Molecular Xenomonitoring (MX) allows real-time surveillance of West Nile and Usutu virus in mosquito populations.

West Nile Virus (WNV) and Usutu virus (USUV) circulate through complex cryptic transmission cycles involving mosquitoes as vectors, birds as amplifying hosts and several mammal species as dead-end hosts. Both viruses can be transmitted to humans through mosquito bites, which can lead to neuroinvasive and potentially fatal disease. Notably, WNV can also be transmitted through blood donations and organ transplants.

Analytical and clinical evaluation of a duplex RT-qPCR assay for the detection and identification of o'nyong-nyong and chikungunya virus.

The mosquito-borne alphavirus o'nyong-nyong virus (ONNV) has proven its potential to cause major human outbreaks. On the African continent, ONNV causes unspecific febrile illness and co-circulates with the close relative chikungunya virus (CHIKV). The true scale of ONNV burden is poorly understood in Africa, because of the scarce availability of molecular in-house and commercial assays, strong cross-reactivity between ONNV and CHIKV in serological assays and a lack of surveillance.

Sand flies and Toscana virus: Intra-vector infection dynamics and impact on Phlebotomus perniciosus life-history traits.

Toscana virus (TOSV) is a leading cause of summer viral meningitis in Southern Europe (Central Italy, south of France, Spain and Portugal) and can cause severe neurological cases. Within the Mediterranean basin, it is transmitted by hematophagous sand flies belonging to the Phlebotomus genus. Despite the identification of the primary TOSV vectors, the viral developmental cycle in vector species remains largely unknown.

Noninvasive detection of Zika virus in mosquito excreta sampled from wild mosquito populations in French Guiana.

Arboviruses can be difficult to detect in the field due to relatively low prevalence in mosquito populations. The discovery that infected mosquitoes can release viruses in both their saliva and excreta gave rise to low-cost methods for the detection of arboviruses during entomological surveillance. We implemented both saliva and excreta-based entomological surveillance during the emergence of Zika virus (ZIKV) in French Guiana in 2016 by trapping mosquitoes around households of symptomatic cases with confirmed ZIKV infection.

The Wood equation allows consistent fitting of individual antibody-response profiles of Zika virus or SARS-CoV-2 infected patients.

Antibody kinetic curves obtained during a viral infection are often fitted using aggregated patient data, hiding the heterogeneity of individual humoral immune responses. Individual antibody responses can be modeled using the Wood equation and grouped according to their profile. Such modeling takes into account several important kinetic parameters, such as the day when antibody detection becomes positive [daypos], the day of the maximal response [daymax], the maximum antibody level [levelmax], and the day when antibody detection becomes negative [dayneg].

Analysis of trapped mosquito excreta as a noninvasive method to reveal biodiversity and arbovirus circulation.

Emerging and endemic mosquito-borne viruses can be difficult to detect and monitor because they often cause asymptomatic infections in human or vertebrate animals or cause nonspecific febrile illness with a short recovery waiting period. Some of these pathogens circulate into complex cryptic cycles involving several animal species as reservoir or amplifying hosts. Detection of cases in vertebrate hosts can be complemented by entomological surveillance, but this method is not adapted to low infection rates in mosquito populations that typically occur in low or nonendemic areas.

[Gestion of arboviral alerts: Experience feedback from the Secproch working group of the French "Haut Conseil de la santé publique" (2019-2021)].

The Secproch working group (for "sécurité des produits issus du corps humain") was created in 2019 within the « Haut Conseil de la santé publique » (HCSP) for addressing all the questions related to labile blood products, organs, tissues, cells (OTC) and gametes issued from human body. It is notably in charge of the management of alerts regarding arbovirus infections. These infections due to arthropod-transmitted viruses are responsible for emergence and reemergence, notably in the context of global warming.

Emergence of Indian lineage of ECSA chikungunya virus in Djibouti, 2019.

The chikungunya virus (CHIKV) originated from Africa and has spread worldwide. Since 2017, multiple chikungunya outbreaks have been reported in the Horn of Africa, without molecular characterization. In November 2019, an autochthonous acute chikungunya infection was diagnosed in a French patient living in Djibouti, marking the re-emergence of the virus in the country.

Discriminating Tonate Virus from Dengue Virus Infection: A Matched Case-Control Study in French Guiana, 2003-2016.

Tonate virus (TONV) is an arbovirus discovered in 1973 in French Guiana (FG) belonging to the Venezuelan equine encephalitis virus complex, Alphavirus genus. Only few publications and cases have been reported in FG. The objectives of the present study were to describe the clinical picture of TONV and to compare its presentation with that of dengue virus (DENV).

High specificity and sensitivity of Zika EDIII-based ELISA diagnosis highlighted by a large human reference panel.

