Mobile laboratory reveals the circulation of Dengue virus serotype I of Asian origin in Medina Gounass (Guediawaye), Senegal

With the growing success of controlling malaria in Sub-Saharan Africa, the incidence of fever due to malaria is in decline, whereas the proportion of patients with non-malaria febrile illness (NMFI) is increasing. Clinical diagnosis of NMFI is hampered by unspecific symptoms but early diagnosis is a key factor for better patient care and for disease control. The aim of this study was to determine the arboviral aetiologies of NMFI in a low resources settings using a mobile laboratory based on Recombinase Polymerase Amplification (RPA) assays. The panel of tests for this study was expanded to five arboviruses including (Dengue virus (DENV), Zika virus (ZIKV), Yellow fever virus (YFV), Chikungunya virus (CHIKV), and Rift valley fever virus (RVFV). One hundred and four children aged between one month and 115 months were enrolled and screened. Three of 104 blood samples of children < 10 years presenting at an outpatient clinic tested positive for DENV. The results were confirmed by real-time RT-PCR, partial sequencing, and non structural protein 1 (NS1) antigen capture ELISA (Biorad, France). Phylogenetic analysis of the derived DENV-1 sequences clustered them with sequences of DENV-1 isolates from Guangzhou in China in 2014. In conclusion, this mobile setup proved reliable for the rapid identification of the causative agent of NMFI, with results consistent with those obtained in the reference laboratory`s settings

Origin and Spread of the Dengue Virus Type 1, Genotype V in Senegal, 2015–2019

Dengue virus (DENV) is the most widespread arthropod-borne virus, with the number and severity of outbreaks increasing worldwide in recent decades. Dengue is caused by genetically distinct serotypes, DENV-1&ndash;4. Here, we present data on DENV-1, isolated from patients with dengue fever during an outbreak in Senegal and Mali (Western Africa) in 2015&ndash;2019, that were analyzed by sequencing the envelope (E) gene. The emergence and the dynamics of DENV-1 in Western Africa were inferred by using maximum likelihood and Bayesian methods. The DENV-1 grouped into a monophyletic cluster that was closely related to those from Southeast Asia. The virus appears to have been introduced directly into Medina Gounass (Suburb of Dakar), Senegal (location probability = 0.301, posterior = 0.76). The introduction of the virus in Senegal occurred around 2014 (95% HPD = 2012.88&ndash;2014.84), and subsequently, the virus moved to regions within Senegal (e.g., Louga and Fatick), causing intense outbreaks in the subsequent years. The virus appears to have been introduced in Mali (a neighboring country) after its introduction in Senegal. In conclusion, we present evidence that the outbreak caused by DENV-1 in urban environments in Senegal and Mali after 2015 was caused by a single viral introduction from Asia

Usutu Virus Isolated from Rodents in Senegal

Usutu virus (USUV) is a Culex-associated mosquito-borne flavivirus of the Flaviviridae family. Since its discovery in 1959, the virus has been isolated from birds, arthropods and humans in Europe and Africa. An increasing number of Usutu virus infections in humans with neurological presentations have been reported. Recently, the virus has been detected in bats and horses, which deviates from the currently proposed enzootic cycle of USUV involving several different avian and mosquito species. Despite this increasing number of viral detections in different mammalian hosts, the existence of a non-avian reservoir remains unresolved. In Kedougou, a tropical region in the southeast corner of Senegal, Usutu virus was detected, isolated and sequenced from five asymptomatic small mammals: Two different rodent species and a single species of shrew. Additional molecular characterization and in vivo growth dynamics showed that these rodents/shrew-derived viruses are closely related to the reference strain (accession number: AF013412) and are as pathogenic as other characterized strains associated with neurological invasions in human. This is the first evidence of Usutu virus isolation from rodents or shrews. Our findings emphasize the need to consider a closer monitoring of terrestrial small mammals in future active surveillance, public health, and epidemiological efforts in response to USUV in both Africa and Europe

Whole Genome Sequencing Analysis of African Orthobunyavirus Isolates Reveals Naturally Interspecies Segments Recombinations between Bunyamwera and Ngari Viruses

