HIV/AIDS
Retrovirus causing AIDS, manageable but incurable.
HIV (human immunodeficiency virus) is a retrovirus that attacks the immune system, and without treatment can lead to acquired immunodeficiency syndrome (AIDS). Recognized worldwide in the early 1980s, HIV/AIDS has had a large impact on society as both an illness and a source of discrimination, and is considered a pandemic. While there is no cure or vaccine, antiretroviral treatment can manage the disease, allowing those infected to live a normal life and die with the virus, not of it.
The virus is spread primarily through unprotected sexual contact (including anal, oral, and vaginal sex), contaminated needles or blood transfusions, and from mother to child during pregnancy, delivery, or breastfeeding. Saliva, sweat, and tears do not transmit it, and oral sex carries very little risk. Prevention methods include safe sex, pre-exposure prophylaxis (PrEP), post-exposure prophylaxis (PEP), treating infected individuals, and needle exchange programs. Giving antiretroviral medication to both mother and child can often prevent transmission to the baby.
Without treatment, HIV infection progresses through three stages. The acute stage, occurring two to four weeks after exposure, often brings flu-like symptoms such as fever, swollen lymph nodes, sore throat, rash, and mouth or genital sores. These symptoms are frequently misdiagnosed. This is followed by a long clinical latency period, which can last from roughly three to over twenty years, during which few or no symptoms appear. Eventually, the immune system weakens, leading to AIDS, characterized by opportunistic infections like tuberculosis, rare tumors, and unintended weight loss. Untreated, life expectancy is about eleven years.
Antiretroviral therapy, started as soon as possible after diagnosis, suppresses the virus to undetectable levels. A person with an undetectable viral load has effectively no risk of sexually transmitting HIV, a concept widely promoted as Undetectable = Untransmittable. With effective lifelong treatment, an HIV-positive person can expect a nearly normal lifespan, dying with the virus rather than from it. Early testing is crucial to begin treatment, halt disease progression, and prevent further spread. HIV originated from primates in west-central Africa in the early-to-mid-20th century, and since its identification in 1981, it has caused tens of millions of deaths worldwide. The disease h
- Cause identified
- Early 1980s
- Estimated deaths (through 2024)
- At least 42.3 million
- People living with HIV (2025)
- 40.9 million
- New infections (2025)
- 1.2 million
- Origin
- West-central Africa, early-to-mid-20th century
- Known for
- Pandemic retrovirus causing AIDS
Lore & Background
HIV is a retrovirus that attacks the immune system, and without treatment it can progress to AIDS. The virus is spread primarily through unprotected sex (including anal, oral, and vaginal), contaminated hypodermic needles or blood transfusions, and from mother to child during pregnancy, delivery, or breastfeeding. Bodily fluids such as saliva, sweat, and tears do not transmit the virus, and oral sex carries little risk. Following initial infection, many individuals experience a brief influenza-like illness, though some have no symptoms; this acute stage is often misdiagnosed. After this, a prolonged incubation period with no symptoms typically follows, lasting on average about eight years without treatment. Eventually, the infection weakens the immune system, increasing the risk of opportunistic infections like tuberculosis and rare tumors, and often leads to unintended weight loss. Without treatment, life expectancy is around 11 years. However, with lifelong antiretroviral treatment, the virus can be suppressed to an undetectable level, allowing a person to live a nearly normal lifespan and die with the virus, not from it. An undetectable viral load means effectively no risk of transmitting HIV sexually, a concept known as Undetectable = Untransmittable. The disease was recognized worldwide in the early 1980s, having jumped from other primates to humans in west-central Africa earlier in the 20th century. It has had a large societal and economic impact, and is considered an active pandemic. There is no cure or vaccine, but treatment is recommended as soon as diagnosis is made to stop progression and prevent transmission.
Reader's Guide
HIV/AIDS has had a large impact on society, both as an illness and as a source of discrimination, and has large economic impacts. There are many misconceptions about HIV/AIDS, such as the belief that it can be transmitted by casual non-sexual contact. The disease has become subject to many controversies involving religion, including the Catholic Church's position not to support condom use as prevention. It has attracted international medical and political attention as well as large-scale funding since it was identified in the 1980s. The United States' National Institutes of Health (NIH) and the Gates Foundation have pledged $200 million focused on developing a global cure for AIDS. Treatment is recommended as soon as diagnosis is made, and an HIV-positive person with an undetectable viral load has effectively no risk of transmitting HIV sexually, communicated as Undetectable = Untransmittable.
Did You Know?
- Without treatment, life expectancy of an individual with HIV is around 11 years.
- An HIV-positive person on treatment can expect to live a normal life and die with the virus, not of it.
- Oral sex has little risk of transmitting the virus.
More in Infectious Diseases 1-24
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record