The Experts below are selected from a list of 102 Experts worldwide ranked by ideXlab platform
Charles F. Fulhorst - One of the best experts on this subject based on the ideXlab platform.
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NATURAL RODENT HOST ASSOCIATIONS OF GUANARITO AND PIRITAL VIRUSES (FAMILY ARENAVIRIDAE) IN CENTRAL VENEZUELA
2013Co-Authors: Charles F. Fulhorst, Michael D. Bowen, Rosa Alba Salas, Nuris De Manzione, Gloria Duno, Antonio Utrera, Thomas G. Ksiazek, Edith De Miller, Clovis Vasquez, Clarence J. PetersAbstract:Abstract. The objective of this study was to elucidate the natural rodent host relationships of Guanarito and Pirital viruses (family Arenaviridae) in the plains of central Venezuela. Ninety-two arenavirus isolates from 607 animals, representing 10 different rodent species, were characterized to the level of serotype. The 92 isolates comprised 19 Guanarito virus strains and 73 Pirital virus strains. The 19 Guanarito virus isolates were from Zygodontomys brevicauda; 72 (98.6%) of the 73 Pirital virus isolates were from Sigmodon alstoni. These results indicate that the natural rodent associations of these 2 sympatric arenaviruses are highly specific and that Z. brevicauda and S. alstoni are the principal rodent hosts of Guanarito and Pirital viruses, respectively. Guanarito (GTO) virus (family Arenaviridae) is the etiologic agent of Venezuelan Hemorrhagic Fever (VHF), a rodent-borne zoonosis that is endemic in the plains of central Venezuela. 1,2 In the first large-scale study on the epidemiology of VHF, 3 31 arenavirus isolates (all presumed to be strains of GTO virus) were recovered from 206 wild rodents collected in 1992 from the Municipality of Guanarito, State of Portuguesa. The 31 virus isolates included 19 from 3
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Transmission of Guanarito and Pirital Viruses among Wild Rodents, Venezuela
2013Co-Authors: Mary L. Milazzo, Gloria Duno, Antonio Utrera, Maria N.b. Cajimat, Freddy Duno, Charles F. FulhorstAbstract:Samples from rodents captured on a farm in Venezuela in February 1997 were tested for arenavirus, antibody against Guanarito virus (GTOV), and antibody against Pirital virus (PIRV). Thirty-one (48.4%) of 64 short-tailed cane mice (Zygodontomys brevicauda) were infected with GTOV, 1 Alston’s cotton rat (Sigmodon alstoni) was infected with GTOV, and 36 (64.3%) of 56 other Alston’s cotton rats were infected with PIRV. The results of analyses of fi eld and laboratory data suggested that horizontal transmission is the dominant mode of GTOV transmission in Z. brevicauda mice and that vertical transmission is an important mode of PIRV transmission in S. alstoni rats. The results also suggested that bodily secretions and excretions from most GTOV-infected short-tailed cane mice and most PIRVinfected Alston’s cotton rats may transmit the viruses to humans. The Tacaribe serocomplex viruses (family Arenaviridae, genus Arenavirus) known to occur in Venezuela are Guanarito virus (GTOV) and Pirital virus (PIRV) (1,2). GTOV is the etiologic agent of Venezuelan Hemorrhagic Fever (VHF) (1). The human health significance of PIRV has not been rigorously investigated (3). Specific members of the rodent family Cricetidae (4) are the principal hosts of the Tacaribe complex viruses for which natural host relationships have been well characterized. It is generally accepted that humans usually become infected with arenaviruses by inhalation of virus i
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Transmission of Guanarito and Pirital Viruses among Wild Rodents, Venezuela
Emerging infectious diseases, 2011Co-Authors: Mary Louise Milazzo, Gloria Duno, Antonio Utrera, Maria N.b. Cajimat, Freddy Duno, Charles F. FulhorstAbstract:The Tacaribe serocomplex viruses (family Arenaviridae, genus Arenavirus) known to occur in Venezuela are Guanarito virus (GTOV) and Pirital virus (PIRV) (1,2). GTOV is the etiologic agent of Venezuelan Hemorrhagic Fever (VHF) (1). The human health significance of PIRV has not been rigorously investigated (3). Specific members of the rodent family Cricetidae (4) are the principal hosts of the Tacaribe complex viruses for which natural host relationships have been well characterized. It is generally accepted that humans usually become infected with arenaviruses by inhalation of virus in aerosolized droplets of saliva, respiratory secretions, urine, or blood from infected rodents or by inhalation of virus-contaminated dust particles. The results of published studies (2,5) indicated that the short-tailed cane mouse (Zygodontomys brevicauda) is the principal host of GTOV and that the Alston’s cotton rat (Sigmodon alstoni) is the principal host of PIRV. The objective of our study was to extend knowledge of the natural host relationships of these arenaviruses, particularly the relative importance of various modes of intraspecies virus transmission and the prevalence of virus shedding among naturally infected rodents.
