2002 HIV Sentinel Surveillance QA Experience in Zambia

1. 2002 HIV Sentinel Surveillance QA Experience in Zambia Ms Chanda Mulenga, Dr Victor Mudenda, Dr Mwaka Monze, & Dr Francis Kasolo

2. Study Design Repeated cross-sectional surveys to monitor changes over time: 1994 1998 2002 2004 Conducted in the same way each time for comparability of data and to be certain that any changes are real: Person: pregnant women attending ante natal clinic Place: original sites maintained with some additions Time: four month period Data: same questionnaire Unlinked anonymous HIV testing model using a blood sample collected during routine ante-natal care

3. Sentinel Surveillance Site Map Map of 24 Sentinel Surveillance Sites for 2002: Zambia is 3-5 times the size of the US, in terms of travel time for health officials. In rainy season a number of clinics are inaccessible. Logistics remain a tremendous challenge for every part of the Zambian health system; this includes transport of people, supplies, equipment, documents and information. Perhaps the last is most amenable to quick intervention. 71 of 72 districts have at least 1 computer, and most of these have telephone service in proximity to the computer. A major hurdle has been keeping phone bills paid. Map of 24 Sentinel Surveillance Sites for 2002: Zambia is 3-5 times the size of the US, in terms of travel time for health officials. In rainy season a number of clinics are inaccessible. Logistics remain a tremendous challenge for every part of the Zambian health system; this includes transport of people, supplies, equipment, documents and information. Perhaps the last is most amenable to quick intervention. 71 of 72 districts have at least 1 computer, and most of these have telephone service in proximity to the computer. A major hurdle has been keeping phone bills paid.

4. Sentinel Surveillance Sites Per Administrative Zone Northern Zone: Tropical Diseases Research Center (TDRC), Ndola Ndola Ibenga Mansa Nchelenge Kasaba Kasama Isoka Solwezi Mukinge Kabompo Serenje Southern Zone: University Teaching Hospital, Virology Laboratory, Lusaka Lusaka (Chelstone, Chilenje, Kalingalinga, Matero) Luangwa Kabwe Kapiri Mposhi Chipata Minga Mongu Kalabo Livingstone Macha

5. Study Population ESS Recruitment criteria Pregnant women Attending ANC at study site for 1st time this pregnancy Accepting routine syphilis testing Sample size First such 500 women per site (800 for Ndola and Lusaka sites) or Women enrolled during 4 month enrollment period

7. MAINTAINING ANONYMITY & CONFIDENTIALITY Lab tests and interview/blood drawing done by different individuals Specimens preserved and tested in batch on date later than date of collection Specimens and results will have an anonymous ID number not linked in any way to the client A maximum of two lab staff will have access to lab results and two midwives will have access to the questionnaires No site staff will have access to both questionnaires and results

8. MAINTAINING ANONYMITY & CONFIDENTIALITY Clients anonymous questionnaire will be stored securely and separate from anonymous lab data at the same site During supervisory visits the supervisor will review both sets of records separately and in a confidential manner The questionnaire and lab results will be linked at data entry but the ID numbers will be replaced with different anonymous numbers The linked dataset will be treated as confidential and access will be restricted

9. WHO/UNAIDS Testing Strategies Strategy I � up to one test Strategy II � up to two test Strategy III � up to three test ANC Sentinel Surveillance � Strategy III (even though Zambia prevalence is 15.6%)

10. Types of kits used for 2002 ANC SS ANC SS Capillus� at field collection sites ELISA-Welcozyme- at central lab Bionor- Magnetic EIA- central lab for tie break

11. ESS Testing Algorithm And EQA

12. Zambia QA Process in 2002 Post Test QA following Data Analysis effort 3 test protocol provided opportunity to assess internal integrity of results Mix of Field vs. Central parts of algorithm provided opportunity to assess field lab effect Mix of Field sites provided opportunity to assess site admin. group effect

14. Algorithm performance Expected N,P,P frequency should be about 0.2% Observed About 10% of 10,000 Neg. were retested Of the 1,300 retested, 32 were N,P,P or 2% 31 of 32 were in one of two reference labs

16. Post test QA Occurrence Management Intensive review revealed several testing processes in field and reference labs needing strengthening The case of the N,P,P results review validated the initial N result Retested specimens from sites where expected and observed differed significantly

17. Lessons Learned Comparison of Expected and Observed results in a 3 test protocol can yield a useful QA process Testing in both field and central labs also provides a basis for checking quality

19. Thank you