tetano
Editor, Senior Moderator
CMAJ
. 2021 Apr 9;cmaj.210263.
doi: 10.1503/cmaj.210263. Online ahead of print.
Infectivity of severe acute respiratory syndrome coronavirus 2 in children compared with adults
Jared Bullard[SUP] 1 [/SUP], Duane Funk[SUP] 1 [/SUP], Kerry Dust[SUP] 1 [/SUP], Lauren Garnett[SUP] 1 [/SUP], Kaylie Tran[SUP] 1 [/SUP], Alex Bello[SUP] 1 [/SUP], James E Strong[SUP] 1 [/SUP], Santina J Lee[SUP] 1 [/SUP], Jillian Waruk[SUP] 1 [/SUP], Adam Hedley[SUP] 1 [/SUP], David Alexander[SUP] 1 [/SUP], Paul Van Caeseele[SUP] 1 [/SUP], Carla Loeppky[SUP] 1 [/SUP], Guillaume Poliquin[SUP] 1 [/SUP]
Affiliations
Abstract
Background: The role of children in the transmission and community spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. We aimed to quantify the infectivity of SARS-CoV-2 in nasopharyngeal samples from children compared with adults.
Methods: We obtained nasopharyngeal swabs from adult and pediatric cases of coronavirus disease 2019 (COVID-19) and from their contacts who tested positive for SARS-CoV-2 in Manitoba between March and December 2020. We compared viral growth in cell culture, cycle threshold values from the reverse tran-scription polymerase chain reaction (RT-PCR) of the SARS-CoV-2 envelope (E) gene and the 50% tissue culture infective dose (TCID50/mL) between adults and children.
Results: Among 305 samples positive for SARS-CoV-2 by RT-PCR, 97 samples were from children aged 10 years or younger, 78 were from children aged 11-17 years and 130 were from adults (? 18 yr). Viral growth in culture was present in 31% of samples, including 18 (19%) samples from children 10 years or younger, 18 (23%) from children aged 11-17 years and 57 (44%) from adults (children v. adults, odds ratio 0.45, 95% confidence interval [CI] 0.28-0.72). The cycle threshold was 25.1 (95% CI 17.7- 31.3) in children 10 years or younger, 22.2 (95% CI 18.3-29.0) in children aged 11-17 years and 18.7 (95% CI 17.9-30.4) in adults (p < 0.001). The median TCID50/mL was significantly lower in children aged 11-17 years (316, interquartile range [IQR] 178-2125) than adults (5620, IQR 1171 to 17 800, p < 0.001). Cycle threshold was an accurate predictor of posi-tive culture in both children and adults (area under the receiver-operator curve, 0.87, 95% CI 0.81-0.93 v. 0.89, 95% CI 0.83-0.96, p = 0.6).
Interpretation: Compared with adults, children with nasopharyngeal swabs that tested positive for SARS-CoV-2 were less likely to grow virus in culture, and had higher cycle thresholds and lower viral concentrations, suggesting that children are not the main drivers of SARS-CoV-2 transmission.
. 2021 Apr 9;cmaj.210263.
doi: 10.1503/cmaj.210263. Online ahead of print.
Infectivity of severe acute respiratory syndrome coronavirus 2 in children compared with adults
Jared Bullard[SUP] 1 [/SUP], Duane Funk[SUP] 1 [/SUP], Kerry Dust[SUP] 1 [/SUP], Lauren Garnett[SUP] 1 [/SUP], Kaylie Tran[SUP] 1 [/SUP], Alex Bello[SUP] 1 [/SUP], James E Strong[SUP] 1 [/SUP], Santina J Lee[SUP] 1 [/SUP], Jillian Waruk[SUP] 1 [/SUP], Adam Hedley[SUP] 1 [/SUP], David Alexander[SUP] 1 [/SUP], Paul Van Caeseele[SUP] 1 [/SUP], Carla Loeppky[SUP] 1 [/SUP], Guillaume Poliquin[SUP] 1 [/SUP]
Affiliations
- PMID: 33837039
- DOI: 10.1503/cmaj.210263
Abstract
Background: The role of children in the transmission and community spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. We aimed to quantify the infectivity of SARS-CoV-2 in nasopharyngeal samples from children compared with adults.
Methods: We obtained nasopharyngeal swabs from adult and pediatric cases of coronavirus disease 2019 (COVID-19) and from their contacts who tested positive for SARS-CoV-2 in Manitoba between March and December 2020. We compared viral growth in cell culture, cycle threshold values from the reverse tran-scription polymerase chain reaction (RT-PCR) of the SARS-CoV-2 envelope (E) gene and the 50% tissue culture infective dose (TCID50/mL) between adults and children.
Results: Among 305 samples positive for SARS-CoV-2 by RT-PCR, 97 samples were from children aged 10 years or younger, 78 were from children aged 11-17 years and 130 were from adults (? 18 yr). Viral growth in culture was present in 31% of samples, including 18 (19%) samples from children 10 years or younger, 18 (23%) from children aged 11-17 years and 57 (44%) from adults (children v. adults, odds ratio 0.45, 95% confidence interval [CI] 0.28-0.72). The cycle threshold was 25.1 (95% CI 17.7- 31.3) in children 10 years or younger, 22.2 (95% CI 18.3-29.0) in children aged 11-17 years and 18.7 (95% CI 17.9-30.4) in adults (p < 0.001). The median TCID50/mL was significantly lower in children aged 11-17 years (316, interquartile range [IQR] 178-2125) than adults (5620, IQR 1171 to 17 800, p < 0.001). Cycle threshold was an accurate predictor of posi-tive culture in both children and adults (area under the receiver-operator curve, 0.87, 95% CI 0.81-0.93 v. 0.89, 95% CI 0.83-0.96, p = 0.6).
Interpretation: Compared with adults, children with nasopharyngeal swabs that tested positive for SARS-CoV-2 were less likely to grow virus in culture, and had higher cycle thresholds and lower viral concentrations, suggesting that children are not the main drivers of SARS-CoV-2 transmission.