Cobas ampliprep cobas taqman system

We stored DBS and plasma samples at -20°C and -80°C respectively, tested on site using robust affordable real-time PCR instruments (Mini-opticon). We transported plasma samples in dry-ice to the reference laboratory in Kampala for the reference testing (VL_ref) using the COBASAmpliPrep/ COBASTaqManSystem,Roche version 2.

Reverse transcription polymerase chain reaction (RT-PCR) was used to determine plasma HIV RNA levels. The process was performed using the COBAS® AmpliPrep®/COBAS Taqman system (Roche Diagnostic Systems, Indianapolis, IN, USA); the detection range of this assay is 20–10,000,000 copies/mL. The manufacturer's reference standards were used to calculate HIV RNA copy number.

Serum HBV DNA was quantified by quantitative polymerase chain reaction (qPCR) using a Roche COBAS AmpliPrep/COBAS TaqMan system (Roche Diagnostics, Mannheim, Germany) with a lower detection limit of 20 IU/mL. HBV genotypes were determined by real-time PCR with a commercial kit (Shanghai ZJ Bio-Tech, China). HBsAg, HBeAg, anti-HBs, anti-HBe, and anti-HBc were quantitated by chemiluminescence microparticle immunoassays using the Architect i2000SR platform and Abbott Architect reagents (Abbott Laboratories, Chicago, IL) according to manufactures’ instruction. Laboratory assessments were performed at baseline, week 4, week 12, week 24, week 36, and week 48.

The NSEBA Demonstration Project was conducted in Choma District, Southern Province, Zambia, in 2018–2019 and was nested within the Novel Screening for Exposed Babies (NSEBA) Study. In Southern Province, the HIV prevalence was estimated to be 13.3% among adults 15–59 years of age in 2016 [18 ]. At the time of the study, universal treatment of HIV-infected pregnant women was the standard of care [19 ], and testing for EID was recommended at birth, 6 weeks and 6 months of age with a nucleic acid test, and at 9, 12 and 18–24 months of age and at least 6 weeks after breastfeeding cessation with a serologic test [19 ]. In the study area, the standard of care was for DBS samples to be collected at the clinics and transported by the Ministry of Health to a central laboratory at Choma General Hospital for EID testing (COBAS^® AmpliPrep/COBAS^® TaqMan^® Systems [Roche Diagnostics, Risch-Rotkreuz, Switzerland]). Hardcopy results were transported back to the clinics using the same transport system. As the time for results to return to the clinics was variable, mothers typically received the result at their next clinic visit. In the event of a positive result, mothers were contacted by clinic staff to return as soon as possible.