Many countries have closed schools and kindergartens to minimize COVID-19, but the role children play in disease transmission is unclear. 700 scientific articles and letters and 47 complete texts were identified.
- Children account for a small fraction of COVID-19 cases and mostly have had social contact with peers or parents rather than older people at risk of serious illness.
- Data on viral loads are scarce, but indicate that children may have lower levels than adults, in part because they often have fewer symptoms and this should reduce the risk of transmission.
Family transmission studies show that children are rarely the index case, and case studies suggested that children with COVID-19 rarely cause outbreaks. However, children are very likely to be able to transmit the SARS-COV-2 virus, which causes COVID-19, and even asymptomatic children can have viral loads.
COVID-19 in Children and the Dynamics of Infection in Families
Most of the children in the study had mild or atypical symptoms: headache and nasal discharge in more than half of the cases and anosmia and abdominal symptoms in more than 20%. Some of these symptoms may be underestimated, because younger children may not be able to describe them.
In 79% of families, at least one adult family member was suspected or confirmed of COVID-19 prior to the onset of symptoms in the child under study, confirming that children become infected primarily within family clusters.
Only in 8% of families did a child develop symptoms before any other family contact, which is in line with previous data showing that children are index cases in less than 10% of SARS-Cov-2 cases. However, the study design cannot confirm that child-to-adult transmission occurs.
May 1, 2020. Shedding of infectious SARS-CoV-2 in symptomatic neonates, children and adolescents
This study included 23 patients under the age of 16 who tested positive for SARS-CoV-2 by nasopharyngeal swab RT-PCR. The mean age of pediatric patients is 12 years. Most patients had an upper respiratory infection (n = 13), followed by fever and pneumonia (each, n = 2).
Samples were collected at a median of 2 days after symptom onset.
The median viral load (VL) at the time of diagnosis was 3.0×106 copies / mL.
The researchers tried to grow the virus present in 23 patients in the laboratory and were successful in 12/23 (52%) patients with a median viral load of 1.7×108 copies / ml, values comparable to those observed in the adult population. April 26, 2020. An analysis of SARS-CoV-2 viral load by patient age
To allow for an estimate of infectivity in children, viral loads observed during routine testing were analyzed in a large laboratory in Berlin (Charité Institute of Virology and Labor Berlin), the first laboratory qualified for testing for SARS-CoV. -2 in Germany.
From January to April 26, 2020, 59,831 patients were screened for COVID-19 infection, 3,712 (6.2%) with a positive real-time RT-PCR result.
Patients were divided into two categories to investigate whether there is a relationship between the patient’s age and viral load. The first categorization is based on ten-year age classes. The second categorization is divided into: kindergarten (age 0-6), elementary school (age 7-11), high school (age 12-19), university (age 20-25), adult (age 26-45) ) and mature (over 45 years of age).