Which virus is responsible for causing AIDS?

The human immunodeficiency virus (HIV) is the virus that directly causes acquired immunodeficiency syndrome (AIDS). HIV targets the immune system, specifically the CD4 T lymphocytes, which play a crucial role in the body’s defense against infections. As HIV destroys these cells, the immune system becomes increasingly compromised over time, leading to the development of AIDS, a condition characterized by severe immune system failure and susceptibility to opportunistic infections and certain cancers.

Understanding the role of HIV is critical for recognizing how it progresses to AIDS and the importance of treatment and prevention strategies. Other viruses listed, such as the hepatitis B virus (HBV), primarily affect the liver and can cause liver disease, while the herpes simplex virus (HSV) is primarily associated with oral and genital herpes. Although the human T-lymphotropic virus (HTLV) can impact the immune system, it is not the causative agent of AIDS. Only HIV is specifically linked to the pathogenesis of AIDS, making it the unequivocal answer to this question.