1. Late diagnosis and partner risk: differentiated HIV testing to reach people with advanced disease
Andreas D. Haas, PhD
Postdoctoral fellow, ICAP at Columbia University
21 July 2019

2. The CQUIN Learning Network
HIV testing
Facility-based testing
70% CD4 at diagnosis <350 cells/µL
Community-based testing
25% to 40% CD4 at diagnosis <350 cells/µL
Inefficient: high cost per HIV diagnosis
Early and efficient diagnosis requires targeted community- based HIV testing strategies
Community index testing
Secondary distribution of self-tests
Targeted mobile testing
Sharma et al. Nature 2015, Suthar et al. Plos Med 2013
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Objectives
Describe the proportion of HIV-positive adults who were diagnosed late during the PHIA survey
Characterize populations at risk of late diagnosis
Examine associations between late diagnosis and partners´ risk of HIV acquisition
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4. PHIA Project
Goal: Conduct nationally representative, HIV-focused household surveys to assess the HIV epidemic and the impact of response programs
1o objectives: national HIV incidence and subnational prevalence of viral load suppression (VLS) among adults
2o objectives: HIV prevalence, cascades, detectable antiretrovirals, among others

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Methods: prevalence of late diagnosis and associated factors
Data
PHIA data for Malawi, Zambia and Zimbabwe from
Eligibility
HIV-positive adults unaware of their status who participated in the PHIA surveys
Outcome
Late diagnosis defined as diagnosis at CD4 <350 cells/µL
Statistical analysis
Descriptive statistics
Logistic regression
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Methods: late diagnosis and partner risk
Procedures
HIV-positive adults unaware of their status were linked to their household sexual partners
Estimation of duration of infection based on a CD4 depletion model
Partner with longer duration of infection was classified as index case
Eligibility
People unaware of their positive status who could be linked to an ART-naïve cohabiting sexual partners
Statistical analysis
Logistic regression models with restricted cubic splines
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Results
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8. Awareness of HIV status among HIV+ adults
Unaware
Aware
25%
75%
N: 7,988

9. Characteristics of HIV+ adults unaware of status
Malawi
N=472
Zambia
N=648
Zimbabwe
N=684
Total
N=1,804
Female, n (%)
281 (52)
426 (60)
397 (51)
1,104 (55)
Rural, n (%)
221 (68)
317 (49)
454 (60)
992 (58)
Marital status, n (%)
Never married
59 (13)
142 (24)
98 (14)
299 (17)
Married/cohabiting
302 (66)
336 (52)
411 (63)
1,049 (60)
Divorced/widowed
111 (21)
169 (25)
174 (23)
454 (23)
Age in years, median (IQR)
32 (26-42)
32 (25-40)
33 (26-42)

10. Prevalence of late diagnosis
CD4 <350 cells/µL
CD4 ≥350 cells/µL
N: 1,804
49%
51%

11. Prevalence of advanced disease
CD4 <200 cells/µL
CD4 ≥200 cells/µL
N: 1,804
19%
81%

12. Factors associated with late diagnosis
GENDER
AGE, years

13. Potential reach of index testing
HIV+ adults unaware of status
Men
Women
Positive partner on ART
13.4%
4.4%
Positive partner aware but not on ART
3.8%
2.4%
Potential reach
17.2%
6.8%
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14. Adjusted odds ratios for HIV-positive status among sexual partners
Partners of undiagnosed people with a CD4 count of 350 vs. 250 cells/µL had 43% decreased odds (aOR 0.57 CI ) for being HIV-positive.
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15. Adjusted odds ratios for HIV-positive status among sexual partners
Partners of undiagnosed people with a CD4 count of 500 vs. 250 cells/µL had 76% decreased odds (aOR 0.24 CI ) for being HIV-positive.
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Conclusion
Timely diagnosis of HIV remains a challenge in Southern Africa
Need for innovative (e.g. differentiated) HIV testing strategies to diagnose people who have not been reached by existing HIV testing
Differentiated HIV testing models targeting people 45 or older might be a useful approach to diagnose people in advanced stages of HIV disease
Index testing has great potential but is not a silver bullet.
Need for several targeted HIV testing strategies to reach all HIV- positive people who are unaware of their status
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Thank you
PHIA participants
ICAP, CDC, MOHs and other collaborating institutions
PHIA team in particular Jessica Justman and Elizabeth Radin
Funders: PEPFAR and Swiss National Science Foundation
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