High proportion of low cycle threshold value as an early indicator of COVID‐19 surge

Mishra, Baijayantimala; Ranjan, Jai; Purushotham, Prashanth; Saha, Swarnatrisha; Payal, Poesy; Kar, Punyatoya; Das, Sivasankar; Deshmukh, Vaishnavi

doi:10.1002/jmv.27307

Cited by 33 publications

(24 citation statements)

References 16 publications

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“…At early infection, viral accumulation tends to be high while the Ct values are lower. 22 , 26 Hence, at 0–5 DSO, no significant changes in Ct values were observed due to the constantly high level of viral load, while the sensitivity of the RAHT is at the highest level during these periods of time. Extending the range of DSO may allow for a more accurate evaluation of the correlation between Ct value and DSO.…”

Section: Discussionmentioning

confidence: 93%

Performance evaluation of STANDARD Q COVID‐19 Ag home test for the diagnosis of COVID‐19 during early symptom onset

Shin

Lee

Widyasari

et al. 2022

Clinical Laboratory Analysis

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Background Surveillance and control of SARS‐CoV‐2 outbreak through gold standard detection, that is, real‐time polymerase chain reaction (RT‐PCR), become a great obstacle, especially in overwhelming outbreaks. In this study, we aimed to analyze the performance of rapid antigen home test (RAHT) as an alternative detection method compared with RT‐PCR. Methods In total, 79 COVID‐19‐positive and 217 COVID‐19‐negative patients confirmed by RT‐PCR were enrolled in this study. A duration from symptom onset to COVID‐19 confirmation of <5 days was considered a recruiting criterion for COVID‐19‐positive cases. A nasal cavity specimen was collected for the RAHT, and a nasopharyngeal swab specimen was collected for RT‐PCR. Results Sensitivity of the STANDARD Q COVID‐19 Ag Home Test (SD Biosensor, Korea), compared with RT‐PCR, was 94.94% (75/79) (95% [confidence interval] CI, 87.54%–98.60%), and specificity was 100%. Sensitivity was significantly higher in symptomatic patients (98.00%) than in asymptomatic (89.66%) patients ( p ‐value = 0.03). There was no difference in sensitivity according to the duration of symptom onset to confirmation (100% for 0–2 days and 96.97% for 3–5 days, respectively) ( p ‐value = 1.00). The RAHT detected all 51 COVID‐19 patients whose Ct values were ≤25 (100%), whereas sensitivity was 73.33% (11/15) among patients with Ct values >25 ( p ‐value = 0.01). Conclusion The RAHT showed an excellent sensitivity for COVID‐19‐confirmed cases, especially for those with symptoms. There was a decrease in sensitivity when the Ct value is over 25, indicating that RAHT screening may be useful during the early phase of symptom onset, when the viral numbers are higher and it is more transmissible.

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Section: Discussionmentioning

confidence: 93%

Performance evaluation of STANDARD Q COVID‐19 Ag home test for the diagnosis of COVID‐19 during early symptom onset

Shin

Lee

Widyasari

et al. 2022

Clinical Laboratory Analysis

View full text Add to dashboard Cite

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“…The relationship between symptom profile and cycle threshold (Ct) value from PCR testing (an established proxy for viral load, 8–10 which in turn correlates with infectiousness 11,12 ) has also yet to be fully investigated. Identifying individuals who are more likely to be i) infected, and ii) infectious on the basis of symptom profile would have clinical value as governments move away from mass testing programmes and mandatory isolation measures.…”

mentioning

confidence: 99%

Variant-specific symptoms of COVID-19 among 1,542,510 people in England

Whitaker

Elliott

Bodinier

et al. 2022

Preprint

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Infection with SARS-CoV-2 virus is associated with a wide range of symptoms. The REal-time Assessment of Community Transmission -1 (REACT-1) study has been monitoring the spread and clinical manifestation of SARS-CoV-2 among random samples of the population in England from 1 May 2020 to 31 March 2022. We show changing symptom profiles associated with the different variants over that period, with lower reporting of loss of sense of smell and taste for Omicron compared to previous variants, and higher reporting of cold-like and influenza-like symptoms, controlling for vaccination status. Contrary to the perception that recent variants have become successively milder, Omicron BA.2 was associated with reporting more symptoms, with greater disruption to daily activities, than BA.1. With restrictions lifted and routine testing limited in many countries, monitoring the changing symptom profiles associated with SARS-CoV-2 infection and induced changes in daily activities will become increasingly important.

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“…To construct Fig. 3 a, a cycle threshold (Ct) cut-off of [ 19 ] for S-gene, N-gene and ORF1ab (see [ 20 ] for details) is required to determine whether it is the Delta or another variant. Only infection data from processing labs that routinely looked at the 3 genes was used.…”

Section: Methodsmentioning

confidence: 99%

Effectiveness of the BNT162b2 (Pfizer-BioNTech) and the ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccines for reducing susceptibility to infection with the Delta variant (B.1.617.2) of SARS-CoV-2

Pattni

Hungerford

Adams³

et al. 2022

BMC Infect Dis

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Background From January to May 2021 the alpha variant (B.1.1.7) of SARS-CoV-2 was the most commonly detected variant in the UK. Following this, the Delta variant (B.1.617.2) then became the predominant variant. The UK COVID-19 vaccination programme started on 8th December 2020. Prior to the Delta variant, most vaccine effectiveness studies focused on the alpha variant. We therefore aimed to estimate the effectiveness of the BNT162b2 (Pfizer-BioNTech) and the ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccines in preventing symptomatic and asymptomatic infection with respect to the Delta variant in a UK setting. Methods We used anonymised public health record data linked to infection data (PCR) using the Combined Intelligence for Population Health Action resource. We then constructed an SIR epidemic model to explain SARS-CoV-2 infection data across the Cheshire and Merseyside region of the UK. Vaccines were assumed to be effective after 21 days for 1 dose and 14 days for 2 doses. Results We determined that the effectiveness of the Oxford-AstraZeneca vaccine in reducing susceptibility to infection is 39% (95% credible interval [34, 43]) and 64% (95% credible interval [61, 67]) for a single dose and a double dose respectively. For the Pfizer-BioNTech vaccine, the effectiveness is 20% (95% credible interval [10, 28]) and 84% (95% credible interval [82, 86]) for a single-dose and a double dose respectively. Conclusion Vaccine effectiveness for reducing susceptibility to SARS-CoV-2 infection shows noticeable improvement after receiving two doses of either vaccine. Findings also suggest that a full course of the Pfizer-BioNTech provides the optimal protection against infection with the Delta variant. This reinforces the need to complete the full course programme to maximise individual protection and reduce transmission.

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High proportion of low cycle threshold value as an early indicator of COVID‐19 surge

Cited by 33 publications

References 16 publications

Performance evaluation of STANDARD Q COVID‐19 Ag home test for the diagnosis of COVID‐19 during early symptom onset

Performance evaluation of STANDARD Q COVID‐19 Ag home test for the diagnosis of COVID‐19 during early symptom onset

Variant-specific symptoms of COVID-19 among 1,542,510 people in England

Effectiveness of the BNT162b2 (Pfizer-BioNTech) and the ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccines for reducing susceptibility to infection with the Delta variant (B.1.617.2) of SARS-CoV-2

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