Missed diagnostic opportunities within South Africa's early infant diagnosis program, 2010-2015

High Prevalence of Unconfirmed Positive HIV Polymerase Chain Reaction Test Results Among African Infants With HIV Exposure in the International Epidemiology Databases to Evaluate AIDS Consortium

In a large, multiregional cohort of African infants with human immunodeficiency virus (HIV) exposure, 44% of those with a positive HIV polymerase chain reaction test lacked a confirmatory positive test. Efforts are needed to ensure high-fidelity implementation of HIV testing algorithms so that all positive results are confirmed.

Laboratory Data Timeliness and Completeness Improves Following Implementation of an Electronic Laboratory Information System in Côte d'Ivoire: Quasi-Experimental Study on 21 Clinical Laboratories From 2014 to 2020

BACKGROUND

The Ministry of Health in Côte d'Ivoire and the International Training and Education Center for Health at the University of Washington, funded by the United States President's Emergency Plan for AIDS Relief, have been collaborating to develop and implement the Open-Source Enterprise-Level Laboratory Information System (OpenELIS). The system is designed to improve HIV-related laboratory data management and strengthen quality management and capacity at clinical laboratories across the nation.

OBJECTIVE

This evaluation aimed to quantify the effects of implementing OpenELIS on data quality for laboratory tests related to HIV care and treatment.

METHODS

This evaluation used a quasi-experimental design to perform an interrupted time-series analysis to estimate the changes in the level and slope of 3 data quality indicators (timeliness, completeness, and validity) after OpenELIS implementation. We collected paper and electronic records on clusters of differentiation 4 (CD4) testing for 48 weeks before OpenELIS adoption until 72 weeks after. Data collection took place at 21 laboratories in 13 health regions that started using OpenELIS between 2014 and 2020. We analyzed the data at the laboratory level. We estimated odds ratios (ORs) by comparing the observed outcomes with modeled counterfactual ones when the laboratories did not adopt OpenELIS.

RESULTS

There was an immediate 5-fold increase in timeliness (OR 5.27, 95% CI 4.33-6.41; P<.001) and an immediate 3.6-fold increase in completeness (OR 3.59, 95% CI 2.40-5.37; P<.001). These immediate improvements were observed starting after OpenELIS installation and then maintained until 72 weeks after OpenELIS adoption. The weekly improvement in the postimplementation trend of completeness was significant (OR 1.03, 95% CI 1.02-1.05; P<.001). The improvement in validity was not statistically significant (OR 1.34, 95% CI 0.69-2.60; P=.38), but validity did not fall below pre-OpenELIS levels.

CONCLUSIONS

These results demonstrate the value of electronic laboratory information systems in improving laboratory data quality and supporting evidence-based decision-making in health care. These findings highlight the importance of OpenELIS in Côte d'Ivoire and the potential for adoption in other low- and middle-income countries with similar health systems.

Evaluating patient data quality in South Africa's National Health Laboratory Service Data Warehouse, 2017-2020: implications for monitoring child health programmes

Background

South Africa’s National Health Laboratory Service (NHLS), the only clinical laboratory service in the country’s public health sector, is an important resource for monitoring public health programmes.

Objectives

We describe NHLS data quality, particularly patient demographics among infants, and the effect this has on linking multiple test results to a single patient.

Methods

Retrospective descriptive analysis of NHLS data from 1^st January 2017—1^st September 2020 was performed. A validated probabilistic record-linking algorithm linked multiple results to individual patients in lieu of a unique patient identifier. Paediatric HIV PCR data was used to illustrate the effect on monitoring and evaluating a public health programme. Descriptive statistics including medians, proportions and inter quartile ranges are reported, with Chi-square univariate tests for independence used to determine association between variables.

Results

During the period analysed, 485 300 007 tests, 98 217 642 encounters and 35 771 846 patients met criteria for analysis. Overall, 15.80% (n = 15 515 380) of all encounters had a registered national identity (ID) number, 2.11% (n = 2 069 785) were registered without a given name, 63.15% (n = 62 020 107) were registered to women and 32.89% (n = 32 304 329) of all folder numbers were listed as either the patient’s date of birth or unknown. For infants tested at < 7 days of age (n = 2 565 329), 0.099% (n = 2 534) had an associated ID number and 48.87% (n = 1 253 620) were registered without a given name. Encounters with a given name were linked to a subsequent encounter 40.78% (n = 14 180 409 of 34 775 617) of the time, significantly more often than the 21.85% (n = 217 660 of 996 229) of encounters registered with a baby-derivative name (p-value < 0.001).

