Evaluating the performance of the GeneXpert HIV-1 qualitative assay as a consecutive test for a new early infant diagnosis algorithm in South Africa.

BACKGROUND: The proportion of HIV-exposed infants and young children infected with HIV in South Africa (SA) has declined markedly over the past decade as a result of the country's comprehensive prevention of mother-to-child transmission programme. This decrease has in turn reduced the positive predictive value (PPV) of diagnostic assays, necessitating review of early infant diagnosis (EID) algorithms to ensure improved accuracy. OBJECTIVES: To evaluate the performance of the GeneXpert HIV-1 qualitative assay (Xpert EID) as a consecutive test for infants with an 'HIV-detected' polymerase chain reaction screening test at birth. METHODS: We retrospectively analysed a longitudinal cohort of HIV-exposed infants on whom birth testing was performed, using whole-blood ethylenediaminetetra-acetic acid samples, from four tertiary sites in Gauteng Province between June 2014 and December 2019. Birth samples from all infants with a Cobas AmpliPrep/Cobas TaqMan HIV-1 Qualitative Test v2.0 (CAP/CTM v2.0) HIV-detected screening test, a concurrent Xpert EID test and a subsequent confirmatory CAP/CTM v2.0 test on a separate specimen were included. Performance of the Xpert EID in predicting final HIV status was determined as proportions with 95% confidence intervals (CIs). A comparison of indeterminate CAP/CTM v2.0 results, as per National Health Laboratory Service resulting practice, with discordant CAP/CTM v2.0 v. Xpert EID results was performed. RESULTS: Of 150 infants who met the inclusion criteria, 6 (3.9%) had an Xpert EID result discordant with final HIV status: 5 (3.3%) were false negatives and 1 (0.7%) was false positive. As a consecutive test, the Xpert EID yielded a sensitivity of 96.5% (95% CI 92 - 98.9), specificity of 85.7% (95% CI 42.1 - 99.6), PPV of 99.3% (95% CI 95.7 - 99.9), negative predictive value of 54.5% (95% CI 32.5 - 74.9) and overall accuracy of 96.1% (95% CI 91.5 - 98.5). Using discordant CAP/CTM v2.0/Xpert EID results as criteria to verify indeterminate results instead of current practice would have reduced the number of indeterminate screening results by 42.1%, from 18 (12.6%) to 11 (7.2%), without increasing the false-positive rate. CONCLUSIONS: Addition of the Xpert EID as a consecutive test for specimens with an HIV-detected PCR screening result has the potential to improve the PPV and reduce the indeterminate rate, thereby reducing diagnostic challenges and time to final status, in SA's EID programme.

Universal newborn hearing screening in public healthcare in South Africa: Challenges to implementation

Background. The implementation of early hearing detection and intervention (EHDI) remains a challenge in developing countries, despite the known benefits.Objectives. To investigate challenges encountered during implementation of universal newborn hearing screening (UNHS) at a secondarylevel public hospital in Johannesburg, South Africa.Methode. A prospective cohort study design that assessed the feasibility of conducting UNHS was adopted. This feasibility assessment was conducted during a 3-month period, and all challenges encountered were identified and documented. Screening time was also recorded for each neonate. Data were entered into Excel, and later analysed using Stata version 11.Results. Of 2 740 neonates born during the study period, 490 (17.9%) were identified for screening, and distortion product otoacoustic emissions screening was conducted on 121 (4.4%). The majority (74.4%) were screened in the first 24 hours of life. Repeat screening was required in 57 (47.1%) neonates, but only 20 returned for follow-up. The most important challenges to the feasibility of UNHS implementation were the insufficient number of audiologists available to provide screening, the high rate of false positive test results and the unacceptably high rates of loss to follow-up. Two modifiable factors, namely the presence of vernix caseosa in the external ear canal and high ambient noise levels, were found to have significantly influenced the screening process. Conclusion. The identified challenges are important considerations for any successful implementation of universal screening protocols.Careful planning to mitigate the challenges will have a positive impact on EHDI initiatives in these contexts

HIV-associated neurodevelopmental delay: prevalence, predictors and persistence in relation to antiretroviral therapy initiation and viral suppression.

CONTEXT: HIV infection in infancy may influence the developing brain, leading to adverse neurodevelopmental consequences. OBJECTIVE: We aim to describe neurodevelopmental characteristics of a cohort of HIV-infected infants and young children prior to antiretroviral therapy (ART) initiation and after achieving viral suppression. METHODS: As part of the Neverest 2 trial, 195 HIV-infected children under 2 years of age were assessed using the Ages and Stages Questionnaire (ASQ) prior to ART initiation and at subsequent age-appropriate time points after ART had been started. The ASQ is a simple screening questionnaire used to identify children at risk of neurodevelopmental delays. Questionnaires completed by the parent/caregiver assess neurodevelopmental functioning in five domains: communication, gross motor, fine motor, problem solving and personal-social. RESULTS: Median age pre-ART was 8.8 months (range 2.2-24.9) and 53.9% were male. Mean time to viral suppression was 9.4 months (range 5.9-14.5). Compared with pre-ART better outcomes were reported at time of viral suppression with a lower proportion of children failing the gross motor (31.5% vs. 13%, p = 0.0002), fine motor (21.3% vs. 10.2%, p = 0.017), problem solving (26.9% vs. 9.3%, p = 0.0003) and personal-social (19.6% vs. 7.4%, p = 0.019) domains. However, there was no change in the communication domain (14.8% vs. 12.0%, p = 0.6072). CONCLUSION: Although achieving viral suppression on ART resulted in significant improvements in markers of neurodevelopmental function of young HIV-infected children, potential neurodevelopmental delays still persisted in a large proportion. Further interventions are needed to limit potential disabilities and maximize developmental outcomes.

Developmental status of preschool children receiving cART: a descriptive cohort study.

BACKGROUND: HIV is known to cause neurodevelopmental problems in infants and young children. The impact of HIV on the development of preschool-age children has been less well described. METHOD: The study was conducted at an urban paediatric HIV clinic in Johannesburg, South Africa. A sample of convenience was used. Sixty-eight medically stable children between the ages of 3 and 5 years were assessed with the Griffiths Scales of Mental Development. Children were excluded from the study if they had severe HIV encephalopathy, which made it impossible for them to participate in the items on the Griffiths Scales of Mental Development. RESULTS: The children had started combination antiretroviral treatment (cART) at a mean age of 8.1 months. The majority of the children were virologically suppressed and did not present with wasting or stunting. Severe overall developmental delay (z-scores < -2SD) was detected in 55.88% of children. Developmental facets related to speech, cognition and perception were the most severely affected. Personal-social development was the least affected with only 13.4% of the children demonstrating severe delay. CONCLUSION: Despite having early access to cART, children infected with HIV are still at risk for severe developmental delay across a number of facets. Very early initiation of cART may help alleviate this problem. All preschool children infected with HIV should have routine developmental screening.