HIV, or human immunodeficiency virus, is a disease that weakens a person’s immune system by attacking CD4 cells, which help the body fight off infection. If HIV advances, it can lead to acquired immunodeficiency syndrome, or AIDS, a terminal condition. HIV spreads through certain body fluids, most often during unprotected sex, pregnancy and childbirth, transfusion of contaminated blood, or shared use of hypodermic needles. The human body cannot completely eliminate HIV. Therefore, once the virus is contracted, the individual will remain HIV-positive for life. However, HIV can be controlled and its progression slowed significantly by treatment with antiretroviral therapy (ART) medicines. HIV rates vary drastically between countries, particularly in Africa, the continent from which the virus is believed to have originated.
* Additional data appears in the table further down this page.
HIV is a global concern. The World Health Organization (WHO) estimates that there were 37.7 million people worldwide (roughly 0.7% of the world's population) living with HIV in 2020, including 1.5 million new cases. It further estimated that 73% of those cases were being treated with ART, but that 680,000 people died from HIV-related causes (such as AIDS) that same year.
Africa displays a higher prevalence of HIV than any other continent, with an estimated average of 3.9% (anywhere from 3.3-4.5%) of the population living HIV-positive lives. HIV is believed to have evolved from the simian immunodeficiency virus (SIV), which crossed the species barrier from primates in Central Africa on at least two occasions, most likely when human hunters came into contact with an infected primate's blood, and evolved into HIV.
The primary HIV strain, HIV-1, has been traced to chimpanzees (subspecies Pan troglodytes troglodytes) in Cameroon. The less virulent HIV-2 strain has been traced to the sooty mangabey (Cercocebus atys atys), which lives in several countries along Africa's west coast, from Senegal to the Ivory Coast. Researchers believe HIV first manifested in the 1900s and spread slowly across Africa before expanding into the rest of the world, reaching the United States in the mid to late 1970s, being first recognized in the U.S. in 1981.
HIV progresses through three distinct stages, which range in severity from inconvenient but manageable to terminal.
HIV can be controlled and treated—though not fully cured—through the use of antiretroviral therapy (ART) medicines, which can keep patients healthy for many years by reducing the amount of HIV (viral load) present in the body. ART both helps slow the progression of the virus and also reduces the chances of transmitting the virus to other people. ART is typically taken as a combination of three or more medications, which can sometimes be combined into one pill.
Patients whose viral loads drop to fewer than 200 copies of HIV per milliliter of blood are said to have entered viral suppression or viral load suppression. Some even achieve an HIV level so low it is unmeasurable via current tests. This is classified as an undetectable viral load and is the ideal condition for HIV patients. Approximatley 72% of the total population of those diagnosed with HIV are being treated with ART. Testing and treatment coverage of HIV has dramatically improved around the world. That said, poverty, gender inequality, and HIV stigma and discrimination are major barriers to HIV prevention and treatment in many countries.
UNAIDS, the Joint United Nations Program on HIV/AIDS, is the world’s leading advocate for the comprehensive and coordinated global action against the HIV/AIDS pandemic. In 2014, UNAIDS established the 90-90-90 goals, which called for countries around the world to get 90% of people living with HIV diagnosed; 90% of those diagnosed accessing treatment, and 90% of people on treatment to have suppressed viral loads by 2020.
With nearly 27% of its population HIV-positive, Eswatini has the highest HIV prevalence of any country in the world. Perhaps unsurprisingly, HIV/AIDS is the leading cause of death in Eswatini. However, Eswatini's HIV rate is falling. Through the implementation of expanded treatment and prevention services, the country significantly reduced its rate of new infections by nearly half between 2011 and 2016. Additionally, the percentage of adult HIV patients receiving ART treatments increased from 34.8% to 71.3%. While the HIV epidemic is generalized in Eswatini, certain groups—especially those who are marginalized and criminalized—are particularly affected. For example, HIV prevalence among Eswatini sex workers is 60.5%, the highest in the world.
HIV/AIDS is also the leading cause of death in Lesotho, which has the second-highest HIV rate in the world at 21.1%. Lesotho has approximately 280,000 people living with HIV. In 2018, the country saw 13,000 new HIV infections and 6,100 AIDS-related deaths. As of the end of 2020, some 71% of all people living with HIV in Lesotho were receiving ART. Approximately 57% of Lesotho’s population lives in poverty, which often complicates the availability of treatment for HIV/AIDS and has contributed to the country’s low life expectancy of 52 years for men and 56 years for women.
