Use of an Indeterminate Range in HIV Early Infant Diagnosis: A Systematic Review and Meta-Analysis

Loss to follow-up of HIV-exposed infants for confirmatory HIV test under Early Infant Diagnosis program in India: analysis of national-level data from reference laboratories

Background

Early Infant Diagnosis was launched in India in 2010 and its effect on the diagnosis of HIV-exposed infants needs to be assessed. The present study was done to find out the median age at DBS sample collection for early infant diagnosis and its trend over years, the median age at diagnosis of HIV among the HIV-exposed infants with DNA PCR tests, and the proportion of infants who completed testing cascades after detection of HIV-1 in a sample.

Methods

DNA PCR data (from 2013 to 2017) maintained at all regional reference laboratories in India was collated with each infant identified by a unique code. Cohort analysis of the infant data was used to find the median age at sample collection and diagnosis. The outcomes of testing in each cascade and the overall outcomes of testing for infants were prepared.

Results

The median age at sample collection for the four years combined at all India level was 60 days (48–110 days). The median age at diagnosis of HIV was 285 days (174–418 days). HIV-1 was detected in samples of 1897 (6.3%) infants out of 30,216 infants who had a DNA PCR test, out of whom 1070 (56.4%) completed the testing cascade and the rest were lost to follow-up.

Conclusion

The data highlights delay in diagnosis; both due to delay in sample collection and turn-around-times. Loss to follow-up of HIV-exposed infants with virus detection is a significant concern to the Early Infant Diagnosis and tracking systems need to be strengthened.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03656-w.

Assessing the Variability of Cell-Associated HIV DNA Quantification through a Multicenter Collaborative Study

Reliable and accurate quantification of cell-associated HIV DNA (CA HIV DNA) is critical for early infant diagnosis, clinical management of patients under therapy, and to inform new therapeutics efficacy. The present study assessed the variability of CA HIV DNA quantification obtained from various assays and the value of using reference materials to help harmonize the measurements. Using a common set of reagents, our multicenter collaborative study highlights significant variability of CA HIV DNA quantification and lower limit of quantification across assays. The quantification of CA HIV DNA from a panel of infected PBMCs can be harmonized through cross-subtype normalization but assay calibration with the commonly used 8E5 cell line failed to reduce quantification variability between assays, demonstrating the requirement to thoroughly evaluate reference material candidates to help improve the comparability of CA HIV DNA diagnostic assay performance. IMPORTANCE Despite a global effort, HIV remains a major public health burden with an estimated 1.5 million new infections occurring in 2020. HIV DNA is an important viral marker, and its monitoring plays a critical role in the fight against HIV: supporting diagnosis in infants and underpinning clinical management of patients under therapy. Our study demonstrates that HIV DNA measurement of the same samples can vary significantly from one laboratory to another, due to heterogeneity in the assay, protocol, and reagents used. We show that when carefully selected, reference materials can reduce measurement variability and harmonize HIV DNA quantification across laboratories, which will help contribute to improved diagnosis and clinical management of patients living with HIV.

Delays in HIV-1 infant polymerase chain reaction testing may leave children without confirmed diagnoses in the Western Cape province, South Africa

Background

Early diagnosis and confirmation of HIV infection in newborns is crucial for expedited initiation of antiretroviral therapy. Confirmatory testing must be done for all children with a reactive HIV PCR result. There is no comprehensive data on confirmatory testing and HIV PCR test request rejections at National Health Laboratory Service laboratories in South Africa.

Objective

This study assessed the metrics of routine infant HIV PCR testing at the Tygerberg Hospital Virology Laboratory, Cape Town, Western Cape, South Africa, including the proportion of rejected test requests, turn-around time (TAT), and rate of confirmatory testing.

Methods

We retrospectively reviewed laboratory-based data on all HIV PCR tests performed on children ≤ 24 months old (n = 43 346) and data on rejected HIV PCR requests (n = 1479) at the Tygerberg virology laboratory over two years (2017–2019). Data from sample collection to release of results were analysed to assess the TAT and follow-up patterns.

Results

The proportion of rejected HIV PCR requests was 3.3%; 83.9% of these were rejected for various pre-analytical reasons. Most of the test results (89.2%) met the required 96-h TAT. Of the reactive initial test results, 53.5% had a follow-up sample tested, of which 93.1% were positive. Of the initial indeterminate results, 74.7% were negative on follow-up testing.

Conclusion

A high proportion of HIV PCR requests were rejected for pre-analytical reasons. The high number of initial reactive tests without evidence of follow-up suggests that a shorter TAT is required to allow confirmatory testing before children are discharged.

Indeterminate HIV PCR results within South Africa's early infant diagnosis programme, 2010-2019

OBJECTIVES

We describe the extent of, and variables associated with, indeterminate HIV-PCR results and final HIV status within South Africa's early infant diagnosis (EID) programme between 2010 and 2019.

METHODS

Retrospective analysis of routine paediatric HIV-PCR laboratory data from South Africa's National Health Laboratory Service Data Warehouse between 2010 and 2019. Final HIV status was determined by linking patient results (including HIV-PCR, HIV viral load, HIV serology and CD4 counts) using a probabilistic matching algorithm. Multivariate logistic regression was performed to determine variables associated with final HIV status among patients with an indeterminate HIV-PCR result.

RESULTS

Among 4 429 742 specimens registered for HIV-PCR testing from 3 816 166 patients, 113 209 (2.97%) tested positive and 22 899 (0.6%) tested indeterminate. As a proportion of HIV-detected results, 15.7% (23 896/151 832) of total and 31.5% (4900/15 566), 18.8% (11 400/60 794) and 10.1% (7596/75 472) among patients aged <7 days, 7 days-3 months and ≥3 months, respectively, were reported as indeterminate. Overall, 39.7% of patients with an indeterminate result had a linked HIV test to determine HIV status, of which 53.6% were positive with a median time to repeat testing of 30 days (interquartile range 15-69). Among patients who tested indeterminate, variables associated with a significantly higher odds of having a positive HIV status included testing indeterminate at birth (adjusted odds ratio (AOR) 0.63 (0.48-0.83) and 0.52 (0.39-0.69) for testing indeterminate at 7 days-3 months and ≥3 months respectively compared with birth), within a hospital (AOR 2.45 (1.99-3.03)), and in districts with an intra-uterine transmission rate ≥1.1% (AOR 3.14 (1.84-5.35)) (p < 0.001).

DISCUSSION

Indeterminate HIV-PCR results represent a considerable burden of missed diagnostic opportunities, diagnostic dilemmas and delays in making a definite diagnosis among HIV-infected infants within South Africa's EID programme. Alternative EID verification practices are urgently needed.

Current Resources for Evidence-Based Practice, September 2020

An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of “spin” in scientific reporting and its effect on summaries and syntheses of the literature and commentaries on reviews about early versus late amniotomy as part of labor induction protocols and the economic burden associated with maternal morbidity.