Abstract
BACKGROUNDThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a novel viral pneumonia (COVID-19), which is rapidly spreading throughout the world. The positive result of nucleic acid test is a golden criterion to confirm SARS-CoV-2 infection, but the detection features remain unclear.METHODSWe performed a retrospective analysis in 5630 high-risk individuals receiving SARS-CoV-2 nucleic acid tests in Wuhan, China, and investigated their characteristics and diagnosis rates.RESULTSThe overall diagnosis rate was 34.7% (1952/5630). Male (P = 0.025) and older populations (P = 2.525 × 10-39) were at significantly higher risk of SARS-CoV-2 infection. People were generally susceptible, and most cases concentrated in people of 30-79 years. Furthermore, we investigated the association between diagnosis rate and the amount of testing in 501 subjects. Results revealed a 1.27-fold improvement (from 27.9% to 35.5%) of diagnosis rate from testing once to twice (P = 5.847 × 10-9) and a 1.43-fold improvement (from 27.9% to 39.9%) from testing once to 3 times (P = 7.797 × 10-14). More than 3 testing administrations was not helpful for further improvement. However, this improvement was not observed in subjects with pneumonia (P = 0.097).CONCLUSIONAll populations are susceptible to SARS-CoV-2 infection, and male and older-aged populations are at significantly higher risk. Increasing the amount of testing could significantly improve diagnosis rates, except for subjects with pneumonia. It is recommended to test twice in those high-risk individuals whose results are negative the first time, and performing 3 tests is better, if possible.FUNDINGThis work was supported by National Mega Project on Major Infectious Disease Prevention (no. 2017ZX10103005-007) and National Key Research and Development Program of China (no. 2018YFE0204500).