Evaluation of different transport media for survival of H5N1 highly pathogenic avian influenza virus.

In the case of the H5N1 avian influenza outbreak, specific detection is critical for the timely implementation of control and preventive measures to limit the spread of the disease. Sample collection, storage, and transportation are critical for the accurate detection of the virus as its isolation and identification can only be done in a designated laboratory. In this study, we have compared 5 transport media out of which three are laboratory-based media named Phosphate-buffered Saline (PBS), 50% Glycerol + PBS, and Normal Saline (NS) and two are commercially available media including Viral Transport Medium (VTM), Charcoal based Viral Transport Medium (CVTM) to assess their effect on the survivability of virus in fecal swabs kept under field simulation conditions. Swabs from fecal samples spiked with known 50% embryo infectious dose (EID 50 ) H5N1 virus were collected in each of these transport media, sealed, and stored with ice packs in thermocol boxes similar to the field samples that are being sent to the laboratory. Detection of the virus was done by isolation and reverse transcription-PCR. The results of our study suggested that the most effective transport media for H5N1 avian influenza virus was NS, PBS, and CVTM as the virus could be isolated for up to six days in comparison to VTM and PBS + 50% Glycerol.