Wasun ChantratitaChonlaphat SukasemSayomporn SirinavinNipaporn SankuntawChutatip SrichantaratsameeEkawat PasomsubKumthorn MalathumMahidol University2018-05-032018-05-032011-05-01Journal of Infection in Developing Countries. Vol.5, No.5 (2011), 348-35219722680203665902-s2.0-79958103399https://repository.li.mahidol.ac.th/handle/123456789/12052Introduction: We investigated the frequency of H274Y-positive swine-origin 2009 A (H1N1) influenza virus outbreak in Thailand during May-August 2009. Methodology: This study sought to find Oseltamivir resistance mutation H274Y by using pyrosequencing. Results: From 8,710 real-time RT-PCR swine-origin 2009 A(H1N1) influenza virus-positive specimens, 100 randomly selected samples identified one such virus with H274Y mutation using pyrosequencing. Conclusions: The patient probably acquired oseltamivir resistance from natural variation, since he had never received that form of treatment before and recovered from influenza-like symptoms without using anti-influenza drugs. © 2011 Chantratita et al.Mahidol UniversityImmunology and MicrobiologyMedicineArticleSCOPUS