HIV and AIDS

Unique identifier / Notation

BI0214

Synonyms

Acquired immunodeficiency syndrome AIDS Human immunodeficiency virus HIV

Human immunodeficiency virus (HIV) is a virus that attacks the body’s immune system. Acquired immunodeficiency syndrome (AIDS) occurs at the most advanced stage of infection. HIV targets the body’s white blood cells, weakening the immune system. This makes it easier to get sick with diseases like tuberculosis, infections and some cancers. HIV is spread from the body fluids of an infected person, including blood, breast milk, semen and vaginal fluids. WHO now defines Advanced HIV Disease (AHD) as CD4 cell count less than 200 cells/mm3 or WHO stage 3 or 4 in adults and adolescents. All children younger than 5 years of age living with HIV are considered to have advanced HIV disease (WHO, 2024a).

Primary reference(s)

WHO, 2024a. HIV/AIDS. World Health Organization (WHO). Accessed 13 February 2025.

Annotations

Additional scientific description

HIV remains a major global public health issue, having claimed an estimated 42.3 million lives to date. Transmission is ongoing in all countries globally (WHO, 2024a). There were an estimated 39.9 million people living with HIV at the end of 2023, 65% of whom are in the WHO African Region. In 2023, an estimated 630 000 people died from HIV-related causes and an estimated 1.3 million people acquired HIV (WHO, 2024a).

There is no cure for HIV infection. However, with access to effective HIV prevention, diagnosis, treatment and care, including for opportunistic infections, HIV infection has become a manageable chronic health condition, enabling people living with HIV to lead long and healthy lives (WHO, 2024a).

WHO, the Global Fund and UNAIDS all have global HIV strategies that are aligned with the SDG target 3.3 of ending the HIV epidemic by 2030 (WHO, 2024a).

By 2025, 95% of all people living with HIV should have a diagnosis, 95% of whom should be taking lifesaving antiretroviral treatment, and 95% of people living with HIV on treatment should achieve a suppressed viral load for the benefit of the person's health and for reducing onward HIV transmission. In 2023, these percentages were 86%, 89%, and 93% respectively (WHO, 2024a).

In 2023, of all people living with HIV, 86% knew their status, 77% were receiving antiretroviral therapy and 72% had suppressed viral loads (WHO, 2024a).

Metrics and numeric limits

Global data (WHO, 2024b).

People living with HIV - An estimated 39.9 million [36.1-44.6 million] people were living with HIV at the end of 2023, of which

1.4 million [1.1-1.7 million] children (0-14 years old).
38.6 [34.9-43.1 million] adults (15+ years old).

HIV incidence - 1.3 million [1.0-1.7 million] people acquired HIV in 2023. Since 2010, the number of people acquiring HIV has been reduced by 39%, from 2.1 million [1.7-2.7 million].

120 000 [83 000-170 000] children acquired HIV in 2023.
1.2 million [950 000-1.5 million] adults acquired HIV in 2023.
The number of people acquiring HIV decreased to 0.17 [0.13-0.21] per 1000 uninfected population in 2023 from 0.32 [0.25-0.40] in 2010.
Since the start of the epidemic, 88.4 million [71.3 million-112.8 million] people have acquired HIV.

HIV-related mortality - In 2023, 630 000 [500 000-820 000] people died from HIV-related causes globally. Since 2010, HIV-related deaths have been reduced by 51%, from 1.3 million [1.0 million-1.7 million]. The global HIV epidemic claimed 69% fewer lives in 2023 since the peak in 2004.

76 000 [53 000-110 000] children died from HIV-related causes in 2023.
560 000 [430 000-730 000] adults died from HIV-related causes in 2023.

HIV continues to be a major global public health issue, claiming 42.3 million [35.7-51.1 million] lives so far.

Key relevant UN convention / multilateral treaty

International Health Regulations (2005), 3rd ed. (WHO, 2016).

Drivers

HIV can be transmitted via the exchange of body fluids from people living with HIV, including blood, breast milk, semen, and vaginal secretions. HIV can also be transmitted to a child during pregnancy and delivery. People cannot become infected with HIV through ordinary day-to-day contact such as kissing, hugging, shaking hands, or sharing personal objects, food or water.

