Previous #dengue or #Zika virus #exposure can drive to #infection #enhancement or neutralisation of other #flaviviruses (Mem Inst Oswaldo Cruz, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Mem Inst Oswaldo Cruz. 2019;114:e190098. doi: 10.1590/0074-02760190098. Epub 2019 Aug 12.

Previous dengue or Zika virus exposure can drive to infection enhancement or neutralisation of other flaviviruses.

Oliveira RA1,2, de Oliveira-Filho EF1,3, Fernandes AI4,5, Brito CA6, Marques ET1,7, Tenório MC1, Gil LH1.

Author information: 1 Fundação Oswaldo Cruz, Instituto Aggeu Magalhães, Departamento de Virologia, Recife, PE, Brasil. 2 Universidade Federal da Paraíba, Departamento de Fisiologia e Patologia, João Pessoa, PB, Brasil. 3 Charité-Universitätsmedizin Berlin, Berlin, Germany. 4 Universidade Federal da Paraíba, Hospital Universitário Lauro Wanderley, Serviço de Doenças Infecciosas e Parasitárias, João Pessoa, PB, Brasil. 5 Universidade Federal da Paraíba, Escola Técnica de Saúde, Grupo de Estudos e Pesquisas em Imunologia Humana, João Pessoa, PB, Brasil. 6 Universidade Federal de Pernambuco, Departamento de Medicina Clínica, Recife, PE, Brasil. 7 University of Pittsburgh, Center for Vaccine Research, Department of Infectious Diseases and Microbiology, Pittsburgh, PA, USA.

 

Abstract

BACKGROUND:

Dengue virus (DENV) has circulated in Brazil for over 30 years. During this time, one serotype has cyclically replaced the other, until recently, when all four distinct serotypes began to circulate together. Persistent circulation of DENV for long time periods makes sequential infections throughout a person’s life possible. After primary DENV infection, life-long immunity is developed for the infecting serotype. Since DENV and Zika virus (ZIKV) are antigenically similar, the possibility of cross-reactions has attracted attention and has been demonstrated in vitro.

OBJECTIVE:

The aim of this study was to investigate whether immune-sera from DENV and ZIKV infected patients would cross-react in vitro with other Flaviviridae family members.

METHODS:

Cross-reaction of the studied samples with yellow fever virus (YFV), West Nile virus (WNV), Rocio virus (ROCV), Saint Louis virus (SLEV) and Ilheus virus (ILHV) has been investigated by plaque reduction neutralisation test (PRNT) and the antibody-dependent enhancement (ADE) by flow-cytometry.

FINDINGS:

Antibodies against ZIKV and DENV virus cross-reacted with other flaviviruses either neutralising or enhancing the infection. Thus, viral entrance into FcRFcɣRII-expressing cells were influenced by the cross-reactive antibodies. ZIKV or DENV immune sera enhanced cellular infection by WNV, ILHV, ROCV and SLEV. Finally, DENV immune sera presented higher neutralising activity for YFV and SLEV. While ZIKV immune sera neutralised WNV, ILHV and ROCV with high frequencies of positivity.

MAIN CONCLUSIONS:

The co-circulation of those viruses in the same area represents a risk for the development of severe infections if they spread throughout the country. Successive flavivirus infections may have an impact on disease pathogenesis, as well as on the development of safe vaccine strategies.

PMID: 31411310 DOI: 10.1590/0074-02760190098

Keywords: Flavivirus; Dengue fever; Zika Virus; WNV; Rocio Virus; St Louis Virus; Ilheus virus; Yellow Fever; Serology; ADE; Brazil.

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Reemergence of St. Louis #Encephalitis Virus in the #Americas (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 24, Number 12—December 2018 / CME ACTIVITY – Synopsis

Reemergence of St. Louis Encephalitis Virus in the Americas

Adrián Diaz  , Lark L. Coffey, Nathan Burkett-Cadena, and Jonathan F. Day

Author affiliations: Universidad Nacional de Córdoba, Córdoba, Argentina (A. Diaz); University of California, Davis, California, USA (L.L. Coffey); University of Florida, Vero Beach, Florida, USA (N. Burkett-Cadena, J.F. Day)

 

