Virological surveillance and antiviral resistance of human influenza virus in Argentina, 2005-2008 Vigilancia virológica y resistencia a los antivíricos del virus de la gripe humana en la Argentina, 2005-2008

• Main Authors: Andrea Pontoriero, Elsa Baumeister, Ana M. Campos, Vilma L. Savy
• Format: Article in Journal/Newspaper
• Language: English; Spanish; Portuguese
• Published: Pan American Health Organization 2011
• Subjects: Influenza humana; virus de la influenza A; farmacorresistencia viral; agentes antivirales; Argentina; Influenza; human; influenza A virus; drug resistance; viral; antiviral agents; Medicine; R; Arctic medicine. Tropical medicine; RC955-962; Public aspects of medicine; RA1-1270; Arctic; Darby
• Online Access: https://doaj.org/article/6d0e3e8ff9a043f1bc31bc8eb394a662

OBJECTIVE: To describe the virological characteristics of the influenza strains circulating in Argentina in 2005-2008 and to assess the prevalence of antiviral resistance. METHODS: On the basis of their geographical spread and prevalence, influenza A and B isolates grown in Madin-Darby canine kidney cells were selected after antigenic and genomic characterization to be analyzed for antiviral resistance by enzymatic assay and pyrosequencing. Amantadine susceptibility was evaluated by pyrosequencing for known resistance markers on 45 strains of influenza A. Susceptibility to oseltamivir and zanamivir was evaluated by enzymatic assay of 67 influenza A and 46 influenza B strains, some of which were further analyzed by sequencing the neuraminidase gene. RESULTS: Resistance to amantadine was observed only on A(H3N2) strains (29/33); all of them carried the mutation S31N in their M2 sequence. Oseltamivir resistance was observed in 12 (34.3%) of the 35 A(H1N1) strains from 2008; all of them carried the mutation H275Y in their neuraminidase sequence. All these viruses remained sensitive to zanamivir. CONCLUSIONS: This study describes a high incidence of amantadine-resistant influenza A(H3N2) viruses since 2006 and an unprecedented increase in oseltamivir resistance detected only in influenza A(H1N1) viruses isolated in 2008. Influenza A and B viruses were more sensitive to oseltamivir than to zanamivir, and influenza A viruses were more sensitive to both neuraminidase inhibitors than the influenza B viruses. The national data generated and analyzed in this study may help increase knowledge about influenza antiviral drug resistance, which is a problem of global concern. OBJETIVO: Describir las características virológicas de las cepas de virus de la gripe que circulaban en la Argentina entre el 2005 y el 2008, y evaluar la prevalencia de la resistencia a los antivíricos. MÉTODOS: Según su diseminación geográfica y su prevalencia, se seleccionaron aislados de gripe A y B cultivados en células renales caninas de Madin-Darby ...