Can children be infected with the SARS-CoV-2 coronavirus?
Text updated on 2020-05-03
Yes, children can be carriers of the SARS-CoV-2 coronavirus. Many children have been infected in China and European countries. In general, their symptoms are less than in adults, although they show as much viral load in their nose, and are, therefore, a priori as contagious as adults.
In different countries, tests show that the percentage of children among people with COVID-19 is lower than the percentage of children in the total population. These results do not necessarily mean that children have a lower rate of infection than adults, as the proportion of positive tests depends on the selection of people who are tested. Because adults with SARS-CoV-2 have more significant symptoms than children and because testing is done preferentially on symptomatic individuals, more adults are tested and this most likely contributes to finding more positive tests in adults.
In Iceland, South Korea and China, tests were conducted on a relatively random sample of the population, which showed that the probability of being tested positive for SARS-CoV-2 is higher in the 30-40 year age group, lower in the 10-20 year age group, and even lower in the 0-10 year age group.
Based on published epidemiological analyses of cases of COVID-19 and close contacts of children, it is estimated that children have either a lower or similar risk of infection than the general population when they are in contact with a person with COVID-19. It is likely that at the very beginning of the epidemic, as the infected persons were mainly travellers from China or Italy, the virus was initially transmitted mainly via adults. Today, with the closure of schools in most countries, it is difficult to estimate the risk of transmission from child to child. In the high school of Crépy-en-Valois (Oise, France), 38% of the students, 43% of the teachers, and 59% of the staff working in the school, among those who performed a serological test, were positive, confirming an SARS-CoV-2 infection.
Since children can catch the SARS-CoV-2 coronavirus, they must follow the same rules of hygiene and social distancing as adults.
Retrospective study of >40,000 cases COVID-19 in China: 1% of the COVID+ test subjects are in the 10-19 age group (549 children) and 1% of the COVID+ test subjects are children under 10 years of age (416 children).Vital Surveys (2020). The epidemiological characteristics of an outbreak of 2019 novel coronavirus diseases (COVID-19)-China, 2020. China CDC Weekly, 2(8), 113-122.
Children represent 16.8% of the population in China.National Bureau of Statistics, China census data (2020) (last accessed 1 March 2020).
The COVID test of 13,080 volunteers in Iceland showed that the probability of being tested positive is very low (<0,2%) dans="" la="" tranche="" 0-10="" ans,="" autour="" de="" 0,4%="" 10-20="" ans="" alors="" qu’elle="" est="" 1,5%="" 40-50="" (Figure="" 2E).<="" p="">
Gudbjartsson, D. F., Helgason, A., Jonsson, H., Magnusson, O. T., Melsted, P., Norddahl, G. L., ... & Eiriksdottir, B. (2020). Spread of SARS-CoV-2 in the Icelandic population. New England Journal of Medicine.
Testing of 1,391 children in Wuhan between January and February 2020: 12% tested positive.Lu X, Zhang L, Du H, Zhang J, Li YY, Qu J, Zhang W, Wang Y, Bao S, Li Y, Wu C, Liu H, Liu D, Shao J, Peng X, Yang Y, Liu Z, Xiang Y, Zhang F, Silva RM, Pinkerton KE, Shen K, Xiao H, Xu S, Wong GWK; Chinese Pediatric Novel Coronavirus Study Team. SARS-CoV-2 Infection in Children. N Engl J Med. 2020 Mar 18.
The epidemiological study of 391 cases COVID-19 in Shenzhen and their contacts indicates that children have a risk of infection similar to that of the general population.Bi, Q., Wu, Y., Mei, S., Ye, C., Zou, X., Zhang, Z., ... & Gao, W. (2020). Epidemiology and Transmission of COVID-19 in Shenzhen China: Analysis of 391 cases and 1,286 of their close contacts. MedRxiv.
The epidemiological study of 636 cases and their contacts in Wuhan and Shanghai indicates that children have a lower risk of infection than the general population.Zhang J., Litvinova M., Liang Y., et al (2020) Changes in contact patterns shape the dynamics of the COVID-19 outbreak in China. Science, Apr 29;eabb8001.
The epidemiological study of 105 cases of COVID-19 and their close contacts revealed that secondary transmission of SARS-CoV-2 occurred in 64 of 392 household contacts (16.3%). The secondary attack rate in children was 4% compared to 17.1% in adults. The secondary attack rate among household contacts with self-quarantined reference patients since symptom onset was 0%, compared to 16.9% among contacts without quarantined reference patients. The secondary attack rate for contacts who were spouses of index cases was 27.8%, compared with 17.3% for other adult household members.Li, W., Zhang, B., Lu, J., Liu, S., Chang, Z., Cao, P., ... & Chen, J. (2020). The characteristics of household transmission of COVID-19. Clinical Infectious Diseases.
Study of 10 children who caught COVID-19 in January-February 2020: 7 of them caught it at home through direct contact with an adult with COVID-19, and one following a bus journey in which two people from Wuhan who were traveling were found to be affected with COVID-19. For these infected children, the first symptoms appeared on average 6.5 days after exposure to a person with COVID-19. A 3-month-old newborn baby, who was being cared for by others, infected both parents, who developed symptoms 7 days after caring for the baby without protection.Cai, J., Xu, J., Lin, D., Xu, L., Qu, Z., Zhang, Y., ... & Xia, A. (2020). A Case Series of children with 2019 novel coronavirus infection: clinical and epidemiological features. Clinical Infectious Diseases.
In the Crépy-en-Valois high school (Oise, France), 38% of the students, 43% of the teachers, and 59% of the staff working in the school who were given a serological test were positive, confirming SARS-CoV-2 infections. The rate of secondary intra-familial transmission was estimated at 11% to parents and 10% to siblings.Fontanet, A., Shearer, L., Madec, Y., Grant, R., Besombes, C., Jolly, N., ... & Temmam, S. (2020). Cluster of COVID-19 in northern France: A retrospective closed cohort study. medRxiv.
Viral loads measured in children with COVID-19 are as high as in adults.Jones, T.C., Mühlemann, B., Veith, T., Zuchowski, M., Hofmann, J., Stein, A., Edelmann, A., Max Corman, V., Drosten, C. (2020) An analysis of SARS-CoV-2 viral load by patient age.
Analysis of questionnaires in China indicates that children are three times less likely than adults to be infected with SARS-CoV-2Zhang, J., Litninova, M., Liang, Y., Wang, Y, Wang, W., Zhao, S., Wu, Q., Merler, S., CÉCILE VIBOUD, Vespignani, A., Ajelli, M., Yu, H. (2020) Changes in contact patterns shape the dynamics of the COVID-19 outbreak in China. Science, article online on April 29.