Table 1.
Epidemiology of COVID-19 in the paediatric population, mechanisms of transmission of SARS-CoV-2 and risk factors for COVID-19.
| Quality of evidence | Summary of evidence |
|---|---|
| Epidemiological data on SARS-CoV-2 | |
| Moderate | In the overall population (all age groups) worldwide, the seroprevalence of SARS-CoV-2 is 5.3% (95% CI, 4.2%–6.4%). |
| Moderate | In the paediatric population (birth-18 years) the seroprevalence of SARS-CoV-2 is 1.56% (95% CI, 0%–3.12%). |
| Moderate | In the overall population (all age groups) worldwide, the incidence of symptomatic COVID-19 is of 1437/100 000 inhabitants. |
| Low | In the paediatric population (birth-18 years), the incidence of symptomatic COVID-19 corresponds to 0.8%–2.1% of total cases. |
| Moderate | The cumulative mortality associated with COVID-19 worldwide is of 31.90 per 100 000 inhabitants. |
| Moderate | The mortality associated with COVID-19 in Spain is of 146.40/100 000 inhabitants. |
| Moderate | The overall fatality rate of COVID-19 worldwide is: case fatality rate, 2.22%; infection fatality rate, 0.68 % (95% CI, 0.53%–0.82%). |
| Moderate | The overall fatality rate of COVID-19 in Spain is: case fatality rate, 2.16%; infection fatality rate, 1.1% (95% CI, 1.0%–1.2%). |
| Low | The global paediatric mortality rate associated with COVID-19 is of less than 0.08%. |
| High | The paediatric mortality rate COVID-19 in children aged < 14 years in Spain is of 0.042/100 000 inhabitants. Case fatality rate, 0.0094%. |
| SARS-CoV-2 mechanisms of transmission | |
| Low | SARS-CoV-2 is mainly transmitted through respiratory droplets (>100 μm). |
| Low | Aerosol transmission of SARS-CoV-2 (<100 μm) occurs mainly in closed spaces. |
| Low | Transmission through fomites or physical contact is unlikely. |
| Low | The infectious period usually starts 2 days before the onset of symptoms and lasts for as long as 10 days. It is longer in patients with severe disease (only if symptoms persist). |
| Low | The infectious period of asymptomatic individuals is unknown. This is why control of cases and contacts alone is less effective and why it is very important to maintain social distancing measures. |
| Low | The impact of pollution on SARS-CoV-2 transmission is questionable and the evidence on the subject is from studies with a high probability of bias. |
| Low | The upper respiratory tract viral load seems to be lower in the population under 20 years. |
| Risk factors for development of COVID-19 | |
| Low | Older patients, especially those living in residential care facilities, are at higher risk of developing COVID-19. Incidence per 100 000 individuals: 248 (50−59 years), 3−135 (>90 years), 259 (living in the community), 10 571 (in residential facilities). |
| Moderate | A substantial number of social inequity indicators are significantly associated with the incidence of COVID-19 and the associated mortality. The global social vulnerability index is associated with an increased risk of COVID-19 (RR, 1.14; 95% CI, 1.13%–1.16%). |
| Very low | Vitamin D deficiency may be risk factor for infection in adults (RR, 1.77; 95% CI, 1.12−2.81). |
| Very low | Children with COVID-19 have significantly lower levels of vitamin D (13.14 μg/L; 95% CI, 4.19−69.28) compared to children without COVID-19 (34.81 μg/L; 95% CI, 3.8−77.42). |
| Low | The risk of infection increases with the level of environmental pollution (particles < 2.5 μm) and with humidity. The prevalence of COVID-19 decreases with increasing temperature and exposure to sunlight. |
| Very low | The risk of infection decreases with increasing altitude. |
| Very low | Children with asthma may be at lower risk of infection by SARS-CoV-2. |
CI, confidence interval; RR, relative risk.