Reduction of Wuchereria bancrofti Adult Worm Circulating Antigen after Annual Treatments of Diethylcarbamazine Combined with Ivermectin in French Polynesia

Abstract

Circulating filarial antigen (CFA), determined with Og4C3 ELISA, is a marker of Wuchereria bancrofti adult worm infection. The reduction of CFA over 2 years was determined in 185 microfilaremic and 111 amicrofilaremic but CFA+ adults given an annual dose of either diethylcarbamazine (DEC) or ivermectin or the two combined. Reduction of CFA level was good with DEC but weak with ivermectin and followed the same pattern in amicrofilaremic and microfilaremic groups. Combinations and DEC alone had a similar impact on CFA level. CFA clearance was observed in amicrofilaremic but not in microfilaremic persons in all DEC-containing treatments. However, the highest clearance rate was observed in persons treated with DEC at 6 mg/kg combined with ivermectin. Continuous reduction of CFA level after repeated treatments shows that elimination of W. bancrofti infection, monitored by CFA clearance, might be achieved within a few years with annual treatments of DEC combined with ivermectin.

Comparison of tests for the detection of circulating filarial antigen (Og4C3-ELISA and AD12-ICT) and ultrasound in diagnosis of lymphatic filariasis in individuals with microfilariae

“…Our results contradict these observations and clearly show that there is a significant association (p = 0.001) between the density of MF and the concentration of CFA. Similar results were obtained by Rocha et al (1996), Nicolas et al (1997) and Itoh et al (1999). We also agree with Grove and Davis (1978), who suggest that the detection of microfilarial antibodies depends upon the relative release of MF into the bloodstream and the production of antibodies against those MF.…”

Circulating filarial antigen in the hydrocele fluid from individuals living in a bancroftian filariasis area - Recife, Brazil: detected by the monoclonal antibody Og4C3-assay

“…Many studies (including this article), do not agree with this hypothesis (Rocha et al 1996, Nicolas et al 1997, Itoh et al 1999). These authors demonstrated on the contrary that the CFA intensity is directly proportional to the microfilaremia density, i.e., the higher the MF density, the higher the CFA levels.…”

Worm burden and host responsiveness in Wuchereria bancrofti infection: use of antigen detection to refine earlier assessments from the South Pacific.

“…Such quantitative assays have now been used not only for cross-sectional 15,16 and longitudinal 17 analyses of community prevalence, but also for surveying populations in lymphatic filariasis-endemic regions after treatment. [18][19][20] As the use of antifilarial drugs becomes more widespread in many endemic regions, the opportunities for studying drug-naive populations using these newer, more refined antigen detection techniques become fewer and fewer. Therefore, in the present study, we have taken advantage of the opportunity to reexamine a population residing on an island in the South Pacific, which had been studied before the introduction of antifilarial chemotherapy.…”