Conclusion

Unavailability and poor capturing of patient demographics, especially among infants and children, affects the ability to accurately monitor routine health programmes. A unique national patient identifier, other than the national ID number, is urgently required and must be available at birth if South Africa is to accurately monitor programmes such as the Prevention of Mother-to-Child Transmission of HIV.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13508-y.

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.

Negative Diagnostic PCR Tests in School-Aged, HIV-Infected Children on Antiretroviral Therapy Since Early Life in Johannesburg, South Africa

BACKGROUND

Younger age at antiretroviral therapy (ART) initiation has been associated with smaller HIV reservoirs. We investigated whether younger age of ART initiation is associated with testing negative and weaker signal on a standard HIV diagnostic test in treated children.

METHODS

At exit from a longitudinal study at 2 sites in Johannesburg, South Africa, 316 school-aged, HIV-infected children on continuous ART started at a median age of 6.3 months, were tested with standard total nucleic acid PCR used for infant diagnosis. All negative results were repeated. Simultaneous viral load (VL) and CD4 T-cell counts/percentages, along with data collected over the prior 4 years, were used in multivariable regression to predict negative PCR results and higher cycle threshold (Ct) values (weaker signal).

RESULTS

Seven children (2.2%, 95% confidence interval: 0.6 to 3.8) in the full cohort had negative PCR results; all 7 were in a subset of 102 (6.9%, 95% confidence interval: 2.0 to 11.8) who had initiated ART at age 0-4 months and had VL <50 copies/mL at the time of PCR testing. Only one repeat tested as negative. Younger age at ART initiation, VL <50 copies/mL at time of test, sustained VL <400 copies/mL, lower CD4 T-cell counts, and ever treated with efavirenz were significant predictors of weaker signal on the diagnostic test.

CONCLUSIONS

In a small proportion of children who start ART in the first months of life and remain on continuous therapy, standard diagnostic HIV PCR tests may result as negative. Repeat testing may resolve uncertainty of diagnosis.

HIV diagnostic algorithm requires confirmatory testing for initial indeterminate or positive screens in the first week of life

BACKGROUND

Risk for nondiagnostic and false-positive HIV testing has not been quantified for neonates.

METHODS

From April 2015 to July 2018, we screened HIV-exposed infants in Botswana less than 96 h from birth by qualitative DNA PCR. Repeat blood draws for DNA and RNA PCR testing occurred for initial positive and indeterminate results to establish final diagnosis. We compared screening DNA PCR cycle threshold values with final HIV status of the child.

RESULTS

Of 10 622 HIV-exposed infants, 10 549 (99.3%) had no HIV DNA detected (negative), 42 (0.4%) had HIV DNA detected (positive), and 31 (0.3%) tested indeterminate at first HIV screen. Repeat testing identified 2 (5.0%) of 40 positive screens (2 declined additional testing) as false positives and confirmed 2 (6.5%) of 31 indeterminate screens as infected. Median cycle threshold value at screening was 28.1 (IQR 19.8--34.8) for children with final positive status, and 35.5 (IQR 32.8--41.4) for indeterminates who were ultimately negative. Six (15%) of 40 infants with final positive status had cycle threshold value greater than 33 at first screen, whereas 3 (9.7%) of 31 indeterminates with final negative status had cycle threshold value 33 or less at first screen. This threshold resulted in a negative predictive value of 82% and a positive predictive value of 92% for a single screen.

CONCLUSION

Although a DNA PCR cycle threshold value of 33 was predictive of the final HIV status in newborns, overlap occurred for true positives, false positives, and initial indeterminates. Testing additional samples should be standard practice for positive and indeterminate HIV DNA PCR tests in the first week of life.

Point-of-care HIV maternal viral load and early infant diagnosis testing around time of delivery at tertiary obstetric units in South Africa: a prospective study of coverage, results return and turn-around times

INTRODUCTION

Maternal viral load monitoring (mVL) and early infant diagnosis (EID) are necessary to achieve elimination of mother-to-child transmission of HIV. Point-of-care testing can achieve better outcomes compared to centralized laboratory testing (CLT). We describe the first implementation of point-of-care (POC) mVL and EID testing around delivery at four high volume tertiary obstetric units (TOUs) in Gauteng, South Africa.

