Low-cost tools for diagnosing and monitoring HIV infection in low-resource settings
Grace Wu & Muhammad H Zaman
Volume 90, Number 12, December 2012, 914-920
Table 2. Characteristics of low-cost tests for diagnosing and monitoring human immunodeficiency virus (HIV) infection
| Test purpose, type | Commercial test(s) | Portable | Detection method | Cost (US$) | Time to result | Advantage(s) | Limitation(s) |
|---|---|---|---|---|---|---|---|
| HIV diagnosis | |||||||
| ELISA | Many available |
No | Quantifies HIV DNA or RNA in serum | < 2 | ~3–5 hours | High throughput, sensitive | Requires dedicated laboratory equipment and confirmatory diagnosis, not for early infant diagnosis |
| Simple/rapid test | Many available |
Yes | Qualitatively detects HIV antibodies in whole blood, serum or saliva | < 2 | ~30 minutes | Appropriate for screening large and rural populations, immediate result | For screening only (not quantitative), not high throughput for larger-scale screening |
| p24 test | Perkin-Elmer p24 Ultrakit |
No | Quantifies p24 core protein of HIV | 5–10 | ~4 hours | Sensitive for paediatric diagnosis of HIV infection, cheaper than PCR | Requires dedicated laboratory space, additional buffer reagents and further validation |
| ART initiation, virologic failure | |||||||
| POC CD4+ T-cell count | Pima Test; Point-Care NOW; Partec CyFlow miniPOC; Daktari CD4+ |
Yes | Quantifies CD4+ T-cells | ~6 per test | 20 minutes (Pima), 8 minutes (Point) | Portable, sensitive, faster than flow cytometry | Requires further validation, tests CD4+ T-cell count only (Pima Test), not high throughput |
| POC PCR | Liat HIV Quant Assay (in pipeline) |
Yes | Quantifies HIV DNA in blood | 25 000 per instrument | 88 minutes per sample | Portable | To be determined |
| Reverse transcriptase test | Cavidi EXAVir Load Version 3 |
No | Quantifies reverse transcriptase levels | ~20 | 90 minutes | Cheaper than virus load testing, tests for multiple HIV subtypes | High rate of false-positive results, long testing time, not POC |
ART, antiretroviral therapy; DNA, deoxyribonucleic acid; ELISA, enzyme-linked immunosorbent assay; PCR, polymerase chain reaction; POC, point-of-care; RNA, ribonucleic acid; US$, United States dollars.