An #update on #Toscana virus #distribution, #genetics, medical and diagnostic aspects (Clin Microbiol Infect., abstract)

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

Clin Microbiol Infect. 2020 Jan 2. pii: S1198-743X(19)30672-X. doi: 10.1016/j.cmi.2019.12.015. [Epub ahead of print]

An update on Toscana virus distribution, genetics, medical and diagnostic aspects.

Ayhan N1, Charrel RN2.

Author information: 1 Unite des Virus Emergents (Aix-Marseille Univ – IRD 190 – Inserm 1207 – IHU Mediterranee Infection), Marseille, France; EA7310, Laboratoire de Virologie, Université de Corse-Inserm, Corte, France. 2 Unite des Virus Emergents (Aix-Marseille Univ – IRD 190 – Inserm 1207 – IHU Mediterranee Infection), Marseille, France. Electronic address: remi.charrel@univ-amu.fr.

 

Abstract

BACKGROUND:

Toscana virus is an arbovirus transmitted by sand flies within the Mediterranean area where it can cause febrile illness and neuroinvasive infections during the seasonal circulation period of the vector. Although it is an important cause of meningitis and encephalitis, it remains a neglected virus with limited published data as demonstrated by less than 250 peer-reviewed articles since the 1970’s.

OBJECTIVES:

The last review article on Toscana virus was published in 2012. The aim was to compile peer-reviewed articles in order to provide an updated review highlighting recent findings to complement previous review articles.

SOURCES:

PubMed database was searched using the “Toscana virus” keyword from 2010 to present. A total of 152 articles were retrieved and identified studies were assessed for novel information on virus genetics, and geographic and medical aspects compared with existing knowledge reported in previous review articles.

CONTENT:

Studies addressing medical, veterinary and entomological aspects have provided evidence that Toscana virus is present in North Africa, in the Balkan Peninsula, and in most of the Mediterranean islands. Beside the two previously recognized genetic lineages, a novel evolutionary lineage has been identified in the Balkan Peninsula. Co-circulation of two genetic lineages has been demonstrated in France, in Turkey and in Croatia. In addition to meningitis and meningo-encephalitis that have been reported for forty years, various neuroinvasive forms have been recently reported such as Guillain-Barré syndrome, hydrocephalus, myositis, fasciitis, polymyeloradiculopathy, deafness, facial paralysis.

IMPLICATION:

Because it is endemic in countries bordering the Mediterranean, physicians should include Toscana virus in the differential diagnosis of patients presenting with febrile illness and/or neurological manifestations.

Copyright © 2019. Published by Elsevier Ltd.

PMID: 31904562 DOI: 10.1016/j.cmi.2019.12.015

Keywords: Arbovirus; Toscana virus; Encephalitis; Meningitis; Neurology.

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The #evolutionary #dynamics of #Oropouche Virus in South #America (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

The evolutionary dynamics of Oropouche Virus in South America

Bernardo Gutierrez, Emma L. Wise, Steven T. Pullan, Christopher H. Logue, Thomas A. Bowden, Marina Escalera-Zamudio, Gabriel Trueba, Marcio R. T. Nunes, Nuno R. Faria, Oliver G. Pybus

DOI: 10.1128/JVI.01127-19

 

ABSTRACT

The Amazon basin is home to numerous arthropod-borne viral pathogens that cause febrile disease in humans. Among these, Oropouche orthobunyavirus (OROV) is a relatively understudied member of the genus Orthobunyavirus, family Peribunyaviridae, that causes periodic outbreaks in human populations in Brazil and other South American countries. Although several studies have described the genetic diversity of the virus, the evolutionary processes that shape the OROV genome remain poorly understood. Here we present a comprehensive study of the genomic dynamics of OROV that encompasses phylogenetic analysis, evolutionary rate estimates, inference of natural selective pressures, recombination and reassortment, and structural analysis of OROV variants. Our study includes all available published sequences, as well as a set of new OROV genomes sequences obtained from patients in Ecuador, representing the first set of genomes from this country. Our results show differing evolutionary processes on the three segments that comprise the viral genome. We infer differing times of the most recent common ancestors (TMRCAs) of the genome segments and propose this can be explained by cryptic reassortment. We also present the discovery of previously unobserved putative N-linked glycosylation sites, and codons that evolve under positive selection on the viral surface proteins, and discuss the potential role of these features in the evolution of OROV through a combined phylogenetic and structural approach.

