scholarly journals First confirmed occurrence of the yellow fever virus and dengue virus vector Aedes (Stegomyia) luteocephalus (Newstead, 1907) in Mozambique

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ana Paula Abílio ◽  
Ayubo Kampango ◽  
Eliseu J. Armando ◽  
Eduardo S. Gudo ◽  
Luís C. B. das Neves ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Yellow Fever ◽  
Male Genitalia ◽  
Yellow Fever Virus ◽  
Phylogenetic Analyses ◽  
Mosquito Species ◽  
Fever Virus ◽  
Morphological Identification ◽  
Vector Species ◽  
Vector Systems

Abstract Background Mozambique, same as many other tropical countries, is at high risk of arthropod-borne virus (arbovirus) diseases and recently two dengue virus (DENV) outbreaks occurred in the northern part of the country. The occurrence of some important vector species, such as Aedes (Stegomyia) aegypti (Linnaeus) and Ae. (Stg.) albopictus (Skuse), besides several other sylvatic vectors, have been reported in the country, which may indicate that the transmission of some arboviruses of public health importance may involve multiple-vector systems. Therefore, knowing the occurrence and distribution of existing and the new important vectors species, is crucial for devising systematic transmission surveillance and vector control approaches. The aim of this study was to map the occurrence and distribution of mosquito species with potential for transmitting arboviruses of human and veterinary relevance in Niassa Province, Northern Mozambique. Methods Field entomological surveys were undertaken in April 2016 in Lago District, Niassa Province, northern Mozambique. Breeding sites of mosquitoes were inspected and immature stages were collected and reared into adult. Mosquitoes in the adult stages were morphologically identified using taxonomic keys. Morphological identification of Aedes (Stegomyia) luteocephalus (Newstead) were later confirmed using dissected male genitalia and molecular based on the phylogenetic analyses of the sequenced barcode (cox1 mtDNA) gene. Results A total of 92 mosquito larvae collected developed into adults. Of these, 16 (17.39%) were morphologically identified as Ae. luteocephalus. The remaining specimens belonged to Ae. (Stg.) aegypti (n = 4, 4.35%), Ae. (Aedimorphus) vittatus (n = 24, 26.09%), Anopheles garnhami (n = 1, 1.09%), Culex (Culiciomyia) nebulosus (n = 28, 30.43%), Eretmapodites subsimplicipes (n = 18, 19.57%) and Toxorhynchites brevipalpis (n = 1, 1.09%), taxa already known to the country. Male genitalia and phylogenetic analyses confirmed the identity of Ae. luteocephalus specimens collected in this study. Conclusions To our knowledge, this is the first detection of Ae. luteocephalus in Mozambican territory, a vector species of yellow fever virus (YFV), Zika virus (ZIKV) and dengue virus (DENV) in Africa. Further studies are encouraged to investigate the role of Ae. luteocephalus in the transmission of arboviral diseases in Mozambique.

scholarly journals Yellow Fever Outbreak in Eastern Senegal, 2020–2021

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1475
Author(s):  
Moussa Moïse Diagne ◽  
Marie Henriette Dior Ndione ◽  
Alioune Gaye ◽  
Mamadou Aliou Barry ◽  
Diawo Diallo ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Mosquito Species ◽  
Virus Transmission ◽  
Genomic Analysis ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
World Health ◽  
Effective Vaccine ◽  
Ministry Of Health

Yellow fever virus remains a major threat in low resource countries in South America and Africa despite the existence of an effective vaccine. In Senegal and particularly in the eastern part of the country, periodic sylvatic circulation has been demonstrated with varying degrees of impact on populations in perpetual renewal. We report an outbreak that occurred from October 2020 to February 2021 in eastern Senegal, notified and managed through the synergistic effort yellow fever national surveillance implemented by the Senegalese Ministry of Health in collaboration with the World Health Organization, the countrywide 4S network set up by the Ministry of Health, the Institut Pasteur de Dakar, and the surveillance of arboviruses and hemorrhagic fever viruses in human and vector populations implemented since mid 2020 in eastern Senegal. Virological analyses highlighted the implication of sylvatic mosquito species in virus transmission. Genomic analysis showed a close relationship between the circulating strain in eastern Senegal, 2020, and another one from the West African lineage previously detected and sequenced two years ago from an unvaccinated Dutch traveler who visited the Gambia and Senegal before developing signs after returning to Europe. Moreover, genome analysis identified a 6-nucleotide deletion in the variable domain of the 3′UTR with potential impact on the biology of the viral strain that merits further investigations. Integrated surveillance of yellow fever virus but also of other arboviruses of public health interest is crucial in an ecosystem such as eastern Senegal.