METHODS

Prospective study of pregnant women living with HIV (WLHIV) and their infants. During the period 1 June 2018 to 31 March 2019, routine staff collected blood specimens from women and their infants around delivery. Specimen collection occurred throughout the week while dedicated POC operators, conducted testing during working hours on weekdays. Descriptive statistics and multivariable Poisson regression with robust error variance were used to describe outcomes and associated factors. Outcomes determined were (i) coverage of mVL and EID testing defined as a proportion of live births to WLHIV admitted at each facility (ii) results returned prior to discharge (iii) turn-around time (TAT) and iv) performance of POC testing compared to CLT.

RESULTS

In total, 8147 live births to pregnant WLHIV were recorded in the implementation period. Of these, 2912 mVL and 5074 EID specimens were included in the analysis, with 131 (4.5%) mVL and 715 (14.1%) EID specimens having initial invalid/error results. Overall coverage of POC mVL and EID testing was 35.6% (range 20.9% to 60.1%) and 61.9% (range 47.0% to 88.0%) respectively. Proportions of POC tested mothers and infants with results returned prior to discharge were 74.3% (range 39.0% to 95.7%) and 73.0% (range 50.0 to 97.9%). Return of results was independently associated with TOU, after-hours specimen collection, having an initial invalid or error result and period of implementation. Overall TAT for specimens collected from mother-infant pairs where both had POC testing, during weekdays was longer for EID compared to mVL testing (median 3.3 hours vs. 2.9 hours, p-value sign test <0.001). POC results were comparable to those from laboratory testing.

CONCLUSION

Accurate and timely POC mVL and EID testing around delivery was implemented with variable success across TOUs. Further scale up would need to address health system factors at facility level and high analytical error rates.

Evolving complexities of infant HIV diagnosis within Prevention of Mother-to-Child Transmission programs

Early diagnosis of HIV infection among infants and children is critical as prompt initiation of antiretroviral therapy prevents morbidity and death. Yet despite advances in the accuracy and availability of infant HIV diagnostic testing, there are increasing challenges with making an early definitive diagnosis. These challenges relate primarily to advances in prevention of mother-to-child transmission (PMTCT) of HIV. Although PMTCT programs have proven to be highly effective in reducing infant HIV infection, infants who are HIV-infected may achieve virological suppression and loss of detectability of HIV nucleic acid prior to diagnosis because of antiretroviral drug exposure. Hence, false-negative and indeterminate HIV polymerase chain reaction (PCR) results can occur, especially among high-risk infants given multi-drug prophylactic regimens. However, the infant HIV diagnostic landscape is also complicated by the inevitable decline in the positive predictive value of early infant diagnosis (EID) assays. As PMTCT programs successfully reduce the mother-to-child transmission rate, the proportion of false-positive EID results will increase. Consequently, false-negative and false-positive HIV PCR results are increasingly likely despite highly accurate diagnostic assays. The problem is compounded by the seemingly intractable prevalence of maternal HIV within some settings, resulting in a considerable absolute burden of HIV-infected infants despite a low mother-to-child transmission rate.

Common causes of EID sample rejection in Zimbabwe and how to mitigate them

Early infant diagnosis (EID) of HIV provides an opportunity for early HIV detection and access to appropriate Antiretroviral treatment (ART). Dried Blood Spot (DBS) samples are used for EID of exposed infants, born to HIV-positive mothers. However, DBS rejection rates in Zimbabwe have been exceeding the target of less than 2% per month set by the National Microbiology Reference Laboratory (NMRL), in Harare. The aim of this study was to determine the DBS sample rejection rate, the reasons for rejection and the possible associations between rejection and level of health facility where the samples were collected. This is an analytical cross-sectional study using routine DBS sample data from the NMRL in Harare, Zimbabwe, between January and December 2017.A total of 34 950 DBS samples were received at the NMRL. Of these, 1291(4%) were rejected. Reasons for rejection were insufficient specimen volume (72%), missing request form (11%), missing sample (6%), cross-contamination (6%), mismatch of information (4%) and clotted sample (1%). Samples collected from clinics/rural health facilities were five times more likely to be rejected compared to those from a central hospital. Rejection rates were above the set target of <2%. The reasons for rejection were ‘pre-analytical’ errors including labelling errors, missing or inconsistent data, and insufficient blood collected. Samples collected at primary healthcare facilities had higher rejection rates.

Point-of-care HIV testing best practice for early infant diagnosis: an implementation study

Background

With Universal Health Coverage and Integrated People-centred Health Care, streamlined health-systems and respectful care are necessary. South Africa has made great strides in prevention of mother-to-child transmission (PMTCT) but with the great burden of HIV, a minimum of birth and 10-week HIV-PCR testing are required for the estimated 360,000 HIV-exposed infants born annually which presents many challenges including delayed results and loss to follow-up. Point-of-care (POC) HIV testing of infants addresses these challenges well and facilitates initiation of HIV-infected infants rapidly after diagnosis for best clinical outcomes.