 

Importance

The emergence and re-emergence of pathogens such as Zika virus (ZIKV), Chikungunya virus (CHIKV) and yellow fever virus (YFV) have drawn attention towards other co-circulating arboviruses in South America. Oropouche virus (OROV) is a poorly-studied pathogen responsible for over a dozen outbreaks since the early 1960s, and represents a public health burden to countries such as Brazil, Panama and Peru. OROV is likely underreported as its symptomatology can be easily confounded with other febrile illnesses (e.g. dengue fever and leptospirosis), and point-of-care testing for the virus is still uncommon. With limited data, there is a need to optimise the information currently available. Analysis of OROV genomes can help us understand how the virus circulates in nature and can reveal the evolutionary forces that shape the genetic diversity of the virus, which has implications for molecular diagnostics and the design of potential vaccines.

Copyright © 2019 Gutierrez et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.

Keywords: Arbovirus; Orthobunyavirus; Oropouche virus.

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Characterization of #Usutu virus NS5 protein. #Polymerase activity, protein-protein interaction and cellular localization (Antimicrob Agents Chemother., abstract)

[Source: Antimicrobial Agents and Chemotherapy, full page: (LINK). Abstract, edited.]

Characterization of Usutu virus NS5 protein. Polymerase activity, protein-protein interaction and cellular localization.

L. Albentosa-González, P. Clemente-Casares, R. Sabariegos, A. Mas

DOI: 10.1128/AAC.01573-19

 

ABSTRACT

Usutu virus (USUV) has become increasingly relevant in recent years with large outbreaks that sporadically have affected humans, being reported in wildlife. Similarly to the rest of flaviviruses, USUV contains a positive single-stranded RNA genome which is replicated by the activity of the non-structural protein 5 (NS5). USUV NS5 shows high sequence identity with the remaining viruses in this genus. This permitted us to identify the predicted methyl-transferase domain and the RNA-dependent RNA polymerase domain (RdRpD). Owing to their high degree of conservation, viral polymerases are considered priority targets for the development of antiviral compounds. In the present study, we have cloned and expressed the entire NS5 and the RdRpD in a heterologous system and have used purified preparations for protein characterizations. We have determined the optimal reaction conditions by investigating how variations in different physicochemical parameters, such as buffer concentration, temperature, and pH, affect RNA polymerization activity. We also found that USUV polymerase, but not the full-length NS5, exhibits cooperative activity in the synthesis of RNA, and that the RdRp activity is not inhibited by Sofosbuvir. To further examine the characteristics of USUV polymerase in a more biological context, we have expressed NS5 and the RdRpD in eukaryotic cells and analyzed its subcellular location. NS5 is predominantly found in the cytoplasm, a significant proportion is directed to the nucleus and this translocation involves nuclear location signals (NLS) located, at least, between the MTase and RdRpD domains.

Copyright © 2019 Albentosa-González et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.

Keywords: Arbovirus; Flavivirus; Usutu virus; Viral pathogenesis.

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Infected #Mosquitoes Have Altered #Behavior to #Repellents: A Systematic Review and Meta-analysis (J Med Entomol., abstract)

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

J Med Entomol. 2019 Nov 22. pii: tjz209. doi: 10.1093/jme/tjz209. [Epub ahead of print]

Infected Mosquitoes Have Altered Behavior to Repellents: A Systematic Review and Meta-analysis.

Lajeunesse MJ1, Avello DA1, Behrmann MS1, Buschbacher TJ1, Carey K1, Carroll J1, Chafin TJ1, Elkott F1, Faust AM1, Fauver H1, Figueroa GD1, Flaig LL1, Gauta SA1, Gonzalez C1, Graham RM1, Hamdan K1, Hanlon T1, Hashami SN1, Huynh D1, Knaffl JL1, Lanzas M1, Libell NM1, McCabe C1, Metzger J1, Mitchell I1, Morales MA1, Nayyar YR1, Perkins A1, Phan TA1, Pidgeon NT1, Ritter CL1, Rosales VC1, Santiago O1, Stephens R1, Taylor EJ1, Thomas AJ1, Yanez NE1.

