RESUMEN
In 2023, dengue virus serotype 2 (DENV2) affected most French overseas territories. In the French Caribbean Islands, viral circulation continues with > 30,000 suspected infections by March 2024. Genome sequence analysis reveals that the epidemic lineage in the French Caribbean islands has also become established in French Guiana but not Réunion. It has moreover seeded autochthonous circulation events in mainland France. To guide prevention of further inter-territorial spread and DENV introduction in non-endemic settings, continued molecular surveillance and mosquito control are essential.
Asunto(s)
Epidemias , Humanos , Guyana Francesa/epidemiología , Epidemiología Molecular , Indias Occidentales/epidemiología , Francia/epidemiologíaRESUMEN
Here we propose a strategy allowing implementing efficient and practicable large-scale seroepidemiological studies for Zika Virus (ZIKV). It combines screening by a commercial NS1 protein-based Zika IgG ELISA, and confirmation by a cytopathic effect-based virus neutralization test (CPE-based VNT). In post-epidemic samples from Martinique Island blood donors (a population with a dengue seroprevalence above 90%), this strategy allowed reaching specificity and sensitivity values over 98%. The CPE-based VNT consists of recording CPE directly under the optical microscope, which is easy to identify with ZIKV strain H/PF/2013 at day 5 pi. Overall, considered that CPE-based VNT is cost effective and widely automatable, the NS1 protein-based Zika IgG ELISA+CPE-based VNT combination strategy represents a convenient tool to expedite ZIKV seroprevalence studies.
Asunto(s)
Anticuerpos Antivirales/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Tamizaje Masivo/métodos , Pruebas de Neutralización/métodos , Pruebas Serológicas/métodos , Infección por el Virus Zika/diagnóstico , Virus Zika/inmunología , Anticuerpos Neutralizantes/sangre , Efecto Citopatogénico Viral , Humanos , Inmunoglobulina G/sangre , Martinica/epidemiología , Microscopía , Sensibilidad y Especificidad , Estudios Seroepidemiológicos , Infección por el Virus Zika/epidemiologíaRESUMEN
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. Both patients recovered within a few days. The increasing occurrence of cases in unvaccinated travellers highlights the need to reinforce vaccination recommendation for travellers at-risk.