1. HIV/AIDS Estimation and Projections: Overview of Methods and Activities

2. Increased Need for Credible HIV/AIDS Estimates l Advocacy: There are xx many infected. YY million have died, and we/you havent done enough. l Planning: Xx millions need treatment. Yy need outreach programmes. Relative numbers in geographic areas. Resource needs in-country and globally. l Monitoring: progress towards targets. E.g. prevalence reduction, denominators for ART treatment and PMTCT.

3. UNAIDS/WHO Schedule for Dissemination of Estimates l November 2003: publication of regional estimates (World AIDS Day): need final estimates in September l June 2004: publication of country estimates (report on the global HIV/AIDS epidemic): need final estimates by February

4. Classification of HIV/AIDS Epidemics l Low-level: no group has prevalence >5% l Concentrated: prevalence among pregnant women below 1% in urban areas, but some groups at high risk have prevalence >5% l Generalised: prevalence among pregnant women consistently over 1%

5. Overview for Low-level/Concentrated Epidemics Surveillance data and size estimates for HRG and LRP Spreadsheet Adult HIV Prevalence UN Population Divisions Population estimates Epidemiology assumptions Spectrum PLWHA New Infections AIDS Deaths

6. Calculating HIV Prevalence in Low- level/Concentrated Epidemics l Prevalence estimates are based primarily on surveillance data collected from IDU, SW, MSM, (STI clinics), (mobile groups), (women attending antenatal clinics) l Calculation of number of infected needs estimate of size of each group as an input.

7. Overview for Generalised Epidemics Surveillance data from ANC EPP Adult HIV Prevalence UN Population Divisions Population estimates Epidemiology assumptions Spectrum PLWHA New Infections AIDS Deaths

8. Calculating HIV Prevalence in Generalised Epidemics l Prevalence estimates are based primarily on surveillance data collected from women attending antenatal clinics l Assumed that prevalence among pregnant women 15-49 years sampled at ANC is broadly similar to prevalence among men and women 15-49 years in the community.

9. Projection Page in EPP

10. EPP Model Parameters t0t0 f0f0 r

11. Generating numbers of PLWHA, incidence and mortality Adult HIV Prevalence UN Population Divisions Population estimates Epidemiology assumptions Spectrum PLWHA New Infections AIDS Deaths

12. Outputs from Spectrum, used for HIV/AIDS estimates l Estimates of prevalence in males and females (using female- male ratio over time), in children and adults (using age prevalence pattern over time, fertility assumptions, and MTCT assumptions) l Estimates of incidence: based on the prevalence curve and mortality assumptions l Mortality for adults and children: based on the prevalence curve and mortality assumptions for adults and children

13. Projections l EPP can produce 5 year HIV prevalence projections for generalised epidemics l Longer term projections need more sophisticated model structure, and additional assumptions l Spectrum: projects populations; generates prevalence, incidence, mortality

14. Development of Methods l Based on recommendations of the UNAIDS Reference Group on Estimates, Modelling and Projections l Incorporates latest research findings l Implemented in software on a regular basis

15. Training Workshops Schedule l Africa: 23-25 and 28-30 April (Zimbabwe); 13-15 May (Benin) l Asia: 11-13 and 16-18 June (Bangkok) l LAC: 4-6 and 9-11 June (Guatemala), and 22-24 July (Jamaica) l Europe: 3-5 and 7-9 July (Croatia) l North Africa and Middle East: 9-11 (Tunis) and 16-18 (Cairo) September