AIDS is a severe immunological disorder caused by the retrovirus HIV, resulting in a defect in cell-mediated immune response that is manifested by increased susceptibility to opportunistic infections and to certain rare cancers, especially Kaposi's sarcoma. It is transmitted primarily by venereal routes or exposure to contaminated blood or blood products.

爱滋病是一种由逆转录酶病毒引起的严重免疫系统混乱，导致细胞中介免疫反应的缺失，表现为容易受感染和受某些罕见癌症的侵袭，尤其是卡波济氏肿瘤。主要经过性交渠道或接触受感染的血液或血液制品而传播。

HIV is a retrovirus that causes AIDS. HIV was formerly known as HTLV-III.

HIV 病毒是一种引起爱滋病的反录酶病毒，它原先被认为是人体T细胞白血病毒三期。