Author information: 1 Department of Integrative Biology, University of South Florida, Tampa, FL.

 

Abstract

Here we conducted a systematic review and meta-analysis to reach a consensus on whether infected and uninfected mosquitoes respond differently to repellents. After screening 2,316 published studies, theses, and conference abstracts, we identified 18 studies that tested whether infection status modulated the effectiveness of repellents. Thirteen of these studies had outcomes available for meta-analysis, and overall, seven repellents were tested (typically DEET with 62% of outcomes), six mosquito species had repellence behaviors measured (typically Aedes aegypti (L.) (Diptera: Culicidae) mosquitoes with 71% of outcomes), and a broad diversity of infections were tested including Sindbis virus (Togaviridae: Alphavirus) (33% of outcomes), Dengue (Flaviviridae: Flavivirus) (31%), malaria (Plasmodium berghei Vincke & Lips (Haemospororida: Plasmodiidae) or P. falciparum Welch (Haemospororida: Plasmodiidae); 25%), Zika (Flaviviridae: Flavivirus) (7%), and microsporidia (4%). Pooling all outcomes with meta-analysis, we found that repellents were less effective against infected mosquitoes-marking an average 62% reduction in protective efficacy relative to uninfected mosquitoes (pooled odds ratio = 0.38, 95% confidence interval = 0.22-0.66; k = 96). Older infected mosquitoes were also more likely to show altered responses and loss of sensitivity to repellents, emphasizing the challenge of distinguishing between age or incubation period effects. Plasmodium- or Dengue-infected mosquitoes also did not show altered responses to repellents; however, Dengue-mosquito systems used inoculation practices that can introduce variability in repellency responses. Given our findings that repellents offer less protection against infected mosquitoes and that these vectors are the most dangerous in terms of disease transmission, then trials on repellent effectiveness should incorporate infected mosquitoes to improve predictability in blocking vector-human contact.

© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

KEYWORDS: feeding behavior; malaria; mosquito repellent and attractant; mosquito-borne disease

PMID: 31755530 DOI: 10.1093/jme/tjz209

Keywords: Arbovirus; Mosquitoes; Mosquitoe repellents.

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#Clinical and #virological #findings in patients with #Usutu virus #infection, northern #Italy, 2018 (Euro Surveill., abstract)

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

Clinical and virological findings in patients with Usutu virus infection, northern Italy, 2018

Monia Pacenti 1,2, Alessandro Sinigaglia 2,3, Thomas Martello 2, Elena De Rui 3, Elisa Franchin 2,3, Silvana Pagni 2,3, Elektra Peta 3, Silvia Riccetti 3, Adelaide Milani 4, Fabrizio Montarsi 4, Gioia Capelli 4, Carlo Giovanni Doroldi 5, Francesco Bigolin 5, Luca Santelli 6, Lucia Nardetto 6, Marco Zoccarato 6, Luisa Barzon 2,3

Affiliations: 1 Microbiology and Virology Unit, Padua University Hospital, Padova, Italy; 2 These authors contributed equally as first authors; 3 Department of Molecular Medicine, University of Padova, Padova, Italy; 4 Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro PD, Italy; 5 Medicine Unit, Camposampiero Hospital, Azienda ULSS 6 Euganea, Padova, Italy; 6 Neurology Department, Ospedale S. Antonio, Azienda ULSS 6 Euganea, Padova, Italy

Correspondence:  Luisa Barzon

Citation style for this article: Pacenti Monia, Sinigaglia Alessandro, Martello Thomas, De Rui Elena, Franchin Elisa, Pagni Silvana, Peta Elektra, Riccetti Silvia, Milani Adelaide, Montarsi Fabrizio, Capelli Gioia, Doroldi Carlo Giovanni, Bigolin Francesco, Santelli Luca, Nardetto Lucia, Zoccarato Marco, Barzon Luisa. Clinical and virological findings in patients with Usutu virus infection, northern Italy, 2018. Euro Surveill. 2019;24(47):pii=1900180. https://doi.org/10.2807/1560-7917.ES.2019.24.47.1900180

Received: 12 Mar 2019;   Accepted: 20 May 2019

 

Abstract

Background

Usutu virus (USUV) is a mosquito-borne flavivirus, which shares its transmission cycle with the phylogenetically related West Nile virus (WNV). USUV circulates in several European countries and its activity has increased over the last 5 years.

