1. 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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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?

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

9. 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.

10. Kenya AIDS Indicator Survey 2007

11. 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

12. 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 

13. Ongoing Research

14. 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?

15. Conclusions
Need consensus in Research priorities in HIV surveillance

16. 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

17. Gracias por la atencion