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Summary: Background: Antigen-detecting rapid diagnostic tests (Ag-RDTs) for SARS-CoV-2 are important diagnostic tools. We assessed clinical performance and ease-of-use of seven Ag-RDTs in a prospective, manufacturer-independent, multi-centre cross-sectional diagnostic accuracy study to inform global decision makers. Methods: Unvaccinated participants suspected of a first SARS-CoV-2 infection were recruited at six sites (Germany, Brazil). Ag-RDTs were evaluated sequentially, with collection of paired swabs for routine reverse transcription polymerase chain reaction (RT-PCR) testing and Ag-RDT testing. Performance was compared to RT-PCR overall and in sub-group analyses (viral load, symptoms, symptoms duration). To understandusability a System Usability Scale (SUS) questionnaire and ease-of-use (EoU) assessment were performed. Findings: 7471 participants were included in the analysis. Sensitivities across Ag-RDTs ranged from 70·4%-90·1%, specificities were above 97·2% for all Ag-RDTs but one (93·1%).Ag-RDTs, Mologic, Bionote, Standard Q, showed diagnostic accuracy in line with WHO targets (> 80% sensitivity, > 97% specificity). All tests showed high sensitivity in the first three days after symptom onset (≥87·1%) and in individuals with viral loads≥ 6 log10SARS-CoV2 RNA copies/mL (≥ 88·7%). Usability varied, with Rapigen, Bionote and Standard Q reaching very good scores; 90, 88 and 84/100, respectively. Interpretation: Variability in test performance is partially explained by variable viral loads in population evaluated over the course of the pandemic. All Ag-RDTs reach high sensitivity early in the disease and in individuals with high viral loads, supporting their role in identifying transmission relevant infections. For easy-to-use tests, performance shown will likely be maintained in routine implementation. Funding: Ministry of Science, Research and Arts, State of Baden-Wuerttemberg, Germany, internal funds from Heidelberg University Hospital, University Hospital Charité − Universitätsmedizin Berlin, UK Department of International Development, WHO, Unitaid.

A new point-of-care HIV viral load, mPIMA HIV-1/2 VL, Abbott, USA, has been recently developed. This point-of-care viral load requires no skilled person to run and uses a small plasma volume (50 μL). However, obtaining 50 μL of plasma can be a challenge in limited resource settings. We validated a simple and easy method to obtain enough amount of plasma to run a point-of-care viral load. The study utilized 149 specimens from patients failing antiretroviral therapy. At least 250 μL of whole blood was collected in a microtube/EDTA from fingerstick (fs-plasma) and immediately centrifuged. Parallel collection of venous blood to obtain plasma (vp-plasma) was used to compare performance in a point-of-care viral load assay and in methodology used in centralized laboratories Abbott M2000, Abbott, USA. The procedure for plasma collection takes less than 10 min and in 94% of the cases only one fingerstick was sufficient to collect at least 250 μL of blood. The Pearson correlation coefficient value for vp-plasma versus fs-plasma ran on mPIMA was 0.990. The Bland–Altman mean difference (md) for this comparison were virtually zero (md = −0.001) with limits of agreement between −0.225 and 0.223. In addition, the Pearson correlation coefficient value for fs-plasma in mPIMA versus vp-plasma in Abbott M2000 was 0.948 for values above the mPIMA limit of quantification (LoQ; from 800 to 1,000,000 copies/mL). These results validate this simple plasma isolation method capable to be implemented in low resource countries where point-of-care decentralization is deeply needed.

Background and rationale. Epidemics of hepatitis B and C are a public health burden, and their prevalence in Brazil varies among regions. We determined the prevalence of hepatitis markers in an urban university population in order to support the development of a comprehensive program for HBV immunization and HBV/HCV diagnosis. Students, employees, and visitors (n = 2,936, 31 years IQR 24.5-50, female = 69.0% and 81.1% with at least 12 years of education) were enrolled from May to November 2013. Antibodies against hepatitis B surface antigen (anti-HBs), against hepatitis B core antigen (anti-HBc), and hepatitis B surface antigen (HBsAg) were detected with enzyme immunoassays and anti-hepatitis C virus (anti-HCV) antibodies with a chemiluminescence immunoassay. The results were confirmed with polymerase chain reaction for HCV and nucleic acid amplification test for hepatitis B virus (HBV).Results. The overall prevalence of markers among the participants was 0.136% (95% confidence interval [CI]: 0.003-0.270) for HBsAg, 6.44% (95% CI: 5.55-7.33%) for anti-HBc, 50.8% (95% CI: 48.9-52.7%) for anti-HBs > 10 mIU/mL, and 0.44% (95% CI: 0.20-0.68) for anti-HCV. Almost 30.4% had anti-HBs titers > 100 mIU/mL. Participants with a detectable HCV viral load (n = 9) were infected with genotype 1a.Conclusions. In an urban university population, in which 80% of participants had > 11 years of education, prevalence increased with age, and self-declared ethnicity for anti-HBc and with age, marital status and professional activity for anti-HCV antibodies. A periodical offer of HCV rapid testing should be implemented, and HBsAg rapid testing should be offered to individuals above 20 years of age.