Study on application of filarial specific IgG4 kit in disease surveillance of lymphatic filariasis

Objective: To investigate the filarial specific IgG4 kits in disease surveillance of basic filariasis eliminated and filariasis eliminated area. Methods: filarial specific IgG4 kit was applied in filariasis endemic areas in China. While in some cases, blood were taken at night for microfilaria examination under microscope. Results: In high and middle filariasis endemic areas, results of filarial specific IgG4 in residents were consistent with the results of microfilaria examination results (χ2 = 2.42, χ2 = 1.57, P > 0.05), indicating the detection of filarial-specific IgG4 can reflect local filariasis prevalence levels and the status quo. We detected filarial specific IgG4 in people who birthed before and after substantially eliminated filariasis periods, and the results showed significant difference (χ2 = 17.15, P < 0.05), indicating that in basic filariasis eliminated areas people with positive rate of filarial-specific IgG4 were existed and it showed an increasing trend with aging. We detected filarial specific IgG4 levels in filariasis substantially eliminated areas at different times, and the results showed that through years of prevention and monitoring after filariasis substantial elimination, in former filarial endemic areas the filariasis specific IgG4 level decreased in different populations, while the preventive and control effects were solid. We detected duration and propagation effects of specific filarial IgG4 in heartworm microfilaria hyperlipidemia patients, and the results showed that there were medium-density and high-density of microfilaria hyperlipidemia patients in basic filariasis eliminated areas with low efficiency transmission effect. We detected filarial specific IgG4 levels of floating population and entry-exit personnel in filariasis substantially eliminated areas, and the results showed that the positive came from former endemic areas and infected areas. Therefore we should strengthen monitoring floating population who came from former endemic areas and entry-exit personnel who came from the affected areas. Conclusion: Filarial specific IgG4 kits in disease surveillance of basic filariasis eliminated and filariasis eliminated area have good value.