Behaviours and conditions that put people at greater risk of contracting HIV include:

having anal or vaginal sex without a condom;
having another sexually transmitted infection (STI) such as syphilis, herpes, chlamydia, gonorrhoea and bacterial vaginosis;
harmful use of alcohol or drugs in the context of sexual behaviour;
sharing contaminated needles, syringes and other injecting equipment, or drug solutions when injecting drugs;
receiving unsafe injections, blood transfusions, or tissue transplantation; and
medical procedures that involve unsterile cutting or piercing; or accidental needle stick injuries, including among health workers.

Impacts

Since the beginning of the epidemic, 88.4 million [71.3–112.8 million] people have been infected with the HIV virus and about 42.3 million [35.7–51.1 million] people have died of HIV. Globally, 39.9 million [36.1–44.6 million] people were living with HIV at the end of 2023. An estimated 0.6% [0.6-0.7%] of adults aged 15–49 years worldwide are living with HIV, although the burden of the epidemic continues to vary considerably between countries and regions. The WHO African Region remains most severely affected, with one in every 30 adults (3.4%) living with HIV and accounting for more than two-thirds of the people living with HIV worldwide (WHO, 2024c).

The symptoms of HIV vary depending on the stage of infection. HIV spreads more easily in the first few months after a person is infected, but many are unaware of their status until the later stages. In the first few weeks after being infected, people may not experience symptoms. Others may have an influenza-like illness including fever, headache, rash, and sore throat. The infection progressively weakens the immune system. This can cause other signs and symptoms swollen lymph nodes, weight loss, fever, diarrhoea and cough.

Without treatment, people living with HIV infection can also develop severe illnesses, for example, such as tuberculosis (TB), cryptococcal meningitis, severe bacterial infections and cancers such as lymphomas and Kaposi's sarcoma. HIV causes other infections to get worse, such as hepatitis C, hepatitis B and mpox.

People living with HIV who are taking anti-retroviral therapy (ART) and have an undetectable viral load will not transmit HIV to their sexual partners. Early access to ART and support to remain on treatment is therefore critical not only to improve the health of people living with HIV but also to prevent HIV transmission.

Multi-hazard context

Multi-hazard consequences include tuberculosis (TB), cryptococcal meningitis, severe bacterial infections and cancers such as lymphomas and Kaposi's sarcoma. HIV causes other infections to get worse, such as hepatitis C, hepatitis B and mpox.

Risk Management

HIV can be diagnosed through rapid diagnostic tests that provide same-day results. This greatly facilitates early diagnosis and linkage with treatment and prevention. People can also use HIV self-tests to test themselves. However, no single test can provide a full HIV-positive diagnosis; confirmatory testing is required, conducted by a qualified and trained health worker or community worker. HIV infection can be detected with great accuracy using WHO-prequalified tests within a nationally approved testing strategy and algorithm.

Most widely used HIV diagnostic tests detect antibodies produced by a person as part of their immune response to fight HIV. In most cases, people develop antibodies to HIV within 28 days of infection. During this time, people are in the so-called “window period” when they have low levels of antibodies which cannot be detected by many rapid tests, but they may still transmit HIV to others. People who have had a recent high-risk exposure and test negative can have a further test after 28 days.

Following a positive diagnosis, people should be retested before they are enrolled in treatment and care to rule out any potential testing or reporting errors. While testing for adolescents and adults has been made simple and efficient, this is not the case for babies born to HIV-positive mothers. For children less than 18 months of age, rapid antibody testing is not sufficient to identify HIV infection – virological testing must be provided as early as birth or at 6 weeks of age. New technologies are now available to perform this test at the point of care and enable same-day results, which accelerate appropriate linkage with treatment and care.

HIV is a preventable disease. Reduce the risk of HIV infection by:

using a male or female condom during sex
- being tested for HIV and sexually transmitted infections
- having a voluntary medical male circumcision
using harm reduction services for people who inject and use drugs.

People taking antiretroviral therapy (ART) and who have no evidence of the virus in their blood will not pass HIV to their sexual partners. Access to testing and ART is an important part of preventing HIV.