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Genetic diversity between and within the arenavirus species indigenous to western Venezuela
Virology, 2008Co-Authors: Charles F. Fulhorst, Rosa Alba Salas, Nuris De Manzione, Hector Paredes, Maria N.b. Cajimat, Mary Louise Milazzo, Pierre E. Rollin, Thomas G. KsiazekAbstract:The results of analyses of Z, RNA-dependent RNA polymerase, glycoprotein precursor, and nucleocapsid protein gene sequence data suggested that Guanarito virus was the most common cause of Venezuelan Hemorrhagic Fever in a 7-year period in the 1990s and that the evolution of Pirital virus in association with Sigmodon alstoni (Alston's cotton rat) has occurred at a significantly higher rate than the evolution of Guanarito virus in association with Zygodontomys brevicauda (short-tailed cane mouse) on the plains of western Venezuela. The results of analyses of the primary structures of the glycoproteins of the 8 strains of Guanarito virus isolated from humans suggested that these strains would be highly cross-reactive in neutralization assays. Thus, passive antibody therapy may prove beneficial in the treatment of human disease caused by strains of Guanarito virus that are enzootic in the region in which Venezuelan Hemorrhagic Fever is endemic.
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Phylogeny of the Venezuelan arenaviruses.
Virus research, 2004Co-Authors: Maria N.b. Cajimat, Charles F. FulhorstAbstract:Guanarito virus (the etiologic agent of Venezuelan Hemorrhagic Fever, VHF) and Pirital virus coexist in the region of Venezuela in which Venezuelan Hemorrhagic Fever is endemic. The purpose of this study was to extend our knowledge of the evolutionary relationship between these two arenaviruses. We determined that the large genomic segments of Guanarito virus and Pirital virus are similar in size and identical in structural organization to the large genomic segments of other South American arenaviruses. For example, the Z proteins and RNA-dependent RNA polymerases of Guanarito virus and Pirital virus are encoded in nonoverlapping open reading frames of opposite polarities. Phylogenetic analyses of Z protein gene nucleotide sequences and RNA-dependent RNA polymerase gene nucleotide sequences grouped Pirital virus with Pichinde virus (a South American arenavirus which, like Pirital virus, does not appear to be pathogenic for humans) and placed the Pirital-Pichinde lineage in a sister relationship to a lineage represented by Guanarito virus and the three other arenaviruses known to cause Hemorrhagic Fever in South America. These results are concordant with the results of studies on the phylogeny of the arenavirus small genomic segment. Thus, the exchange of genomic elements between Guanarito virus and Pirital virus via recombination or reassortment likely did not contribute to the emergence of Venezuelan Hemorrhagic Fever.
Clarence J. Peters - One of the best experts on this subject based on the ideXlab platform.
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diseases of the central nervous system caused by lymphocytic choriomeningitis virus and other arenaviruses
Handbook of Clinical Neurology, 2014Co-Authors: Michael R Wilson, Clarence J. PetersAbstract:Abstract This chapter highlights the neurologic sequelae of viruses from two major groups of arenaviruses, the Lassa-lymphocytic choriomeningitis serocomplex and the Tacaribe serocomplex. Fundamental features of these viruses are reviewed, including the rich history of their discovery and the large influence that the study of arenaviruses has had on the disciplines of virology and immunology more generally. Virus morphology, viral genome organization, individual viral protein functions, and small-animal models of disease are also discussed. The epidemiology, natural history, and laboratory evaluation of the arenaviruses that cause human illness are presented. In particular, the neurologic complications of lymphocytic choriomeningitis virus in immunocompetent, pregnant, and solid-organ transplant patients are highlighted. The neurologic sequelae of the arenaviruses that cause Hemorrhagic Fever (i.e., Lassa Fever, Argentine Hemorrhagic Fever, Bolivian Hemorrhagic Fever, Venezuelan Hemorrhagic Fever) are also presented. Lastly, potential treatment and vaccine strategies of these diseases are reviewed.
