Infection of Western Gray #Kangaroos (Macropus fuliginosus) with #Australian #Arboviruses Associated with #Human #Infection (Vector Borne Zoo Dis., abstract)

[Source: Vector Borne and Zoonotic Diseases, full page: (LINK). Abstract, edited.]

Infection of Western Gray Kangaroos (Macropus fuliginosus) with Australian Arboviruses Associated with Human Infection

Narayan Gyawali, Andrew W. Taylor-Robinson, Richard S. Bradbury, Abbey Potter, and John G. Aaskov

Published Online: 26 Sep 2019

 

Abstract

More than 75 arboviruses (arthropod-borne viruses) have been identified in Australia. While Alfuy virus (ALFV), Barmah Forest virus (BFV), Edge Hill virus (EHV), Kokobera virus (KOKV), Murray Valley encephalitis virus (MVEV), Sindbis virus (SINV), Ross River virus (RRV), Stratford virus (STRV), and West Nile virus strain Kunjin (KUNV) have been associated with human infection, there remains a paucity of data regarding their respective transmission cycles and any potential nonhuman vertebrate hosts. It is likely that these viruses are maintained in zoonotic cycles involving native animals rather than solely by human-to-human transmission. A serosurvey (n = 100) was undertaken to determine the prevalence of neutralizing antibodies against a panel of Australian arboviruses in western gray kangaroos (Macropus fuliginosus) obtained from 11 locations in the midwest to southwest of Western Australia. Neutralizing antibodies against RRV were detected in 25%, against BFV in 14%, and antibodies to both viruses in 34% of serum samples. The prevalence of antibodies against these two viruses was the same in males and females, but higher in adult than in subadult kangaroos (p < 0.05). Twenty-one percent of samples had neutralizing antibodies against any one or more of the flaviviruses ALFV, EHV, KOKV, MVEV, and STRV. No neutralizing antibodies against SINV and KUNV were detected. If this sample of kangaroo sera was representative of the broader Australian population of macropods, it suggests that they are common hosts for RRV and BFV. The absence or low seroprevalence of antibodies against the remaining arboviruses suggests that they are not prevalent in the region or that kangaroos are not commonly infected with them. The detection of neutralizing antibodies to MVEV requires further investigation as this virus has not been identified previously so far south in Western Australia.

Keywords: Arbovirus; Flavivirus; Kangaroos; Wildlife; Human; Australia.

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#Density-dependence and #persistence of #Morogoro #arenavirus #transmission in a fluctuating population of its reservoir host (J Anim Ecol., abstract)

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

J Anim Ecol. 2019 Sep 23. doi: 10.1111/1365-2656.13107. [Epub ahead of print]

Density-dependence and persistence of Morogoro arenavirus transmission in a fluctuating population of its reservoir host.

Mariën J1, Borremans B1,2,3, Verhaeren C1, Kirkpatrick L1, Gryseels S1,4,5, Goüy de Bellocq J6, Günther S7, Sabuni CA8, Massawe AW8, Reijniers J1,9, Leirs H1.

Author information: 1 Evolutionary Ecology Group, University of Antwerp, Antwerp, Belgium. 2 Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA. 3 Interuniversity Institute for Biostatistics and statistical Bioinformatics (I-BIOSTAT), Hasselt University, Hasselt, Belgium. 4 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, USA. 5 Clinical and Epidemiological Virology, Rega Institute, KU Leuven, Leuven, Belgium. 6 Institute of Vertebrate Biology, Research Facility Studenec, The Czech Academy of Sciences, Brno, Czech Republic. 7 Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany. 8 PestManagement Centre, Sokoine University of Agriculture, Morogoro, Tanzania. 9 Department of Engineering Management, University of Antwerp, Antwerp, Belgium.

 

Abstract

1.A key aim in wildlife disease ecology is to understand how host and parasite characteristics influence parasite transmission and persistence. Variation in host population density can have strong impacts on transmission and outbreaks, and theory predicts particular transmission-density patterns depending on how parasites are transmitted between individuals. Here, we present the results of a study on the dynamics of Morogoro arenavirus in a population of multimammate mice (Mastomys natalensis). This widespread African rodent, which is also the reservoir host of Lassa arenavirus in West Africa, is known for its strong seasonal density fluctuations driven by food availability.

2.We investigated to what degree virus transmission changes with host population density and how the virus might be able to persist during periods of low host density.

