RESUMEN

Biennial H1N1pdm09 influenza A virus (IAV) epidemics have been associated with major severity of respiratory disease in Mexico. Atypically and in contrast with what happened in USA, Canada and Europe during 2017, an increase of infections due to the H1N1pdm09 pandemic virus instead of H3N2 was observed. In order to determine the viral contribution to severe acute respiratory disease, we characterized the pathogenicity determinants of IAV in Mexico during the 2015-2016 and 2016-2017 seasons. The RNA segments of 20 IAV samples were sequenced by NGS platform and phylogenetic analysis was conducted. The analysis of the hemagglutinin (HA) sequences established that all virus samples, except one, belong to clade (6B.1). The IAVs presented the substitution S162 N, which introduces a new glycosylation site in the hemagglutinin. We also found the D222 G substitution, which has been associated with a higher tropism towards the lower respiratory tract, and a non-reported insertion of one Ile in NS1 (Ile113). The IAVs from 2016 to 2017 in Mexico belong to the new clade 6B.1. The new glycosylation site in HA (S162 N) is a major change that may affect the efficacy of the current vaccine. We detected in several patients pathogenicity determinants associated with the severity of the respiratory disease.

Asunto(s)

Sustitución de Aminoácidos , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Subtipo H1N1 del Virus de la Influenza A/genética , Gripe Humana/epidemiología , Gripe Humana/virología , Adolescente , Adulto , Anciano , Secuencia de Aminoácidos , Niño , Preescolar , Comorbilidad , Femenino , Glicoproteínas Hemaglutininas del Virus de la Influenza/química , Historia del Siglo XXI , Humanos , Lactante , Recién Nacido , Subtipo H1N1 del Virus de la Influenza A/clasificación , Gripe Humana/diagnóstico , Masculino , México/epidemiología , Persona de Mediana Edad , Modelos Moleculares , Filogenia , Estaciones del Año , Relación Estructura-Actividad , Evaluación de Síntomas , Adulto Joven