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NATURAL RODENT HOST ASSOCIATIONS OF GUANARITO AND PIRITAL VIRUSES (FAMILY ARENAVIRIDAE) IN CENTRAL VENEZUELA
2013Co-Authors: Charles F. Fulhorst, Michael D. Bowen, Rosa Alba Salas, Nuris De Manzione, Gloria Duno, Antonio Utrera, Thomas G. Ksiazek, Edith De Miller, Clovis Vasquez, Clarence J. PetersAbstract:Abstract. The objective of this study was to elucidate the natural rodent host relationships of Guanarito and Pirital viruses (family Arenaviridae) in the plains of central Venezuela. Ninety-two arenavirus isolates from 607 animals, representing 10 different rodent species, were characterized to the level of serotype. The 92 isolates comprised 19 Guanarito virus strains and 73 Pirital virus strains. The 19 Guanarito virus isolates were from Zygodontomys brevicauda; 72 (98.6%) of the 73 Pirital virus isolates were from Sigmodon alstoni. These results indicate that the natural rodent associations of these 2 sympatric arenaviruses are highly specific and that Z. brevicauda and S. alstoni are the principal rodent hosts of Guanarito and Pirital viruses, respectively. Guanarito (GTO) virus (family Arenaviridae) is the etiologic agent of Venezuelan Hemorrhagic Fever (VHF), a rodent-borne zoonosis that is endemic in the plains of central Venezuela. 1,2 In the first large-scale study on the epidemiology of VHF, 3 31 arenavirus isolates (all presumed to be strains of GTO virus) were recovered from 206 wild rodents collected in 1992 from the Municipality of Guanarito, State of Portuguesa. The 31 virus isolates included 19 from 3
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Experimental Infection of the Cane Mouse Zygodontomys brevicauda (Family Muridae) with Guanarito Virus (Arenaviridae), the Etiologic Agent of Venezuelan Hemorrhagic Fever
The Journal of infectious diseases, 1999Co-Authors: Charles F. Fulhorst, Thomas G. Ksiazek, Clarence J. Peters, Robert B. TeshAbstract:Chronic infections in specific rodents appear to be crucial to the long-term persistence of arenaviruses in nature. The cane mouse, Zygodontomys brevicauda, is a natural host of Guanarito virus (family Arenaviridae), the etiologic agent of Venezuelan Hemorrhagic Fever. The purpose of this study was to elucidate the natural history of Guanarito virus infection in Z. brevicauda. Thirty-nine laboratory-reared cane mice each were inoculated subcutaneously with 3.0 log10 plaque-forming units of the Guanarito virus prototype strain INH-95551. No lethality was associated with infection in any animal, regardless of age at inoculation. The 13 newborn, 14 weanling, and 8 of the 12 adult animals developed chronic viremic infections characterized by persistent shedding of infectious virus in oropharyngeal secretions and urine. These findings indicate that Guanarito virus infection in Z. brevicauda can be chronic and thus support the concept that this rodent species is the natural reservoir of Guanarito virus.
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Isolation and Characterization of Pirital Virus, a Newly Discovered South American Arenavirus
The American journal of tropical medicine and hygiene, 1997Co-Authors: Charles F. Fulhorst, Michael D. Bowen, Rosa Alba Salas, Nuris De Manzione, Gloria Duno, Antonio Utrera, Thomas G. Ksiazek, Clarence J. Peters, Stuart T. Nichol, Edith De MillerAbstract:Abstract Specific rodent species are principal hosts for each of the well-characterized members of the virus family Arenaviridae. Guanarito virus (Arenaviridae) is the etiologic agent of Venezuelan Hemorrhagic Fever. A previous study on the epidemiology of Venezuelan Hemorrhagic Fever revealed extensive arenavirus infection (presumed to be caused by Guanarito virus) in two rodent species, Sigmodon alstoni and Zygodontomys brevicauda, collected from the region of Venezuela in which the disease is endemic. In the present study, four arenavirus isolates recovered from the Municipality of Guanarito (two isolates each from S. alstoni and Z. brevicauda) were characterized to learn more about the natural rodent host relationships of Guanarito virus. Serologic tests and analyses of nucleocapsid protein gene sequence data indicated that the two isolates from Z. brevicauda are strains of Guanarito virus and that the two isolates from S. alstoni are representatives of a novel New World arenavirus (proposed name Pirital) that is antigenically and phylogenetically distinct from all known New World arenaviruses. The results of the present study provide further evidence that the cane mouse Z. brevicauda is a natural host of Guanarito virus and suggest that the cotton rat S. alstoni is the natural reservoir host of Pirital but not Guanarito virus.
