ArticleJournal of clinical virology : the official publication of the Pan American Society for Clinical Virology2022
SARS-CoV-2 cycle threshold (Ct) values predict future COVID-19 cases.
Article in Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers.
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Who cites it
16 citing papers in PubMed.
- Article
- Hospital SARS-CoV-2 surveillance across inpatient testing, fever clinic, and general outpatient settings: positivity, Ct gradients, and short-lag warning signals.Frontiers in public health · 2026Observational
- Nationwide population-level influenza cycle threshold values and trends in influenza incidence: a longitudinal study.Scientific reports · 2025Article
- Semi-quantitative software evaluation of COVID-19 CT examinations-correlation with clinical parameters.Journal of thoracic disease · 2025Article
- Comparative Analysis of RT-PCR and a Colloidal Gold Immunochromatographic Assay for SARS-CoV-2 Detection.Diagnostics (Basel, Switzerland) · 2025Article
- Article
- Estimating the time-varying effective reproduction number via Cycle Threshold-based Transformer.PLoS computational biology · 2024Article
- Comparison of a Commercial SARS-CoV-2 Rapid Antigen Test with Real-Time PCR.Infectious diseases & clinical microbiology · 2024Article
- Cycle Threshold Values of SARS-CoV-2 RT-PCR during Outbreaks in Nursing Homes: A Retrospective Cohort Study.Epidemiologia (Basel, Switzerland) · 2024Article
- Using intrahost single nucleotide variant data to predict SARS-CoV-2 detection cycle threshold values.PloS one · 2024Article
- Standardization and Comparison of Emergency Use Authorized COVID-19 Assays and Testing Laboratories.medRxiv : the preprint server for health sciences · 2023Article
- Systematic Review on the Correlation Between SARS-CoV-2 Real-Time PCR Cycle Threshold Values and Epidemiological Trends.Infectious diseases and therapy · 2023Review
- Article
- Associations of SARS-CoV-2 cycle threshold values with age, gender, sample collection setting, and pandemic period.Revista do Instituto de Medicina Tropical de Sao Paulo · 2023Article
- Population-level median cycle threshold (Ct) values for asymptomatic COVID-19 cases can predict the trajectory of future cases.PloS one · 2023Article
- Bimodal distribution pattern associated with the PCR cycle threshold (Ct) and implications in COVID-19 infections.Scientific reports · 2022Article
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Authors and funding
5 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
aimAnticipating local surges in COVID-19 cases has predominantly been based on observation of increasing cases. We sought to determine if temporal trends in SARS-CoV-2 Cycle threshold (Ct) values from clinical testing were predictive of future cases.
methodsData were collected from a large, safety-net hospital in Los Angeles, California. Ct values for all SARS-CoV-2 detections by the GeneXpert system (Cepheid) between October 2020 to March 2021 were analyzed.
resultsA total of 2,114 SARS-CoV-2-positive samples were included. Cases increased dramatically in December 2020, peaking the first week of January, before returning to pre-surge numbers by mid-February. Ct values fell during this same period, with values in December and January (25.6 ± 7.8 and 27±7.9, respectively) significantly lower than those of the other months (30±9.3 to 37.7 ± 6.3). Average weekly Ct values for all patients negatively correlated with the number of tests run two weeks in the future (r= -0.74, p<0.0001), whereas Ct values for asymptomatic patients negatively correlated most strongly with total number of tests performed one month later (r= -0.88, p<0.0001). Predictive modeling using these Ct values correctly predicted whether cases would increase or decrease 65% of the time for a subsequent surge (May-July 2021).
conclusionsDuring the largest COVID-19 surge in Los Angeles to date, we observed significantly lower Ct values (representing higher levels of viral RNA) suggesting that increased transmission of COVID-19 was temporarily associated with higher viral loads. Decreasing Ct values appear to be a leading indicator for predicting future COVID-19 cases, which can facilitate improved hospital-level surge planning.
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