Abstract

We summarize and analyze historical and current data regarding the reemergence of St. Louis encephalitis virus (SLEV; genus Flavivirus) in the Americas. Historically, SLEV caused encephalitis outbreaks in the United States; however, it was not considered a public health concern in the rest of the Americas. After the introduction of West Nile virus in 1999, activity of SLEV decreased considerably in the United States. During 2014–2015, SLEV caused a human outbreak in Arizona and caused isolated human cases in California in 2016 and 2017. Phylogenetic analyses indicate that the emerging SLEV in the western United States is related to the epidemic strains isolated during a human encephalitis outbreak in Córdoba, Argentina, in 2005. Ecoepidemiologic studies suggest that the emergence of SLEV in Argentina was caused by the introduction of a more pathogenic strain and increasing populations of the eared dove (amplifying host).

Keywords: St Louis Encephalitis Virus; Flavivirus; American Region; USA; Argentina; Human; Wildlife.

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Ilheus and Saint Louis #encephalitis viruses elicit cross-protection against a lethal #Rocio virus challenge in mice (PLoS One, abstract)

[Source: PLoS One, full page: (LINK). Abstract, edited.]

OPEN ACCESS /  PEER-REVIEWED / RESEARCH ARTICLE

Ilheus and Saint Louis encephalitis viruses elicit cross-protection against a lethal Rocio virus challenge in mice

Alberto Anastacio Amarilla , Marcilio Jorge Fumagalli , Mario Luis Figueiredo , Djalma S. Lima-Junior, Nilton Nascimento Santos-Junior, Helda Liz Alfonso, Veronica Lippi, Amanda Cristina Trabuco, Flavio Lauretti, Vanessa Danielle Muller, David F. Colón, João P. M. Luiz, Andreas Suhrbier,  [ … ], Victor Hugo Aquino

Published: June 13, 2018 / DOI: https://doi.org/10.1371/journal.pone.0199071

 

Abstract

Rocio virus (ROCV) was the causative agent of an unprecedented outbreak of encephalitis during the 1970s in the Vale do Ribeira, Sao Paulo State, in the Southeast region of Brazil. Surprisingly, no further cases of ROCV infection were identified after this outbreak; however, serological surveys have suggested the circulation of ROCV among humans and animals in different regions of Brazil. Cross-protective immunity among flaviviruses is well documented; consequently, immunity induced by infections with other flaviviruses endemic to Brazil could potentially be responsible for the lack of ROCV infections. Herein, we evaluated the cross-protection mediated by other flaviviruses against ROCV infection using an experimental C57BL/6 mouse model. Cross-protection against ROCV infection was observed when animals had prior exposure to Ilheus virus or Saint Louis encephalitis virus, suggesting that cross-reactive anti-flavivirus antibodies may limit ROCV disease outbreaks.

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Citation: Amarilla AA, Fumagalli MJ, Figueiredo ML, Lima-Junior DS, Santos-Junior NN, Alfonso HL, et al. (2018) Ilheus and Saint Louis encephalitis viruses elicit cross-protection against a lethal Rocio virus challenge in mice. PLoS ONE 13(6): e0199071. https://doi.org/10.1371/journal.pone.0199071

Editor: Eric Mossel, Center for Disease Control and Prevention, UNITED STATES

Received: April 18, 2018; Accepted: May 29, 2018; Published: June 13, 2018

Copyright: © 2018 Amarilla et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper and its Supporting Information files.

Funding: This work was supported by the Sao Paulo Research Foundation (FAPESP), Brazil, Grant Nº. 2014/15548-4 and 2014/02438-6. AAO was supported by an FAPESP Scholarships Nº. 2012/08778-8 and Fundação de Apoio ao Ensino, Pesquisa e Assistência (FAEPA) from the Hospital of the Medical School of Ribeirão Preto, University of Sao Paulo (Scholarships Nº 97/16). VHA holds a CNPq-PQ scholarship (Grant no. 310735/2013-0). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: Flavivirus; Rocio Virus; Ilheus Virus; St Louis Encephalitis Virus; Viral Encephalitis; Animal Models.

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Impact of #environmental #factors on neglected emerging #arboviral #diseases (PLoS Negl Trop Dis., abstract)

[Source: PLoS Neglected Tropical Diseases, full page: (LINK). Abstract, edited.]

