Point-of-Care Testing of HIV-Exposed Infants Improves Linkage to Care

A study published recently in the Lancet HIV found that point-of-care testing (POCT) of HIV-exposed infants at birth increases overall result return rates and reduces time to result and time to antiretroviral therapy initiation.

“We found that POCT at birth compared very well with the standard-of-care laboratory-based test with high sensitivity and specificity, and thus appears to be a reliable method that could be used to test for HIV in newborn babies instead of using the current standard of care, but this requires further study of the necessary logistics,” Dr Karl-Günter Technau, senior medical officer, Empilweni Services and Research Unit, Department of Paediatrics & Child Health, Rahima Moosa Mother and

Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa, said in an email interview with Infectious Disease Advisor.

“With the new guideline of birth HIV PCR testing, it was important to us to document the experiences and evaluate the testing method at the time of birth,” he added.

An observational cohort study of routine universal birth HIV screening included a field evaluation study of POCT (Xpert HIV-1 Qualitative assay) conducted at Rahima Moosa Mother and Child Hospital in Johannesburg, South Africa. Of 4141 mothers carrying HIV-exposed infants who were offered HIV testing at birth, 4112 (96%) consented to testing and 4034 (93%) had laboratory-based testing (LABT). Of the mothers who underwent LABT, 3970 (98%) agreed to enroll in the field evaluation study and 2238 (56%) of those 3970 also underwent concurrent POCT.

LABT assessed HIV status (positive vs negative) and distinguished between indeterminate and error results; POCT revealed the following results: HIV status (detected vs not detected), error, invalid, and no result. A positive result on either of the 2 tests prompted antiretroviral therapy initiation and an additional round of testing via repeat LABT and an HIV viral load test.

POCT proved to be an accurate and useful tool for HIV testing of neonates: It detected all 30 cases of HIV (sensitivity, 100%; 95% CI, 88.4-100), as well as 2 false-positives (specificity, 99.9%; 95% CI, 99.7-100). The percentage of positive (100%) and negative (96.2%) POCT results returned to mothers was higher compared with the percentage of returned positive (88.9%) and negative (52.8%) LABT results. Because of active tracing, positive LABT results were returned at a similar rate as positive POCT results. The median time of POCT result return was 1 day, which is significantly earlier than 10 days typically needed for LABT result return (P <.0001). Antiretroviral therapy was initiated in 100% of infants with positive POCT results, a median of 5 days earlier, compared with 88.9% of infants with positive LABT only.

“Evaluation of point-of-care testing is important and should be done at all points where testing is likely to be performed,” emphasized Dr Technau. “With the new guideline of birth HIV PCR testing, it was important to us to document the experiences and evaluate the testing method at the time of birth.”

Although the findings of this study demonstrated that early infant diagnosis POCT can potentially improve the outcomes for HIV-infected children, additional research is warranted before this approach can become standard routine practice.

“Further evaluations will be needed to assess the costs and feasibility and whether it will be advisable to introduce this into national programs or not, or whether to consider partial implementation in specific sites or for specific groups of HIV-exposed infants,” said Dr Technau, who concluded: “Implementation will likely be different in different sites with different staff complements and patient loads, and this must still be further investigated so that policy makers can make decisions as to what will be appropriate for different settings and countries.”

Reference

1. Technau KG, Kuhn L, Coovadia, A, et al. Xpert HIV-1 point-of-care test for neonatal diagnosis of HIV in the birth testing programme of a maternity hospital: a field evaluation study [published online July 12, 2017]. Lancet HIV. doi: 10.1016/S2352-3018(17)30097-8