comparison of multiplex nested rt-pcr with vi­rus isolation for detection of influenza viruses a and b

background: influenza a viruses bearing all known ha and na subtypes have been isolated from avian hosts: but only the a/h1n1,a/h2n2 and a/h3n2 influenza subtypes have been associated with widespread epidemics in humans un­til now .while influenza b detected only in humans. subtype h5 infection in humans occurred for the first time dur­ing 1997-1998 in hong kong, then china in 2003, vietnam and thailand in 2004 and continued to 2005-2006 in tur­key and egypt. in this study a multiplex nested rt-pcr was developed for simultaneous detection of influenza virus a and b in clinical samples. methods: throat swab and throat wash was collected between october 2005 and september 2006 from 689 patients with a suspected influenza virus infection. samples were transported to the national influenza center (tehran univer­sity of medical science, school of public health). each sample is divided into two parts in order to virus isolation and nested rt-pcr. results: the rt-pcr detected in 75 cases of influenza a and b, compared to 26 cases by virus isolation and 74 cases are positive by rt-pcr. in total, 50 out of 74 rt-pcr positive specimens were negative by virus isolation. the rt-pcr provides a sensitive and specific method for detecting and typing influenza viruses a and b. conclusion : the rt-pcr provides a sensitive and specific method for detecting and typing influenza viruses a and b. multi­plex rt-pcr can also be used to accurately detect more than one viral template in the same reaction mixture, allow­ing viral confections to be identified with the same respiratory specimen.