino virus (LATV) and Oliveros virus (20.6%). Last, nonidentity between the N protein amino acid sequences of AV B1030026 and TCRV was greater than the nonidentities between N protein amino acid sequences of 7 viruses from South America in 5 pairwise comparisons: AMAV and CPXV, AMAV and GTOV, CPXV and GTOV, CHPV and SABV, JUNV and MACV (Table).



Arenaviruses AV B1030022 and AV B1030026 are direct evidence that arenaviruses phylogenetically closely related to the South American hemorrhagic fever arenaviruses are enzootic in North America. Results of Bayesian analyses of GPC gene sequence data, Bayesian analyses of the N protein gene sequence data, and pairwise comparisons of amino acid sequences collectively indicate that AV B1030026 is a strain of a novel species (proposed name Ocozocoautla de Espinosa virus) in the family Arenaviridae, genus Arenavirus (1).

The hallmark of the arenaviruses is their ability to establish chronic infections in their respective principal hosts. The failure to isolate arenavirus from Mexican deer mice in this study could be caused by small sample size or poor specimen quality. Alternatively, a cricetid rodent other than the Mexican deer mouse is the principal host of Ocozocoautla de Espinosa virus (OCEV).

Members of the rodent family Cricetidae, subfamily Sigmodontinae (8) are the principal hosts of GTOV, JUNV, MACV, and other Tacaribe serocomplex viruses in South America for which natural host relationships have been well characterized (24). The available fossil record suggests that sigmodontine rodents originally invaded South America from North America after formation of the Panamanian Isthmus 2.5-3.5 million years ago.

The presence of OCEV in Mexico suggests that the last common ancestor of the 9 viruses in group B (Figure 2) emerged in North America. As such, arenaviruses phylogenetically closely related to OCEV, in association with cricetid rodents, may be widely distributed in North America. We note that antibody against AMAV has been found in northern pygmy mice (Baiomys taylori) captured in Texas and northern Mexico (14).

The history of the State of Chiapas includes an outbreak of a highly lethal hemorrhagic fever in 1967 (17). Antibody against Parana virus (PARV) or LATV was found in convalescent-phase serum samples from persons who survived the fever, by an assay in which antibodies against PARV and LATV reacted with GTOV, JUNV, TCRV, and other Tacaribe serocomplex viruses (25). Of note, hemorrhagic fever in Chiapas clinically resembled hemorrhagic fevers caused by arenaviruses from South America, the outbreak was preceded by large-scale destruction of forested areas in the epidemic area, the P. mexicanus deer mouse is a relatively common species in forests of southern Mexico (26), and abundance of rodents in and around houses in the epidemic area had increased to disturbing proportions in the 3-year period before 1967 (17). Hypothetically, OCEV or an arenavirus phylogenetically closely related to OCEV was the etiologic agent in the hemorrhagic fever epidemic in Chiapas in 1967 and presently is the cause of a human disease that is clinically indistinct from dengue hemorrhagic fever and other severe febrile illnesses that are endemic to Chiapas.

It is generally accepted that humans usually become infected with arenaviruses by inhalation of virus in aerosolized droplets of secretions or excretions from infected rodents. Another source of infection may be ingestion of infected rodents (27).

Human consumption of wild rodents is common in rural areas in some regions of Mexico. For example, Mexican deer mice and other cricetid rodents are consumed by the Tzeltal Indians in the highlands of Chiapas (28). Future studies on arenaviruses native to North America should include work to assess whether humans who consume wild rodents or live or work in close association with cricetid rodents in the highlands of Mexico acquire illness from OCEV or other North American Tacaribe serocomplex viruses.


We thank Robert Baker for facilitating loan of tissue samples from the Museum of Texas Tech University.

This study was supported by National Institutes of Health grants AI-41435 and AI-67947.

Dr Cajimat is a senior postdoctoral research scientist at The University of Texas Medical Branch, Galveston. Her scientific interests include the pathogenesis of infection and disease in laboratory animal models of the human diseases caused by arenaviruses and hantaviruses.


(1.) Salvato MS, Clegg JC, Buchmeier MJ, Charrel RN, Gonzalez J-P, Lukashevich IS, et al. Family Arenaviridae. In: Fauquet CM, Mayo MA, Maniloff J, Desselberger U, Ball LA, editors: Virus taxonomy: eighth report of the International Committee on Taxonomy of Viruses. New York: Elsevier Academic Press; 2005. p. 725-33.

