Molecular and Serological Evidence for the Presence of Novel Phleboviruses in Sandflies from Northern Algeria

During summer 2007, a total of 785 phlebotomine flies were trapped in northern Algeria, identified morphologically, organised as monospecific pools and tested for the presence of phlebovirus RNA using degenerate primers. Three pools were positive, and the corresponding PCR products were cloned and sequenced. Viral sequences corresponding to two phleboviruses distinct from each other were detected in sandflies circulating in two close locations (140 km apart) in Northern Algeria. The 3 sequences were aligned with homologous polymerase sequences retrieved from the Genbank database, in order to examine their phylogenetic relationships. One viral sequence (from Phlebotomus papatasi) was closely related to but distinct from a sequence obtained from Phlebotomus ariasi sandflies trapped in Algeria in 2006. The two other viral sequences (from Phlebotomus longicuspis) were genetically distantly related to sequences corresponding to virus members of the Sandfly fever Naples virus species and although falling within the same group, this clearly represents a second distinct novel lineage. These results are indicative of a high genetic heterogeneity within sandflies trapped in a relatively small geographic area. Seroprevalence studies conducted on sera from populations living in the same areas indicated that humans can be infected by these viruses

Ecuador Paraiso Escondido virus, a new flavivirus isolated from New World sand flies in Ecuador, is the first representative of a novel clade in the genus flavivirus

A new flavivirus, Ecuador Paraiso Escondido virus (EPEV), named after the village where it was discovered, was isolated from sand flies (Psathyromyia abonnenci, formerly Lutzomyia abonnenci) that are unique to the New World. This represents the first sand fly-borne flavivirus identified in the New World. EPEV exhibited a typical flavivirus genome organization. Nevertheless, the maximum pairwise amino acid sequence identity with currently recognized flaviviruses was 52.8%. Phylogenetic analysis of the complete coding sequence showed that EPEV represents a distinct clade which diverged from a lineage that was ancestral to the nonvectored flaviviruses Entebbe bat virus, Yokose virus, and Sokoluk virus and also the Aedes-associated mosquito-borne flaviviruses, which include yellow fever virus, Sepik virus, Saboya virus, and others. EPEV replicated in C6/36 mosquito cells, yielding high infectious titers, but failed to reproduce either in vertebrate cell lines (Vero, BHK, SW13, and XTC cells) or in suckling mouse brains. This surprising result, which appears to eliminate an association with vertebrate hosts in the life cycle of EPEV, is discussed in the context of the evolutionary origins of EPEV in the New World.The flaviviruses are rarely (if ever) vectored by sand fly species, at least in the Old World. We have identified the first representative of a sand fly-associated flavivirus, Ecuador Paraiso Escondido virus (EPEV), in the New World. EPEV constitutes a novel clade according to current knowledge of the flaviviruses. Phylogenetic analysis of the virus genome showed that EPEV roots the Aedes-associated mosquito-borne flaviviruses, including yellow fever virus. In light of this new discovery, the New World origin of EPEV is discussed together with that of the other flaviviruses

Concurrent Chikungunya and Dengue Virus Infections during Simultaneous Outbreaks, Gabon, 2007

An outbreak of febrile illness occurred in Gabon in 2007, with 20,000 suspected cases. Chikungunya or dengue-2 virus infections were identified in 321 patients; 8 patients had documented co-infections. Aedes albopictus was identified as the principal vector for the transmission of both viruses

Sandfly Fever Sicilian Virus, Algeria

To determine whether sandfly fever Sicilian virus (SFSV) is present in Algeria, we tested sandflies for phlebovirus RNA. A sequence closely related to that of SFSV was detected in a Phlebotomus ariasi sandfly. Of 60 human serum samples, 3 contained immunoglobulin G against SFSV. These data suggest SFSV is present in Algeria

