... after 1951. During the 1984 survey 82 chronic carriers were identified in Keneba and 108 in Manduar. They have been followedat 3 time points 5 (in 1989), 9 (in 1993 )and 19 (in 2003)years after ... Dartfort, UK) and by radioimmunoassay (RIA)(DiaSorin Biomedica, Sallugia, Italy). In 2003 following the discontinuation of RPHA and RIA assays, the sampleswere tested for HBsAg by Determine™ (Abbott ... H.25. Whittle HC, Maine N, Pilkington J, Mendy M, Fortuin M, Bunn J, Alli-son L, Howard C, Hall A: Long-term efficacy of continuing hep-atitis B vaccination in infancy in two Gambian villages....