HIV and AIDS (Human)

Primary reference(s)

WHO, 2019. HIV/AIDS. World Health Organization (WHO). Accessed 13 December 2019.

Additional scientific description

The human immunodeficiency virus (HIV) / acquired immunodeficiency syndrome (AIDS) is a global pandemic (WHO, 2019).

The human immunodeficiency virus (HIV) targets the CD4 cells of the immune system leading to immunodeficiency which results in increased susceptibility to a wide range of infections, cancers and other diseases that people with healthy immune systems can fight off. The HIV can be transmitted via the exchange of body fluids from infected people, such as blood, breastmilk, semen and vaginal secretions. It can also be transmitted from a mother to her child during pregnancy and delivery. People at higher risk include gay men and other men who have sex with men; people who inject drugs; people in prisons and other closed settings; sex workers and their clients; and transgender people. Other particularly vulnerable population are adolescents and young women in southern and eastern Africa and indigenous peoples (WHO, 2019).

The symptoms of HIV infection and AIDS vary depending on the stage of infection. Although people living with HIV tend to be most infectious in the first few months following infection, many are unaware of their status until the later stages (WHO, 2019).

In the first few weeks after infection people may experience no symptoms or an influenza-like illness. As the infection progressively weakens the immune system, they may go on to develop severe illnesses such as tuberculosis, cryptococcal meningitis, severe bacterial infections, and cancers such as lymphomas and Kaposi’s sarcoma. Notably, among people living with HIV, tuberculosis is the most common illness and is the leading cause of death, responsible for nearly a third of HIV-associated deaths (WHO, 2019).

The HIV can be diagnosed through rapid diagnostic tests that provide results in a very short period of time. This greatly facilitates early diagnosis and linkage with treatment and care. People can also determine their own status using HIV self-tests. While testing for adolescents and adults has been made simple and efficient, this is not the case for infants born to HIV-positive mothers. For children less than 18 months of age, serological testing is not sufficient to identify HIV infection – virological testing must be provided as early as birth or at six weeks of age (WHO, 2019). There is no cure for HIV infection. However, effective antiretroviral therapy can control the virus over the course of a lifetime and help prevent onward transmission to other people.

Metrics and numeric limits

According to the World Health Organization (WHO), in 2018: there were approximately 37.9 million people living with HIV; approximately 770,000 people died from HIV-related causes; and 1.7 million people were newly infected (WHO, no date).

HIV is geographically widespread, but over two-thirds of all people infected live in the WHO African Region (25.7 million), where the disease is prevalent among the general population and incidence is increasing among key population groups, including young urban dwellers (WHO, 2019).

There are global standards, guidelines and tools to improve HIV surveillance (WHO, 2013, 2017). The US Centres for Disease Control and Prevention has also published case definition for HIV infection (CDC, 2014).

Examples of drivers, outcomes and risk management

HIV disease continues to be a major global public health issue, having claimed more than 32 million lives so far (WHO, 2019). Effective antiretroviral treatment enables people with HIV to live long and healthy lives and decreases the risk of transmitting HIV to uninfected sexual partners by 96% (WHO, 2019).

The 90-90-90 testing and treating targets for 2020 were developed by the Joint United Nations Programme on HIV/AIDS in 2013 (UNAIDS, 2017). These are as follows: by 2020, 90% of all people living with HIV will know their HIV status; by 2020, 90% of all people with diagnosed HIV infection will receive sustained antiretroviral therapy; and by 2020, 90% of all people receiving antiretroviral therapy will have viral suppression (UNAIDS, 2017).

In 2018, an estimated 79% of people living with HIV knew their status. 62% were receiving effective antiretroviral treatment and 53% had achieved suppression of the HIV virus with no risk of infecting others (WHO, 2019).