Using the method of shifting assay of standardized indirect agglutination (SSIA) for testing samples of chicken feces and tonsil swab supernatant liquids collecting from slaughtered and live chickens at some districts of Thua Thien Hue province in the Spring-Summer season of 2011 indicated that ratio of Gumboro virus infection in chicken feces was approximate 36 percent, fluctuating from 30 percent (Huong Thuy district) to 46 percent (A Luoi district), meanwhile in tonsil liquids Gumboro virus infection ratio was 30 percent, fluctuating from 21 percent (in Huong Thuy district) to 43 percent (in A Luoi district)
However, the ratio of this virus infection in the areas was not statistically significant difference. The tests also showed that the fecal samples given result of antigen detection was higher compared to tonsil samples, but there was not statistically significant difference either. Therefore, both samples (fecal and tonsil liquid samples) could be used for diagnosis/detection of Gumboro antigen. However, fecal sample was better than tonsil liquid sample due to easy collection and higher sensitive in detecting Gumboro antigen. Besides, with the technique of indirect haemagglutination (IHA), testing results also indicated that ratio of Gumboro antigen detection from samples of chicken serum was low, accounting for 20 percent of the tested chickens having antibody against Gumboro virus with low geometric mean titre (GMT) of 1.54. Therefore, the possibility of Gumboro disease outbreak in the local chickens was still high.