Living with HIV/AIDS  

Global Incidence: Number of New HIV Infections Worldwide

There were an estimated 5 million new HIV infections (incident infections) worldwide in 2003. More than 95% of these new cases were in developing countries, and about 50% were women. Every day in 2003:

  • approximately 14,000 people became infected with HIV
  • approximately 2,000 of these people were children under the age of 15
  • approximately 6,000 of these people were aged 15-24

Global Prevalence: Number of People Living with HIV

  • As of 2003, an estimated 40 million people worldwide were living with HIV.
  • Approximately two-thirds of people living with HIV were in Sub-Saharan Africa.
  • Approximately 18% were in Asia and the Pacific Islands.
  • As of 2003, 2.5 million people living with HIV were children under 15 years of age.
  • Among people aged 15-49, approximately 11 out of every 1000 (that is, 1.1%) had HIV.
  • In Sub-Saharan Africa, about 8% of 15-49 year-olds were infected with HIV.

Understanding Global HIV and AIDS Surveillance Data

Statistics like those offered above are based on surveillance data. Surveillance is the ongoing, systematic collection, analysis, interpretation, and sharing of health data (3). These data not only show patterns of disease incidence, prevalence, and mortality, but also help predict how much a disease will affect a specific population.

In the United States, one of the major collectors and distributors of data about the HIV/AIDS epidemic in the United States is the Centers for Disease Control and Prevention (CDC), which tracks both HIV and AIDS surveillance data. In contrast, global data are collected by many different sources and compiled by a few key international organizations. These include The Joint United Nations Programme on HIV/AIDS and the World Health Organization (WHO). UNAIDS and WHO estimate global HIV/AIDS morbidity and mortality rates using all available data, including surveys of pregnant women, and population-based surveys, such as household surveys conducted in Kenya, Mali, Zambia and Zimbabwe (2). UNAIDS and WHO also publish updated country estimates biannually.

1. Joint United Nations Programme on HIV/AIDS (UNAIDS). AIDS epidemic update, December 2003. Geneva, Switzerland: United Nations Programme on HIV/AIDS, 2003.

2. Joint United Nations Programme on AIDS (UNAIDS). How do UNAIDS/WHO arrive at estimates? Retrieved on May 20, 2004 from

© Sociometrics Corporation, 2004