Effects of cigarette advertising: reply to Boddewyn.

2.3,95% C.I. 1.0-5.3). HTLV-1 seropositivity was also associated with frequency of needle sharing (Table 1). Re-use of contaminated needles and other paraphernalia to prepare the dose were not associated with HTLV-I seropositivity. Anti-HTLV-I antibodies were detected more commonly among females (25%) than males (15%), but the difference was not significant (Odds Ratio=2.9, 95% C.I. 0.9-4.0). Having sex with more than 10 partners in one year was reported by 24% IDUs (42% seropositive and 19% seronegative IDUs), resulting associated with HTLV-I (OR=3.7, 95% C.I. 1.7-8.2). A large number of sexual partners was the only risk behaviour in 9 subjects who did not admit to needle sharing in the last 5 years. This pattern of sexual behaviour was not associated with needle sharing, acting as an independent risk factor.