Abstract Body

Point-of-Care (PoC) HIV testing for early infant diagnostics (EID) enables nurse-based, decentralized testing with the potential to replace centralized laboratory EID procedures which are complicated by linkage. Additionally, PoC maternal viral load (VL) monitoring around delivery can immediately identify high VL as a risk factor for mother-to-child transmission. In our study we investigated the operational feasibility and accuracy of a novel PoC technology for EID and maternal VL monitoring in primary obstetric health centers in Mbeya, Tanzania.

In this prospective cohort study we included HIV-infected pregnant women and their exposed infants during delivery. Maternal plasma HIV-RNA monitoring was performed by quantitative HIV PoC testing (Cepheid Xpert HIV-1 Quant) during delivery. Nurse based qualitative HIV EID PoC testing (Cepheid Xpert HIV-1 Qual) was performed at birth, and after 1, 2, 3 and 6 weeks postpartum. Maternal viral loads and positive EID PoC test results were confirmed from plasma and infants dry blood spots (DBS) using the Roche COBAS TaqMan system. HIV negativity in infants was confirmed from DBS at the last study visit.

Between July 2015 and August 2016, 600 mother-child pairs were included, and 15 (2.5%) infants were diagnosed HIV positive. Of those 11 (73%) were diagnosed at birth suggesting intra-uterine infection, and 4 were either detected at week 1, 2 or 3 suggesting peripartal transmission. The Xpert HIV-1 Qual PoC test correctly identified all HIV infected and non-infected infants (no false positive or negative test results). In mothers we found a good agreement between the quantitative Xpert HIV-1 Quant PoC test and the TaqMan plasma HIV-RNA, however, the Xpert HIV-1 Quant HIV-RNA results indicated slightly higher viral loads as compared to the TaqMan with a mean difference of 0.34 log10 (range -0.46 to 1.14). PoC test procedures were well accepted by nurses/midwives and mothers.

We could demonstrate an excellent Xpert HIV-1 PoC test performance and operational feasibility for EID at birth up to week 6 and maternal viral load monitoring at delivery. Both tests have the potential to facilitate rapid infant antiretroviral treatment initiation or use of enhanced postnatal infant prophylaxis.