Typing of poultry virus (H5 and H7) by reverse transcription-polymerase chain reaction

The ability of the influenza Orthomixovirus to undergo to continually antigenically changes that can affect its pathogenicity and its diffusion, explains the growing seriousness of this disease and the recent epizoozies in various parts of the world. There have been 15 HA and 9 NA type A sub-types of the influenza virus identified all of which are present in birds. Until now the very virulent avian influenza viruses identified were all included to the H5 and H7 sub-types. We here show that is possible to identify the H5 and H7 sub-types with reverse transcription-polymerase chain reaction (RT-PCR) by using a set of specific primers for each HA sub-type. The RT-PCR is a quick and sensitive method of identifying the HA sub-types of the influenza virus directly from homogenised organs.