Molecular characterization of chicken infectious anaemia virus isolated from village chickens in Maiduguri, Nigeria

The presence and genetic variability of chicken infectious anaemia virus (CIAV) among apparently healthy village chickens in Maiduguri, Nigeria, were investigated using conventional polymerase chain reaction (PCR) and Sanger’s sequencing, respectively. A total of 100 tissue samples (thymus, liver, bursa of Fabricius, and spleen) were collected from 100 apparently healthy village chickens of 1-13 weeks old. The tissues from each bird were pooled and then frozen at -20oC. Chicken infectious anaemia virus DNA was extracted from the pooled tissues and subjected to PCR and DNA sequencing. The PCR results showed that a total of 42/100 (42%) of the pooled tissue samples were positive for CIAV. The result of the sequencing indicated genetic variations among the field CIAVs detected in the pooled tissues of the village chickens. The evolutionary relationship inferred between six of the isolates (CIAV 15, 41, 42, 80, 43, and 37) obtained in this study formed a cluster with isolates from India, Thailand, Japan, South India, Taiwan, China, USA, and Australia, while CIAV 14 and CIAV 36 (with 87% homology) diverged to formed a sub-clade. Two other Nigerian isolates, CIAV 79 (with 52% homology with the six isolates) and CIAV 39 (57% homology with CIAV 79) formed a separate clade. Therefore, CIAV had been found in apparently healthy village chickens in Maiduguri, and some of the isolates formed a cluster with isolates from other parts of Asia, America, and Europe. There is a need to investigate the interactions between CIAV and immune cells of village chickens so that accurate preventive measures against the disease will be taken.