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field studies on the epidemiology of Venezuelan Hemorrhagic Fever implication of the cotton rat sigmodon alstoni as the probable rodent reservoir
American Journal of Tropical Medicine and Hygiene, 1993Co-Authors: Robert B. Tesh, Nuris De Manzione, Thomas G. Ksiazek, R. Salas, Mark L Wilson, D Tovar, Clarence J. PetersAbstract:During February 1992, field studies on the epidemiology of Venezuelan Hemorrhagic Fever (VHF) were carried out in a rural area of Portuguesa State in central Venezuela. The objective of this work was to determine the prevalence of infection with Guanarito virus, the etiologic agent of VHF, among wild rodents and humans living within an endemic focus of the disease. A total of 234 rodents, representing nine different species, were collected and their spleens were cultured for virus. Thirty-one Guanarito virus isolates were made from two rodent species: 19 from 40 Sigmodon alstoni and 12 from 106 Zygodontomys brevicauda. Guanarito virus antibody rates among these two species were 5.1% and 15.0%, respectively. Nine of the 12 Z. brevicauda that yielded virus from their spleens also had Guanarito virus antibodies in their sera. In contrast, none of the 19 Guanarito virus-positive S. alstoni had antibodies to the virus. These data suggest that S. alstoni usually develops a persistent nonimmunizing infection with Guanarito virus, while Z. brevicauda develops an immunizing infection. Based on knowledge of the behavior of other human pathogenic arenaviruses, these results imply that S. alstoni is the principal rodent reservoir of Guanarito virus in nature. To determine the prevalence of Guanarito virus infection among humans in the same region, 195 people living near one of the rodent collecting sites were bled and their sera were tested for antibodies to the virus. Five individuals (2.6%) had Guanarito virus antibodies; all were adults, and two had been diagnosed previously as having VHF.(ABSTRACT TRUNCATED AT 250 WORDS)
Robert B. Tesh - One of the best experts on this subject based on the ideXlab platform.
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Guanarito virus (Arenaviridae) isolates from endemic and outlying localities in Venezuela: sequence comparisons among and within strains isolated from Venezuelan Hemorrhagic Fever patients and rodents.
Virology, 2000Co-Authors: Scott C. Weaver, James N. Mills, Charles F. Fulhorst, Rosa Alba Salas, Nuris De Manzione, Gloria Duno, Antonio Utrera, Thomas G. Ksiazek, Duilia Tovar, Robert B. TeshAbstract:Abstract Despite intensive surveillance, Venezuelan Hemorrhagic Fever (VHF), caused by Guanarito (GTO) virus, has been detected in only a small region of western Venezuela. To determine whether VHF is associated with a particular regional GTO virus strain(s), 29 isolates from rodents and humans throughout the surrounding regions were analyzed by partial sequencing of the nucleocapsid protein gene. Phylogenetic trees delineated nine distinct GTO genotypes that differ by 4–17% in nucleotides and up to 9% in amino acid sequences; most appeared to be restricted to discrete geographic regions, although a few genotypes were isolated in several locations. Each genotype included at least one strain recovered from a rodent, but only two genotypes were isolated from VHF cases. The presence outside of the endemic/epidemic region of two genotypes isolated also from VHF cases suggests that human pathogenic viruses occur outside of the endemic zone, but do not frequently infect people and/or cause apparent disease there. VHF does not appear to be associated with a GTO virus genotype that is restricted to a certain rodent species. When quasispecies diversity was examined, rodent isolates had higher sequence variation than human isolates. One rodent isolate included a mixture of two phylogenetically distinct genotypes, suggesting a dual infection.
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Experimental Infection of the Cane Mouse Zygodontomys brevicauda (Family Muridae) with Guanarito Virus (Arenaviridae), the Etiologic Agent of Venezuelan Hemorrhagic Fever
The Journal of infectious diseases, 1999Co-Authors: Charles F. Fulhorst, Thomas G. Ksiazek, Clarence J. Peters, Robert B. TeshAbstract:Chronic infections in specific rodents appear to be crucial to the long-term persistence of arenaviruses in nature. The cane mouse, Zygodontomys brevicauda, is a natural host of Guanarito virus (family Arenaviridae), the etiologic agent of Venezuelan Hemorrhagic Fever. The purpose of this study was to elucidate the natural history of Guanarito virus infection in Z. brevicauda. Thirty-nine laboratory-reared cane mice each were inoculated subcutaneously with 3.0 log10 plaque-forming units of the Guanarito virus prototype strain INH-95551. No lethality was associated with infection in any animal, regardless of age at inoculation. The 13 newborn, 14 weanling, and 8 of the 12 adult animals developed chronic viremic infections characterized by persistent shedding of infectious virus in oropharyngeal secretions and urine. These findings indicate that Guanarito virus infection in Z. brevicauda can be chronic and thus support the concept that this rodent species is the natural reservoir of Guanarito virus.
