HIV infection and AIDS

Overview

HIV infects and progressively damages the immune system if untreated. Soon after acquisition, some people develop an acute retroviral illness with fever, rash, sore throat, lymph-node swelling or other nonspecific symptoms; others notice nothing. A chronic phase can then remain clinically quiet for years even while the virus continues replicating. Testing, rather than symptoms, is therefore the only reliable way to know HIV status. ^{[1] [2]}

Modern ART changes the natural history of HIV. Consistent treatment can reduce plasma HIV RNA below the level detected by standard viral-load tests, allow CD4 recovery and prevent progression to AIDS. NIH and CDC state that people who achieve and maintain an undetectable viral load do not sexually transmit HIV—summarized as U=U. ^{[1] [3]}

Symptoms and warning signs

Acute HIV can resemble influenza or mononucleosis, with fever, fatigue, rash, sore throat, swollen lymph nodes, muscle aches or mouth ulcers. Chronic HIV may have no symptoms. Advanced immune suppression can present with weight loss, persistent fever, chronic diarrhea, thrush, recurrent infections or opportunistic illnesses, but these findings are not specific and should never replace HIV testing. ^{[2] [4]}

Diagnosis

Laboratory HIV antigen/antibody tests are the standard screening approach in many settings, followed by supplemental differentiation testing according to the diagnostic algorithm. Nucleic acid testing can detect infection earlier and is used in selected recent-exposure or discordant-result situations. Rapid and self-tests expand access but reactive results need confirmation. ^{[2] [3]}

After diagnosis, baseline evaluation includes viral load, CD4 count, resistance testing and screening for coinfections and comorbidities such as hepatitis B/C, tuberculosis and other STIs according to setting and history. ART can usually begin rapidly while this evaluation proceeds. ^{[1] [4]}

How HIV is transmitted — and how it is not

HIV can be transmitted through sexual fluids, blood and shared injection equipment, and from parent to infant during pregnancy, birth or breastfeeding. It is not spread by ordinary social contact, sharing food, toilets, hugging, mosquito bites or intact-skin contact. Effective ART during pregnancy and appropriate infant/feeding management can reduce perinatal transmission dramatically. ^{[2] [3]}

What AIDS means

AIDS is the most advanced stage of HIV infection. In U.S. clinical definitions, it is diagnosed when the CD4 count falls below a defined threshold or when certain AIDS-defining illnesses occur. A person who once met AIDS criteria still has HIV even after immune recovery on ART, but successful treatment can prevent further opportunistic disease. ^{[3] [4]}

Treatment and management

Antiretroviral therapy is recommended for everyone with HIV and should begin as soon as possible after diagnosis. Modern regimens usually combine drugs that block HIV at different stages of replication, commonly in a simple once-daily tablet or, for selected already-suppressed patients, long-acting injectable options. Regimen choice accounts for resistance, kidney/liver function, hepatitis B status, pregnancy, drug interactions and patient preference. ^{[1] [4]}

Successful ART reduces viral load to undetectable and maintains it there. Adherence and follow-up are essential; missed therapy can allow viral rebound and, in some situations, resistance. Treatment also includes vaccination, cardiovascular and metabolic prevention, mental-health care, sexual and reproductive health, and prevention or treatment of opportunistic infections when CD4 counts are low. ^{[1] [4]}

U=U: what undetectable means for sexual transmission

Large studies of couples with different HIV status observed no linked sexual transmissions when the partner with HIV maintained viral suppression. This is the basis of U=U. The message applies to sexual transmission while viral suppression is maintained; it does not eliminate the need to consider other STIs or pregnancy prevention, and it does not mean HIV has been cured. ^{[1] [3]}

PrEP, PEP and prevention for people without HIV

People without HIV who have ongoing exposure risk can use pre-exposure prophylaxis (PrEP). Post-exposure prophylaxis (PEP) is an emergency prevention option after a substantial recent exposure and should be started as soon as possible within the recommended time window. Condoms and sterile injection equipment also prevent HIV and other infections. ^[3]

Long-term outlook

With early diagnosis, sustained ART and routine care, many people with HIV have life expectancy approaching that of the general population. Long-term care increasingly focuses on cardiovascular, kidney, liver, bone, cancer and mental-health risks alongside HIV control. Stigma and barriers to medication access can still harm outcomes and are themselves important care issues. ^{[1] [4]}

Sources

1. NIH HIVinfo — HIV Treatment: The Basics
2. CDC — About HIV
3. CDC — HIV Treatment as Prevention / U=U
4. NIH ClinicalInfo — Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents With HIV

This article is based on trusted medical sources and is awaiting clinician review. It is not a substitute for personalized medical advice.