OPEN ACCESS /  PEER-REVIEWED / RESEARCH ARTICLE

Impact of environmental factors on neglected emerging arboviral diseases

Camila Lorenz , Thiago S. Azevedo, Flávia Virginio, Breno S. Aguiar, Francisco Chiaravalloti-Neto , Lincoln Suesdek

Published: September 27, 2017 / DOI: https://doi.org/10.1371/journal.pntd.0005959 / This is an uncorrected proof.

 

Abstract

Background

Brazil is a tropical country that is largely covered by rainforests and other natural ecosystems, which provide ideal conditions for the existence of many arboviruses. However, few analyses have examined the associations between environmental factors and arboviral diseases. Thus, based on the hypothesis of correlation between environment and epidemiology, the proposals of this study were (1) to obtain the probability of occurrence of Oropouche, Mayaro, Saint Louis and Rocio fevers in Brazil based on environmental conditions corresponding to the periods of occurrence of the outbreaks; (2) to describe the macroclimatic scenario in Brazil in the last 50 years, evaluating if there was any detectable tendency to increase temperatures and (3) to model future expansion of those arboviruses in Brazil based on future temperature projections.

Methodology/Principal findings

Our model assessed seven environmental factors (annual rainfall, annual temperature, elevation, seasonality of temperature, seasonality of precipitation, thermal amplitude, and daytime temperature variation) for their association with the occurrence of outbreaks in the last 50 years. Our results suggest that various environmental factors distinctly influence the distribution of each arbovirus, with temperature being the central determinant of disease distribution in all high-risk areas. These areas are subject to change, since the average temperature of some areas has increased significantly over the time.

Conclusions/Significance

This is the first spatio-temporal study of the Oropouche, Mayaro, Saint Louis, and Rocio arboviruses, and our results indicate that they may become increasingly important public health problems in Brazil. Thus, next studies and control programs should include these diseases and also take into consideration key environmental elements.

 

Author summary

The Oropouche, Mayaro, Saint Louis, and Rocio viruses are neglected emerging mosquito-borne viruses that are spreading and causing wide-scale epidemics in South America. However, under-reporting of these cases is possible, as the symptoms are shared with other endemic diseases. Moreover, little is known regarding environmental conditions that favor these tropical outbreaks of arboviral diseases. This study examined the association of environmental factors with the probability of occurrence of Oropouche, Mayaro, Saint Louis and Rocio fever outbreaks (present and future) and finds that temperature is a central variable that determines the distribution of high-risk areas. This fact is very worrying, because the average temperature of some areas has increased significantly over the time. Results from this study strongly suggest that these four diseases have the potential to become important public health problems or become increasingly relevant in Brazil and other tropical areas in the coming years and should be monitored as part of effective control programs.

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Citation: Lorenz C, Azevedo TS, Virginio F, Aguiar BS, Chiaravalloti-Neto F, Suesdek L (2017) Impact of environmental factors on neglected emerging arboviral diseases. PLoS Negl Trop Dis 11(9): e0005959. https://doi.org/10.1371/journal.pntd.0005959

Editor: Marilia Sá Carvalho, Fundacao Oswaldo Cruz, BRAZIL

Received: May 30, 2017; Accepted: September 12, 2017; Published: September 27, 2017

Copyright: © 2017 Lorenz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper and its Supporting Information files.

Funding: CL was supported by funding from Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP) (2013/05521-9). FV was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) (23038.005.274/2011-24 and 1275/2011). LS was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)(311805/2014-0). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: Arbovirus; Brazil; Emerging Diseases; Oropuche Virus; Rocio Virus; Mayaro Virus.

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#Diagnosis of #Fatal #Human Case of St. Louis #Encephalitis Virus #Infection by Metagenomic Sequencing, #California, 2016 (@CDC_EIDjournal, abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 23, Number 10—October 2017 / Dispatch

Diagnosis of Fatal Human Case of St. Louis Encephalitis Virus Infection by Metagenomic Sequencing, California, 2016

Charles Y. Chiu  , Lark L. Coffey, Jamie Murkey, Kelly Symmes, Hannah A. Sample, Michael R. Wilson, Samia N. Naccache, Shaun Arevalo, Sneha Somasekar, Scot Federman, Doug Stryke, Paul Vespa, Gary Schiller, Sharon Messenger, Romney Humphries, Steve Miller, and Jeffrey D. Klausner

