Géraldine Piorkowski

Evidence of Sexual Transmission of Zika Virus

Zika virus is known to be transmitted by mosquitoes. The authors report the sexual transmission of Zika virus to a woman in Paris from a man who had recently traveled from Brazil.

Prospective detection of chikungunya virus in blood donors, Caribbean 2014.

To the editor: On December 5, 2013, chikungunya virus (CHIKV) was introduced into the Western Hemisphere. The first cases of autochthonous chikungunya fever were reported in Saint Martin, French West Indies (FWI), demonstrating local transmission.[1][1] As of March 30, 2014, autochthonous cases

Hepatitis E virus mutations associated with ribavirin treatment failure result in altered viral fitness and ribavirin sensitivity

BACKGROUND & AIMS Ribavirin monotherapy is the preferred treatment for chronic hepatitis E, although occasional treatment failure occurs. We present a patient with chronic hepatitis E experiencing ribavirin treatment failure with a completely resistant phenotype. We aimed to identify viral mutations associated with treatment failure and explore the underlying mechanisms. METHODS Viral genomes were deep-sequenced at different time points and the role of identified mutations was assessed in vitro using mutant replicons, antiviral assays, cell culture of patient-derived virus and deep-sequencing. RESULTS Ribavirin resistance was associated with Y1320H, K1383N and G1634R mutations in the viral polymerase, but also an insertion in the hypervariable region comprising a duplication and a polymerase-derived fragment. Analysis of these genome alterations in vitro revealed replication-increasing roles for Y1320H and G1634R mutations and the hypervariable region insertion. In contrast, the K1383N mutation in the polymerase F1-motif suppressed viral replication and increased the in vitro sensitivity to ribavirin, contrary to the clinical phenotype. Analysis of the replication of mutant full-length virus and in vitro culturing of patient-derived virus confirmed that sensitivity to ribavirin was retained. Finally, deep-sequencing of hepatitis E virus genomes revealed that ribavirin is mutagenic to viral replication in vitro and in vivo. CONCLUSIONS Mutations Y1320H, G1634R and the hypervariable region insertion compensated for K1383N-associated replication defects. The specific role of the K1383N mutation remains enigmatic, but it appears to be of importance for the ribavirin resistant phenotype in this patient. LAY SUMMARY Ribavirin is the most common treatment for chronic hepatitis E and is mostly effective, although some cases of ribavirin treatment failure have been described. Here, we report on a particular case of ribavirin resistance and investigate the underlying causes of treatment failure. Mutations in the viral polymerase, an essential enzyme for viral replication, appear to be responsible.

The viral capping enzyme nsP1: a novel target for the inhibition of chikungunya virus infection.

The chikungunya virus (CHIKV) has become a substantial global health threat due to its massive re-emergence, the considerable disease burden and the lack of vaccines or therapeutics. We discovered a novel class of small molecules ([1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones) with potent in vitro activity against CHIKV isolates from different geographical regions. Drug-resistant variants were selected and these carried a P34S substitution in non-structural protein 1 (nsP1), the main enzyme involved in alphavirus RNA capping. Biochemical assays using nsP1 of the related Venezuelan equine encephalitis virus revealed that the compounds specifically inhibit the guanylylation of nsP1. This is, to the best of our knowledge, the first report demonstrating that the alphavirus capping machinery is an excellent antiviral drug target. Considering the lack of options to treat CHIKV infections, this series of compounds with their unique (alphavirus-specific) target offers promise for the development of therapy for CHIKV infections.

Widespread circulation of a new echovirus 30 variant causing aseptic meningitis and non-specific viral illness, South-East France, 2013

BACKGROUND Human enteroviruses (HEVs) are major cause of aseptic meningitis. A new outbreak of E-30 occurred between April and September 2013 in Marseille, South-East France. OBJECTIVES Better understand what happen locally when an E-30 outbreak occurs. STUDY DESIGN Laboratory data (identification and characterization of circulating E-30 strains by partial/complete genome sequencing) were analyzed together with clinical data from emergency ward of the public hospital of Marseille. RESULTS Compared with data from previous years, we observed an excess of HEV infections between April and September 2013. A total of 202 patients were tested positive of which 79% (160/202) had a cerebrospinal fluid tested positive. Because we performed genotyping using clinical specimens, we obtained representative molecular data related to patients tested positive and found a majority (105/119) of echoviruses 30 (E-30). Phylogenetic analysis revealed that E-30 circulating in Europe since 2000 belong to a unique lineage and showed at the intra-genogroup level the temporal circulation of E-30. Molecular data also indicated that majority of E-30 detected (92%) were almost identical. Compared with data from previous years, this outbreak was finally associated with an excess of patients admitted to an emergency ward for meningitis but also for non-specific viral illness. CONCLUSIONS Our data provide new insights into microevolution of E-30: almost all E-30 emerged from local circulation of one parental virus. Moreover, our findings showed that HEV outbreaks cause an excess of emergency ward consultations but probably also an excess of consultations to general practitioners who receive majority of the non-specific viral illness.

