RESUMO
HTLV-I has been aetiologically linked with adult T-cell leukaemia and tropical spastic paraparesis. Studies from Japan have shown that transmission from mother to child is the principal mode of early-life infection; breast milk has been implicated as the route of this transmission. To study the frequency of, and risk factors for, maternal-infant transmission in Jamaica, we screened women attending a Kingston antenatal clinic for the presence of HTLV-I antibodies. Of 2,329 women screened, 81 (3.5 percent) were seropositive. Two to three years following screening, 35 seropositive mothers were successfully recontacted, a questionnaire was administered, and blood was collected from the mothers and the child of the original pregnancy (index child) as well as any other children. Five of 34 (15 percent) index children and 8 of 31 (26 percent) siblings were seropositive. Having a seropositive child was significantly associated with older maternal age (p<0.05) and a higher level of maternal antibody titre (p<0.05). Seropositive index children tended to breast feed for longer than seronegative index children (11 months vs 1 month; p=0.18). We conclude that HTLV-I transmission occurs in Jamaica at rates similar to those seen in Japan. Older age and measures of higher "viral load" such as elevated antibody titre are associated with transmission. Although the evidence is suggestive that transmission occurs through breast-milk, a larger study is currently underway to this tissue (AU)