3.A seven-year capture-mark-recapture study was conducted in Tanzania where rodents were trapped monthly and screened for the presence of antibodies against Morogoro virus. Observed seasonal seroprevalence patterns were compared with those generated by mathematical transmission models to test different hypotheses regarding the degree of density-dependence and the role of chronically infected individuals.

4.We observed that Morogoro virus seroprevalence correlates positively with host density with a lag of one to four months. Model results suggest that the observed seasonal seroprevalence dynamics can be best explained by a combination of vertical and horizontal transmission, and that a small number of animals needs to be infected chronically to ensure viral persistence.

5.Transmission dynamics and viral persistence were best explained by the existence of both acutely and chronically infected individuals, and by seasonally changing transmission rates. Due to the presence of chronically infected rodents, rodent control is unlikely to be a feasible approach for eliminating arenaviruses such as Lassa virus from Mastomys populations.

© 2019 The Authors. Journal of Animal Ecology © 2019 British Ecological Society.

PMID: 31545505 DOI: 10.1111/1365-2656.13107

Keywords: Arenavirus; Wildlife; Rodents; Morogoro virus; Seroprevalence; Tanzania.

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#Dengue and #chikungunya among outpatients with acute undifferentiated #fever in #Kinshasa, #DRC: A cross-sectional study (PLoS Negl Trop Dis., abstract)

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

OPEN ACCESS /  PEER-REVIEWED / RESEARCH ARTICLE

Dengue and chikungunya among outpatients with acute undifferentiated fever in Kinshasa, Democratic Republic of Congo: A cross-sectional study

Sam Proesmans , Freddy Katshongo, John Milambu, Blaise Fungula, Hypolite Muhindo Mavoko, Steve Ahuka-Mundeke, Raquel Inocêncio da Luz, Marjan Van Esbroeck, Kevin K. Ariën, Lieselotte Cnops, Birgit De Smet, Pascal Lutumba, Jean-Pierre Van geertruyden, Veerle Vanlerberghe

Published: September 5, 2019 / DOI: https://doi.org/10.1371/journal.pntd.0007047 / This is an uncorrected proof.

 

Abstract

Background

Pathogens causing acute fever, with the exception of malaria, remain largely unidentified in sub-Saharan Africa, given the local unavailability of diagnostic tests and the broad differential diagnosis.

Methodology

We conducted a cross-sectional study including outpatient acute undifferentiated fever in both children and adults, between November 2015 and June 2016 in Kinshasa, Democratic Republic of Congo. Serological and molecular diagnostic tests for selected arboviral infections were performed on blood, including PCR, NS1-RDT, ELISA and IFA for acute, and ELISA and IFA for past infections.

Results

Investigation among 342 patients, aged 2 to 68 years (mean age of 21 years), with acute undifferentiated fever (having no clear focus of infection) revealed 19 (8.1%) acute dengue–caused by DENV-1 and/or DENV-2 –and 2 (0.9%) acute chikungunya infections. Furthermore, 30.2% and 26.4% of participants had been infected in the past with dengue and chikungunya, respectively. We found no evidence of acute Zika nor yellow fever virus infections. 45.3% of patients tested positive on malaria Rapid Diagnostic Test, 87.7% received antimalarial treatment and 64.3% received antibacterial treatment.

Discussion

Chikungunya outbreaks have been reported in the study area in the past, so the high seroprevalence is not surprising. However, scarce evidence exists on dengue transmission in Kinshasa and based on our data, circulation is more important than previously reported. Furthermore, our study shows that the prescription of antibiotics, both antibacterial and antimalarial drugs, is rampant. Studies like this one, elucidating the causes of acute fever, may lead to a more considerate and rigorous use of antibiotics. This will not only stem the ever-increasing problem of antimicrobial resistance, but will–ultimately and hopefully–improve the clinical care of outpatients in low-resource settings.

Trial registration ClinicalTrials.gov NCT02656862.

 

Author summary

Malaria remains one of the most important causes of fever in sub-Saharan Africa. However, its share is declining, since the diagnosis and treatment of malaria have improved significantly over the years. Hence leading to an increase in the number of patients presenting with non-malarial fever. Often, obvious clinical signs and symptoms like cough or diarrhea are absent, probing the question: “What causes the fever?” Previous studies have shown that the burden of arboviral infections–like dengue and chikungunya–in sub-Saharan Africa is underestimated, which is why we screened for four common arboviral infections in patients presenting with ‘undifferentiated fever’ at an outpatient clinic in suburban Kinshasa, Democratic Republic of Congo. Among the patients tested, we found that one in ten presented with an acute arboviral infection and that almost one in three patients had been infected in the past. These findings suggest that clinicians should think about arboviral infections more often, thereby refraining from the prescription of antibiotics, a practice increasingly problematic given the global rise of antimicrobial resistance.

