Performance of a True Point-of-Care Assay for HIV-1/2 Viral Load Measurement at Antenatal and Postpartum Services.

BACKGROUND: Timely viral load (VL) results during pregnancy and the postpartum period are crucial for HIV disease management and for preventing mother-to-child transmission. Point-of-care (POC) VL testing could reduce turnaround times and streamline patient management. We evaluated the diagnostic performance of the novel m-PIMA HIV-1/2 VL assay (Abbott, Chicago, IL) in Mozambique. SETTING: The study was conducted in prenatal and postpartum consultation rooms in 2 primary health care clinics. Sample collection and testing on m-PIMA were performed by trained nurses. METHODS: HIV-infected pregnant and postpartum women on antiretroviral treatment (ART) or ART naive were tested using both on-site m-PIMA POC and referral laboratory-based real-time VL assays. Linear regression analysis and Bland-Altman plots were used to calculate the agreement between both. FINDINGS: Correlation between venous blood plasma POC and plasma laboratory-based VL was strong (r2 = 0.850, P < 0.01), with good agreement between the methods [overall bias 0.202 log copies/mL (95% CI: 0.366 to 0.772 log copies/mL)]. Using the threshold of 1000 copies/mL, which is used to determine ART failure, the sensitivity and specificity of the POC VL assay were 95.0% (95% CI: 91.6% to 97.3%) and 96.5% (95% CI: 94.2% to 98.0%), respectively. The correlation coefficient between the venous and capillary sample types was 0.983 (r2 = 0.966). CONCLUSIONS: On-site, nurse-performed POC VL testing is feasible and accurate in resource-limited primary health care settings. The operational challenge of plasma separation within clinics for POC testing was successfully overcome using minicentrifuges. The use of capillary blood could simplify the execution of the assay in a clinical environment.

Performance of point-of-care birth HIV testing in primary health care clinics: An observational cohort study.

BACKGROUND: Failure to timely diagnose HIV in infants is a major barrier for scaling-up paediatric antiretroviral treatment (ART). WHO recommends birth testing for earlier diagnosis and to improve test coverage, but current diagnosis takes 2-3 weeks to complete, thereby limiting the ability of care givers to provide follow-on care, especially in low-resource settings. We evaluated the benefit of implementing rapid diagnosis of HIV at birth in primary health care maternity wards in Mozambique. METHODS AND FINDINGS: Infants born to HIV-infected mothers delivering consecutively at eight primary health care clinics were tested within 24 hours of delivery using on-site POC (Alere q HIV1/2 Detect) and standard laboratory (Roche COBAS AmpliPrep/TaqMan HIV-1 qualitative assay v2.0) testing. Infants were also tested at 4-6 weeks of age with both assays. Of 2,350 HIV-exposed infants enrolled in this implementation research study, 33 tested HIV-positive at birth on both assays. Sensitivity and specificity of POC testing compared with laboratory testing at birth were 100% (95% CI 89·4-100·0) and 100% (95% CI 99·8-100·0), respectively. At 4-6 weeks of age, 61 infants were identified as HIV-positive; of these 29 (47·5%) had a positive test at birth. Testing at both birth and 4-6 weeks identified 71 HIV-positive infants compared with 61 infants by testing at 4-6 weeks alone, a 16% increase. Two infants tested positive at birth but tested HIV-negative during follow-up. CONCLUSIONS: Adding POC birth testing to the 4-6 week screen may increase access to HIV diagnosis and expedite ART initiation in primary health care settings within low resource settings. Guidance on appropriate confirmatory HIV testing algorithms for birth testing is needed.

Effect of point-of-care early infant diagnosis on antiretroviral therapy initiation and retention of patients.

OBJECTIVE: We measured the effect of point-of-care (POC) early infant HIV testing on antiretroviral therapy initiation rates and retention in care among infants in Mozambique. DESIGN: A cluster-randomized trial was conducted in 16 primary healthcare centres providing either on-site POC arm (n = 8) or referred laboratory [standard-of-care (SOC) arm; n = 8] infant HIV testing. METHODS: The primary outcomes were the proportion of HIV-positive infants initiating antiretroviral therapy within 60 days of sample collection, and the proportion of HIV-positive infants who initiated antiretroviral therapy that were retained in care at 90 days of follow-up. RESULTS: The proportion of HIV-positive infants initiating antiretroviral therapy within 60 days of sample collection was 89.7% (157 of 175) for the POC arm and 12.8% (13 of 102) for the SOC arm [relative risk (RR)(adj) 7.34; P < 0.001]. The proportion of HIV-positive infants who initiated antiretroviral therapy that were retained in care at 90 days of follow-up was 61.6% (101 of 164) for the POC arm and 42.9% (21 of 49) for the SOC arm [RR(adj) 1.40; P < 0.027]. The median time from sample collection to antiretroviral therapy initiation was less than 1 day (interquartile range: 0-1) for the POC arm and 127 days (44-154; P < 0.001) for the SOC arm. CONCLUSION: POC infant HIV testing enabled clinics to more rapidly diagnose and provide treatment to HIV-infected infants. This reduced opportunities for pretreatment loss to follow-up and enabled a larger proportion of infants to receive test results and initiate antiretroviral therapy. The benefits of faster HIV diagnosis and antiretroviral treatment may also improve early retention in care.