RESULTS
A total of 287 articles were found in the systematic review of the
literature (254 in PubMed and 38 in other databases). After removing
duplicates, screening by title and abstract, 58 articles were selected
for full-text evaluation, 14 were excluded for different reasons. A
total 44 articles were chosen for qualitative analysis, 38 for
quantitative analysis of clinical findings [17,18,
21-30,32-38,40,42-48,50-52,54-58,60,62] and 43 for quantitative
analysis of illness severity severity[17,18,31-56,58,60-62].Figure 1. All were observational studies, twenty-six studies
were done in China [21-37,], five were from USA
[18,39,50,59,60], five from Italy [40,44,47,56,57], three from
Spain [49,51,61], two from France [48,62], one was made in
Malaysia [38], Iraqi Kurdistan [41] and UK [17]. The main
characteristics of included studies and individual risk of bias are
shown in Table 1 .
Epidemiology
A total of 6026 children with confirmed or suspected COVID-19 were
included. 55.25% cases were males. Age ranged from newborn to 21 years,
a total of 5754 patients were distributed as follows: 19.09%
(< 1 year), 17.18% (1-5 years), 20.17% (6-10 years) and
43.53% (>10 years)
[21,27,29-35,38-48,50-52,54,56,59,61]. Supplementary
Material . Mean incubation period was 6.33 (± 2.48) days. Fourteen
studies noted 165 patients with comorbidities
[17,21,26,27,30,34,39,41,47-49,51,57], the most common are
neoplasms, overweight and obesity, cardiac diseases, neurological and
chronic respiratory diseases, mostly asthma. In addition 5 studies
reported 6 severe/critical cases with comorbidities, a teenager with
obesity, one scholar with acute lymphoblastic leukemia, 3 infants with
congenital cardiac disease, one infant with chronic wheezes.
[21,27,30,49,58]. A total of 68.48% cases (526/768) had previous
contact with an infected family member. Diagnosis was performed with
real time polymerase chain reaction (RT-PCR) by nasopharyngeal swab in
1656 patients, 110 patients were diagnosed by serum antibodies (IgM,
IgG). [17,18,44,48,61,62]. Seven studies assessed the presence of
SARS-CoV-2 in stools [25,29,30,32,45,48,61], finding 18.82%
(32/170) positive cases. All RT-PCR tests in stool samples were made in
confirmed cases of COVID-19.
Illness severity
Illness severity distribution among 3175 cases (2 lost) [31] were:
asymptomatic 6% (CI95% 3-10%), I2 84.92%
p<0.001 (all of them diagnosed after contact with family
member), mild disease 28%(CI 95% 19-38%) I2 92.05%
p<0.001, moderate disease 33%(CI 95% 24-43%)
I2 92.20% p<0.001, severe illness 2% (CI
95% 0-5%) I2 77.52% p<0.001 and critical
disease 3% (CI 95% 1-6%) with I2 90.04% and
p<0.001 Figure 2 .
Hence approximately 89.73% cases in pediatric population were
non-severe. Pooled Odds Ratio (OR) of severe or critical illness in
children <1y was 2.07 (CI 95% 1.40-3.05) p<0.001,
but heterogeneity statistics were unable to calculate since a single
study weighs almost 100% and in patients >10y pooled OR
was 0.75 (CI 95% 0.16-3.43) but it was not statistically significant.