Introduction

Acquired Immune Deficiency Syndrome (AIDS) is a disease due to infection by the Human Immunodeficiency Virus (HIV). It is spread primarily by unprotected sex (including anal and oral sex), contaminated blood transfusions, hypodermic needles, and from mother to child during pregnancy, delivery, or breastfeeding.

How many people live with HIV today?

In 2016, it is estimated that 37 million people worldwide live with HIV, a number which includes 18 million women and 2 million children. The number of newly infected people was 1.8 million, and the number of deaths caused by AIDS was 1.0 million for that year.
Sub-Saharan Africa remains the most heavily affected area, with more than 25 million people living with HIV.

Has the number of new HIV infections declined?

Since 2010, the annual number of new HIV infections (all ages) has declined by 16% to 1.8 million. Even if local efforts to strengthen HIV prevention and treatment programmes are reducing the transmission of HIV, this is however much slower than expected to meet the 2020 target of less than 500 000 new infections per year. Since 2010, the annual number of new HIV infections (all ages) has declined by 16% to 1.8 million.
Regional trends in the annual number of new HIV infections for people of all ages varied. The steepest declines between 2010 and 2016 were achieved in eastern and southern Africa (29% ), followed by Asia and the Pacific (13% ), western and central Africa (9% ), western and central Europe and North America (9% ), the Caribbean (5% ), and the Middle East and North Africa (4%).
Trends over the same time period in Latin America were stable, but in Eastern Europe and central Asia, the annual number of new infections climbed by an alarming 60%.

Has the number of the deaths due to AIDS also declined?

As antiretroviral therapy became more available around the world, deaths have decreased from a maximum of almost 2 million deaths in 2005, down to 1 million in 2016.
The number of children (aged 0–14 years) dying of AIDS-related illnesses has been nearly cut in half in just six years, from 210 000 in 2010 to 120 000 in 2016. Much of the decline is due to steep reductions in new HIV infections among children, with increased access to pediatric antiretroviral therapy also playing an important role.
Meanwhile, worrying increases in AIDS-related mortality have occurred over the past decade in the Middle East and North Africa (48% increase) and in eastern Europe and central Asia (38% increase).

What populations are at a greater risk of HIV infection?

In areas where a lot of people are infected, young women remain at unacceptably high risk of HIV infection. In all settings, a large part of HIV infections occurs among key populations - people who inject drugs, sex workers, transgender people, prisoners, homosexuals other men who have sex with men- and their sexual partners.
Outside of sub-Saharan Africa, key populations and their sexual partners accounted for 80% of new HIV infections in 2015. Even in sub-Saharan Africa, key populations and their sexual partners are an important part of the HIV epidemic: in 2015, 25% of new infections occurred among this group, underlining the importance of reaching them with adapted means.

What targets for AIDS treatment have been set?

In 2016, the Joint United Nations Programme on HIV and AIDS (UNAIDS) has set out to reach by 2020 the “90-90-90” target for treatment of the AIDS epidemic. This means that more than 90% of people living with HIV should know their status, more than 90 % of are treated, and the 90% or those who are treated have suppressed viral loads.
The data needed to assess how far this objective is met is not yet available for all countries, but progress is being made, with 76 countries having access to data for all three targets in 2016, an increase over just the preceding year, where only 55 countries had that data.
It is an ambitious target, with some regions lagging far behind, like in western and central Africa, where it is estimated that only 42% of people infected know their HIV status.
At this stage, UNAIDS is confident that the actual numbers of people living with HIV, who are newly infected with HIV or who have died from AIDS-related causes lie within the reported ranges. Over time, more and better data from countries will steadily reduce uncertainties.