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Objectives The high diagnostic accuracy indices for saliva SARS-CoV-2 reverse-transcriptase polymerase chain reaction (RT-PCR) reported in adults has not been demonstrated in children and adequately powered studies focused on the paediatric population are lacking. This study was carried out to determine the diagnostic accuracy of saliva for SARS-CoV-2 RT-PCR in ambulatory children. Methods From 1 st -23 rd October 2020, we recruited a population-based sample of children presenting for COVID-19 screening in Dubai, United Arab Emirates. Each child provided paired nasopharyngeal (NP) swab and saliva for SARS-CoV-2 RT-PCR N , E and RdRp genes detection. Results Paired NP swab and saliva samples were obtained from 476 children with mean (±SD) age of 10.8 years (±3.9) and 58.1% were male (n/N=277/476). Nine participants were sampled twice, hence 485 pairs of NP swab/saliva were tested. Viral detection in at least one specimen type was reported in 17.9% (n/N=87/485), with similar detection in NP swab (16.7%; n/N=81/485) and saliva (15.9%; n/N=77/485). Sensitivity and specificity of saliva RT-PCR was 87.7% (95% CI 78.5%-93.9%) and 98.5% (95% CI 96.8%-99.5%). The positive and negative predictive values were 92.2% (95% CI 84.2%-96.3%) and 97.6% (95% CI 95.7%-98.6%) with Kappa coefficient 0.879 (95% CI 0.821-0.937). Concordance of findings between NP swab and saliva did not differ by age (p=0.67) or gender (p=0.29). Cycle threshold (Ct) values were significantly higher in NP swab/saliva pairs with discordant findings compared to those with both specimens positive. Conclusion In light of these findings, we recommend saliva as a diagnostic specimen for COVID-19 screening in children.

We report the first case of native aortic and mitral valve endocarditis due toGemella bergeriaefrom the Middle East in a young patient with rheumatic heart disease. Our case illustrates a fulminant course of infection withG. bergeriaeendocarditis that was complicated by embolic stroke, as well as intracerebral and subarachnoid haemorrhage secondary to rupture of a mycotic aneurysm in the right middle cerebral artery. This case highlights the dire, unreported neurological complications of infective endocarditis due to a rare causative organism—G. bergeriae.

Background With the gradual reopening of economies and resumption of social life, robust surveillance mechanisms should be implemented to control the ongoing COVID-19 pandemic. Unlike RT-qPCR, SARS-CoV-2 whole genome sequencing (cWGS) has the added advantage of identifying cryptic origins of the virus, and the extent of community-based transmissions versus new viral introductions, which can in turn influence public health policy decisions. However, the practical and cost considerations of cWGS should be addressed before it is widely implemented. Methods We performed shotgun transcriptome sequencing using RNA extracted from nasopharyngeal swabs of patients with COVID-19, and compared it to targeted SARS-CoV-2 genome amplification and sequencing with respect to virus detection, scalability, and cost-effectiveness. To track virus origin, we used open-source multiple sequence alignment and phylogenetic tools to compare the assembled SARS-CoV-2 genomes to publicly available sequences. Results We found considerable improvement in whole genome sequencing data quality and viral detection using amplicon-based target enrichment of SARS-CoV-2. With enrichment, more than 99% of the sequencing reads mapped to the viral genome compared to an average of 0.63% without enrichment. Consequently, an increase in genome coverage was obtained using substantially less sequencing data, enabling higher scalability and sizable cost reductions. We also demonstrated how SARS-CoV-2 genome sequences can be used to determine their possible origin through phylogenetic analysis including other viral strains. Conclusions SARS-CoV-2 whole genome sequencing is a practical, cost-effective, and powerful approach for population-based surveillance and control of viral transmission in the next phase of the COVID-19 pandemic.