Reduction in HIV prevalence

Export Indicator

Percentage of young people aged 15–24 who are HIV infected
What it measures

To assess progress towards reducing HIV infection.

Rationale

The goal in the response to HIV is to reduce HIV infection. As the highest rates of new HIV infections
typically occur in young adults, more than 180 countries have committed themselves to achieving major
reductions in HIV prevalence among young people—a 25% reduction in the most affected countries by
2005 and a 25% reduction globally by 2010.

Numerator

Number of antenatal clinic attendees (aged 15–24) tested whose HIV test results are positive

Denominator

Number of antenatal clinic attendees (aged 15–24) tested for their HIV infection status

Calculation

Numerator / Denominator

Method of measurement

This indicator is calculated using data from pregnant women attending antenatal clinics in HIV sentinel surveillance sites in the capital city, other urban areas and rural areas.
 The sentinel surveillance sites used for the calculation of this indicator should remain constant to allow for the tracking of changes over time.

The proportion of the total female population aged 15–24 living in the capital city, in other urban areas and in rural areas should be provided so that national estimates can be calculated, where possible.

Measurement frequency

Annual

Disaggregation

Condom type: N/A

Education: N/A

Gender: N/A

Geographic location: Urban, Rural, Capital City

HIV status: N/A

Pregnancy status: N/A

Sector: N/A

Service Type: N/A

Target: N/A

Time period: N/A

Type of orphan: N/A

Vulnerability status: N/A

Explanation of the numerator
Explanation of the denominator
Strengths and weaknesses

HIV prevalence at any given age is the difference between the cumulative numbers of people that have
become infected with HIV up to this age minus the number who have died, expressed as a percentage of the total number alive at this age. At older ages, changes in HIV prevalence are slow to reflect changes in the rate of new infections (HIV incidence) because the average duration of infection is long. Furthermore, declines in HIV prevalence can refl ect saturation of infection among those individuals who are most vulnerable and rising mortality rather than behaviour change. At young ages, trends in HIV prevalence are a better indication of recent trends in HIV incidence and risk behaviour. Thus, reductions in HIV incidence associated with genuine behaviour change should first become detectable in HIV prevalence figures for 15–19-year-olds. Where available, parallel behavioural surveillance survey data should be used to aid interpretation of trends in HIV prevalence.

In countries where the age at which young people first have sexual intercourse is late and/or levels of
contraception use are high, HIV prevalence among pregnant women of 15–24 years of age will differ from that among all women in the age group.

This indicator (using data from antenatal clinics) gives a fairly good estimate of relatively recent trends in
HIV infection in locations where the epidemic is heterosexually driven. It is less reliable as an indicator
of HIV-epidemic trends in locations where most infections remain temporarily confined to most-at-risk
populations.

To supplement data from antenatal clinics, an increasing number of countries have included HIV testing
in population-based surveys. If a country has produced HIV prevalence estimates from survey data these
estimates should be included in the comments box for this indicator to allow for comparisons between
multiple surveys. If available, survey based estimates should be disaggregated by sex.

The addition of new sentinel sites will increase the samples representativeness and will therefore give a
more robust point estimate of HIV prevalence. However, the addition of new sentinel sites reduces the
comparability of values. As such it is important to exclude new sites from the calculation of this indicator
when undertaking trend analyses.
 

Further information