HUMAN T-LYMPHOTROPIC VIRUS (HTLV) TYPE-I AND TYPE-II INFECTION IN SEXUAL CONTACTS AND FAMILY MEMBERS OF BLOOD-DONORS WHO ARE SEROPOSITIVE FOR HTLV TYPE-I OR TYPE-II

Interviews and laboratory testing were conducted for 168 contacts refe rred by former blood donors identified as seropositive for antibody to human T-lymphotropic virus type I (HTLV-I) or type II (HTLV-II). Thir ty-two (28%) of 114 heterosexual contacts of seropositive donors, incl uding 12 women and 20 men, were found to be antibody positive. None of 40 offspring (except one adult man who reported sexual contact in Pue rto Rico) or 14 other (nonspousal) family members were seropositive. T hirty-one of the seropositive contacts were typeable as having either HTLV-I (52%) or HTLV-II (48%). Assessment of couples found that the me dian duration of the sexual relationship was significantly longer (p = 0.03) for those in which both partners were infected than in discorda nt pairs. Analysis of risk history data for 22 infected couples reveal ed that, in three cases, risk factors (Japanese ancestry or sexual con tact with an injecting drug user) could be identified in the women, bu t not in their male partners. Among couples in which the male had the greater risk history, the risk factor was either a history of transfus ion, birth or sexual exposure in an endemic area, or injected drug use . Counseling strategies for individuals with HTLV-I or HTLV-II infecti on should take into account the relatively high seroprevalence in thei r partners and should address the potential for sexual transmission in both directions.