Bunyamwera virus is the prototype of the Bunyamwera serogroup, which belongs to the order Bunyavirales of the Orthobunyavirus genus in the Peribunyaviridae family. Bunyamwera is a negative-sense RNA virus composed of three segments S, M, and L. Genetic recombination is possible between members of this order as it is already documented. Additionally, it can lead to pathogenic or host range improvement, if it occurs with viruses of public health and agricultural importance such as Rift Valley fever virus and Crimea–Congo hemorrhagic fever virus. Here, we characterize five African Orthobunyavirus viruses from different geographical regions. Our results suggest that the five newly characterized strains are identified as Bunyamwera virus strains. Furthermore, two of the five strains sequenced in this study are recombinant strains, as fragments of their segments are carried by Ngari and Bunyamwera strains. Further investigations are needed to understand the functional impact of these recombinations

Vector competence of anthropophilic mosquitoes for a new mesonivirus in Senegal

International audienceThe mesoniviruses (MESOVs) belong to the newly described Mesoniviridae family (Order: Nidovirales). They have never been reported in Senegal until recently during a study in arbovirus emergence with the detection of a new species of MESOV named Dianke virus (DKV) from common mosquitoes from eastern Senegal. Actually, their vector competence for this newly described DKV is unknown. We, therefore, estimated the vector competence of Culex tritaeniorhynchus, Culex quinquefasciatus, Aedes aegypti, and Anopheles gambiae mosquitoes collected in Senegal for DKV using oral infection. Whole bodies, legs/wings, and saliva samples were tested for DKV by RT-PCR to estimate infection, dissemination, and transmission rates. The infectivity of virus particles in the saliva was confirmed by infecting C6/36 cells. Virus transmission rates were up to 95.45% in Culex tritaeniorhynchus, 28% in Cx. quinquefasciatus and 9.09% in Aedes aegypti. Viral particles in the saliva were confirmed infectious by C6/36 cell culture. An. gambiae was able to disseminate DKV only at 20 days post-infection. This study shows that Culex mosquitoes are more competent than Ae. aegypti for DKV, while Anopheles gambiae is not likely a competent vector

Novel Amplicon-Based Sequencing Approach to West Nile Virus

West Nile virus is a re-emerging arbovirus whose impact on public health is increasingly important as more and more epidemics and epizootics occur, particularly in America and Europe, with evidence of active circulation in Africa. Because birds constitute the main reservoirs, migratory movements allow the diffusion of various lineages in the world. It is therefore crucial to properly control the dispersion of these lineages, especially because some have a greater health impact on public health than others. This work describes the development and validation of a novel whole-genome amplicon-based sequencing approach to West Nile virus. This study was carried out on different strains from lineage 1 and 2 from Senegal and Italy. The presented protocol/approach showed good coverage using samples derived from several vertebrate hosts and may be valuable for West Nile genomic surveillance

Data_Sheet_3_The Delta variant wave in Tunisia: Genetic diversity, spatio-temporal distribution and evidence of the spread of a divergent AY.122 sub-lineage.PDF

IntroductionThe Delta variant posed an increased risk to global public health and rapidly replaced the pre-existent variants worldwide. In this study, the genetic diversity and the spatio-temporal dynamics of 662 SARS-CoV2 genomes obtained during the Delta wave across Tunisia were investigated.MethodsViral whole genome and partial S-segment sequencing was performed using Illumina and Sanger platforms, respectively and lineage assignemnt was assessed using Pangolin version 1.2.4 and scorpio version 3.4.X. Phylogenetic and phylogeographic analyses were achieved using IQ-Tree and Beast programs.ResultsThe age distribution of the infected cases showed a large peak between 25 to 50 years. Twelve Delta sub-lineages were detected nation-wide with AY.122 being the predominant variant representing 94.6% of sequences. AY.122 sequences were highly related and shared the amino-acid change ORF1a:A498V, the synonymous mutations 2746T>C, 3037C>T, 8986C>T, 11332A>G in ORF1a and 23683C>T in the S gene with respect to the Wuhan reference genome (NC_045512.2). Spatio-temporal analysis indicates that the larger cities of Nabeul, Tunis and Kairouan constituted epicenters for the AY.122 sub-lineage and subsequent dispersion to the rest of the country.DiscussionThis study adds more knowledge about the Delta variant and sub-variants distribution worldwide by documenting genomic and epidemiological data from Tunisia, a North African region. Such results may be helpful to the understanding of future COVID-19 waves and variants.</p

Data_Sheet_4_The Delta variant wave in Tunisia: Genetic diversity, spatio-temporal distribution and evidence of the spread of a divergent AY.122 sub-lineage.PDF

