RESUMEN
Three autochthonous cases of tick-borne encephalitis (TBE) acquired in rural areas of France where Lyme borreliosis, but not TBE, is endemic highlight the emergence of TBE in new areas. For patients with neurologic involvement who have been in regions where Ixodes ticks circulate, clinicians should test for TBE virus and other tickborne viruses.
Asunto(s)
Virus de la Encefalitis Transmitidos por Garrapatas , Encefalitis Transmitida por Garrapatas/epidemiología , Anciano , Animales , Niño , Encefalitis Transmitida por Garrapatas/diagnóstico , Femenino , Francia/epidemiología , Humanos , Ixodes/virología , Masculino , Pruebas Serológicas/métodosRESUMEN
In August 2017, an autochthonous chikungunya case was reported in south-east France. By mid-September, eight additional autochthonous cases were found in the index case's neighbourhood, where the chikungunya virus vector Aedes albopictus was observed. Genomic characterisation identified an East-Central South African (ECSA) lineage strain, probably from the Central African region and carrying an adaptive mutation facilitating transmission by Ae. albopictus. The event confirms we need early case detection and response to contain chikungunya in Europe.
Asunto(s)
Aedes/virología , Fiebre Chikungunya/epidemiología , Virus Chikungunya/aislamiento & purificación , Brotes de Enfermedades , Animales , Fiebre Chikungunya/diagnóstico , Virus Chikungunya/genética , Francia/epidemiología , Variación Genética , Humanos , Insectos Vectores/virología , Mutación , Reacción en Cadena en Tiempo Real de la Polimerasa , Vigilancia de GuardiaRESUMEN
The RIG-I-like receptors (RLRs) play a major role in sensing RNA virus infection to initiate and modulate antiviral immunity. They interact with particular viral RNAs, most of them being still unknown. To decipher the viral RNA signature on RLRs during viral infection, we tagged RLRs (RIG-I, MDA5, LGP2) and applied tagged protein affinity purification followed by next-generation sequencing (NGS) of associated RNA molecules. Two viruses with negative- and positive-sense RNA genome were used: measles (MV) and chikungunya (CHIKV). NGS analysis revealed that distinct regions of MV genome were specifically recognized by distinct RLRs: RIG-I recognized defective interfering genomes, whereas MDA5 and LGP2 specifically bound MV nucleoprotein-coding region. During CHIKV infection, RIG-I associated specifically to the 3' untranslated region of viral genome. This study provides the first comparative view of the viral RNA ligands for RIG-I, MDA5 and LGP2 in the presence of infection.