Simultaneous detection of Dengue virus, Chikungunya virus, Zika virus, Yellow fever virus and West Nile virus

2019 ◽  
Vol 268 ◽  
pp. 53-55 ◽  
Author(s):  
José A. Boga ◽  
Marta E. Alvarez-Arguelles ◽  
Susana Rojo-Alba ◽  
Mercedes Rodríguez ◽  
María de Oña ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Dengue Virus ◽  
Yellow Fever ◽  
Zika Virus ◽  
Chikungunya Virus ◽  
Yellow Fever Virus ◽  
Simultaneous Detection ◽  
Fever Virus ◽  
West Nile ◽  
Virus Zika

scholarly journals Yellow Fever Virus/Dengue-2 Virus and Yellow Fever Virus/Dengue-4 Virus Chimeras: Biological Characterization, Immunogenicity, and Protection against Dengue Encephalitis in the Mouse Model

2003 ◽  
Vol 77 (6) ◽  
pp. 3655-3668 ◽  
Author(s):  
Thomas J. Chambers ◽  
Yan Liang ◽  
Deborah A. Droll ◽  
Jacob J. Schlesinger ◽  
Andrew D. Davidson ◽  
...  
Keyword(s):  
Mouse Model ◽  
Dengue Virus ◽  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Fever Virus ◽  
E Proteins ◽  
Dengue Viruses ◽  
Intracerebral Inoculation ◽  
Intraperitoneal Route ◽  
Chimeric Viruses

ABSTRACT Two yellow fever virus (YFV)/dengue virus chimeras which encode the prM and E proteins of either dengue virus serotype 2 (dengue-2 virus) or dengue-4 virus within the genome of the YFV 17D strain (YF5.2iv infectious clone) were constructed and characterized for their properties in cell culture and as experimental vaccines in mice. The prM and E proteins appeared to be properly processed and glycosylated, and in plaque reduction neutralization tests and other assays of antigenic specificity, the E proteins exhibited profiles which resembled those of the homologous dengue virus serotypes. Both chimeric viruses replicated in cell lines of vertebrate and mosquito origin to levels comparable to those of homologous dengue viruses but less efficiently than the YF5.2iv parent. YFV/dengue-4 virus, but not YFV/dengue-2 virus, was neurovirulent for 3-week-old mice by intracerebral inoculation; however, both viruses were attenuated when administered by the intraperitoneal route in mice of that age. Single-dose inoculation of either chimeric virus at a dose of 105 PFU by the intraperitoneal route induced detectable levels of neutralizing antibodies against the homologous dengue virus strains. Mice which had been immunized in this manner were fully protected from challenge with homologous neurovirulent dengue viruses by intracerebral inoculation compared to unimmunized mice. Protection was associated with significant increases in geometric mean titers of neutralizing antibody compared to those for unimmunized mice. These data indicate that YFV/dengue virus chimeras elicit antibodies which represent protective memory responses in the mouse model of dengue encephalitis. The levels of neurovirulence and immunogenicity of the chimeric viruses in mice correlate with the degree of adaptation of the dengue virus strain to mice. This study supports ongoing investigations concerning the use of this technology for development of a live attenuated viral vaccine against dengue viruses.

scholarly journals High Fidelity of Yellow Fever Virus RNA Polymerase

2004 ◽  
Vol 78 (2) ◽  
pp. 1032-1038 ◽  
Author(s):  
Konstantin V. Pugachev ◽  
Farshad Guirakhoo ◽  
Simeon W. Ocran ◽  
Fred Mitchell ◽  
Megan Parsons ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Rna Polymerase ◽  
Yellow Fever ◽  
Error Rate ◽  
Yellow Fever Virus ◽  
Protein A ◽  
Fever Virus ◽  
Genome Replication ◽  
Virus Rna

ABSTRACT Three consecutive plaque purifications of four chimeric yellow fever virus-dengue virus (ChimeriVax-DEN) vaccine candidates against dengue virus types 1 to 4 were performed. The genome of each candidate was sequenced by the consensus approach after plaque purification and additional passages in cell culture. Our data suggest that the nucleotide sequence error rate for SP6 RNA polymerase used in the in vitro transcription step to initiate virus replication was as high as 1.34 × 10−4 per copied nucleotide and that the error rate of the yellow fever virus RNA polymerase employed by the chimeras for genome replication in infected cells was as low as 1.9 × 10−7 to 2.3 × 10−7. Clustering of beneficial mutations that accumulated after multiple virus passages suggests that the N-terminal part of the prM protein, a specific site in the middle of the E protein, and the NS4B protein may be essential for nucleocapsid-envelope interaction during flavivirus assembly.

scholarly journals A community-level investigation of the yellow fever virus outbreak in South Omo Zone, South-West Ethiopia, 2012–2014

2018 ◽  
Author(s):  
Ranya Mulchandani ◽  
Fekadu Massebo ◽  
Fekadu Bocho ◽  
Claire L Jeffries ◽  
Thomas Walker ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Mosquito Species ◽  
Breeding Site ◽  
Fever Virus ◽  
Entomological Surveillance ◽  
Breeding Sites ◽  
South Omo ◽  
South West Ethiopia ◽  
Aedes Simpsoni