Methods

Objectives were to determine accuracy, feasibility and acceptability of POC testing compared to standard-of-care (SOC) central-laboratory testing. HIV-exposed infants for birth PCR testing in hospital (n = 323) and follow-up at a primary health care clinic (n = 117) in Durban, South Africa were included. A baseline situational-analysis reviewed registers and phoned mothers of HIV-exposed infants prior to the intervention. An effectiveness-implementation study of the Alere™q HIV-1/2 Detect POC test (heel-prick specimen processed in 50 min) was compared with SOC with questionnaires to mothers and staff. Stata 14 was used for analysis.

Results

At baseline 2% of birth HIV tests were missed; only 40% of mothers could be contacted; 17% did not receive birth test result; 19% did not have a 10-week test; 39% had not received the 10-week results. There were 5(1.5%) HIV-infected and 318(98.5%) HIV-negative infants detected in hospital with all clinic babies negative. All positive infants commenced ART before discharge. Ultimately POC and SOC had perfect concordance but for 10 SOC tests researchers actively tracked-down results or repeated tests. Turn around times for SOC tests were on average 8-days (IQR 6-10  days) and for POC testing was 0-days. The POC error-rate was 9,6% with all giving a result when repeated. The majority of mothers (92%) preferred POC testing with 7% having no preference. No staff preferred SOC testing with 79% preferring POC and 21% having no preference.

Conclusions

Point-of-care HIV testing for EID is accurate, feasible and acceptable, with benefits of early ART for all positive infants at birth facilities. We recommend that it be considered best practice for EID.

Trial registration

ISRCTN38911104 registered 9 January 2018 – retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6990-z) contains supplementary material, which is available to authorized users.

Brief Report: Declining Baseline Viremia and Escalating Discordant HIV-1 Confirmatory Results Within South Africa's Early Infant Diagnosis Program, 2010-2016

OBJECTIVE

To describe baseline HIV-1 RNA viral load (VL) trends within South Africa's Early Infant Diagnosis program 2010-2016, with reference to prevention of mother-to-child transmission guidelines.

METHODS

HIV-1 total nucleic acid polymerase chain reaction (TNA PCR) and RNA VL data from 2010 to 2016 were extracted from the South African National Health Laboratory Service's central data repository. Infants with a positive TNA PCR and subsequent baseline RNA VL taken at age <7 months were included. Descriptive statistics were performed for quantified and lower-than-quantification limit (LQL) results per annum and age in months. Trend analyses were performed using log likelihood ratio tests. Multivariable linear regression was used to model the relationship between RNA VL and predictor variables, whereas logistic regression was used to identify predictors associated with LQL RNA VL results.

RESULTS

Among 13,606 infants with a positive HIV-1 TNA PCR linked to a baseline RNA VL, median age of first PCR was 57 days and VL was 98 days. Thirteen thousand one hundred ninety-five (97.0%) infants had a quantified VL and 411 (3.0%) had an LQL result. A significant decline in median VL was observed between 2010 and 2016, from 6.3 log10 (interquartile range: 5.6-6.8) to 5.6 log10 (interquartile range: 4.2-6.5) RNA copies per milliliter, after controlling for age (P < 0.001), with younger age associated with lower VL (P < 0.001). The proportion of infants with a baseline VL <4 Log10 RNA copies per milliliter increased from 5.4% to 21.8%. Subsequent to prevention of mother-to-child transmission Option B implementation in 2013, the proportion of infants with an LQL baseline VL increased from 1.5% to 6.1% (P < 0.001).

CONCLUSIONS

Between 2010 and 2016, a significant decline in baseline viremia within South Africa's Early Infant Diagnosis program was observed, with loss of detectability among some HIV-infected infants.

Differentiating clearly positive from indeterminate results: A review of irreproducible HIV-1 PCR positive samples from South Africa's Early Infant Diagnosis Program, 2010-2015

We describe the extent of and variables associated with irreproducible HIV-1 PCR positive results within South Africa's Early Infant Diagnosis (EID) program from 2010 to 2015 and propose criteria for differentiating indeterminate from clearly positive results using the COBAS® AmpliPrep/COBAS® TaqMan HIV-1 Qualitative Test version 2.0 (CAP/CTM Qual v2.0). Fourteen percent of specimens with an instrument-positive result that were repeat-tested yielded a negative result for which cycle threshold (Ct) proved to be the only predictive variable. A Ct <33.0 was found to be the most accurate threshold value for differentiating clearly positive from irreproducible cases, correctly predicting 96.8% of results. Among 70 patients with an irreproducible positive result linked to a follow up HIV-1 PCR test, 67 (95.7%) were negative and 3 (4.3%) were instrument-positive. Criteria differentiating clearly positive from indeterminate results need to be retained within EID services and infants with indeterminate results closely monitored and final HIV status determined.

