A KKH study has found that the amount of SARS-CoV-2 virus was higher in the nasopharynx of symptomatic compared to asymptomatic children. It also confirmed the potential for asymptomatic children to transmit the virus.1

 

​Key points:

  • Children who were symptomatic had higher viral loads in the nasopharynx compared to asymptomatic children, indicating the possibility of higher transmissibility.
  • Peak viral loads occurred around day two to three of illness/diagnosis. As this is the early stage of illness, this may indicate viral shedding and transmission in the pre-symptomatic phase.
  • Understanding the temporal trend of COVID-19 viral load in Singapore children aids in estimation of transmission potential and the role of children in community transmission.

 

Higher Viral Loads May Indicate Higher Transmissibility

Of the 17 children included in the study, 10 were symptomatic, displaying mild illness with upper respiratory tract infection. Their symptoms resolved by day five of illness and no complications or evidence of pneumonia were observed. The other seven were asymptomatic, remaining well with no development of symptoms until discharge.

“The children who were symptomatic had higher viral loads in the nasopharynx compared to asymptomatic children, which may indicate that symptomatic children have higher transmissibility,” shares corresponding author, Dr Kam Kai Qian, Associate Consultant, Infectious Disease Service, KKH.

Within the cohort, the mean duration of viral shedding was about 16 days, and the longest duration of viral shedding was 30 days in a previously symptomatic child.


Possible Viral Shedding and Transmission in Pre-symptomatic Phase

“The peak viral loads occurred around day two to three of illness/diagnosis in the infected children. As this is the early stage of illness, we postulate that viral shedding and transmission in the pre-symptomatic phase may be possible.”

“Understanding the temporal trend of COVID-19 viral load in Singapore children helps us to estimate the transmission potential and postulate the role of children in the transmission of COVID-19 in the community,” adds co-author Dr Yung Chee Fu, Consultant, Infectious Disease Service, KKH.

These findings are important to inform the screening/management of COVID-19 in the paediatric cohort, towards optimal containment of the virus in our Singaporean context.”

Read the full study here.

The authors would like to thank all the staff of the Microbiology Section, Department of Pathology and Laboratory Medicine, KKH for their dedication and commitment in the challenging working conditions during the COVID-19 pandemic.

 

​Reference:

  1. Kam KQ, Thoon KC, Maiwald M, et al. SARS-CoV-2 Viral RNA Load Dynamics in the Nasopharynx of Infected Children. Preprint posted on 2 September 2020 on medRxiv 2020.08.31.20185488; https://doi.org/10.1101/2020.08.31.20185488

 

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