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Citation: Proesmans S, Katshongo F, Milambu J, Fungula B, Muhindo Mavoko H, Ahuka-Mundeke S, et al. (2019) Dengue and chikungunya among outpatients with acute undifferentiated fever in Kinshasa, Democratic Republic of Congo: A cross-sectional study. PLoS Negl Trop Dis 13(9): e0007047. https://doi.org/10.1371/journal.pntd.0007047

Editor: Stuart D. Blacksell, Mahidol Univ, Fac Trop Med, THAILAND

Received: November 28, 2018; Accepted: August 6, 2019; Published: September 5, 2019

Copyright: © 2019 Proesmans 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 manuscript and its Supporting Information files.

Funding: This study was co-funded by the framework agreement between the Institute of Tropical Medicine and the Belgian development cooperation (https://www.itg.be/E/cooperation) to VV and Vlaamse Interuniversitaire Raad – Universitaire Ontwikkelingssamenwerking (https://www.vliruos.be/en) (VLIR-UOS, Grant reference ZRDC2014MP083) to JPVG. 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; Dengue fever; Chikungunya fever; Malaria; Serology; Seroprevalence; DRC.

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Decreased #humoral #immunity to #mumps in young #adults immunized with #MMR #vaccine in #childhood (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Decreased humoral immunity to mumps in young adults immunized with MMR vaccine in childhood

Mohammed Ata Ur Rasheed, Carole J. Hickman, Marcia McGrew, Sun Bae Sowers, Sara Mercader, Amy Hopkins, Vickie Grimes, Tianwei Yu, Jens Wrammert, Mark J. Mulligan, William J. Bellini, Paul A. Rota, Walter A. Orenstein, Rafi Ahmed, and Srilatha Edupuganti

PNAS first published September 3, 2019 / DOI: https://doi.org/10.1073/pnas.1905570116

Contributed by Rafi Ahmed, July 18, 2019 (sent for review April 2, 2019; reviewed by Rino Rappuoli and Robert Seder)

 

Significance

The live-attenuated mumps-measles-rubella (MMR) vaccine has been highly successful in the United States since its introduction 47 years ago. However, for the past decade, mumps outbreaks have been occurring among young adults who were vaccinated as children. Waning immunity has been proposed as a key contributing factor to mumps resurgence. In our sample (n = 71) of 18- to 23-year-old college students, the majority had detectable mumps IgG antibodies by enzyme-linked immunosorbent assay (ELISA) but the magnitude was lower than rubella. Neutralizing antibody titers were 6-fold lower to a circulating genotype G mumps strain versus the vaccine strain. Ten percent of our participants had no detectable memory B cells to mumps. Strategies are needed to improve immunity to the mumps vaccine.

 

Abstract

In the past decade, multiple mumps outbreaks have occurred in the United States, primarily in close-contact, high-density settings such as colleges, with a high attack rate among young adults, many of whom had the recommended 2 doses of mumps-measles-rubella (MMR) vaccine. Waning humoral immunity and the circulation of divergent wild-type mumps strains have been proposed as contributing factors to mumps resurgence. Blood samples from 71 healthy 18- to 23-year-old college students living in a non-outbreak area were assayed for antibodies and memory B cells (MBCs) to mumps, measles, and rubella. Seroprevalence rates of mumps, measles, and rubella determined by IgG enzyme-linked immunosorbent assay (ELISA) were 93, 93, and 100%, respectively. The index standard ratio indicated that the concentration of IgG was significantly lower for mumps than rubella. High IgG avidity to mumps Enders strain was detected in sera of 59/71 participants who had sufficient IgG levels. The frequency of circulating mumps-specific MBCs was 5 to 10 times lower than measles and rubella, and 10% of the participants had no detectable MBCs to mumps. Geometric mean neutralizing antibody titers (GMTs) by plaque reduction neutralization to the predominant circulating wild-type mumps strain (genotype G) were 6-fold lower than the GMTs against the Jeryl Lynn vaccine strain (genotype A). The majority of the participants (80%) received their second MMR vaccine ≥10 years prior to study participation. Additional efforts are needed to fully characterize B and T cell immune responses to mumps vaccine and to develop strategies to improve the quality and durability of vaccine-induced immunity.

