Abstract
The sensitivity of SARS-CoV-2 diagnostic tests is inherently linked to viral load. We explored whether average viral loads changed at a population level in Queensland, Australia during the early phase of the pandemic. RT-PCR threshold cycle (C T ) values, a crude marker for viral load, were compared for samples collected in February/March-2020 to those collected in April/May-2020, noting that the major public health interventions began in late-March 2020. Positive detections peaked mid-March, which coincided with the highest detection numbers and lowest C T values. However, this changed from April where the later C T samples (C T > 30) predominated. Overall, in February/March 29% (267/922) of samples had C T values >30 cycles compared to 88% (559/636) in April/May. Our study shows that SARS-CoV-2 viral loads in patients may vary at a population level over time. This needs considering when assessing suitability of diagnostic methods, particularly when methods in question are known to have reduced sensitivity.
Keywords: SARS-CoV-2; diagnosis; phase; viral load.
【저자키워드】 SARS-CoV-2, Diagnosis, Viral load, phase, 【초록키워드】 pandemic, diagnostic test, RT-PCR, sensitivity, Viral load, diagnostic tests, Patient, diagnostic methods, threshold, marker, Public health intervention, early phase, SARS-CoV-2 viral load, average, population level, SARS-CoV-2 viral loads, lowest, highest, collected, peaked, reduced, question, changed, 【제목키워드】 SARS-CoV-2 testing, COVID-19 epidemic, implication, changes in,