[Vertical transmission of HTLV-I]

Vertical transmission of the human T-cell leukemia type 1 (HTLV-1) from seropositive mothers to their offspring has been extensively studied. Transmission occurs mainly through breastfeeding. Prevention relies on screening pregnant women (and wet-nurses) for HTLV-1 antibodies and advising seropositive women to refrain breast feeding. Recently, antigen detection or genome detection (using PCR) studies on lymphocytes from neonates born to HTLV-1 positive mothers have established that prenatal vertical transmission does occur, although in only a small proportion of cases (0.5 to 7%). Studies on the HTLV-1 and improved understanding of its modes of transmission may provide new insight into the transmission of the HIV.