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Description of Guanarito virus (Arenaviridae: Arenavirus), the etiologic agent of Venezuelan Hemorrhagic Fever.
The American journal of tropical medicine and hygiene, 1994Co-Authors: Robert B. Tesh, P. B. Jahrling, R. Salas, Robert E. ShopeAbstract:This paper characterizes Guanarito virus, the etiologic agent of Venezuelan Hemorrhagic Fever. Based on its morphology and antigenic properties, Guanarito virus appears to be a new member of the Tacaribe complex of the genus Arenavirus, family Arenaviridae. Complement fixation and indirect fluorescent antibody tests showed that Guanarito virus and its antiserum are broadly cross-reactive with other members of the Tacaribe complex, but it can be differentiated from other members of the complex by neutralization test. Guanarito virus causes mortality in suckling mice and adult guinea pigs, but not in adult mice. Inoculated rhesus monkeys developed viremia and became ill; however, they subsequently recovered and responded with production of antibody. To date, all isolates of Guanarito virus have come from sick persons or wild rodents living within a single geographic focus in the central plains of Venezuela.
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field studies on the epidemiology of Venezuelan Hemorrhagic Fever implication of the cotton rat sigmodon alstoni as the probable rodent reservoir
American Journal of Tropical Medicine and Hygiene, 1993Co-Authors: Robert B. Tesh, Nuris De Manzione, Thomas G. Ksiazek, R. Salas, Mark L Wilson, D Tovar, Clarence J. PetersAbstract:During February 1992, field studies on the epidemiology of Venezuelan Hemorrhagic Fever (VHF) were carried out in a rural area of Portuguesa State in central Venezuela. The objective of this work was to determine the prevalence of infection with Guanarito virus, the etiologic agent of VHF, among wild rodents and humans living within an endemic focus of the disease. A total of 234 rodents, representing nine different species, were collected and their spleens were cultured for virus. Thirty-one Guanarito virus isolates were made from two rodent species: 19 from 40 Sigmodon alstoni and 12 from 106 Zygodontomys brevicauda. Guanarito virus antibody rates among these two species were 5.1% and 15.0%, respectively. Nine of the 12 Z. brevicauda that yielded virus from their spleens also had Guanarito virus antibodies in their sera. In contrast, none of the 19 Guanarito virus-positive S. alstoni had antibodies to the virus. These data suggest that S. alstoni usually develops a persistent nonimmunizing infection with Guanarito virus, while Z. brevicauda develops an immunizing infection. Based on knowledge of the behavior of other human pathogenic arenaviruses, these results imply that S. alstoni is the principal rodent reservoir of Guanarito virus in nature. To determine the prevalence of Guanarito virus infection among humans in the same region, 195 people living near one of the rodent collecting sites were bled and their sera were tested for antibodies to the virus. Five individuals (2.6%) had Guanarito virus antibodies; all were adults, and two had been diagnosed previously as having VHF.(ABSTRACT TRUNCATED AT 250 WORDS)
Thomas G. Ksiazek - One of the best experts on this subject based on the ideXlab platform.
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NATURAL RODENT HOST ASSOCIATIONS OF GUANARITO AND PIRITAL VIRUSES (FAMILY ARENAVIRIDAE) IN CENTRAL VENEZUELA
2013Co-Authors: Charles F. Fulhorst, Michael D. Bowen, Rosa Alba Salas, Nuris De Manzione, Gloria Duno, Antonio Utrera, Thomas G. Ksiazek, Edith De Miller, Clovis Vasquez, Clarence J. PetersAbstract:Abstract. The objective of this study was to elucidate the natural rodent host relationships of Guanarito and Pirital viruses (family Arenaviridae) in the plains of central Venezuela. Ninety-two arenavirus isolates from 607 animals, representing 10 different rodent species, were characterized to the level of serotype. The 92 isolates comprised 19 Guanarito virus strains and 73 Pirital virus strains. The 19 Guanarito virus isolates were from Zygodontomys brevicauda; 72 (98.6%) of the 73 Pirital virus isolates were from Sigmodon alstoni. These results indicate that the natural rodent associations of these 2 sympatric arenaviruses are highly specific and that Z. brevicauda and S. alstoni are the principal rodent hosts of Guanarito and Pirital viruses, respectively. Guanarito (GTO) virus (family Arenaviridae) is the etiologic agent of Venezuelan Hemorrhagic Fever (VHF), a rodent-borne zoonosis that is endemic in the plains of central Venezuela. 1,2 In the first large-scale study on the epidemiology of VHF, 3 31 arenavirus isolates (all presumed to be strains of GTO virus) were recovered from 206 wild rodents collected in 1992 from the Municipality of Guanarito, State of Portuguesa. The 31 virus isolates included 19 from 3
