Health conditions

HIV and AIDS has become a major public health problem in many countries and monitoring the course of the epidemic and impact of interventions is crucial. Both the Sustainable Development Goals (SDGs) and the 2021 United Nations Political Declaration have set goals of reducing people new HIV infections and HIV-related mortality.

The number of people with HIV infection, whether or not they have developed symptoms of AIDS, estimated to be alive at the end of a specific year.

• Gender (female, male, other*)

• Age (0-14, 10–19, 15+,15–24,15–49, 50+ years)

• Key populations (men who have sex with men, people living in prisons, people who inject drugs, sex workers, trans and gender diverse people)

• Cities and other administrative regions of epidemiologic importance

*The category of other includes trans and gender diverse people who choose an identity other than male or female.

1. Direct estimates from HIV case surveillance systems

Estimation models such as Spectrum are the preferred source for the number of people living with HIV. If models other than Spectrum are used, documentation of the estimation method and uncertainty bounds should be provided. On case surveillance methods. An HIV case surveillance system is considered to be functioning well if reporting from all facilities providing confirmatory HIV testing, care and treatment services has been in place since at least 2015, and if people who have died, been lost to follow-up or emigrated are removed from the numerator. Only confirmed HIV diagnoses should be counted, although countries should be sure to adjust for reporting delays by including an estimate of the number of people diagnosed but not yet reported during the latest calendar year (if necessary). Mechanisms should be in place to deduplicate individuals diagnosed and reported multiple times or from multiple facilities.

2. Modelled estimates

Estimation models such as Spectrum are the preferred source for the number of people living with HIV. UNAIDS is working with countries to develop a Spectrum model that matches the estimates of people living with HIV if estimates other than those produced through Spectrum are used. On estimating the number of children who know their status in countries with modelled estimates based on household survey data. Since household surveys are often restricted to respondents of reproductive age, a separate estimate of knowledge of HIV status among children (0–14 years old) may need to be constructed using programme data in order to produce an overall (i.e., all ages) estimate. In this case, UNAIDS recommends that countries use the number of children on treatment as a proxy measure. This approach represents the most conservative measure of knowledge of status in the population.

Impact

Countries produce national estimates of the number of people living with HIV, which are compiled and published annually by UNAIDS and WHO. Standard methods and tools for HIV estimates that are appropriate to the pattern of the HIV epidemic are used. However, to obtain the best possible estimates, judgement needs to be used as to the quality of the data and how representative it is of the population.

Regional estimates are the sum of the country data in each WHO region.

Cases

Annual

Annual

beusenbergm@who.int

Michel Beusenberg

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