Microorganisms
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Since mid-November 2019, when the first SARS-CoV-2-infected patient was officially reported, the new coronavirus has affected over 10 million people from which half a million died during this short period. There is an urgent need to monitor, predict, and restrict COVID-19 in a more efficient manner. This is why Auto-Regressive Integrated Moving Average (ARIMA) models have been developed and used to predict the epidemiological trend of COVID-19 in Ukraine, Romania, the Republic of Moldova, Serbia, Bulgaria, Hungary, USA, Brazil, and India, these last three countries being otherwise the most affected presently. ⋯ Several ARIMA models were formulated with different ARIMA parameters. ARIMA (1, 1, 0), ARIMA (3, 2, 2), ARIMA (3, 2, 2), ARIMA (3, 1, 1), ARIMA (1, 0, 3), ARIMA (1, 2, 0), ARIMA (1, 1, 0), ARIMA (0, 2, 1), and ARIMA (0, 2, 0) models were chosen as the best models, depending on their lowest Mean Absolute Percentage Error (MAPE) values for Ukraine, Romania, the Republic of Moldova, Serbia, Bulgaria, Hungary, USA, Brazil, and India (4.70244, 1.40016, 2.76751, 2.16733, 2.98154, 2.11239, 3.21569, 4.10596, 2.78051). This study demonstrates that ARIMA models are suitable for making predictions during the current crisis and offers an idea of the epidemiological stage of these regions.
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Rapid and sensitive screening of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential to limit the spread of the global pandemic we are facing. Quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) is currently used for the clinical diagnosis of SARS-CoV-2 infection using nasopharyngeal swabs, tracheal aspirates, or bronchoalveolar lavage (BAL) samples. Despite the high sensitivity of the qRT-PCR method, false negative outcomes might occur, especially in patients with a low viral load. ⋯ Notably, patients with few copies of SARS-CoV-2 RNA (<5 copies/reaction) were successfully detected by the novel multiplex qRT-PCR method. Finally, we assessed the efficacy of multiplex qRT-PCR on human nasopharyngeal swabs without RNA extraction. Collectively, our results provide evidence of a novel and reliable tool for SARS-CoV-2 RNA detection in human specimens, which allows the testing capacity to be expanded and the RNA extraction step to be bypassed.