Evaluation of the practical efficacy of a colloidal gold detection reagent of rabies virus antibody

Abstract

Objective To evaluate the practical efficacy of a colloidal gold (CG) detection reagent of rabies virus antibody. Methods Series dilutions of rabies immunoglobulin and serum samples of rabies vaccine immunized population were tested by a CG detection reagent of rabies virus antibody and rapid fluorescent focus inhibition test (RFFIT). The consistency of the qualitative results of rabies virus antibodies between the two methods were compared. The comparison of rates was made by Chi-square test. Results For rabies immunoglobulin diluent, the detection limit of the rabies virus antibody CG detection reagent was higher than 6.53 IU/ml but lower than 9.53 IU/ml. For the serum samples, the detection limit of the rabies virus antibody CG detection reagent was higher than 2.80 IU/ml but lower than 3.30 IU/ml. The positive rates of serum rabies virus antibodies detected by CG and RFFIT were 26% and 67% respectively, and the difference was statistically significant (χ2 =13.66, P=0.000). The results of RFFIT were regarded as gold standard, false negative results but no false positive results were observed when CG was used to detect serum rabies virus antibodies. Conclusions The sensitivity of the rabies virus antibody CG detection reagent is poor, and attention should be paid to the phenomenon of missing some practically positive results in practical application of CG detection reagent. Key words: Rabies virus; Antibody; Colloidal gold; Rapid fluorescent focus inhibition test