tetano
Editor, Senior Moderator
PLoS One
. 2021 Nov 11;16(11):e0259908.
doi: 10.1371/journal.pone.0259908. eCollection 2021.
Evaluation of the SARS-CoV-2 positivity ratio and upper respiratory tract viral load among asymptomatic individuals screened before hospitalization or surgery in Flanders, Belgium
Laura Heireman[SUP] 1 [/SUP], Steven Abrams[SUP] 2 3 [/SUP], Peggy Bruynseels[SUP] 1 [/SUP], Reinoud Cartuyvels[SUP] 4 [/SUP], Lize Cuypers[SUP] 5 [/SUP], Pieter De Schouwer[SUP] 1 [/SUP], Wim Laffut[SUP] 6 [/SUP], Katrien Lagrou[SUP] 5 [/SUP], Niel Hens[SUP] 2 7 [/SUP], Erwin Ho[SUP] 8 [/SUP], Elizaveta Padalko[SUP] 9 [/SUP], Marijke Reynders[SUP] 10 [/SUP], Sarah Vandamme[SUP] 11 [/SUP], Nathalie Van der Moeren[SUP] 1 [/SUP], Walter Verstrepen[SUP] 1 [/SUP], Philippe Willems[SUP] 12 [/SUP], Reinout Naesens[SUP] 1 [/SUP]
Affiliations
Abstract
Introduction: The incidence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections in the Belgian community is mainly estimated based on test results of patients with coronavirus disease (COVID-19)-like symptoms. The aim of this study was to investigate the evolution of the SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) positivity ratio and distribution of viral loads within a cohort of asymptomatic patients screened prior hospitalization or surgery, stratified by age category.
Materials/methods: We retrospectively studied data on SARS-CoV-2 real-time RT-PCR detection in respiratory tract samples of asymptomatic patients screened pre-hospitalization or pre-surgery in nine Belgian hospitals located in Flanders over a 12-month period (1 April 2020-31 March 2021).
Results: In total, 255925 SARS-CoV-2 RT-PCR test results and 2421 positive results for which a viral load was reported, were included in this study. An unweighted overall SARS-CoV-2 real-time RT-PCR positivity ratio of 1.27% was observed with strong spatiotemporal differences. SARS-CoV-2 circulated predominantly in 80+ year old individuals across all time periods except between the first and second COVID-19 wave and in 20-30 year old individuals before the second COVID-19 wave. In contrast to the first wave, a significantly higher positivity ratio was observed for the 20-40 age group in addition to the 80+ age group compared to the other age groups during the second wave. The median viral load follows a similar temporal evolution as the positivity rate with an increase ahead of the second wave and highest viral loads observed for 80+ year old individuals.
Conclusion: There was a high SARS-CoV-2 circulation among asymptomatic patients with a predominance and highest viral loads observed in the elderly. Moreover, ahead of the second COVID-19 wave an increase in median viral load was noted with the highest overall positivity ratio observed in 20-30 year old individuals, indicating they could have been the hidden drivers of this wave.
. 2021 Nov 11;16(11):e0259908.
doi: 10.1371/journal.pone.0259908. eCollection 2021.
Evaluation of the SARS-CoV-2 positivity ratio and upper respiratory tract viral load among asymptomatic individuals screened before hospitalization or surgery in Flanders, Belgium
Laura Heireman[SUP] 1 [/SUP], Steven Abrams[SUP] 2 3 [/SUP], Peggy Bruynseels[SUP] 1 [/SUP], Reinoud Cartuyvels[SUP] 4 [/SUP], Lize Cuypers[SUP] 5 [/SUP], Pieter De Schouwer[SUP] 1 [/SUP], Wim Laffut[SUP] 6 [/SUP], Katrien Lagrou[SUP] 5 [/SUP], Niel Hens[SUP] 2 7 [/SUP], Erwin Ho[SUP] 8 [/SUP], Elizaveta Padalko[SUP] 9 [/SUP], Marijke Reynders[SUP] 10 [/SUP], Sarah Vandamme[SUP] 11 [/SUP], Nathalie Van der Moeren[SUP] 1 [/SUP], Walter Verstrepen[SUP] 1 [/SUP], Philippe Willems[SUP] 12 [/SUP], Reinout Naesens[SUP] 1 [/SUP]
Affiliations
- PMID: 34762704
- DOI: 10.1371/journal.pone.0259908
Abstract
Introduction: The incidence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections in the Belgian community is mainly estimated based on test results of patients with coronavirus disease (COVID-19)-like symptoms. The aim of this study was to investigate the evolution of the SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) positivity ratio and distribution of viral loads within a cohort of asymptomatic patients screened prior hospitalization or surgery, stratified by age category.
Materials/methods: We retrospectively studied data on SARS-CoV-2 real-time RT-PCR detection in respiratory tract samples of asymptomatic patients screened pre-hospitalization or pre-surgery in nine Belgian hospitals located in Flanders over a 12-month period (1 April 2020-31 March 2021).
Results: In total, 255925 SARS-CoV-2 RT-PCR test results and 2421 positive results for which a viral load was reported, were included in this study. An unweighted overall SARS-CoV-2 real-time RT-PCR positivity ratio of 1.27% was observed with strong spatiotemporal differences. SARS-CoV-2 circulated predominantly in 80+ year old individuals across all time periods except between the first and second COVID-19 wave and in 20-30 year old individuals before the second COVID-19 wave. In contrast to the first wave, a significantly higher positivity ratio was observed for the 20-40 age group in addition to the 80+ age group compared to the other age groups during the second wave. The median viral load follows a similar temporal evolution as the positivity rate with an increase ahead of the second wave and highest viral loads observed for 80+ year old individuals.
Conclusion: There was a high SARS-CoV-2 circulation among asymptomatic patients with a predominance and highest viral loads observed in the elderly. Moreover, ahead of the second COVID-19 wave an increase in median viral load was noted with the highest overall positivity ratio observed in 20-30 year old individuals, indicating they could have been the hidden drivers of this wave.