[Application of immunochromatographic test for diagnosis and surveillance of bancroftian filariasis].
OBJECTIVE
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 microfilaria 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 microfilaremia, 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 reappeared 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 with negative blood examination, only 1 was ICT positive.


CONCLUSIONS
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.
Zheng
H
H
Guizhou Provincial Institute of Parasitic Diseases, Guiyang 550004.
Tao
Z
Z
Fang
R
R
Chang
B
B
Zhang
Y
Y
Turner
P
P
D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth / Q000032:analysis* / Q000276:immunology; D002845:Chromatography / Q000379:methods; D005368:Filariasis / Q000175:diagnosis* / Q000188:drug therapy; D005500:Follow-Up Studies; D006801:Humans; D007559:Ivermectin / Q000008:administration & dosage / Q000627:therapeutic use*; D014958:Wuchereria bancrofti / Q000276:immunology*
D000871:Anthelmintics; D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth; D007559:Ivermectin