Prevalence and outcomes of HIV-1 diagnostic challenges during universal birth testing - an urban South African observational cohort

Introduction: HIV‐1 polymerase chain reaction (PCR) testing at birth aims to facilitate earlier initiation of antiretroviral therapy (ART) for HIV‐infected neonates. Data from two years of universal birth testing implementation in a high‐burden South African urban setting are presented to demonstrate the prevalence and outcomes of diagnostic challenges in this context.

Methods: HIV‐exposed neonates born at Rahima Moosa Mother and Child Hospital between 5 June 2014 and 31 August 2016 were routinely screened at birth for HIV‐1 on whole blood samples using the COBAS® AmpliPrep/COBAS® TaqMan (CAP/CTM) HIV‐1 Qualitative Test, version 2.0 (Roche Molecular Systems, Inc., Branchburg, NJ, USA). Virological results were interpreted according to standard operating procedures with the South African National Health Laboratory Service. All neonates with non‐negative results were actively followed‐up and categorized according to HIV infection status as positive, negative, uncertain and lost to follow‐up (LTFU).

Results: 104 (1.8%) of 5743 HIV‐exposed neonates received a non‐negative birth PCR result, for which laboratory data were available for 102 (98%) cases – 78 (76%) tested positive and 24 (24%) indeterminate. HIV infection status was confirmed positive in 83 (81%) infants, negative in 8 (8%), uncertain in 5 (5%) and LTFU in 6 (6%) cases. The positive predictive value (excluding cases of uncertain diagnosis and inadequate testing) following a non‐negative HIV‐1 PCR screening test at birth was 0.91 (83/91; 95% confidence interval: 0.85–0.96). Neonates testing positive at birth had significantly higher viral load (VL) results than those testing indeterminate at birth of 4.5 and 3.0 log copies/ml (p = 0.0007), respectively. Similarly, mothers of neonates with positive as compared to indeterminate birth test results had higher VLs of 4.5 and 2.7 log copies/ml (p = 0.0013), respectively. Half of neonates with an indeterminate birth test were shown to be HIV‐infected on subsequent confirmatory testing, with time to final diagnosis 30 days longer for these neonates (p < 0.0001).

Conclusion: Indeterminate HIV‐1 PCR results accounted for a quarter of non‐negative results at birth and were associated with a high risk of infection in comparison to the risk of in utero transmission. Indeterminate birth results with positive HIV PCR results on repeat testing were associated with later final diagnosis. The HIV‐1 status remains uncertain in a minority of cases because of repeatedly indeterminate results, highlighting the need for more sensitive and specific virological tests.

Field Evaluation of Performance of Alere and Cepheid Qualitative HIV Assays for Pediatric Point-of-Care Testing in an Academic Hospital in Soweto, South Africa

Point-of-care (POC) technologies for HIV diagnosis in infants have the potential to overcome logistical challenges that delay treatment initiation and prevent improvements in morbidity and mortality. This study aimed to evaluate the performance of two POC technologies against the current standard-of-care (SOC) laboratory-based assay in South Africa, when operated by nurses in a hospital environment. Children <18 months of age who were treatment naive (excluding prophylaxis) and in whom an HIV PCR test was indicated were eligible for the study. To increase the rate of enrollment of HIV PCR-positive children, HIV-exposed neonates at high risk of mother-to-child transmission and children requiring confirmatory HIV testing were preferentially enrolled. The two POC technologies demonstrated excellent concordance, with 315 (97.8%) results consistent with the SOC result. The POC technologies yielded 102 positive and 220 negative tests each. The SOC assay had 101 positive, 214 negative, 4 indeterminate, 1 invalid, and 2 specimen-rejected results. To include the indeterminate results in sensitivity/specificity calculations, a sensitivity analysis was performed, which yielded a simulated sensitivity of 0.9904 (interquartile range [IQR], 0.9808 to 0.9904) and a specificity of 0.9954 (IQR, 0.9954 to 1.0). This study confirmed that both POC technologies can be successfully used outside the laboratory environment to yield precise sensitivity/specificity values for pediatric, including neonatal, HIV testing.