Evaluation of the Og34C filter paper technique in lymphatic filariasis prevalence studies

Currently there are several tests which can be used for monitoring and evaluating lymphatic filariasis prevalence in mass drug administration (MDA) programs with the ICT as most commonly accepted field test. However, other techniques to determine circulating antigen are available that also could be suitable in these programs. Our aim was to determine the suitability of the Og4C3 filter paper technique to determine antigen prevalence for lymphatic filariasis. We compared multiple antigen methods during the course of baseline clinical prevalence studies in Papua, New Guinea in over 800 subjects. We found that the ICT and Og4C3 filter paper techniques and using blood from the ICT card in the Og4C3 ELISA were equivalent in performance and that the serum Og4C3 ELISA test detected significantly more antigenic individuals. In addition, we found that modification of the Og4C3 assay by removing the boiling step did not affect its performance. Our results indicate that the Og4C3 filter paper technique is suitable for use in elimination of transmission of lymphatic filariasis monitoring and evaluation programs, quality control of ICT testing could be accomplished by using blood from the ICT test card, and with appropriate logistics in place, venous sampling and testing by the serum Og4C3 ELISA is achievable in monitoring and evaluation and would better identify areas with low level antigenaemia prevalence and possible ongoing transmission.