The country with the third-highest HIV prevalence is Botswana, where an estimated 19.9% of the population is HIV-positive. Those affected by HIV in Botswana often face significant barriers including gender inequality, punitive laws against marginalized groups, and the withdrawal of international funding. However, as in many other African nations, the percentage of HIV-positive people is slowly dropping. With the help of organizations such as the Center for Disease Control and Prevention (CDC), Botswana offers universal free antiretroviral treatment to all people living with HIV. In 2020, more than 98% of all HIV-positive pregnant women received ART treatments, which helped reduce mother-to-child HIV transmission to 1.91%.
The HIV prevalence in South Africa is 19.10%, making it the fourth-highest rate in the world. However, given the country's large population, this percentage amounts to 7.8 million HIV-positive people, more than any other country and roughly one-fifth of all the HIV cases in the world. The country has the world’s largest ART program, with 68% of people HIV receiving ART in 2021 and 93% of those patients achieving viral load suppression. The success of South Africa’s ART program is a major reason the national life expectancy increased from 56 years in 2010 to 63 years in 2018. Moreover, mother-to-child transmission of HIV during birth fell from 3.5% in 2010 to lower than 1% in 2021. This is especially important as adolescent girls and young women, who are among the most likely to become pregnant, are 2.5 times more likely than same-aged males to have HIV.
Zimbabwe’s HIV rate is 11.9%, the fifth-highest in the world. There are 1.3 million people living with HIV in Zimbabwe. 82% of adult men, 88% of women, and 78% of children living with HIV in Zimbabwe are receiving ART. Zimbabwe has achieved a decline of new HIV infections among infants thanks to PMTCT services allowing nearly every pregnant woman to receive ART. As in South Africa, women are disproportionately affected by HIV in Zimbabwe, especially adolescent girls and young women. One of Zimbabwe’s largest barriers in providing HIV services is the illegal nature of sex work and homosexuality in the country, making it extremely difficult for these groups to seek prevention and treatment help.
Namibia has the sixth-highest rate of HIV in the world of 11.60%. HIV is a leading cause of death in the country. About 200,000 people in Namibia are living with HIV with about 6,100 newly infected individuals in 2018. About 92% of adults and children living with HIV in the country are receiving ART. According to the Namibia Population-Based HIV Impact Assessment (NAMPHIA), the country exceeded many of the 90-90-90 targets—90% of HIV-positive people have been tested and know their status, 90% are receiving treatment, and 90% have achieved viral suppression—set by UNAIDS. As a result of various AIDS-suppression efforts in Namibia, HIV/AIDS-related deaths were reduced by 50% from 2002 to 2018.
As of 2020, 2.1 million people lived with HIV in Mozambique, including some 150,000 people newly infected. Women are disproportionately infected by HIV in Mozambique, with females making up about 60% of the adults living with HIV and young women (ages 15-24) almost twice as likely as young men to contract the virus. On a more positive note, more than 95% of pregnant women living with HIV were able to access ART to prevent transmitting it to their newborns, likely preventing thousands of new HIV infections among infants.
Zambia has the eighth-highest HIV rate in the world of 11.10%. 1.5 million people in Zambia have HIV, which is the leading cause of death in the country. However, 88% of affected individuals were receiving ART as of December 2021), and approximately 75% are virally suppressed. As a result, life expectancy among people living with HIV has improved significantly. As in many African countries, the primary cause of HIV-related deaths in Zambia is tuberculosis, which immuno-compromised HIV patients are increasingly likely to contract. 88% of HIV-positive patients were screened for tuberculosis in 2021.
At 8.1%, Malawi's HIV rate is the first on the list to fall below 10%. Roughly 970,000-990,000 people lived with HIV in Malawi in 2020, with young people at particular risk. Around one-third of all new HIV infections in the country occurred among young people aged 15 to 24 years old. Among those living with HIV, 89.9% (870,000) were receiving ART as of June 2021, an increase of more than 10% from just a few years ago. One of Malawi’s largest barriers to HIV progress is the stigma associated with the disease, which prevents some would-be patients from seeking diagnosis and treatment. Despite this, Malawi is very close to reaching the UNAIDS 90-90-90 targets.
While Equatorial Guinea's 2020 HIV rate of 7.3% may seem at first glance to be an increase from its estimated 6.2% in 2014, this may not be the case. As in much of Africa, the medical sector in Equatorial Guinea has historically fallen short in the area of detecting and diagnosing HIV. As such, a significant percentage of HIV-positive people in countries such as Equatorial Guinea have been untested, undiagnosed, and unaware of their infection status. In light of this fact, Equatorial Guinea's increased HIV numbers are quite possibly the result of more and improved testing rather than increased virus frequency. Provided the country follows through with aggressive and comprehensive treatment programs, its HIV/AIDS percentage—as well as its mortality rate—should fall again in coming years.
With 26.8%, Eswatini has the highest rate of HIV infections in the world. South Africa has the most number of cases with 7.8 million.
At 0.8% of their population respectively, Moldova, Estonia, and Djibouti are the three countries with the lowest HIV rate.