AIM: To evaluate the usefulness of immunochromatographic test (ICT) for rapid diagnosis and
surveillance of Wuchereria bancrofti infection. METHODS: The monoclonal antibody based ICT assay was used to
detect filarial antigens in the sera from bancroftian filariasis patients. RESULTS: 111 out of 116 bancroftian
microfilarmia cases showed positive ICT reaction, giving a positive rate of 95.7%. Serum samples from 12
malayian microfilaremia cases, 33 ascariasis cases, 20 schistosomiasis japonica cases and 6 trichinellosis cases were all found negative in ICT , demonstrating a specificity of 100%. In 73 chronic filariasis cases
with elephantiasis, hydrocoele, and chyluria cases, 18 showed ICT positive, among whom 16 revealed microfilarem ia, suggesting that the ICT positive cases were with active infections. Of the 30 microfilaremia cases before single dose ivermectin treatment, 29 were ICT positive (96. 7% ). A negative conversion of microfilaremia was observed in all cases 8- 14 days post-treatment. Upon following up to 6 and 12 months, microfilaremia eappeared in 5 and 7 cases, respectively. 5 out of 13 ICT positive cases were found microfilaremic at 6 month post-treatment, while among the rest of 8 , 5 were found microfilaremic at 12 month post-treatment. Parallel use of ICT with routine blood film examination in Houda village,Zhecheng County, Henan Province for a post-control surveillance survey in 132 local individuals revealed 9 microfilaremia cases were also ICT positive. Of the 123 persons w th negative blood examination, only 1 was ICT positive. CONCLUSION: ICT is a rapid and simple method with high sensitivity and specificity, and might be used for the diagnosis, efficacy evaluation as well as a tool for post-control surveillance of bancroftian filarasis.
