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Updated: Feb 18, 2026
Comprehensive & Cost Effective Laboratory Monitoring of HIV/AIDS: an African Role Model
Published on: October 31, 2010
The value of confirmatory testing in early infant HIV diagnosis programmes in South Africa: A cost-effectiveness
Lorna Dunning1,2, Jordan A Francke2, Divya Mallampati3
1Division of Epidemiology and Biostatistics, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa.
Insights
Confirmatory HIV testing for infants significantly reduces false-positive diagnoses, preventing unnecessary antiretroviral therapy (ART) and saving costs. This approach is cost-saving and should be standard in early infant diagnosis (EID) programs.
Area of Science:
- Public Health
- Pediatric Infectious Diseases
- Health Economics
Background:
- Nucleic acid amplification tests (NAATs) for early infant diagnosis (EID) of HIV have imperfect specificity.
- False-positive results lead to unnecessary antiretroviral therapy (ART) in HIV-uninfected infants.
- The World Health Organization recommends confirmatory testing, but implementation is limited.
Purpose of the Study:
- To determine the impact and cost-effectiveness of confirmatory HIV testing for EID programs in South Africa.
Main Methods:
- The Cost-effectiveness of Preventing AIDS Complications (CEPAC)-Pediatric model simulated EID testing with and without confirmatory testing.
- Model parameters included NAAT cost, specificity, sensitivity, mother-to-child transmission (MTCT) rate, and ART initiation rates.
- Outcomes assessed were false-positive diagnoses, life expectancy, and lifetime HIV-related healthcare costs.
Main Results:
- Without confirmatory testing, 128/1,000 ART initiations were false-positive; with confirmatory testing, only 1/1,000 were false-positive.
- Confirmatory testing averted costs, with a total cost of $1,790/infant tested compared to $1,830/infant tested without it.
- Confirmatory testing remained cost-saving under various sensitivity analyses.
Conclusions:
- Over 10% of infants initiating ART may have false-positive diagnoses without confirmatory testing in similar settings.
- Confirmatory testing effectively prevents inappropriate HIV diagnoses and unnecessary ART.
- Confirmatory testing is cost-saving and should be adopted in all EID programs.
Background:
The specificity of nucleic acid amplification tests (NAATs) used for early infant diagnosis (EID) of HIV infection is <100%, leading some HIV-uninfected infants to be incorrectly identified as HIV-infected. The World Health Organization recommends that infants undergo a second NAAT to confirm any positive test result, but implementation is limited. Our objective was to determine the impact and cost-effectiveness of confirmatory HIV testing for EID programmes in South Africa.
Method And Findings:
Using the Cost-effectiveness of Preventing AIDS Complications (CEPAC)-Pediatric model, we simulated EID testing at age 6 weeks for HIV-exposed infants without and with confirmatory testing. We assumed a NAAT cost of US$25, NAAT specificity of 99.6%, NAAT sensitivity of 100% for infants infected in pregnancy or at least 4 weeks prior to testing, and a mother-to-child transmission (MTCT) rate at 12 months of 4.9%; we simulated guideline-concordant rates of testing uptake, result return, and antiretroviral therapy (ART) initiation (100%). After diagnosis, infants were linked to and retained in care for 10 years (false-positive) or lifelong (true-positive). All parameters were varied widely in sensitivity analyses. Outcomes included number of infants with false-positive diagnoses linked to ART per 1,000 ART initiations, life expectancy (LE, in years) and per-person lifetime HIV-related healthcare costs. Both without and with confirmatory testing, LE was 26.2 years for HIV-infected infants and 61.4 years for all HIV-exposed infants; clinical outcomes for truly infected infants did not differ by strategy. Without confirmatory testing, 128/1,000 ART initiations were false-positive diagnoses; with confirmatory testing, 1/1,000 ART initiations were false-positive diagnoses. Because confirmatory testing averted costly HIV care and ART in truly HIV-uninfected infants, it was cost-saving: total cost US$1,790/infant tested, compared to US$1,830/infant tested without confirmatory testing. Confirmatory testing remained cost-saving unless NAAT cost exceeded US$400 or the HIV-uninfected status of infants incorrectly identified as infected was ascertained and ART stopped within 3 months of starting. Limitations include uncertainty in the data used in the model, which we examined with sensitivity and uncertainty analyses. We also excluded clinical harms to HIV-uninfected infants incorrectly treated with ART after false-positive diagnosis (e.g., medication toxicities); including these outcomes would further increase the value of confirmatory testing.
Conclusions:
Without confirmatory testing, in settings with MTCT rates similar to that of South Africa, more than 10% of infants who initiate ART may reflect false-positive diagnoses. Confirmatory testing prevents inappropriate HIV diagnosis, is cost-saving, and should be adopted in all EID programmes.
