Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina.

St. Louis encephalitis virus (SLEV) (Flavivirus) is a reemerging arbovirus in the southern cone of South America. In 2005, an outbreak of SLEV in central Argentina resulted in 47 human cases with 9 deaths. In Argentina, the ecology of SLEV is poorly understood. Because certain birds are the primary...

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Main Authors: Luis Adrián Diaz, Agustín Ignacio Quaglia, Brenda Salomé Konigheim, Analia Silvana Boris, Juan Javier Aguilar, Nicholas Komar, Marta Silvia Contigiani
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2016-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC5001705?pdf=render
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author Luis Adrián Diaz
Agustín Ignacio Quaglia
Brenda Salomé Konigheim
Analia Silvana Boris
Juan Javier Aguilar
Nicholas Komar
Marta Silvia Contigiani
author_facet Luis Adrián Diaz
Agustín Ignacio Quaglia
Brenda Salomé Konigheim
Analia Silvana Boris
Juan Javier Aguilar
Nicholas Komar
Marta Silvia Contigiani
author_sort Luis Adrián Diaz
collection DOAJ
description St. Louis encephalitis virus (SLEV) (Flavivirus) is a reemerging arbovirus in the southern cone of South America. In 2005, an outbreak of SLEV in central Argentina resulted in 47 human cases with 9 deaths. In Argentina, the ecology of SLEV is poorly understood. Because certain birds are the primary amplifiers in North America, we hypothesized that birds amplify SLEV in Argentina as well. We compared avian SLEV seroprevalence in a variety of ecosystems in and around Córdoba city from 2004 (before the epidemic) and 2005 (during the epidemic). We also explored spatial patterns to better understand the local ecology of SLEV transmission. Because West Nile virus (WNV) was also detected in Argentina in 2005, all analyses were also conducted for WNV. A total of 980 birds were sampled for detection of SLEV and WNV neutralizing antibodies. SLEV seroprevalence in birds increased 11-fold from 2004 to 2005. Our study demonstrated that a high proportion (99.3%) of local birds were susceptible to SLEV infection immediately prior to the 2005 outbreak, indicating that the vertebrate host population was primed to amplify SLEV. SLEV was found distributed in a variety of environments throughout the city of Córdoba. However, the force of viral transmission varied among sites. Fine scale differences in populations of vectors and vertebrate hosts would explain this variation. In summary, we showed that in 2005, both SLEV and to a lesser extent WNV circulated in the avian population. Eared Dove, Picui Ground-Dove and Great Kiskadee are strong candidates to amplify SLEV because of their exposure to the pathogen at the population level, and their widespread abundance. For the same reasons, Rufous Hornero may be an important maintenance host for WNV in central Argentina. Competence studies and vector feeding studies are needed to confirm these relationships.
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spelling doaj.art-f06ced36156e40e09a69fe458056978b2022-12-22T00:28:56ZengPublic Library of Science (PLoS)PLoS ONE1932-62032016-01-01118e016187110.1371/journal.pone.0161871Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina.Luis Adrián DiazAgustín Ignacio QuagliaBrenda Salomé KonigheimAnalia Silvana BorisJuan Javier AguilarNicholas KomarMarta Silvia ContigianiSt. Louis encephalitis virus (SLEV) (Flavivirus) is a reemerging arbovirus in the southern cone of South America. In 2005, an outbreak of SLEV in central Argentina resulted in 47 human cases with 9 deaths. In Argentina, the ecology of SLEV is poorly understood. Because certain birds are the primary amplifiers in North America, we hypothesized that birds amplify SLEV in Argentina as well. We compared avian SLEV seroprevalence in a variety of ecosystems in and around Córdoba city from 2004 (before the epidemic) and 2005 (during the epidemic). We also explored spatial patterns to better understand the local ecology of SLEV transmission. Because West Nile virus (WNV) was also detected in Argentina in 2005, all analyses were also conducted for WNV. A total of 980 birds were sampled for detection of SLEV and WNV neutralizing antibodies. SLEV seroprevalence in birds increased 11-fold from 2004 to 2005. Our study demonstrated that a high proportion (99.3%) of local birds were susceptible to SLEV infection immediately prior to the 2005 outbreak, indicating that the vertebrate host population was primed to amplify SLEV. SLEV was found distributed in a variety of environments throughout the city of Córdoba. However, the force of viral transmission varied among sites. Fine scale differences in populations of vectors and vertebrate hosts would explain this variation. In summary, we showed that in 2005, both SLEV and to a lesser extent WNV circulated in the avian population. Eared Dove, Picui Ground-Dove and Great Kiskadee are strong candidates to amplify SLEV because of their exposure to the pathogen at the population level, and their widespread abundance. For the same reasons, Rufous Hornero may be an important maintenance host for WNV in central Argentina. Competence studies and vector feeding studies are needed to confirm these relationships.http://europepmc.org/articles/PMC5001705?pdf=render
spellingShingle Luis Adrián Diaz
Agustín Ignacio Quaglia
Brenda Salomé Konigheim
Analia Silvana Boris
Juan Javier Aguilar
Nicholas Komar
Marta Silvia Contigiani
Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina.
PLoS ONE
title Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina.
title_full Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina.
title_fullStr Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina.
title_full_unstemmed Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina.
title_short Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina.
title_sort activity patterns of st louis encephalitis and west nile viruses in free ranging birds during a human encephalitis outbreak in argentina
url http://europepmc.org/articles/PMC5001705?pdf=render
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