Author affiliations: University of California, San Francisco, California, USA (C.Y. Chiu, H.A. Sample, M.R. Wilson, S. Arevalo, S. Somasekar, S. Miller); University of California, San Francisco–Abbott Viral Diagnostics and Discovery Center, San Francisco (C.Y. Chiu, S. Arevalo, S. Somasekar, S. Miller); University of California, Davis, California, USA (L.L. Coffey, K. Symmes); University of California, Los Angeles, California, USA (J. Murkey, S. Federman, D. Stryke, P. Vespa, G. Schiller, R. Humphries, J.D. Klausner); University of Southern California, Los Angeles (S.N. Naccache); California Department of Public Health, Richmond, California, USA (S. Messenger)

 

Abstract

We used unbiased metagenomic next-generation sequencing to diagnose a fatal case of meningoencephalitis caused by St. Louis encephalitis virus in a patient from California in September 2016. This case is associated with the recent 2015–2016 reemergence of this virus in the southwestern United States.

Keywords: St Louis Encephalitis Virus; Encephalitis; USA; California.

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#Reemergence of #StLouis #Encephalitis Virus, #California, 2015 (@CDC_EIDjournal, abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 22, Number 12—December 2016 / Dispatch

Reemergence of St. Louis Encephalitis Virus, California, 2015

Gregory S. White1, Kelly Symmes1, Pu Sun, Ying Fang, Sandra Garcia, Cody Steiner, Kirk Smith, William K. Reisen, and Lark L. Coffey

Author affiliations: Coachella Valley Mosquito and Vector Control District, Indio, California, USA (G.S. White); School of Veterinary Medicine, University of California, Davis, California (K. Symmes, P. Sun, Y. Fang, S. Garcia, C. Steiner, W.K. Reisen, L.L. Coffey); Environmental Services Department, Maricopa County, Phoenix, Arizona, USA (K. Smith)

 

Abstract

St. Louis encephalitis virus infection was detected in summer 2015 in southern California after a 12-year absence, concomitant with an Arizona outbreak. Sequence comparisons showed close identity of California and Arizona isolates and a relationship with 2005 Argentine isolates, suggesting virus introduction from South America and underscoring the value of continued arbovirus surveillance.

Keywords: St Louis Encephalitis; USA; California.

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#Activity #Patterns of St. Louis #Encephalitis and #WestNile Viruses in Free Ranging #Birds during a #Human Encephalitis #Outbreak in #Argentina (PLoS One, abstract)

[Source: PLoS One, full page: (LINK). Abstract, edited.]

OPEN ACCESS / PEER-REVIEWED / RESEARCH ARTICLE

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

Luis Adrián Diaz , Agustín Ignacio Quaglia, Brenda Salomé Konigheim, Analia Silvana Boris, Juan Javier Aguilar, Nicholas Komar, Marta Silvia Contigiani

Published: August 26, 2016 / http://dx.doi.org/10.1371/journal.pone.0161871

 

Abstract

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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Citation: Diaz LA, Quaglia AI, Konigheim BS, Boris AS, Aguilar JJ, Komar N, et al. (2016) Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina. PLoS ONE 11(8): e0161871. doi:10.1371/journal.pone.0161871

Editor: Lark L. Coffey, University of California Davis, UNITED STATES

Received: April 6, 2016; Accepted: August 12, 2016; Published: August 26, 2016

This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Data Availability: All relevant data are within the paper.

Funding: This work was funded by grants from Ministerio de Ciencia y Tecnología de la Nación Argentina (MINCYT, PICT 2013/1779, MSC), Consejo Nacional de Ciencia y Tecnología (CONICET PIP 11220120100544), Secretaría de Ciencia y Tecnología Universidad Nacional de Córdoba (SECYT 203/14, LAD) and Fundación Bunge y Born. AIQ is a recipient of a doctorate scholarship from Council for Scientific and Technical Research (CONICET). LAD´s internship at the CDC Ft. Collins was supported by the International Union of Microbiological Societies (http://www.iums.org/) and International Society of Infectious Diseases (http://www.isid.org/).

Competing interests: The authors have declared that no competing interests exist.

Keywords: Research; Abstracts; Flavivirus; St. Louis Encephalitis Virus; West Nile Virus; Argentina; Wildbirds.

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