VIAL CLARO, PABLO AGUSTIN
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VIAL CLARO, PABLO AGUSTIN
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pvial@udd.cl
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17339613100

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2006 2006 2005 2005 2004 2004 2003 2003 0.0 0.0 0.5 0.5 1.0 1.0 1.5 1.5 2.0 2.0 2.5 2.5 3.0 3.0

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Serological assays for the detection of human Andes hantavirus infections based on its yeast-expressed nucleocapsid protein

2006-01-01 , Schmidt, Jonas , Meisel, Helga , Capria, Silvana G. , Petraityte, Rasa , Lundkvist, Åke , Hjelle, Brian , VIAL CLARO, PABLO AGUSTIN , Padula, Paula , Krüger, Detlev H. , Ulrich, Rainer

Background: The objective of the study was to develop and evaluate IgM and IgG ELISAs and an IgG Western blottest for the serological detection of human infections with Andes virus (ANDV), the major cause of hantavirus cardiopulmonary syndrome (HCPS) in South America. Methods: The entire nucleocapsid (N) protein-encoding sequence of ANDV (strain AH-1) was cloned and expressed in the yeast Saccharomyces cerevisiae. The polyhistidine-tagged recombinant N (rN) protein of ANDV was purified by nickel-chelation chromatography and characterized by its reactivity with different N-specific monoclonal antibodies. To detect an antibody response directed against ANDV in humans, indirect IgM and IgG ELISAs and an IgG Western blot test based on ANDV rN antigen were developed. The evaluation of the tests was performed using a negative serum panel and 63 blinded sera from Argentina and Chile, containing acute-phase and convalescent sera from HCPS patients. Results: The specificities and sensitivities for the IgM and IgG ELISAs were demonstrated to be very high. The IgG ELISA data were confirmed by the IgG Western blot assay based on the same rN antigen. Almost all anti-ANDV-positive sera reacted to higher endpoint titers with N protein of ANDV than with those of Sin Nombre, Laguna Negra or Puumala virus. The cross-reactivity of anti-ANDV-N IgG-positive sera to rN proteins of other hantaviruses was found to be increased with time after the onset of HCPS. Conclusion: The high sensitivity of the novel assays should facilitate early diagnosis of ANDV infections and might contribute to a successful treatment of HCPS patients. Copyright © 2006 S. Karger AG.

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Hantavirus prevalence in the IX Region of Chile

2003-07-01 , Frey, Marlis Täger , VIAL CLARO, PABLO AGUSTIN , Castillo, Constanza H. , Godoy, Paula M. , Hjelle, Brian , Ferrés, Marcela G.

An epidemiologic and seroprevalence survey was conducted (n=830) to assess the proportion of persons exposed to hantavirus in IX Region Chile, which accounts for 25% of reported cases of hantavirus cardiopulmonary syndrome. This region has three geographic areas with different disease incidences and a high proportion of aboriginals. Serum samples were tested for immunoglobulin (Ig) G antibodies by enzyme-linked immunosorbent assay against Sin Nombre virus N antigen by strip immunoblot assay against Sin Nombre, Puumala, Rio Mamoré, and Seoul N antigens. Samples from six patients were positive for IgG antibodies reactive with Andes virus; all patients lived in the Andes Mountains. Foresting was also associated with seropositivity; but not sex, age, race, rodent exposure, or farming activities. Exposure to hantavirus varies in different communities of IX Region. Absence of history of pneumonia or hospital admission in persons with specific IgG antibodies suggests that infection is clinically inapparent.

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Neutralizing antibodies in survivors of Sin Nombre and Andes hantavirus infection

2006-01-01 , Valdivieso, Francisca , VIAL CLARO, PABLO AGUSTIN , Ferres, Marcela , Ye, Chunyan , Goade, Diane , Cuiza, Analia , Hjelle, Brian

We evaluated titers of homotypic and heterotypic neutralizing antibodies (NAbs) to Andes and Sin Nombre hantaviruses in plasma samples from 20 patients from Chile and the United States. All but 1 patient had high titers of NAb. None of the plasma samples showed high titers against the heterologous virus.

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Diagnosis and treatment of new world hantavirus infections

2006-10-01 , Mertz, Gregory J. , Hjelle, Brian , Crowley, Mark , Iwamoto, Gary , Tomicic, Vinko , VIAL CLARO, PABLO AGUSTIN

PURPOSE OF REVIEW: The purpose of this review is to summarize the current knowledge regarding the diagnosis and treatment of indigenous new world hantavirus infections. RECENT FINDINGS: Recent studies have defined the incubation period of new world hantavirus infections, provided additional evidence for person-to-person transmission of Andes virus, described a rapid method for the presumptive diagnosis of infection in the cardiopulmonary phase through a review of the peripheral smear, and suggested that intravenous ribavirin is probably not effective for the treatment of new world hantavirus infections when started in the cardiopulmonary phase. SUMMARY: Presumptive diagnosis may be made by a review of the peripheral blood smear after the onset of the cardiopulmonary phase. Critical care management includes the avoidance of fluid overload, pressors to maintain cardiac output, and the use of extracorporeal membrane oxygenation in the most severe cases, but treatment with intravenous ribavirin is probably not effective. © 2006 Lippincott Williams & Wilkins.

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