In fact, in sexual activity, transmission can only occur if there is breakage in the mucous membrane, so it is only natural that the rate of infection is much lower.
事實上，要藉由性行為傳染，必須要接觸者皮膚黏膜破裂，病毒才得以進入感染者的血液系統，機率自然比不上血液直接感染。