Increased transmissibility of SARS-CoV-2 alpha variant (B.1.1.7) in children: three large primary school outbreaks revealed by whole genome sequencing in the Netherlands.

Autor: Gorgels KMF; Department of Sexual Health, Infectious Diseases and Environmental Health, South Limburg Public Health Service, PO Box 33, 6400 AA, Heerlen, The Netherlands. koengorgels@gmail.com., van Alphen LB; Department of Medical Microbiology, Care and Public Health Research Institute (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Centre (MUMC+), P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands., van der Veer BMJW; Department of Medical Microbiology, Care and Public Health Research Institute (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Centre (MUMC+), P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands., Hackert VH; Department of Sexual Health, Infectious Diseases and Environmental Health, South Limburg Public Health Service, PO Box 33, 6400 AA, Heerlen, The Netherlands.; Department of Medical Microbiology, Care and Public Health Research Institute (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Centre (MUMC+), P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands.; Department of Social Medicine, Care and Public Health Research Institute (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands., Hensels AYJ; Department of Sexual Health, Infectious Diseases and Environmental Health, South Limburg Public Health Service, PO Box 33, 6400 AA, Heerlen, The Netherlands., Heijer CDJD; Department of Sexual Health, Infectious Diseases and Environmental Health, South Limburg Public Health Service, PO Box 33, 6400 AA, Heerlen, The Netherlands.; Department of Social Medicine, Care and Public Health Research Institute (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands., Dingemans J; Department of Medical Microbiology, Care and Public Health Research Institute (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Centre (MUMC+), P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands., Savelkoul PHM; Department of Medical Microbiology, Care and Public Health Research Institute (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Centre (MUMC+), P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands., Hoebe CJPA; Department of Sexual Health, Infectious Diseases and Environmental Health, South Limburg Public Health Service, PO Box 33, 6400 AA, Heerlen, The Netherlands.; Department of Medical Microbiology, Care and Public Health Research Institute (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Centre (MUMC+), P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands.; Department of Social Medicine, Care and Public Health Research Institute (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
Jazyk: angličtina
Zdroj: BMC infectious diseases [BMC Infect Dis] 2022 Aug 29; Vol. 22 (1), pp. 713. Date of Electronic Publication: 2022 Aug 29.
DOI: 10.1186/s12879-022-07623-9
Abstrakt: Background: Variant of concern (VOC) SARS-CoV-2 alpha variant (B.1.1.7) was the dominant strain in the Netherlands between March 2021-June 2021. We describe three primary school outbreaks due to the alpha variant using whole genome sequencing with evidence of large-scale transmission among children, teachers and their household contacts.
Method: All outbreaks described were investigated by the South Limburg Public Health Service, the Netherlands. A case was defined as an individual with a real-time polymerase chain reaction test or antigen test positive for SARS-CoV-2. Whole genome sequencing was performed on random samples from at least one child and one teacher of each affected class.
Results: Peak attack rates in classes were 53%, 33% and 39%, respectively. Specific genotypes were identified for each school across a majority of affected classes. Attack rates were high among staff members, likely to promote staff-to-children transmission. Cases in some classes were limited to children, indicating child-to-child transmission. At 39%, the secondary attack rate (SAR) in household contacts of infected children was remarkably high, similar to SAR in household contacts of staff members (42%). SAR of household contacts of asymptomatic children was only 9%.
Conclusion: Our findings suggest increased transmissibility of the alpha variant in children compared to preceding non-VOC variants, consistent with a substantial rise in the incidence of cases observed in primary schools and children aged 5-12 since the alpha variant became dominant in March 2021. Lack of mandatory masking, insufficient ventilation and lack of physical distancing also probably contributed to the school outbreaks. The rise of the delta variant (B.1.617.2) since July 2021 which is estimated to be 55% more transmissible than the alpha variant, provides additional urgency to adequate infection prevention in school settings.
(© 2022. The Author(s).)
Databáze: MEDLINE
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