[14] An HIV-positive person who has an undetectable viral load as a result of long-term treatment has effectively no risk of transmitting HIV sexually.

[27] The United States' National Institutes of Health (NIH) and the Gates Foundation have pledged $200 million focused on developing a global cure for AIDS.

[31][32] Symptoms occur in 40–90% of cases and most commonly include fever, large tender lymph nodes, throat inflammation, a rash, headache, tiredness, and/or sores of the mouth and genitals.

[1] Between 50% and 70% of people also develop persistent generalized lymphadenopathy, characterized by unexplained, non-painful enlargement of more than one group of lymph nodes (other than in the groin) for over three to six months.

[32] The most common initial conditions that alert to the presence of AIDS are pneumocystis pneumonia (40%), cachexia in the form of HIV wasting syndrome (20%), and esophageal candidiasis.

[42] Additionally, people with AIDS frequently have systemic symptoms such as prolonged fevers, sweats (particularly at night), swollen lymph nodes, chills, weakness, and unintended weight loss.

[45] HIV is spread by three main routes: sexual contact, significant exposure to infected body fluids or tissues, and from mother to child during pregnancy, delivery, or breastfeeding (known as vertical transmission).

[18] There is no risk of acquiring HIV if exposed to feces, nasal secretions, saliva, sputum, sweat, tears, urine, or vomit unless these are contaminated with blood.

[15][16] The existence of functionally noncontagious HIV-positive people on antiretroviral therapy was controversially publicized in the 2008 Swiss Statement, and has since become accepted as medically sound.

[33][112] In many areas of the world, a third of HIV carriers only discover they are infected at an advanced stage of the disease when AIDS or severe immunodeficiency has become apparent.

Since the WHO's staging system does not require laboratory tests, it is suited to the resource-restricted conditions encountered in developing countries, where it can also be used to help guide clinical management.

[116] In those greater than six years of age it is:[116] For surveillance purposes, the AIDS diagnosis still stands even if, after treatment, the CD4+ T cell count rises to above 200 per μL of blood or other AIDS-defining illnesses are cured.

[119] Application of a vaginal gel containing tenofovir (a reverse transcriptase inhibitor) immediately before sex seems to reduce infection rates by approximately 40% among African women.

[131][132] A substantial minority of young people continues to engage in high-risk practices despite knowing about HIV/AIDS, underestimating their own risk of becoming infected with HIV.

[155][156][157] Rapid initiation of antiretroviral therapy within one week of diagnosis appear to improve treatment outcomes in low and medium-income settings and is recommend for newly diagnosed HIV patients.

[161] The World Health Organization and the United States recommend antiretrovirals in people of all ages (including pregnant women) as soon as the diagnosis is made, regardless of CD4 count.

[33] Reasons for non-adherence to treatment include poor access to medical care,[167] inadequate social supports, mental illness and drug abuse.

[178] The combination of Rekambys and Vocabria injection is intended for maintenance treatment of adults who have undetectable HIV levels in the blood (viral load less than 50 copies/mL) with their current ARV treatment, and when the virus has not developed resistance to a certain class of anti-HIV medicines called non-nucleoside reverse transcriptase inhibitors (NNRTIs) and integrase strand transfer inhibitors (INIs).

[197] If the pregnant or lactating mother has been advised to take anti-retroviral medication to prevent mother-to-child HIV transmission, multivitamin supplements should not replace these treatments.

[204][205] ART and appropriate prevention of opportunistic infections reduces the death rate by 80%, and raises the life expectancy for a newly diagnosed young adult to 20–50 years.

[33][218] Even with anti-retroviral treatment, over the long term HIV-infected people may experience neurocognitive disorders,[219] osteoporosis,[220] neuropathy,[221] cancers,[222][223] nephropathy,[224] and cardiovascular disease.

[228] At the end of 2019, United States indicated that approximately 1.2 million people aged ≥13 years were living with HIV, resulting in about 18,500 deaths in 2020.

[249] In 1983, two separate research groups led by Robert Gallo and Luc Montagnier declared that a novel retrovirus may have been infecting people with AIDS, and published their findings in the same issue of the journal Science.

At the same time, Montagnier's group isolated a virus from a person presenting with swelling of the lymph nodes of the neck and physical weakness, two characteristic symptoms of AIDS.

[261] While transmission rates of HIV during vaginal intercourse are low under regular circumstances, they are increased manyfold if one of the partners has a sexually transmitted infection causing genital ulcers.

[261] An alternative view holds that unsafe medical practices in Africa after World War II, such as unsterile reuse of single-use syringes during mass vaccination, antibiotic and anti-malaria treatment campaigns, were the initial vector that allowed the virus to adapt to humans and spread.

[266] In July 1960, in the wake of Congo's independence, the United Nations recruited Francophone experts and technicians from all over the world to assist in filling administrative gaps left by Belgium, who did not leave behind an African elite to run the country.

By 1978, the prevalence of HIV-1 among gay male residents of New York City and San Francisco was estimated at 5%, suggesting that several thousand individuals in the country had been infected.

[290] The Synagogue Church Of All Nations advertised an "anointing water" to promote God's healing, although the group denies advising people to stop taking medication.

In 1996, Ugandan-born Canadian Johnson Aziga was diagnosed with HIV; he subsequently had unprotected sex with eleven women without disclosing his diagnosis.