INTRA-FAMILIAL TRANSMISSION OF HUMAN T-LY MPHOTROPIC VIRUS, TYPE-1 (HTLV-1)

We are reporting the results of a familial study carried out in positi ve subjects. This study aims at appraising the different modes of intr a-familial transmission of this retrovirus. The study has included 212 persons: 33 seropositive subjects (identified during two previous ser oprevalence surveys and followed up since 1991), and 179 members of th eir families. Blood specimens have been taken from each of these subje cts Sera have been screened for HTLV-I antibodies by ELISA test and po sitive results confirmed by Western blot test. Out of 18 children born during the follow up period, a cases Of seroconversion have been obse rved. One case of seroconversion has also been noted among the 17 coup les in which either of the spouses is seropositive. Among the 136 chil dren of the cohort: 17.8 % of them are HTLV-I positive when both paren ts are seropositive 26.1 % if the mother only is seropositive and 0 % if the father only is seropositive. The incidence rate in this cohort is estimated to be 0.43 %. These data relative to the intra-familial t ransmission of HTLV-1 in Benin appear to be consistent with those prev iously reported in Japan.