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Genetic diversity between and within the arenavirus species indigenous to western Venezuela
Virology, 2008Co-Authors: Charles F. Fulhorst, Rosa Alba Salas, Nuris De Manzione, Hector Paredes, Maria N.b. Cajimat, Mary Louise Milazzo, Pierre E. Rollin, Thomas G. KsiazekAbstract:The results of analyses of Z, RNA-dependent RNA polymerase, glycoprotein precursor, and nucleocapsid protein gene sequence data suggested that Guanarito virus was the most common cause of Venezuelan Hemorrhagic Fever in a 7-year period in the 1990s and that the evolution of Pirital virus in association with Sigmodon alstoni (Alston's cotton rat) has occurred at a significantly higher rate than the evolution of Guanarito virus in association with Zygodontomys brevicauda (short-tailed cane mouse) on the plains of western Venezuela. The results of analyses of the primary structures of the glycoproteins of the 8 strains of Guanarito virus isolated from humans suggested that these strains would be highly cross-reactive in neutralization assays. Thus, passive antibody therapy may prove beneficial in the treatment of human disease caused by strains of Guanarito virus that are enzootic in the region in which Venezuelan Hemorrhagic Fever is endemic.
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Guanarito virus (Arenaviridae) isolates from endemic and outlying localities in Venezuela: sequence comparisons among and within strains isolated from Venezuelan Hemorrhagic Fever patients and rodents.
Virology, 2000Co-Authors: Scott C. Weaver, James N. Mills, Charles F. Fulhorst, Rosa Alba Salas, Nuris De Manzione, Gloria Duno, Antonio Utrera, Thomas G. Ksiazek, Duilia Tovar, Robert B. TeshAbstract:Abstract Despite intensive surveillance, Venezuelan Hemorrhagic Fever (VHF), caused by Guanarito (GTO) virus, has been detected in only a small region of western Venezuela. To determine whether VHF is associated with a particular regional GTO virus strain(s), 29 isolates from rodents and humans throughout the surrounding regions were analyzed by partial sequencing of the nucleocapsid protein gene. Phylogenetic trees delineated nine distinct GTO genotypes that differ by 4–17% in nucleotides and up to 9% in amino acid sequences; most appeared to be restricted to discrete geographic regions, although a few genotypes were isolated in several locations. Each genotype included at least one strain recovered from a rodent, but only two genotypes were isolated from VHF cases. The presence outside of the endemic/epidemic region of two genotypes isolated also from VHF cases suggests that human pathogenic viruses occur outside of the endemic zone, but do not frequently infect people and/or cause apparent disease there. VHF does not appear to be associated with a GTO virus genotype that is restricted to a certain rodent species. When quasispecies diversity was examined, rodent isolates had higher sequence variation than human isolates. One rodent isolate included a mixture of two phylogenetically distinct genotypes, suggesting a dual infection.
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Experimental Infection of the Cane Mouse Zygodontomys brevicauda (Family Muridae) with Guanarito Virus (Arenaviridae), the Etiologic Agent of Venezuelan Hemorrhagic Fever
The Journal of infectious diseases, 1999Co-Authors: Charles F. Fulhorst, Thomas G. Ksiazek, Clarence J. Peters, Robert B. TeshAbstract:Chronic infections in specific rodents appear to be crucial to the long-term persistence of arenaviruses in nature. The cane mouse, Zygodontomys brevicauda, is a natural host of Guanarito virus (family Arenaviridae), the etiologic agent of Venezuelan Hemorrhagic Fever. The purpose of this study was to elucidate the natural history of Guanarito virus infection in Z. brevicauda. Thirty-nine laboratory-reared cane mice each were inoculated subcutaneously with 3.0 log10 plaque-forming units of the Guanarito virus prototype strain INH-95551. No lethality was associated with infection in any animal, regardless of age at inoculation. The 13 newborn, 14 weanling, and 8 of the 12 adult animals developed chronic viremic infections characterized by persistent shedding of infectious virus in oropharyngeal secretions and urine. These findings indicate that Guanarito virus infection in Z. brevicauda can be chronic and thus support the concept that this rodent species is the natural reservoir of Guanarito virus.