Virus isolation, genetic characterization and seroprevalence of Toscana virus in Algeria

Toscana virus (TOSV; Bunyaviridae, Phlebovirus) is transmitted by sandflies of the genus Phlebotomus in the Mediterranean area. One strain of TOSV was isolated from a total of almost 23 000 sandflies collected in Kabylia, Algeria. The complete genome was sequenced, and phylogenetic studies indicated that it was most closely related with TOSV strain from Tunisia within lineage A, which also includes Italian, French and Turkish strains. A seroprevalence study performed on 370 sera collected from people living in the same area showed that almost 50% possessed neutralizing antibodies against TOSV, a rate much higher than that observed in Southern Europe. Sandfly species distribution in the study area suggests that the vector of TOSV in this region belongs to the subgenus Larroussius. These data support the rapid implementation of the diagnosis of TOSV in clinical microbiology laboratories to estimate the burden in patients presenting with neuroinvasive infections and febrile illness.

Isolation, full genomic characterization and neutralization-based human seroprevalence of Medjerda Valley virus, a novel sandfly-borne phlebovirus belonging to the Salehabad virus complex in northern Tunisia

A new phlebovirus, Medjerda Valley virus (MVV), was isolated from one pool of Phlebotomus sp. (Diptera; Psychodidae) sandflies trapped in the vicinity of the Utique site, northern Tunisia. Genetic analysis based on complete coding of genomic sequences of the three RNA segments indicated that MVV is most closely related to members of the Salehabad virus species, where it is the fourth virus for which the complete sequence is available. A seroprevalence study was performed to search for neutralizing antibodies in human sera in the same region. The results demonstrate that in this area, MVV can readily infect humans despite low seroprevalence rates. Salehabad species viruses have generally been considered to be a group of viruses with little medical or veterinary interest. This view deserves to be revisited according to our human seroprevalence results, together with high animal infection rate of Adana virus and recent evidence of human infection with Adria virus in Greece. Further studies are needed to investigate the capacity of each specific member of the Salehabad virus species to cause human or animal diseases.

Complete coding sequence of Zika virus from Martinique outbreak in 2015.

Zika virus is an Aedes-borne Flavivirus causing fever, arthralgia, myalgia rash, associated with Guillain–Barré syndrome and suspected to induce microcephaly in the fetus. We report here the complete coding sequence of the first characterized Caribbean Zika virus strain, isolated from a patient from Martinique in December, 2015.

Importance of mosquito "quasispecies" in selecting an epidemic arthropod-borne virus.

Most arthropod-borne viruses (arboviruses), perpetuated by alternation between a vertebrate host and an insect vector, are likely to emerge through minor genetic changes enabling the virus to adapt to new hosts. In the past decade, chikungunya virus (CHIKV; Alphavirus, Togaviridae) has emerged on La Réunion Island following the selection of a unique substitution in the CHIKV E1 envelope glycoprotein (E1-A226V) of an East-Central-South African (ECSA) genotype conferring a higher transmission rate by the mosquito Aedes albopictus. Assumed to have occurred independently on at least four separate occasions, this evolutionary convergence was suspected to be responsible for CHIKV worldwide expansion. However, assumptions on CHIKV emergence were mainly based on viral genetic changes and the role of the mosquito population quasispecies remained unexplored. Here we show that the nature of the vector population is pivotal in selecting the epidemic CHIKV. We demonstrate using microsatellites mosquito genotyping that Ae. albopictus populations are genetically differentiated, contributing to explain their differential ability to select the E1-226V mutation. Aedes albopictus, newly introduced in Congo coinciding with the first CHIKV outbreak, was not able to select the substitution E1-A226V nor to preferentially transmit a CHIKV clone harboring the E1-226V as did Ae. albopictus from La Réunion.

Rapid next-generation sequencing of dengue, EV-A71 and RSV-A viruses

Accurate characterisation of viral strains constitutes a crucial objective for the management of modern virus collections. Next-generation sequencing (NGS) provides technical solution for fast and cost-effective full genome sequencing. Here, we report protocols for rapid full-genome characterisation of RNA viruses of medical importance: dengue virus, enterovirus A71 and respiratory syncytial virus A, based on a specific amplification step followed by NGS-sequencing. A subset of full-length genome sequences representing the genetic diversity of each virus type was selected in GenBank and used to design primer sets allowing the amplification of the complete genome in 3-8 overlapping PCR fragments. The technique was used for characterising 53 strains (33 DENV, 8 EV-A71, 12 RSV-A) from various genotypes and origins. In a single assay, and in just 4 days, it provided for all strains an excellent genomic coverage (∼ 99% including complete ORF for all strains) and accurate sequences with high number of reads per position (250-3500 on average). The elaboration of specific PCR-based full-genome sequencing protocols for diverse virus groups is likely to revolutionise the characterisation of viral isolates in modern collection, but also to contribute in the next future to the study of RNA viruses directly from biological samples.