XVI I IAC Mexico 3-8 August 2008 Txema Calleja WHO/OMS Epidemiology research and epidemiological surveillance: Encounters and mismatches research priorities for improving surveillance Good morning XVI I IAC Mexico 3-8 August 2008 Txema Calleja WHO/OMS

Outline Basic concepts: surveillance, research and risk factors Research issues for surveillance around MTCT scale up Research issues for surveillance around ART scale up Conclusions

Epidemiology research and epidemiological surveillance Surveillance : Surveillance is the ongoing systematic collection, analysis, and interpretation of outcome– specific data for use in planning, implementing and evaluating public health policies and practices Research : research refers to the systematic investigation to establish facts, principles or knowledge with the objective of advancing or confirming human knowledge

The Proximate-Determinants Framework J. Ties Boermaa and Sharon S. Weir Integrating Demographic and Epidemiological Approaches to Research on HIV/AIDS: The Proximate-Determinants Framework Framework for HIV/AIDS Research • JID 2005:191 (Suppl 1) • S61

From biomedical individualism to social epidemiology A heuristic framework for the social epidemiology K. E. Poundstone, S. A. Strathdee, and D. D. Celentano The Social Epidemiology of Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome Epidemiol Rev 2004;26:22–35

Key research issues in the effects of ART on the known biases for ANC and DHS Improve health of HIV positive women, who would become better able to conceive be more inclined to have children appear less stigmatised and thus more “marriagable” thereby raising their fertility rates Increase VCT proportion in HIV+ men & women, who might worry about leaving orphans want to protect partner from infection thereby lowering their fertility rates Likely to have different overall effects on fertility in different population

Research issues regarding MTCT scale up The introduction of new services in ANC clinics have an impact on selected populations. Under what circumstances can PMTCT data be used instead of ANC data? There is bias in ANC surveillance data and there are bias in programmatic data, are those the same ? Can prevalence trends among ANC clinics be used to approximate HIV incidence trends, with the introduction of ART?

Uganda: (Gulu District)Age-specific adjusted prevalence ANC vs PMTCT ( 2005) Fabiani et al 2005

Research issues in scaling up ART ART is impacting the biological behavioural surveillance surveys that are being implemented in countries ART impact on HIV prevalence ART progammes availability may modify behaviour risk HRG ART programmes may impact HIV incidence among those groups. Increase prevalence may be due to increase incidence or may be increased because increase survival.

Kenya AIDS Indicator Survey 2007

HIV surveillance, estimates and ART needs Does ART programmes change the HIV age distribution Main issue is around estimation of treatment need; Population data on the distribution of clinical stages and CD4 cell counts among a random sample (or all) HIV infected persons in the study population: KIAS 2007 Requires the HIV infected participants in surveys to know their status

ART and Behaviours: Research Issues Does a reduction in unsafe behaviour over time necessarily reflect the effect of program, or can it be the result of differential AIDS mortality among those with highest risk ? In concentrated epidemics: Behaviours before ART versus during ART-era in specific groups with high risk behaviour: MSM, SW, IDU. In concentrated epidemics: Comparison of behaviours at clinical and VCT sites versus those found in surveillance among specific groups with high risk behaviour: MSM, SW, IDU 

Ongoing Research

Additional research questions How can trends in behaviour be best monitored in clinical / treatment populations? What are the key issues in terms of behavioural history and future monitoring of concurrency and discordant couples? Does the linking of biological and behavioural trends in the longitudinal studies give the expected results? Is there a continuity in the relationship across the time in which ART was introduced?

Conclusions Need consensus in Research priorities in HIV surveillance

Conclusions Main measure for HIV epidemics is HIV prevalence among general or vulnerable populations, Impact of interventions on proximate determinants or individual factors : how is this affected by interventions Need to know new bias in sampling or in programmatic data HIV surveillance: development of new tools and/ or refined old ones Need to measure other proximate determinants and individual factors to monitor HIV dynamics Need to introduce operational research activities within HIV surveillance in NAP

Gracias por la atencion