Aim

To describe human cases of USUV infection identified by surveillance for WNV and USUV infection in the Veneto Region of northern Italy in 2018.

Methods

From 1 June to 30 November 2018, all cases of suspected autochthonous arbovirus infection and blood donors who had a reactive WNV nucleic acid test were investigated for both WNV and USUV infection by in-house molecular methods. Anti-WNV and anti-USUV IgM and IgG antibodies were detected by ELISA and in-house immunofluorescence assay, respectively; positive serum samples were further tested by WNV and USUV neutralisation assays run in parallel.

Results

Eight cases of USUV infection (one with neuroinvasive disease, six with fever and one viraemic blood donor who developed arthralgia and myalgia) and 427 cases of WNV infection were identified. A remarkable finding of this study was the persistence of USUV RNA in the blood and urine of three patients during follow-up. USUV genome sequences from two patients shared over 99% nt identity with USUV sequences detected in mosquito pools from the same area and clustered within lineage Europe 2.

Conclusions

Clinical presentation and laboratory findings in patients with USUV infection were similar to those found in patients with WNV infection. Cross-reactivity of serology and molecular tests challenged the differential diagnosis.

©  This work is licensed under a Creative Commons Attribution 4.0 International License.

Keywords: Arbovirus; Flavivirus; Usutu virus; Italy.

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Eastern Equine #Encephalitis Virus [#EEEV] — Another Emergent #Arbovirus in the #US (N Engl J Med., summary)

[Source: The New England Journal of Medicine, full page: (LINK). Summary, edited.]

Eastern Equine Encephalitis Virus — Another Emergent Arbovirus in the United States

David M. Morens, M.D., Gregory K. Folkers, M.S., M.P.H., and Anthony S. Fauci, M.D.

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Humans have always lived in intimate association with arthropods that transmit pathogens between humans or from animals to humans. About 700,000 deaths due to vectorborne diseases occur globally each year, according to World Health Organization estimates. In the summer and fall of 2019, nine U.S. states have reported 36 human cases (14 of them fatal) of one of the deadliest of these diseases: eastern equine encephalitis (EEE), an arthropod-borne viral (arboviral) disease transmitted by mosquitoes. In recent years, the Americas have witnessed a steady stream of other emerging or reemerging arboviruses, such as dengue, West Nile, chikungunya, Zika, and Powassan, as well as increasing numbers of travel-related cases of various other arboviral infections. This year’s EEE outbreaks may thus be a harbinger of a new era of arboviral emergences.

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Disclosure forms provided by the authors are available at NEJM.org.

Author Affiliations: From the Office of the Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD.

Keywords: Arbovirus; Alphavirus; Eastern Equine Encephalitis Virus; USA; Moquitoes.

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The first local cases of #Zika virus in #Europe (Lancet, summary)

[Source: The Lancet, full page: (LINK). Summary, edited.]

The first local cases of Zika virus in Europe

Oliver J Brady, Simon I Hay

Published: November 18, 2019 / DOI: https://doi.org/10.1016/S0140-6736(19)32790-4

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In October, 2019, the first mosquito-transmitted, locally acquired cases of Zika virus were reported in Europe.1 This outbreak event has implications far beyond the three people affected and represents a new phase in the global Zika threat. When Zika virus first emerged in the Pacific in 2007, then spread to the Americas and the Caribbean in 2015–17, the global community treated Zika virus as an epidemic disease. The Zika virus was expected to spread to Asia,2 but when surveillance began, not only were outbreaks in Asia found to be due to indigenous strains of Zika virus, but the virus was found to have been circulating silently for decades.3

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OJB reports grants from Wellcome and SIH declares no competing interests.

Keywords: Zika Virus; France.

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