Antiretroviral drugs given to people without HIV can prevent infection. When given before possible exposure to HIV it is called pre- exposure prophylaxis (PrEP) and when given after exposure it is called post-exposure prophylaxis (PEP). People can use PrEP or PEP when the risk of contracting HIV is high; people should seek advice from a clinician when thinking about using PrEP or PEP.

There is no cure for HIV infection. It is treated with antiretroviral drugs, which stop the virus from replicating in the body.

Current antiretroviral therapy (ART) does not cure HIV infection but allows a person’s immune system to get stronger. This helps them to fight other infections. Currently, ART must be taken every day for the rest of a person’s life. ART lowers the amount of the virus in a person’s body. This stops symptoms and allows people to live full and healthy lives. People living with HIV who are taking ART and who have no evidence of the virus in their blood will not spread the virus to their sexual partners.

Pregnant women with HIV should have access to, and take, ART as soon as possible. This protects the health of the mother and will help prevent HIV transmission to the foetus before birth, or through breast milk.

Advanced HIV disease remains a persistent problem in the HIV response. WHO is supporting countries to implement the advanced HIV disease package of care to reduce illness and death. Newer HIV medicines and short-course treatments for opportunistic infections like cryptococcal meningitis are being developed that may change the way people take ART and prevention medicines, including access to injectable formulations, in the future.

Testing, treatment and viral load suppression cascades among all people living with HIV.

By 2025, 95% of people living with HIV should know their HIV status (first 95)

In 2023, 86% [69–>98%] of people living with HIV knew their status.
To reach the first 95–95–95 target, an additional 3.4 million people living with HIV need to be made aware of their HIV status.

People living with HIV receiving antiretroviral therapy (second 90)

In 2023, 77% [61–89%] of people living with HIV were receiving antiretroviral therapy.
To reach the second 95–90–86 testing, treatment and viral load suppression cascade target, an additional 5.4 million people living with HIV need to know their status and access antiretroviral therapy.

People living with HIV with suppressed viral loads (third 86)

In 2023, 72% [65–80%] of people living with HIV had suppressed viral loads.
To reach the third 95–90–86 testing, treatment and viral load suppression cascade target, an additional 5.6 million people living with HIV need to know their status, access antiretroviral therapy, and have viral load suppression.

Monitoring

Global health sector strategies on HIV, viral hepatitis, and sexually transmitted infections for the period 2022-2030 guide strategic responses to achieve the goals of ending AIDS, viral hepatitis B and C, and sexually transmitted infections by 2030.

WHO's Global HIV, Hepatitis and STIs Programmes recommend shared and disease-specific country actions supported by WHO and partners. They consider the epidemiological, technological, and contextual shifts of previous years, foster learning, and create opportunities to leverage innovation and new knowledge.

WHO's programmes call to reach the people most affected and most at risk for each disease, and to address inequities. Under a framework of universal health coverage and primary health care, WHO's programmes contribute to achieving the goals of the 2030 Agenda for Sustainable Development.

The Global Health Observatory (GHO) data repository is WHO's gateway to health-related statistics for its 194 Member States. It provides access to over 1000 indicators on priority health topics including mortality and burden of diseases, the Millennium Development Goals (child nutrition, child health, maternal and reproductive health, immunization, HIV/AIDS, tuberculosis, malaria, neglected diseases, water and sanitation), non-communicable diseases and risk factors, epidemic-prone diseases, health systems, environmental health, violence and injuries, equity among others (WHO, 2024c).

WHO supports countries to conduct all-hazards strategic risk assessment in the contexts of health emergencies and disasters, which results in the development of a country's risk profile. Empowered with the country risk profile, inclusive of a seasonal risk calendar, countries can anticipate potential emergencies before they occur to trigger early alerts and inform early actions (WHO, 2021).

WHO's Early Warning, Alert and Response System (EWARS) has been designed to improve disease outbreak detection in emergency settings, such as in countries in conflict or following a disaster. It is a simple and cost-effective way to rapidly set up a disease surveillance system. EWARS is deployed during an emergency as an adjunct to the national disease surveillance system. WHO works with Ministries of Health and health sector partners to train local health workers to use the system. After the emergency, EWARS should re-integrate back into the national system (WHO, no date).