The New Epidemiology of Human Immunodeficiency Virus Infection

  • Enrico GirardiEmail author


The overwhelming majority of infection with the Human Immunodeficiency Virus (HIV) is acquired worldwide through sexual contacts. Risk of transmission is higher through anal sex, in presence of ulcerative genital lesion and when the source has high HIV viremia. Conversely, it is reduced by male circumcision, consistent condom use and it is virtually zero when the infected persons in under antiretroviral therapy and has undetectable viremia.

Globally, HIV incidence peaked in the mid-1990s and then slowly decreased. Presently, about two million new infections are estimated to occur each year, and more than 38 million people are estimated to live with HIV/AIDS, most of them in sub-Saharan Africa.

Almost in all settings, some population groups, also called key populations, are disproportionately affected by HIV infection. According to WHO key populations are men who have sex with men, people who inject drugs, sex workers, transgender people, and people in prisons and other closed settings.

Providing effective antiretroviral therapy to all those in need is presently a cornerstone of the efforts to end HIV epidemic. In 2014 UNAIDS has launched to 90-90-90 target, whereby, by the year 2020, 90% of people living with HIV globally know their HIV status, 90% of those who know their HIV status had access to antiretroviral therapy, and 90% of people on treatment had suppressed viral loads.


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Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  1. 1.Clinical Epidemiology UnitNational Institute for Infectious Diseases “L. Spallanzani” – IRCCSRomeItaly

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