(2.) Milazzo ML, Cajimat MNB, Haynie ML, Abbott KD, Bradley RD, Fulhorst CF. Diversity among Tacaribe serocomplex viruses (family Arenaviridae) naturally associated with the white-throated woodrat (Neotoma albigula) in the southwestern United States. Vector Borne Zoonotic Dis. 2008;8:523-40. http://dx.doi.org/10.1089/ vbz.2007.0239

(3.) Cajimat MN, Milazzo ML, Bradley RD, Fulhorst CF. Catarina virus, an arenaviral species principally associated with Neotoma micropus (southern plains woodrat) in Texas. Am J Trop Med Hyg. 2007;77:732-6.

(4.) Cajimat MN, Milazzo ML, Borchert JN, Abbott KD, Bradley RD, Fulhorst CF. Diversity among Tacaribe serocomplex viruses (family Arenaviridae) naturally associated with the Mexican woodrat (Neotoma mexicana). Virus Res. 2008;133:211-7. http://dx.doi. org/10.1016/j.virusres.2008.01.005

(5.) Inizan CC, Cajimat MN, Milazzo ML, Barragan-Gomez A, Bradley RD, Fulhorst CF. Genetic evidence for a Tacaribe serocomplex virus, Mexico. Emerg Infect Dis. 2010;16:1007-10.

(6.) Delgado S, Erickson BR, Agudo R, Blair PJ, Vallejo E, Albarino CG, et al. Chapare virus, a newly discovered arenavirus isolated from a fatal hemorrhagic fever case in Bolivia. PLoS Pathog. 2008;4:e1000047. http://dx.doi.org/10.1371/journal.ppat.1000047

(7.) Peters CJ. Human infection with arenaviruses in the Americas. Curr Top Microbiol Immunol. 2002;262:65-74. http://dx.doi. org/10.1007/978-3-642-56029-3_3

(8.) Musser GG, Carleton MD. Family Cricetidae. In: Wilson DE, Reeder DM, editors. Mammal species of the world: a taxonomic and geographic reference. 3rd ed. Baltimore; The Johns Hopkins University Press; 2005. p. 955-1189.

(9.) Fulhorst CF, Bowen MD, Salas RA, Duno G, Utrera A, Ksiazek TG, et al. Natural rodent host associations of Guanarito and Pirital viruses (family Arenaviridae) in central Venezuela. Am J Trop Med Hyg. 1999;61:325-30.

(10.) Milazzo ML, Cajimat MN, Duno G, Duno F, Utrera A, Fulhorst CF. Transmission of Guanarito and Pirital viruses among wild rodents, Venezuela. Emerg Infect Dis. 2011;17:2209-15. http://dx.doi. org/10.3201/eid1712.110393

(11.) Mills JN, Ellis BA, McKee KT Jr, Calderon GE, Maiztegui JI, Nelson GO, et al. A longitudinal study of Junin virus activity in the rodent reservoir of Argentine hemorrhagic fever. Am J Trop Med Hyg. 1992;47:749-63.

(12.) Acuna-Soto R, Romero LC, Maguire JH. Large epidemics of hemorrhagic fevers in Mexico 1545-1815. Am J Trop Med Hyg. 2000;62:733-9.

(13.) Marr JS, Kiracofe JB. Was the huey cocoliztli a haemorrhagic fever? Med Hist. 2000;44:341-62.

(14.) Milazzo ML, Barragan-Gomez A, Hanson JD, Estrada-Franco JG, Arellano E, Gonzalez-Cozatl FX, et al. Antibodies to Tacaribe serocomplex viruses (family Arenaviridae, genus Arenavirus) in cricetid rodents from New Mexico, Texas, and Mexico. Vector Borne Zoonotic Dis. 2010;10:629-37. http://dx.doi.org/10.1089/ vbz.2009.0206

(15.) Bradley RD, Durish ND, Rogers DS, Miller JR, Engstrom MD, Kilpatrick CW. Toward a molecular phylogeny for Peromyscus: evidence from mitochondrial cytochrome-b sequences. J Mammal. 2007;88:1146-59. http://dx.doi.org/10.1644/06-MAMM-A-342R.1

(16.) Tesh RB, Wilson ML, Salas R, de Manzione NM, Tovar D, Ksiazek TG, et al. Field studies on the epidemiology of Venezuelan hemorrhagic fever: implication of the cotton rat Sigmodon alstoni as the probable rodent reservoir. Am J Trop Med Hyg. 1993;49:227-35.