mumps, measles, rubella – MMR vaccine – memory B cells (MBCs) – plaque reduction  -neutralization titers – IgG ELISA

 

Footnotes

1 To whom correspondence may be addressed. Email: rahmed@emory.edu or sedupug@emory.edu.

Author contributions: M.A.U.R., C.J.H., W.J.B., W.A.O., R.A., J.W., and S.E. designed research; M.A.U.R., C.J.H., M.M., S.B.S., S.M., A.H., V.G., and S.E. performed research; M.A.U.R., C.J.H., S.B.S., S.M., T.Y., and S.E. analyzed data; and M.A.U.R., C.J.H., J.W., M.J.M., W.J.B., P.A.R., W.A.O., R.A., and S.E. wrote the paper.

Reviewers: R.R., GlaxoSmithKline; and R.S., NIH.

The authors declare no conflict of interest.

This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1905570116/-/DCSupplemental.

Published under the PNAS license.

Keywords: Mumps; Vaccines; Serology; Seroprevalence; Immunoglobulins.

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#Enterovirus D68 #serosurvey: evidence for #endemic circulation in the #Netherlands, 2006 to 2016 (Euro Surveill., abstract)

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

Enterovirus D68 serosurvey: evidence for endemic circulation in the Netherlands, 2006 to 2016

Eveliina Karelehto1, Gerrit Koen1, Kimberley Benschop2, Fiona van der Klis2, Dasja Pajkrt3, Katja Wolthers1

Affiliations: 1 Department of Medical Microbiology, Laboratory of Clinical Virology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands; 2 National Institute for Public Health and the Environment, Bilthoven, the Netherlands; 3 Department of Pediatric Infectious Diseases, Emma Children’s Hospital, University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands

Correspondence:  Katja C Wolthers

Citation style for this article: Karelehto Eveliina, Koen Gerrit, Benschop Kimberley, van der Klis Fiona, Pajkrt Dasja, Wolthers Katja. Enterovirus D68 serosurvey: evidence for endemic circulation in the Netherlands, 2006 to 2016. Euro Surveill. 2019;24(35):pii=1800671. https://doi.org/10.2807/1560-7917.ES.2019.24.35.1800671

Received: 12 Dec 2018;   Accepted: 05 Jun 2019

 

Abstract

Background

Enterovirus D68 (EV-D68) has caused major outbreaks of severe respiratory illness worldwide since 2010.

Aim

Our aim was to evaluate EV-D68 circulation in the Netherlands by conducting a serosurvey of EV-D68 neutralising antibodies (nAb) among the Dutch general population.

Methods

We screened 280 sera from children and adults in the Netherlands and used two independent sets of samples collected in the years 2006 and 2007 and in the years 2015 and 2016, time points before and after the first EV-D68 upsurge in 2010. Neutralisation capacity of the sera was tested against the prototype Fermon EV-D68 strain isolated in 1962 and against a recent EV-D68 strain (genotype B3) isolated in France in 2016.

Results

Regardless of the time of serum collection, we found remarkably high overall seropositivity (94.3–98.3%) for nAb against both EV-D68 strains. Geometric mean titres increased in an age-dependent manner.

Conclusions

Our data suggest that EV-D68 has been circulating in the Netherlands for decades and that the enterovirus surveillance does not accurately capture the prevalence of this clinically relevant pathogen.

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

Keywords: Enterovirus; EV-D68; Pediatrics; Netherlands; Seroprevalence.

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A #Report of #Zika Virus #Seroprevalence in Republic of the #Congo (Vector Borne Zoo Dis., abstract)

[Source: Vector Borne and Zoonotic Diseases, full page: (LINK). Abstract, edited.]

