APPLICATION OF MAMMALIAN ERYTHROCYTES AS INDICATORS FOR NEWCASTLE DISEASE VIRUS HAEMAGGLUTINATION-HAEMAGGLUTINATION INHIBITION TESTS

摘要

In this study, the potential of heterologous erythrocyte indicator systems for detecting Newcastle Disease (ND) antibodies was investigated using donkey, horse, dog and pig erythrocytes while guinea pig erythrocyte served as the control for comparison. Previous research had shown that guinea pig erythrocyte is useful as an alternative indicator in Newcastle disease virus haemagglutination inhibition (NDV-HI) titre determination.The haemagglutination and haemagglutination inhibition tests were employed using a constant 1 concentration for all erythrocyte indicators. A total of 91 birds of different age groups (6,9 and 12 weeks) were bled and their NDV antibody titer determined using erythrocyte from the mammals as indicator. Results showed that donkey erythrocyte is not useful as an alternative indicator in NDV-HI titre determination and its haemagglutination (HA) value or HA unit (HAU) is zero. Horse, dog, pig and guinea pig erythrocyte however gave varying haemagglutination (HA) and haemagglutination-inhibition (HI) titre. It is thus recommended that the horse erythrocyte be used as an alternative in HA test and is also suitable for HI test in birds up to 9 weeks of age.When birds are up to 12 weeks old, erythrocyte from guinea pig will serve asa better indicator.The potential of these indicators are discussed in this study.