HIV

HIV (Human Immunodeficiency Virus) attacks the body's immune system, specifically CD4 T cells. Without treatment, HIV can progress to AIDS (Acquired Immunodeficiency Syndrome). With modern antiretroviral therapy (ART), people with HIV can live long, healthy lives and cannot sexually transmit the virus when their viral load is undetectable (U=U).

HIV is transmitted through blood, semen (including pre-seminal fluid), rectal fluids, vaginal fluids, and breast milk. The main routes of sexual transmission are anal and vaginal sex. Receptive anal sex carries the highest per-act risk. HIV cannot be transmitted through saliva, tears, sweat, air, water, or casual contact.

HIV symptoms vary by stage:

• Acute HIV (2–4 weeks after infection): Flu-like symptoms — fever, chills, rash, night sweats, muscle aches, sore throat, fatigue, swollen lymph nodes. These last 2–4 weeks then resolve.
• Chronic HIV: No symptoms for years while the virus slowly damages the immune system
• AIDS: Rapid weight loss, recurring fever, extreme fatigue, swollen lymph glands, chronic diarrhea, pneumonia

Testing options include: 4th-generation Ag/Ab combo tests (detect both HIV antigen and antibody — window period 18–45 days), antibody-only tests (45–90 days), and RNA/NAT tests (10–33 days, mostly used in clinical settings). Home tests are available. The CDC recommends all adults get tested at least once, and people at higher risk get tested at least annually.

HIV is managed (not cured) with antiretroviral therapy (ART) — a combination of HIV medicines taken daily. ART reduces viral load to undetectable levels, preserves immune function, and means you cannot sexually transmit HIV (Undetectable = Untransmittable, U=U). Starting treatment early is essential. PrEP (pre-exposure prophylaxis) prevents HIV in HIV-negative people.

Highly effective prevention options:

• PrEP (daily pill or long-acting injection) — reduces HIV risk by up to 99%
• Condoms — reduce risk by ~99% when used correctly
• U=U (treatment as prevention) — undetectable viral load means zero sexual transmission risk
• PEP (post-exposure prophylaxis) — can prevent HIV if started within 72 hours of exposure

Regular testing enables early treatment and protects partners.