Comparative evaluation of different transport media for H5N1 highly pathogenic avian influenza virus

In developing countries particularly in field conditions unfavorable environmental conditions, lack of availability of appropriate transport media (TM) and maintenance of cold chain during transport; sample collection, storage, and transportation is more challenging. Considering these facts, five TM out of which three laboratory-based media named phosphate-buffered saline (PBS), 50% glycerol + PBS, and normal saline (NS) and two commercially available media including viral transport medium (VTM), charcoal based viral transport medium (CVTM) were compared to protect infectivity of the H5N1 influenza virus. Spiked fecal sample and allantoic fluid with and without these TM were placed in field simulatory storage and transportation conditions and in every 12 h time interval these samples were tested for virus isolation in embryonated chicken egg inoculation and identification by HA test and RT PCR upto 7 days. Survivability of the virus was detected by calculating the percent infectivity and analysed by logistic regression analysis. NS, PBS, and CVTM, were most effective media in maintaining the integrity of the test virus. These media are easily available and economical and less complex to prepare. A significant difference was found in survivability of the virus only in VTM in between allantoic fluid and fecal sample.