Type: Viral

Geography: Worldwide, most infections in Africa

Total Cases at End of 2018: 38 million

Fatality Rate: 30.2%

First Discovered: 1983 by Luc Montagnier in France

Human immunodeficiency virus attacks the immune system’s CD4 white blood cells, weakening a person’s immunity against infections such as tuberculosis and some cancers. Symptoms of HIV vary depending on the stage of infection. People are most infectious in the first few months after being infected, though many are unaware of their status until later stages. 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, symptoms such as swollen lymph nodes, weight loss, fever, diarrhea, and cough can develop. Without treatment, severe illness such as tuberculosis, cryptococcal meningitis, severe bacterial infections, and cancers such as lymphomas are common. The most advanced stage of HIV infection is acquired immunodeficiency syndrome (AIDS), which can take from 2 to 15 years to develop if not treated.

HIV can be transmitted via the exchange of body fluids from infected people, such as blood, breast milk, semen, and vaginal secretions. HIV can be transmitted from a mother to her child during pregnancy and delivery. Risk factors include: having unprotected anal or vaginal sex, having another STI, sharing contaminating needles or syringes when injecting drugs, receiving unsafe injections or blood transfusions, and experiencing accidental needle stick injuries.

Over two-thirds of all people living with HIV are in the African Region (25.7 million). While HIV is prevalent among the general population in this region, an increasing number of new infections occur among key population groups. Key populations include men who have sex with other men, people who inject drugs, people in prisons and other closed settings, sex workers and their clients, and transgender people. Adolescent girls and young women in southern and eastern Africa and indigenous people in some communities are also particularly vulnerable.

HIV continues to be a major global public health issue. Yet, with increasing access to effective prevention, diagnosis, treatment, and care, it has become a manageable chronic health condition. There is no cure for HIV, but effective antiretroviral drugs (ARVs) can control the virus and prevent onward transmission to other people. At the end of 2018, there were 38 million total cases of HIV globally. Since 2000, 13.6 million lives were saved due to antiretroviral therapy.

Photo: HIV (green) budding from a cultured lymphocyte – Electron micrograph.