Can children be infected with the SARS-CoV-2 coronavirus?
Text updated on 2021-04-22
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 those who are positive for SARS-CoV-2 is often 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 who are sick with the SARS-CoV-2 virus have more significant symptoms than children, and because testing is done preferentially on symptomatic people, more adults are tested, and this may contribute to finding more positive tests in adults. See the question Why are the COVID-19 epidemiological data on children difficult to interpret?
In Sweden, where most schools remained widely open, the same proportion of people testing positive for SARS-CoV-2 in mid-June was found among young people aged 0-19 and adults aged 20-64 (6.8% versus 6.4%). In Israel, the percentage of people testing positive for SARS-CoV-2 between January and September 2020 was even slightly higher among children than among adults.
During the emerging phase of the COVID-19 epidemic, the infection began as an almost exclusively adult-to-adult transmission. The virus then spread to families, causing intrafamilial transmission, particularly to the elderly and children, who are vulnerable to infection. The epidemic can then spread through school transmission. See the question Children's role in the COVID-19 epidemic: what do we know?
According to published epidemiological analyses of COVID-19 cases and their close contacts, 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.
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).
COVID tests of 13,080 volunteers in Iceland showed that the probability of being tested positive is very low (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.
Extremely detailed Israeli study of children between January and September 2020, before and after the reopening of schools. 677,982 RT-qPCR tests were conducted on children in Israel between January 27 and September 24, 2020. Of these, 8% (55,288) were positive. In comparison, 157,229 out of 2,548,273 (6%) were positive in adults. The National Serological Survey conducted by the Ministry of Health detected a positive rate in children of 7% compared to 2-5% in adult age groups. It is estimated that approximately 50-70% of children infected with SARS-CoV-2 are asymptomatic. The opening of schools is associated with an increase in the rate of positive children and their closure with a decrease. Excluding transmissions caused by adults, children tend to be infected by other children in their own age group. 7 children each infected 10 people, 3 each infected 12 people, and one child infected 24 persons.Israel, Ministry of Health, COVID-19 Report, 18 October 2020.
Study of blood samples from ambulatory care in Sweden, where most schools remained open. Seroprevalence (the presence of antibodies indicating a past COVID-19 infection) of youth aged 0 to 19 increased from April to early June 2020 to reach values similar to those of adults aged 20 to 64 in mid-June 2020 (6.8% versus 6.4%). Seroprevalence remained lower for people aged ≥ 65 years (1.5%), who were more isolated than others.Public Health Agency of Sweden. Påvisning av anti-kroppar efter genomgången covid-19 i blodprov från öppenvården (delrapport 1).
Study of the immune response of 46 children (0 to 13 years) and 23 adolescents (14 to 20 years) with COVID-19 with asymptomatic or mildly symptomatic forms. In 94% of the 69 individuals, the presence of antibodies against the coronavirus was still detectable 4 months after infection. The immune response in the sera of these children and adolescents was comparable to or better than that observed in the sera of 24 adults with mild COVID-19.Garrido et al (Apr 20, 2021). Asymptomatic or Mild Symptomatic SARS-CoV-2 Infection Elicits Durable Neutralizing Antibody Responses in Children and Adolescents. MedRxiv.