Virus isolation
Hepatocellular carcinoma epithelial cells (LMH) (Kawaguchi et al., 1987) were cultured with 2 µg TCPK Trypsin/mL in T25 culture flasks and infected with 0.5 mL of the NDV-positive samples. Cells were incubated at 37 °C until giant cell formation was observed or for up to 7 days before initiating a second passage following a freeze/thaw cycle. Further confirmation using hemagglutination (HA) and hemagglutination inhibition (HI) tests were conducted on the supernatant culture medium (OIE, 2012). Isolated viruses were aliquoted and kept at -80 0C until further use.