Background: Zika virus (ZIKV) and Dengue virus (DENV) are often co-endemic. The high protein-sequence homology of flaviviruses renders IgG induced by and directed against them highly cross-reactive against their antigen(s), as observed on a large set of sera, leading to poorly reliable sero-diagnosis.

Methods: We selected Domain III of the ZIKV Envelope (ZEDIII) sequence, which is virus specific.

Chikungunya, a Risk Factor for Guillain-Barré Syndrome.

In a matched case-control study where 24 cases developed Guillain-Barré syndrome (GBS) during the 2014 chikungunya outbreak in the French West Indies and 72 controls were blood donors during the same period, chikungunya infection was a risk factor for GBS (odds ratio, 8.3; 95% confidence interval, 2.3-29.

Variability of Zika Virus Incubation Period in Humans.

Zika virus (ZIKV) has recently emerged in numerous tropical countries worldwide. In this study, we estimated ZIKV incubation period distribution using time-to-event models adapted to interval-censored data based on declared date of travels from 123 symptomatic travelers returning from areas with active ZIKV transmission. The median time and 95th percentile of ZIKV incubation period was estimated to 6.

A prospective matched study on symptomatic dengue in pregnancy.

Dengue fever is an increasing problem worldwide, but consequences during pregnancy remain unclear. Much of the available literature suffers from methodological biases that compromise the validity of clinical recommendations. We conducted a matched cohort study during an epidemic in French Guiana to compare events and pregnancy outcomes between two paired groups of pregnant women: women having presented with symptomatic dengue during pregnancy (n = 73) and women having had neither fever nor dengue during pregnancy (n = 219).

Differential transmission of Asian and African Zika virus lineages by Aedes aegypti from New Caledonia.

Zika virus (ZIKV) is a Flavivirus that is transmitted to humans by Aedes mosquitoes. ZIKV is divided into two phylogenetic lineages, African and Asian. In the Asian lineage, Pacific and American clades have been linked to the recent worldwide outbreak of ZIKV.

Yellow fever in two unvaccinated French tourists to Brazil, January and March, 2018.

We report two yellow fever cases in unvaccinated French travellers in Brazil in January and March 2018, respectively; one exposed during an excursion in Minas Gerais and the other in Ilha Grande. Both presented with fever, hepatitis, thrombocytopenia and leucopenia. Yellow fever diagnosis was based on RT-PCR and serological tests.

Estimating the Risk of Vertical Transmission of Dengue: A Prospective Study.

The incidence of dengue worldwide is increasing rapidly. A better understanding of dengue transmission may help improve interventions against this major public health problem. The virus is mostly transmitted by vectors.

Zika virus infection: report of the first imported cases in a Paris travel centre.

We describe characteristics of 17 patients with a Zika virus (ZIKV) infection seen in a Travel Center in Paris during the 4 months following the WHO alert on ZIKV. Sixteen were imported cases, including 13 from the Caribbean. One was a women living in Paris infected through sexual transmission.

Five cases of acute Zika virus infection in French women of reproductive age returning from Central and South America.

Introduction: The favorable season for Aedes albopictus circulation has started in Europe and may lead to autochthonous transmission of Zika virus. Health care providers should be familiar with evocative clinical presentations and able to give updated information to women of reproductive age infected by Zika virus.

Observations: We report five laboratory-confirmed Zika virus infections imported to metropolitan France from Central and South America between January and April, 2016.

Zika Virus Strains Potentially Display Different Infectious Profiles in Human Neural Cells.

The recent Zika virus (ZIKV) epidemic has highlighted the poor knowledge on its physiopathology. Recent studies showed that ZIKV of the Asian lineage, responsible for this international outbreak, causes neuropathology in vitro and in vivo. However, two African lineages exist and the virus is currently found circulating in Africa.

Zika virus infections.

Since its discovery in 1947 in Uganda, the Zika virus (ZIKV) remained in the shadows emerging in 2007 in Micronesia, where hundreds of dengue-like syndromes were reported. Then, in 2013-2014, it was rife in French Polynesia, where the first neurological effects were observed. More recently, its arrival in Brazil was accompanied by an unusually high number of children with microcephaly born to mothers infected with ZIKV during the first trimester of pregnancy.

Whole-Genome Sequencing Analysis from the Chikungunya Virus Caribbean Outbreak Reveals Novel Evolutionary Genomic Elements.

Background: Chikungunya virus (CHIKV), an alphavirus and member of the Togaviridae family, is capable of causing severe febrile disease in humans. In December of 2013 the Asian Lineage of CHIKV spread from the Old World to the Americas, spreading rapidly throughout the New World. Given this new emergence in naïve populations we studied the viral genetic diversity present in infected individuals to understand how CHIKV may have evolved during this continuing outbreak.