AbstractBackgroundA yellow fever (YF) outbreak occurred in South Omo Zone, Ethiopia in 2012-2014. This study aimed to analyse historical epidemiological data, to assess the risk for future YF outbreaks through entomological surveillance, including mosquito species identification and molecular screening for arboviruses, and finally to determine the knowledge, attitudes and current preventative practices within the affected communities.Methodology/Principal FindingsFrom October 2012 to March 2014, 165 cases and 62 deaths were reported, principally in rural areas of South Ari region (83.6%), south-west Ethiopia. The majority of patients were 15-44 years old (74.5%) and most case deaths were males (76%). Between June and August 2017, 688 containers were sampled from across 177 households to identify key breeding sites forAedesmosquitoes.Ensete ventricosum(“false banana”) was identified as the primary natural breeding site, and clay pots outside the home as the most productive artificial breeding site. Entomological risk indices from the majority of sites were classified as “high risk” for future outbreaks under current World Health Organization criteria. Adult trapping resulted in the identification of members of theAedes simpsonicomplex in and around households. Screening of adult females revealed no detection of yellow fever virus (YFV) or other arboviruses. 88% of 177 participants had heard of YF, however many participants easily confused transmission and symptoms of YF with malaria, which is also endemic in the area.Conclusions/SignificanceStudy results emphasise the need for further entomological studies to improve our understanding of local vector species and transmission dynamics. Disease surveillance systems and in-country laboratory capacity also need to be strengthened to facilitate more rapid responses to future YF outbreaks.Author SummaryDespite the availability of a highly effective vaccine, yellow fever virus (YFV) remains an important public health problem across Africa and South America due to its high case-fatality rate. This study aimed to assess and reduce the risk for future outbreaks. During this study, historical data analysis was conducted to understand the epidemiology of the recent outbreak in 2012-2014. Entomological surveillance was also carried out, including both mosquito species identification and molecular screening for arboviruses, as well as a household survey to understand the knowledge and attitudes towards yellow fever (YF) within the affected areas and to assess community-level practices for YF prevention. We found a high abundance ofAedes simpsonicomplex in the context of low vaccination coverage. Community knowledge and practice levels were low for reducing potential breeding sites, highlighting the need for increased dissemination of information to community members on how to reduce their risk of exposure to mosquito vectors of arboviruses.

scholarly journals Dengue Virus and Yellow Fever Virus Damage the Liver: A Systematic Review About the Histopathological Profiles

2019 ◽  
Vol 8 (2) ◽  
pp. 2864-2870 ◽  
Author(s):  
Dacylla Sampaio Costa ◽  
◽  
Lucas Arruda Moita ◽  
Even Herlany Pereira Alves ◽  
Ana Clara Silva Sales ◽  
...  
Keyword(s):  
Systematic Review ◽  
Dengue Virus ◽  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Fever Virus

scholarly journals Yellow Fever Virus Exhibits Slower Evolutionary Dynamics than Dengue Virus

2009 ◽  
Vol 84 (2) ◽  
pp. 765-772 ◽  
Author(s):  
Amadou A. Sall ◽  
Ousmane Faye ◽  
Mawlouth Diallo ◽  
Cadhla Firth ◽  
Andrew Kitchen ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Yellow Fever ◽  
Central African Republic ◽  
Evolutionary Dynamics ◽  
Nucleotide Substitution ◽  
Viral Infections ◽  
Yellow Fever Virus ◽  
Fever Virus ◽  
Limited Information ◽  
Reduced Rate

ABSTRACT Although yellow fever has historically been one of the most important viral infections of humans, relatively little is known about the evolutionary processes that shape its genetic diversity. Similarly, there is limited information on the molecular epidemiology of yellow fever virus (YFV) in Africa even though it most likely first emerged on this continent. Through an analysis of complete E gene sequences, including a newly acquired viral collection from Central and West Africa (Senegal, Cameroon, Central African Republic, Côte d'Ivoire, Mali, and Mauritania), we show that YFV exhibits markedly lower rates of evolutionary change than dengue virus, despite numerous biological similarities between these two viruses. From this observation, along with a lack of clock-like evolutionary behavior in YFV, we suggest that vertical transmission, itself characterized by lower replication rates, may play an important role in the evolution of YFV in its enzootic setting. Despite a reduced rate of nucleotide substitution, phylogenetic patterns and estimates of times to common ancestry in YFV still accord well with the dual histories of colonialism and the slave trade, with areas of sylvatic transmission (such as Kedougou, Senegal) acting as enzootic/epidemic foci.

scholarly journals Heparan Sulfate-Mediated Binding of Infectious Dengue Virus Type 2 and Yellow Fever Virus

Virology ◽  
2002 ◽  
Vol 292 (1) ◽  
pp. 162-168 ◽  
Author(s):  
Raphaële Germi ◽  
Jean-Marc Crance ◽  
Daniel Garin ◽  
Josette Guimet ◽  
Hugues Lortat-Jacob ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Heparan Sulfate ◽  
Yellow Fever ◽  
Virus Type ◽  
Yellow Fever Virus ◽  
Fever Virus ◽  
Dengue Virus Type 2
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