Establishment and evaluation of colloid gold labeled immunochromatographic strip test for rapid detection of visceral leishmaniasis

Objective To establish and evaluate a colloid gold immunochromatographic strip test for detection of visceral leishmaniasis.Methods The streptococcal protein G(SPG) was conjugated with colloid gold as detecting reagent,visceral leishmaniasis antigen and anti-SPG IgY were immobilized on nitrocellulose at proper position,respectively.Serum samples of 129 visceral leishmaniasis patients were used for evaluating the sensitivity.Serum samples from patients with malaria(20 cases),cystechinococcosis (10 cases),schistosomiasis japonica(10 cases),paragonimiasis (5 cases),clonorchiosis(5 cases) and 40 healthy people were used for evaluating the specificity.Detection results of the immunochromatographic strip were compared with that of ELISA.Results Detection on 129 serum samples of patients with visceral leishmaniasis showed a sensitivity of 96.1％(124/129).The cross-reactivity to malaria and schistosomiasis was 10.0％(2/20) and 10.0％ (1/10),respectively.There was no cross-reactivity with schistosomiasis japonica,paragonimiasis and clonorchiosis.One sample out of 40 healthy people showed false positive reaction.The overall specificity was 95.6％(86/90).The corresponding rate of immunochromatographic strip test with ELISA was 99.2％.There was no statistical difference in the sensitivity between immunochromatographic strip test and ELISA (x2 =0.12,P ＞ 0.05).Specificity showed no statistical difference between immunochromatographic strip test and ELISA (x2 =0.42,P＞ 0.05).Conclusion The immunochromatographic strip test was established succesfully,and is a sensitive,specific,simple and rapid assay for visceral leishmaniasis detection. Key words: Visceral leishmaniasis;  Immunochromatographic strip;  Detection;  Evaluation