A Report of Zika Virus Seroprevalence in Republic of the Congo

Elif Nurtop, Nanikaly Moyen, Amelia Dzia-Lepfoundzou, Yannick Dimi, Laetitia Ninove, Jan Felix Drexler, Pierre Gallian, Xavier de Lamballerie, and Stéphane Priet

Published Online: 26 Aug 2019 / DOI: https://doi.org/10.1089/vbz.2019.2466

 

Abstract

Zika virus (ZIKV) is an arthropod-borne RNA virus (arbovirus), belonging to the Spondweni serogroup. ZIKV was first described in Africa in 1947 and remained sporadic until Micronesia outbreak in 2007, which was followed by outbreaks in the Pacific Islands, Latin America, and the Caribbean. Subsequent to the epidemics, ZIKV revealed its severity as virus was sexually transmissible, and it was associated with serious fetal and neurological complications. ZIKV originated from Africa; however, little is known about the epidemiology of the virus in African populations. Following a recent study in Cameroon that evidenced low ZIKV epidemiology associated with a presumptive (peri-)sylvatic transmission, we performed a seroepidemiological study in Republic of the Congo, neighbor of Cameroon. To accomplish this, 386 serum specimens from volunteer blood donors collected in 2011 from rural and urban areas of Republic of the Congo were tested with ZIKV-specific methodology; primary screening with anti-NS1 ZIKV IgG ELISA followed by confirmation with cytopathic effect (CPE)-based virus neutralization test (VNT). ZIKV seropositivity was determined as low as 1.8%, varying slightly between urban and rural areas (1.7% and 3.6%). These results demonstrate that the majority of the population of Republic of the Congo is immunologically naïve against ZIKV with a presumptive (peri-)sylvatic transmission cycle, which emphasizes the importance of surveillance studies in Africa.

Keywords: Zika Virus; Seroprevalence; Rep. of Congo.

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#Epidemiological profile of #Zika, #Dengue and #Chikungunya virus #infections identified by medical and molecular evaluations in #Rondonia, #Brazil (Rev Inst Med Trop Sao Paulo, abstract)

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

Rev Inst Med Trop Sao Paulo. 2019 Aug 19;61:e40. doi: 10.1590/S1678-9946201961040.

Epidemiological profile of Zika, Dengue and Chikungunya virus infections identified by medical and molecular evaluations in Rondonia, Brazil.

Vieira DS1,2,3, Zambenedetti MR4, Requião L4, Borghetti IA4,5, Luna LKS4, Santos AOD1,3, Taborda RLM3, Pereira DB3, Krieger MA4,6, Salcedo JMV1,3, Rampazzo RCP4.

Author information: 1 Fundação Oswaldo Cruz Rondônia, Porto Velho, Rondônia, Brazil. 2 Universidade Federal de Rondônia, Programa de Pós-Graduação em Biologia Experimental, Porto Velho, Rondônia, Brazil. 3 Centro de Pesquisa em Medicina Tropical, Porto Velho, Rondônia, Brazil. 4 Instituto de Biologia Molecular do Paraná, Curitiba, Paraná, Brazil. 5 Universidade Federal do Paraná, Departamento de Engenharia de Bioprocessos e Biotecnologia, Curitiba, Paraná, Brazil. 6 Instituto Carlos Chagas, Curitiba, Paraná, Brazil.

 

Abstract

Several arboviruses have emerged and/or re-emerged in North, Central and South-American countries. Viruses from some regions of Africa and Asia, such as the Zika and Chikungunya virus have been introduced in new continents causing major public health problems. The aim of this study was to investigate the presence of RNA from Zika, Dengue and Chikungunya viruses in symptomatic patients from Rondonia, where the epidemiological profile is still little known, by one-step real-time RT-PCR. The main clinical signs and symtoms were fever (51.2%), headache (78%), chills (6.1%), pruritus (12.2%), exanthema (20.1%), arthralgia (35.3%), myalgia (26.8%) and retro-orbital pain (19.5%). Serum from 164 symptomatic patients were collected and tested for RNA of Zika, Dengue types 1 to 4 and Chikungunya viruses, in addition to antibodies against Dengue NS1 antigen. Direct microscopy for Malaria was also performed. Only ZIKV RNA was detected in 4.3% of the patients, and in the remaining 95.7% of the patients RNA for Zika, Dengue and Chikungunya viruses were not detected. This finding is intriguing as the region has been endemic for Dengue for a long time and more recently for Chikungunya virus as well. The results indicated that medical and molecular parameters obtained were suitable to describe the first report of symptomatic Zika infections in this region. Furthermore, the low rate of detection, compared to clinical signs and symptoms as the solely diagnosis criteria, suggests that molecular assays for detection of viruses or other pathogens that cause similar symptoms should be used and the corresponding diseases could be included in the compulsory notification list.

PMID: 31432989 DOI: 10.1590/S1678-9946201961040

Keywords: Zika Virus; Dengue fever; Chikungunya fever; Seroprevalence; Brazil.

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