INFLUENCE OF STORAGE CONDITIONS OF INFLUENZA VIRUS ON VIRUS DETECTION BY RT-qPCR AND VIRAL ISOLATION

Abstract Influenza virus infection in pigs causes significant losses for the swine industry and concerns for the public health. Therefore, rapid virus detection is important for influenza surveillance in pigs. Storage conditions (such as medium, temperature, and time) of the biological samples are very important for the diagnosis because they can negatively interfere with the viral detection. In this study, influenza virus viability was evaluated in different storage media (UTM commercial medium, "in house" VTM medium, and without storage medium), temperature (4, 23 and 37 °C), and storage time (up to 120 hours). Samples were evaluated by RT-qPCR and isolation in embryonated chicken eggs. Significant effects (p<0.05) were observed for the media and time besides the interaction between the two factors with the viral load. In conclusion, biological samples of pigs sent for influenza diagnosis should be stored, preferably in viral maintenance medium at 4 °C, and the time estimated between the sample collection until the arrival in the laboratory should be less than three days.