| Title: |
Inferring transmission risk of respiratory viral infection from the viral load kinetics of SARS-CoV-2, England, 2020 to 2021 and influenza A virus, Hong Kong, 2008 to 2012 |
| Authors: |
Jonnerby, Jakob; Fenn, Joe; Hakki, Seran; Zhou, Jie; Madon, Kieran J.; Koycheva, Aleksandra; Nevin, Sean; Kundu, Rhia; Crone, Michael A.; Pillay, Timesh D.; Ahmad, Shazaad; Derqui, Nieves; Conibear, Emily; Varro, Robert; Luca, Constanta; Freemont, Paul S.; Taylor, Graham P.; Zambon, Maria; Barclay, Wendy S.; Dunning, Jake; Ferguson, Neil M.; Cowling, Benjamin J.; Lalvani, Ajit; Badhan, A.; Narean, J. S.; Evetts, S.; Quinn, V.; Cutajar, J.; Ketkar, A. V.; Di Biase, B.; Barnett, J.; Tejpal, C.; McDermott, E.; Miserocchi, G.; Catchpole, H.; Nixon, K.; Timcang, K.; Samuel, J.; Russell, J.; Grey, H.; Nichols, N.; Bremang, S.; Hammett, S.; Hopewell, T.; Kondratiuk, A.; Jauhangeer, R.; Vekaria, D.; O’Donnell, D.; Motamed, C.; Gonzalez, S.; Tailor, P.; Harwin, L.; Tarbuck, B. |
| Publisher Information: |
European Centre for Disease Prevention and Control |
| Publication Year: |
2025 |
| Collection: |
University of Hong Kong: HKU Scholars Hub |
| Description: |
Background: Infectiousness of respiratory viral infections is quantified as plaque forming units (PFU), requiring resource-intensive viral culture that is not routinely performed. We hypothesised that RNA viral load (VL) decline time (e-folding time) in people might serve as an alternative marker of infectiousness. Aim: This study’s objective was to evaluate the association of RNAVL decline time with RNA and PFUVL area under the curve (AUC) and transmission risk for SARS-CoV-2 and influenza A virus. Methods: In SARS-CoV-2 and influenza A virus community cohorts, viral RNA was quantified by reverse transcription quantitative PCR in serial upper respiratory tract (URT)-samples collected within households after an initial household-member tested positive for one virus. We evaluated correlations between RNAVL decline time and RNA and PFU-VL AUC. Associations between VL decline time and transmission risk in index-contact pairs were assessed. Results: In SARS-CoV-2 cases, we observed positive correlations between RNAVL decline time and RNA and PFUVL AUC with posterior probabilities 1 and 0.96 respectively. In influenza A cases a positive correlation between RNAVL decline time and RNAVL AUC was observed, with posterior probability of 0.87. Index case VL decline times one standard deviation above the cohort-mean showed a relative increase in secondary attack rates of 39% (95%credible interval (CrI):−6.9to95%) for SARS-CoV-2 and 25% (95% CrI:−11to71%) for influenza A virus. Conclusion: We identify VL decline time as a potential marker of infectiousness and transmission risk for SARS-CoV-2 and influenza A virus. Early ascertainment of VL kinetics as part of surveillance of new viruses or variants could inform public health decision making. ; published_or_final_version |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
Eurosurveillance: Europe's journal on infectious disease surveillance, epidemiology, prevention and control; Eurosurveillance: Europe's journal on infectious disease surveillance, epidemiology, prevention and control, 2025, v. 30, n. 6, p. 2; https://hub.hku.hk/handle/10722/364106; 30 |
| DOI: |
10.2807/1560-7917.ES.2025.30.6.2400234 |
| Availability: |
https://hub.hku.hk/handle/10722/364106; https://doi.org/10.2807/1560-7917.ES.2025.30.6.2400234 |
| Rights: |
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. |
| Accession Number: |
edsbas.E0F51230 |
| Database: |
BASE |