Comparison of an immunochromatographic card test with night blood smear examination for detection of Wuchereria bancrofti microfilaria carriers S. P. PANI, S. L. HOTI, P. VANAMAIL, L. K. DAS Vector Control Research Centre (Indian Council of Medical Research), Pondicherry 605006, India S. P. PANI, S. L. HOTI, P. VANAMAIL, L. K. DAS Correspondence to S. P. PANI; vcrc@vsnl.com; sp_pani@vsnl.com © The National Medical Journal of India 2004 )*564)+6 Background. At present, two diagnostic testsOg4C3 ELISA and an immunochromatographic card test (ICT)are available to detect circulating filarial antigens of Wuchereria bancrofti in serum/whole blood samples collected during the day. We aimed to assess the sensitivity of the new format card test NOW® ICT Filariasis in detecting microfilaria carriers of W. bancrofti in comparison with conventional microscopic tech- niques and Og4C3 ELISA. Methods. A total of 200 persons were selected from two villages following a quota sampling design (100 in each village). The required number of houses was selected using a systematic sampling procedure with a random start of the first household. Blood samples were taken from all the available persons in each selected house until the quota of 100 was reached. The new format ICT test, Og4C3 ELISA and night blood smear exami- nation for microfilaria were carried out following standard procedures. Results. The sensitivity of the new format ICT test was 100% among microfilaria carriers (detected by both early and late readings). The kappa statistic measure of agreement between the two readings of all the samples (n=200) tested was 0.811 (p<0.05). The new format test also reported 25% of micro- filaria-negative individuals as being positive for circulating filarial antigens. However, the diagnostic lines were not stable beyond 10 minutes (particularly in the case of amicrofilaraemic persons). Though there was an overall agreement between the results of ICT and Og4C3 tests (kappa=0.612; p<0.05), the sensitivity of the Og4C3 test was lower than that of ICT. Conclusion. The new format ICT test is highly sensitive in detecting microfilaria carriers in endemic communities. Im- provement in the format to provide stable diagnostic lines, specificity of the format and cost of the test kit are to be considered before its large-scale use. Natl Med J India 2004;17:3046 INTRODUCTION Lymphatic filariasis has been targeted for elimination by 2020 1–4 and India has set 2015 as the deadline for achieving this goal. 5 The availability of a good diagnostic test is essential to map areas endemic for filariasis to delimit, stratify and prioritize them for intervention, as well as for monitoring and evaluating the control/ OA-Ashwani.pmd 1/24/05, 9:32 AM 304 Black Original Articles