Hi doc! I am really confused and tensed .please give me exact answer, it will really be so helpful for me. I know if we have hiv and undectatble viral load and regular on med we cannot pass hiv through sex through our partners .it s negligible almost zero transmission. But I my sister used same syringe used by hiv friend (had undetectable viral load and on med) wil injecting, is transmission stil near to zero in case of syringe use! Please tel me the exact answer.