IntroductionThe Delta variant posed an increased risk to global public health and rapidly replaced the pre-existent variants worldwide. In this study, the genetic diversity and the spatio-temporal dynamics of 662 SARS-CoV2 genomes obtained during the Delta wave across Tunisia were investigated.MethodsViral whole genome and partial S-segment sequencing was performed using Illumina and Sanger platforms, respectively and lineage assignemnt was assessed using Pangolin version 1.2.4 and scorpio version 3.4.X. Phylogenetic and phylogeographic analyses were achieved using IQ-Tree and Beast programs.ResultsThe age distribution of the infected cases showed a large peak between 25 to 50 years. Twelve Delta sub-lineages were detected nation-wide with AY.122 being the predominant variant representing 94.6% of sequences. AY.122 sequences were highly related and shared the amino-acid change ORF1a:A498V, the synonymous mutations 2746T>C, 3037C>T, 8986C>T, 11332A>G in ORF1a and 23683C>T in the S gene with respect to the Wuhan reference genome (NC_045512.2). Spatio-temporal analysis indicates that the larger cities of Nabeul, Tunis and Kairouan constituted epicenters for the AY.122 sub-lineage and subsequent dispersion to the rest of the country.DiscussionThis study adds more knowledge about the Delta variant and sub-variants distribution worldwide by documenting genomic and epidemiological data from Tunisia, a North African region. Such results may be helpful to the understanding of future COVID-19 waves and variants.</p

Data_Sheet_2_The Delta variant wave in Tunisia: Genetic diversity, spatio-temporal distribution and evidence of the spread of a divergent AY.122 sub-lineage.PDF

IntroductionThe Delta variant posed an increased risk to global public health and rapidly replaced the pre-existent variants worldwide. In this study, the genetic diversity and the spatio-temporal dynamics of 662 SARS-CoV2 genomes obtained during the Delta wave across Tunisia were investigated.MethodsViral whole genome and partial S-segment sequencing was performed using Illumina and Sanger platforms, respectively and lineage assignemnt was assessed using Pangolin version 1.2.4 and scorpio version 3.4.X. Phylogenetic and phylogeographic analyses were achieved using IQ-Tree and Beast programs.ResultsThe age distribution of the infected cases showed a large peak between 25 to 50 years. Twelve Delta sub-lineages were detected nation-wide with AY.122 being the predominant variant representing 94.6% of sequences. AY.122 sequences were highly related and shared the amino-acid change ORF1a:A498V, the synonymous mutations 2746T>C, 3037C>T, 8986C>T, 11332A>G in ORF1a and 23683C>T in the S gene with respect to the Wuhan reference genome (NC_045512.2). Spatio-temporal analysis indicates that the larger cities of Nabeul, Tunis and Kairouan constituted epicenters for the AY.122 sub-lineage and subsequent dispersion to the rest of the country.DiscussionThis study adds more knowledge about the Delta variant and sub-variants distribution worldwide by documenting genomic and epidemiological data from Tunisia, a North African region. Such results may be helpful to the understanding of future COVID-19 waves and variants.</p

Data_Sheet_1_The Delta variant wave in Tunisia: Genetic diversity, spatio-temporal distribution and evidence of the spread of a divergent AY.122 sub-lineage.PDF

IntroductionThe Delta variant posed an increased risk to global public health and rapidly replaced the pre-existent variants worldwide. In this study, the genetic diversity and the spatio-temporal dynamics of 662 SARS-CoV2 genomes obtained during the Delta wave across Tunisia were investigated.MethodsViral whole genome and partial S-segment sequencing was performed using Illumina and Sanger platforms, respectively and lineage assignemnt was assessed using Pangolin version 1.2.4 and scorpio version 3.4.X. Phylogenetic and phylogeographic analyses were achieved using IQ-Tree and Beast programs.ResultsThe age distribution of the infected cases showed a large peak between 25 to 50 years. Twelve Delta sub-lineages were detected nation-wide with AY.122 being the predominant variant representing 94.6% of sequences. AY.122 sequences were highly related and shared the amino-acid change ORF1a:A498V, the synonymous mutations 2746T>C, 3037C>T, 8986C>T, 11332A>G in ORF1a and 23683C>T in the S gene with respect to the Wuhan reference genome (NC_045512.2). Spatio-temporal analysis indicates that the larger cities of Nabeul, Tunis and Kairouan constituted epicenters for the AY.122 sub-lineage and subsequent dispersion to the rest of the country.DiscussionThis study adds more knowledge about the Delta variant and sub-variants distribution worldwide by documenting genomic and epidemiological data from Tunisia, a North African region. Such results may be helpful to the understanding of future COVID-19 waves and variants.</p