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Venezuelan Hemorrhagic Fever: Clinical and Epidemiological Studies of 165 Cases
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 1998Co-Authors: Nuris De Manzione, James N. Mills, Charles F. Fulhorst, Rosa Alba Salas, Thomas G. Ksiazek, Hector Paredes, Oswaldo Godoy, Luis Rojas, Francisco Araoz, Barbara A. EllisAbstract:Epidemiological and clinical data are presented on 165 cases of Venezuelan Hemorrhagic Fever (VHF), a newly emerging viral zoonosis caused by Guanarito virus (of the family Arenaviridae). The disease is endemic in a relatively circumscribed area of central Venezuela. Since its first recognition in 1989, the incidence of VHF has peaked each year between November and January, during the period of major agricultural activity in the region of endemicity. The majority of cases have involved male agricultural workers. Principal symptoms among the patients with VHF included Fever, malaise, headache, arthralgia, sore throat, vomiting, abdominal pain, diarrhea, convulsions, and a variety of Hemorrhagic manifestations. The majority of patients also had leukopenia and thrombocytopenia. The overall fatality rate among the 165 cases was 33.3%, despite hospitalization and vigorous supportive care.
Antonio Utrera - One of the best experts on this subject based on the ideXlab platform.
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NATURAL RODENT HOST ASSOCIATIONS OF GUANARITO AND PIRITAL VIRUSES (FAMILY ARENAVIRIDAE) IN CENTRAL VENEZUELA
2013Co-Authors: Charles F. Fulhorst, Michael D. Bowen, Rosa Alba Salas, Nuris De Manzione, Gloria Duno, Antonio Utrera, Thomas G. Ksiazek, Edith De Miller, Clovis Vasquez, Clarence J. PetersAbstract:Abstract. The objective of this study was to elucidate the natural rodent host relationships of Guanarito and Pirital viruses (family Arenaviridae) in the plains of central Venezuela. Ninety-two arenavirus isolates from 607 animals, representing 10 different rodent species, were characterized to the level of serotype. The 92 isolates comprised 19 Guanarito virus strains and 73 Pirital virus strains. The 19 Guanarito virus isolates were from Zygodontomys brevicauda; 72 (98.6%) of the 73 Pirital virus isolates were from Sigmodon alstoni. These results indicate that the natural rodent associations of these 2 sympatric arenaviruses are highly specific and that Z. brevicauda and S. alstoni are the principal rodent hosts of Guanarito and Pirital viruses, respectively. Guanarito (GTO) virus (family Arenaviridae) is the etiologic agent of Venezuelan Hemorrhagic Fever (VHF), a rodent-borne zoonosis that is endemic in the plains of central Venezuela. 1,2 In the first large-scale study on the epidemiology of VHF, 3 31 arenavirus isolates (all presumed to be strains of GTO virus) were recovered from 206 wild rodents collected in 1992 from the Municipality of Guanarito, State of Portuguesa. The 31 virus isolates included 19 from 3
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Transmission of Guanarito and Pirital Viruses among Wild Rodents, Venezuela
2013Co-Authors: Mary L. Milazzo, Gloria Duno, Antonio Utrera, Maria N.b. Cajimat, Freddy Duno, Charles F. FulhorstAbstract:Samples from rodents captured on a farm in Venezuela in February 1997 were tested for arenavirus, antibody against Guanarito virus (GTOV), and antibody against Pirital virus (PIRV). Thirty-one (48.4%) of 64 short-tailed cane mice (Zygodontomys brevicauda) were infected with GTOV, 1 Alston’s cotton rat (Sigmodon alstoni) was infected with GTOV, and 36 (64.3%) of 56 other Alston’s cotton rats were infected with PIRV. The results of analyses of fi eld and laboratory data suggested that horizontal transmission is the dominant mode of GTOV transmission in Z. brevicauda mice and that vertical transmission is an important mode of PIRV transmission in S. alstoni rats. The results also suggested that bodily secretions and excretions from most GTOV-infected short-tailed cane mice and most PIRVinfected Alston’s cotton rats may transmit the viruses to humans. The Tacaribe serocomplex viruses (family Arenaviridae, genus Arenavirus) known to occur in Venezuela are Guanarito virus (GTOV) and Pirital virus (PIRV) (1,2). GTOV is the etiologic agent of Venezuelan Hemorrhagic Fever (VHF) (1). The human health significance of PIRV has not been rigorously investigated (3). Specific members of the rodent family Cricetidae (4) are the principal hosts of the Tacaribe complex viruses for which natural host relationships have been well characterized. It is generally accepted that humans usually become infected with arenaviruses by inhalation of virus i
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Transmission of Guanarito and Pirital Viruses among Wild Rodents, Venezuela
Emerging infectious diseases, 2011Co-Authors: Mary Louise Milazzo, Gloria Duno, Antonio Utrera, Maria N.b. Cajimat, Freddy Duno, Charles F. FulhorstAbstract:The Tacaribe serocomplex viruses (family Arenaviridae, genus Arenavirus) known to occur in Venezuela are Guanarito virus (GTOV) and Pirital virus (PIRV) (1,2). GTOV is the etiologic agent of Venezuelan Hemorrhagic Fever (VHF) (1). The human health significance of PIRV has not been rigorously investigated (3). Specific members of the rodent family Cricetidae (4) are the principal hosts of the Tacaribe complex viruses for which natural host relationships have been well characterized. It is generally accepted that humans usually become infected with arenaviruses by inhalation of virus in aerosolized droplets of saliva, respiratory secretions, urine, or blood from infected rodents or by inhalation of virus-contaminated dust particles. The results of published studies (2,5) indicated that the short-tailed cane mouse (Zygodontomys brevicauda) is the principal host of GTOV and that the Alston’s cotton rat (Sigmodon alstoni) is the principal host of PIRV. The objective of our study was to extend knowledge of the natural host relationships of these arenaviruses, particularly the relative importance of various modes of intraspecies virus transmission and the prevalence of virus shedding among naturally infected rodents.
