Imperial College London
Portrait Picture

ProfessorDeborahAshby

Faculty of Medicine, School of Public Health

Dean of the Faculty of Medicine
 
 
 
//

Contact

 

+44 (0)20 7594 8704deborah.ashby Website

 
 
//

Location

 

2.15Faculty BuildingSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Eales:2022:10.12688/wellcomeopenres.17723.1,
author = {Eales, O and Walters, CE and Wang, H and Haw, D and Ainslie, KEC and Atchison, CJ and Page, AJ and Prosolek, S and Trotter, AJ and Le, Viet T and Alikhan, N-F and Jackson, LM and Ludden, C and Ashby, D and Donnelly, CA and Cooke, G and Barclay, W and Ward, H and Darzi, A and Elliott, P and Riley, S},
doi = {10.12688/wellcomeopenres.17723.1},
journal = {Wellcome Open Research},
pages = {102--102},
title = {Characterising the persistence of RT-PCR positivity and incidence in a community survey of SARS-CoV-2},
url = {http://dx.doi.org/10.12688/wellcomeopenres.17723.1},
volume = {7},
year = {2022}
}
Download

RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Background: The REal-time Assessment of Community Transmission-1 (REACT-1) study has provided unbiased estimates of swab-positivity in England approximately monthly since May 2020 using RT-PCR testing of self-administered throat and nose swabs. However, estimating infection incidence requires an understanding of the persistence of RT-PCR swab-positivity in the community.Methods: During round 8 of REACT-1 from 6 January to 22 January 2021, we collected up to two additional swabs from 896 initially RT-PCR positive individuals approximately 6 and 9 days after their initial swab.Results: Test sensitivity and duration of positivity were estimated using an exponential decay model, for all participants and for subsets by initial N-gene cycle threshold (Ct) value, symptom status, lineage and age. A P-spline model was used to estimate infection incidence for the entire duration of the REACT-1 study. REACT-1 test sensitivity was estimated at 0.79 (0.77, 0.81) with median duration of positivity at 9.7 (8.9, 10.6) days. We found greater duration of positivity in those exhibiting symptoms, with low N-gene Ct values, or infected with the Alpha variant. Test sensitivity was found to be higher for those who were pre-symptomatic or with low N-gene Ct values. Compared to swab-positivity, our estimates of infection incidence included sharper features with evident transient increases around the time of changes in social distancing measures.Conclusions: These results validate previous efforts to estimate incidence of SARS-CoV-2 from swab-positivity data and provide a reliable means to obtain community infection estimates to inform policy response.
AU  - Eales,O
AU  - Walters,CE
AU  - Wang,H
AU  - Haw,D
AU  - Ainslie,KEC
AU  - Atchison,CJ
AU  - Page,AJ
AU  - Prosolek,S
AU  - Trotter,AJ
AU  - Le,Viet T
AU  - Alikhan,N-F
AU  - Jackson,LM
AU  - Ludden,C
AU  - Ashby,D
AU  - Donnelly,CA
AU  - Cooke,G
AU  - Barclay,W
AU  - Ward,H
AU  - Darzi,A
AU  - Elliott,P
AU  - Riley,S
DO  - 10.12688/wellcomeopenres.17723.1
EP  - 102
PY  - 2022///
SN  - 2398-502X
SP  - 102
TI  - Characterising the persistence of RT-PCR positivity and incidence in a community survey of SARS-CoV-2
T2  - Wellcome Open Research
UR  - http://dx.doi.org/10.12688/wellcomeopenres.17723.1
UR  - https://wellcomeopenresearch.org/articles/7-102/v1
UR  - http://hdl.handle.net/10044/1/96716
VL  - 7
ER  -
Download