Génomique des Flavivirus : Contribution à l'analyse taxonomique et phylogénique

Les virus à ARN - à l'exception des rétrovirus - représentent plus de 200 pathogènes humains et/ou vétérinaires majeurs. Ils sont pour la plupart considérés comme émergents, durant les dernières années ils ont été retrouvés au-delà de leur territoire d'origine, dans de nouvelles régions du monde. Les plus connus de ces virus sont le virus du West Nile, le virus chikungunya, la grippe, le coronavirus SRAS, l'entérovirus 71 (agent responsable de la fièvre aphteuse), les virus de la dengue, l'hépatite C virus, le virus de la fièvre hémorragique de Crimée Congo, le virus de la vallée du Rift, l'encéphalite japonaise et plusieurs entérovirus humains. En terme de mortalité et morbidité ils sont à l'origine de plus 100 millions de cas par an et la menace a tendance à augmenter. Ces statistiques sont démoralisantes quand on considère les immenses progrès de la médecine et de la science durant ces dernières dizaines d'années. Les recherches présentées dans ma thèse portent sur le genre Flavivirus, au sein duquel on retrouve le virus de la fièvre jaune, un pathogène humain responsable d'épidémies majeures en Afrique et en Amérique latine durant les 300 à 400 dernières années. Ce virus est toujours responsable d'épidémies majeures en Afrique malgré un vaccin très bien toléré et des plus efficaces. On assiste au même scénario avec le virus de l'encéphalite japonaise en Inde.Without including the retroviruses, there are in excess of 200 RNA viruses that are recognised human and/or animal pathogens, many of which are considered to be emerging viruses because during recent years they have dispersed beyond their original territories causing epidemics in new regions of the World. The more well known of these emerging viruses include, West Nile virus, chikungunya virus, influenza virus, SARS coronavirus, EV71 virus (the aetiological agent of hand foot and mouth disease), dengue virus, hepatitis C virus, Crimean Congo haemorrhagic fever virus, Rift Valley fever virus, Japanese encephalitis virus and many human enteroviruses from a variety of genera. The combined global morbidity and mortality figures for these viruses add up to 100s of millions per year and the current trend appears to be upwards. This is a depressing statistic when one considers the amazing medical and scientific achievements that we have witnessed during the past decades. The studies described in my thesis were focused on the genus Flavivirus the type species of which is yellow fever virus, another terrifyingly virulent human pathogen that has caused so much suffering in Africa and Latin America during the past 300 to 400 years. This virus continues to cause major epidemics in Africa despite the availability of one of the safest and most effective vaccines with which to control infections due to yellow fever virus. Indeed similar comments can be made in the context of the flavivirus Japanese encephalitis virus in India

Flavivirus RNA in phlebotomine sandflies

Sandfly-transmitted phleboviruses, such as Toscana, sandfly fever Sicilian, and sandfly fever Naples, can cause human disease and circulate at high rates in Mediterranean countries. Previous studies have also established that viruses other than phleboviruses may be detected in and isolated from sand flies. The recent detection and isolation (in a large variety of mosquito species) of insect-only flaviviruses related to cell fusing agent virus has indicated that the latter is not an evolutionary remnant but the first discovered member of a group of viruses, larger than initially assumed, that has high genetic heterogeneity. Insect-only flaviviruses have been detected in and/or isolated from various species of mosquitoes, but nevertheless only from mosquitoes to date; other dipterans have not been screened for the presence of insect-only flaviviruses. The possible presence of flaviviruses, including insect-only flaviviruses, was investigated in sand flies collected around the Mediterranean during a trapping campaign already underway. Accordingly, a total of 1508 sand flies trapped in France and Algeria, between August 2006 and July 2007, were tested for the presence of flaviviruses using a PCR assay previously demonstrated experimentally to amplify all recognized members of the genus Flavivirus, including insect-only flaviviruses. Two of 67 pools consisting of male Phlebotomus perniciosus trapped in Algeria were positive. The two resulting sequences formed a monophyletic group and appeared more closely related to insect-only flaviviruses associated with Culex mosquitoes than with Aedes mosquitoes, and more closely related to insect-only flaviviruses than to arthropod-borne or to no-known-vector vertebrate flaviviruses. This is the first description of insect-only flaviviruses in dipterans distinct from those belonging to the family Culicidae (including Aedes, Culex, Mansonia, Culiseta, and Anopheles mosquito genera), namely sand flies within the family Psychodidae. Accordingly, we propose their designation as phlebotomine-associated flaviviruses

Isolation and Characterization of a New Strain of Lymphocytic Choriomeningitis Virus from Rodents in Southwestern France

International audienceA total of 821 tissue samples from rodents trapped during field campaigns organized in Europe and Africa were screened for the presence of arenaviruses by molecular methods and cell culture inoculation when feasible. Two Mus musculus domesticus trapped in the southwestern part of France were infected with a potentially new strain of lymphocytic choriomeningitis virus (LCMV), here referred to as LCMV strain HP65-2009, which was isolated and genetically characterized by whole genome sequencing. Genetic and phylogenetic analyses comparing LCMV HP65-2009 with 26 other LCMV strains showed that it represents a novel highly-divergent strain within the group of Mus musculus-associated LCMV

Newinsights into flavivirus evolution, taxonomy and biogeographic history, extended by analysis of canonical and alternative coding sequences

To generate the most diverse phylogenetic dataset for the flaviviruses to date, we determined the genomic sequences and phylogenetic relationships of 14 flaviviruses, of which 10 are primarily associated with Culex spp. mosquitoes. We analyze these data, in conjunction with a comprehensive collection of flavivirus genomes, to characterize flavivirus evolutionary and biogeographic history in unprecedented detail and breadth. Based on the presumed introduction of yellow fever virus into the Americas via the transatlantic slave trade, we extrapolated a timescale for a relevant subset of flaviviruses whose evolutionary history, shows that different Culex-spp. associated flaviviruses have been introduced from the Old World to the New World on at least five separate occasions, with 2 different sets of factors likely to have contributed to the dispersal of the different viruses. We also discuss the significance of programmed ribosomal frameshifting in a central region of the polyprotein open reading frame in some mosquito-associated flaviviruses