(17.) Goldsmith RS, Shields KP. Epidemic in southern Mexico of disease resembling virus haemorrhagic fevers. Lancet. 1971;298:151-4. http://dx.doi.org/10.1016/S0140-6736(71)92320-8

(18.) Cajimat MN, Milazzo ML, Hess BD, Rood MP, Fulhorst CF. Principal host relationships and evolutionary history of the North American arenaviruses. Virology. 2007;367:235-43. http://dx.doi. org/10.1016/j.virol.2007.05.031

(19.) Bowen MD, Peter CJ, Nichol ST. The phylogeny of New World (Tacaribe complex) arenaviruses. Virology. 1996;219:285-90. http:// dx.doi.org/10.1006/viro.1996.0248

(20.) Erixon P, Svennblad B, Britton T, Oxelman B. Reliability of Bayesian posterior probabilities and bootstrap frequencies in phylogenetics. Syst Biol. 2003;52:665-73. http://dx.doi. org/10.1080/10635150390235485

(21.) Thompson JD, Higgins DG, Gibson TJ. CLUSTAL W (1.7): improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choices. Nucleic Acids Res. 1994;22:4673-80. http:// dx.doi.org/10.1093/nar/22.22.4673

(22.) Huelsenbeck JP, Ronquist FR. MRBAYES: Bayesian inference of phylogenetic trees. Bioinformatics. 2001;17:754-5. http://dx.doi. org/10.1093/bioinformatics/17.8.754

(23.) Swofford DL. PAUP*: phylogenetic analysis using parsimony (*and other methods), version 4.0b10. Sunderland (MA): Sinauer Associates; 2002.

(24.) Bowen MD, Peters CJ, Nichol ST. Phylogenetic analysis of the Arenaviridae: patterns of virus evolution and evidence for cospeciation between arenaviruses and their rodent hosts. Mol Phylogenet Evol. 1997;8:301-16. http://dx.doi.org/10.1006/mpev.1997.0436

(25.) Tesh RB, Jahrling PB, Salas R, Shope RE. Description of Guanarito virus (Arenaviridae: Arenavirus), the etiologic agent of Venezuelan hemorrhagic fever. Am J Trop Med Hyg. 1994;50:452-9.

(26.) Trujano-Alvarez AL, Alvarez-Castaneda ST. Peromysus mexicanus (Rodentia: Cricetidae). Mammalian Species. 2010;42:111-8. http:// dx.doi.org/10.1644/858.1

(27.) Montali RJ, Scanga CA, Pernikoff D, Wessner DR, Ward R, Holmes KV. A common-source outbreak of callitrichid hepatitis in captive tamarins and marmosets. J Infect Dis. 1993;167:946-50. http:// dx.doi.org/10.1093/infdis/167.4.946

(28.) Barragan F, Retana OG, Naranjo EJ. The rodent trade of Tzeltal Indians of Oxchuc, Chiapas, Mexico. Hum Ecol. 2007;35:769-73. http://dx.doi.org/10.1007/s10745-007-9116-7

Author affiliations: University of Texas Medical Branch, Galveston, Texas, USA (M.N.B. Cajimat, M.L. Milazzo, C.F. Fulhorst); and Texas Tech University, Lubbock, Texas, USA (R.D. Bradley)

DOI: http://dx/doi.org/10.3201/eid1803.111602

Address for correspondence: Charles F. Fulhorst, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0609, USA; email: cfulhors@utmb.edu
Table. Nonidentities among amino acid sequences of glycoprotein
precursors and amino acid sequences of nucleocapsid proteins of
Ocozocoautla de Espinosa virus strain AV B1030026, Mexico, and 8
arenaviruses from South America *

        % Amino acid sequence nonidentity


OCEV     --    43.7   45.1   44.8   46.5   31.6   33.5   46.8   24.7
AMAV    27.7    --    44.8   30.4   29.9   42.0   42.3   46.0   45.3
CHPV    31.6   27.3    --    43.3   43.9   42.7   42.8   22.3   45.1
CXPV    27.7   17.1   28.4    --    31.2   45.2   44.8   43.5   45.7
GTOV    27.0   14.6   27.9   17.1    --    43.0   44.2   44.8   45.9
JUNV    16.1   26.3   30.3   27.1   25.2    --    29.3   44.6   32.6
MACV    17.9   25.7   29.1   25.9   23.7   12.2    --    43.6   34.9
SABV    32.3   27.7   16.2   29.3   29.5   29.9   28.3    --    47.4
TCRV    18.8   29.8   31.2   30.5   28.7   21.3   20.4   33.0    --

* Nonidentities (p model distances) among sequences of glycoprotein
precursors are listed above the diagonal and those among sequences of
nucleocapsid proteins below the diagonal. OCEV, Ocozocoautla de
Espinosa virus; AMAV, Amapari virus strain BeAn 70563; CHPV, Chapare
virus, 200001071; CPXV, Cupixi virus, BeAn 119303; GTOV, Guanarito
virus, INH-95551; JUNV, Junin virus, XJ13; MACV, Machupo virus,
Carvallo; SABV, Sabia virus, SPH 114202; TCRV, Tacaribe virus, TRVL
Gale Copyright: Copyright 2012 Gale, Cengage Learning. All rights reserved.