Application of the soluble antigen fluorescent antibody (SAFA) test to the serodiagnosis of rabies.
The adaptation and evaluation of the Soluble Antigen Fluorescent Antibody (SAFA) test for the serologic diagnosis of rabies is described. Evaluation of the SAFA test was based on a comparison between serum titers obtained in the SAFA test, the mouse Serum Neutralization (SN) test and in the Indirect Fluorescent Antibody (IFAT) test. Dog, fox, raccoon and skunk sera were used for the comparison with mouse SN titers. Human serum was used for the comparison with the IFAT titer. The purity and concentration of the test antigen is a crucial factor in determining the efficiency of the SAFA test for rabies serodiagnosis. Viral antigen obtained by the AIPO4 gel method for rabies virus purification and concentration was found to be sufficiently purified and concentrated for use in the SAFA test. Conjugate dilution decreased the level of non-specific staining. Although specific activity was also decreased, there was a statistically significant difference (P less than or equal to 0.05; Student's t test) between the rabies positive and the rabies negative serum samples at all conjugate dilutions for all species studied. In three cases (fox, raccoon, skunk) SAFA titers were greater than mouse SN titers. In one case (dog) the SAFA titer was less than the mouse SN titer. The IFAT titer of the human serum sample was greater than the SAFA titer. Comparison of Fluorometer Dial Readings (FDR) of sera obtained in separate protocols demonstrated satisfactory reproducibility of the SAFA test for rabies serodiagnosis.
D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D000937:Antigen-Antibody Reactions; D004285:Dogs; D004306:Dose-Response Relationship, Immunologic; D005455:Fluorescent Antibody Technique; D005589:Foxes; D012889:Mephitidae; D051379:Mice; D009500:Neutralization Tests; D011818:Rabies / Q000175:diagnosis*; D011820:Rabies virus / Q000276:immunology; D011821:Raccoons; D012698:Serologic Tests; D012995:Solubility
D000914:Antibodies, Viral