Epidemiological assessment of continuing transmission of lymphatic filariasis in Samoa

Ongoing transmission of lymphatic filariasis (LF) was assessed in five Samoan villages by measuring microfilaraemia (Mf), circulating filarial antigen (CFA) and antibody prevalence. Compared to the other villages, Fasitoo-Tai had a significantly higher Mf prevalence (3.2%), CFA prevalence (14.6%) and antibody prevalence in children (62.0%) (P<0.05). Puapua had a significantly lower CFA prevalence (2.5%), no detectable Mf-positive individuals and significantly low antibody prevalence in children (7.9%) (P<0.05). Siufaga, previously believed to be LF-free, recorded >1% CFA prevalence and a high antibody prevalence in children (46.6%). Overall, antibody prevalence in children appeared to reflect the transmission dynamics in the villages and, in Siufaga, identified an area of ongoing transmission. The Filariasis Cellabs Enzyme-Linked Immunosorbent Assay (CELISA), based on recombinant antigen Bm14, to detect antibodies, could potentially be a promising diagnostic tool for inclusion in future surveillance in the South Pacific.