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Guanarito virus (Arenaviridae) isolates from endemic and outlying localities in Venezuela: sequence comparisons among and within strains isolated from Venezuelan Hemorrhagic Fever patients and rodents.
Virology, 2000Co-Authors: Scott C. Weaver, James N. Mills, Charles F. Fulhorst, Rosa Alba Salas, Nuris De Manzione, Gloria Duno, Antonio Utrera, Thomas G. Ksiazek, Duilia Tovar, Robert B. TeshAbstract:Abstract Despite intensive surveillance, Venezuelan Hemorrhagic Fever (VHF), caused by Guanarito (GTO) virus, has been detected in only a small region of western Venezuela. To determine whether VHF is associated with a particular regional GTO virus strain(s), 29 isolates from rodents and humans throughout the surrounding regions were analyzed by partial sequencing of the nucleocapsid protein gene. Phylogenetic trees delineated nine distinct GTO genotypes that differ by 4–17% in nucleotides and up to 9% in amino acid sequences; most appeared to be restricted to discrete geographic regions, although a few genotypes were isolated in several locations. Each genotype included at least one strain recovered from a rodent, but only two genotypes were isolated from VHF cases. The presence outside of the endemic/epidemic region of two genotypes isolated also from VHF cases suggests that human pathogenic viruses occur outside of the endemic zone, but do not frequently infect people and/or cause apparent disease there. VHF does not appear to be associated with a GTO virus genotype that is restricted to a certain rodent species. When quasispecies diversity was examined, rodent isolates had higher sequence variation than human isolates. One rodent isolate included a mixture of two phylogenetically distinct genotypes, suggesting a dual infection.
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Isolation and Characterization of Pirital Virus, a Newly Discovered South American Arenavirus
The American journal of tropical medicine and hygiene, 1997Co-Authors: Charles F. Fulhorst, Michael D. Bowen, Rosa Alba Salas, Nuris De Manzione, Gloria Duno, Antonio Utrera, Thomas G. Ksiazek, Clarence J. Peters, Stuart T. Nichol, Edith De MillerAbstract:Abstract Specific rodent species are principal hosts for each of the well-characterized members of the virus family Arenaviridae. Guanarito virus (Arenaviridae) is the etiologic agent of Venezuelan Hemorrhagic Fever. A previous study on the epidemiology of Venezuelan Hemorrhagic Fever revealed extensive arenavirus infection (presumed to be caused by Guanarito virus) in two rodent species, Sigmodon alstoni and Zygodontomys brevicauda, collected from the region of Venezuela in which the disease is endemic. In the present study, four arenavirus isolates recovered from the Municipality of Guanarito (two isolates each from S. alstoni and Z. brevicauda) were characterized to learn more about the natural rodent host relationships of Guanarito virus. Serologic tests and analyses of nucleocapsid protein gene sequence data indicated that the two isolates from Z. brevicauda are strains of Guanarito virus and that the two isolates from S. alstoni are representatives of a novel New World arenavirus (proposed name Pirital) that is antigenically and phylogenetically distinct from all known New World arenaviruses. The results of the present study provide further evidence that the cane mouse Z. brevicauda is a natural host of Guanarito virus and suggest that the cotton rat S. alstoni is the natural reservoir host of Pirital but not Guanarito virus.
