The hospitalization time ranged from 1 to 240 days (Me= 13.7; SD +/- 31.85; Md= 6; IQR (4-9) days). The length of stay in the ICU ranged from 1 to 40 days (Me= 9.14; SD +/- 10.84; IQR (3-10) days). Only 17% (17/101) of the patients required ICU (Me= 4.9; SD+/- 4.27; Md= 4; IQR (3 -10). Among these cases, 24% (4/17) of the patients were hospitalized due to decompensation of the underlying disease, and the highest hospitalization rate was due to flu syndrome, representing 47% (8/17) of ICU patients. However, there was no correlation between the time of hospitalization and the ICU admission with age ILI syndrome.
Regarding the viral load (CV) of the patient, CT was used as a proxy, which is inversely proportional to the CVs, that is, the lower the CT, the higher the CV. The general CT of the patients presented Me=27.57 DP+/- 6.71; Md= 29; IQR (22 - 34).
Hospitalization for ILI had CT value of Me=25.17 SD +/- 6.42 Md=25; IQR (20.5- 31), the decompensation of the underlying disease a CT value of Me = 29.27 SD +/- 6.72 Md = 33 IQR (23-35) and for other factors value of Me = 28 SD +/- 6.21; Md=30.5 IQR (24-33.5). There was only a statistically significant association between ILI and CT value (p= 0.028; OR =1.072; CI 95% (1.00 - 1.14)). That is, for each point lower than CT, it is 1.07 times more likely to be hospitalized for ILI.
The last two data evaluated were deaths and hospital cases readmission. Death was approximately 2% (2/101) of the cases, both of which had comorbidities. One case occurred in 2021, the patient had cystic fibrosis; hospitalization was due to the EG and remained in the ICU until death. The other case occurred in 2022; the patient with congenital heart disease was admitted for decompensation of the underlying disease.
Hospital readmission occurred in 26% (26/101) of the cases, with higher frequency in children over 5 years (46%) of the cases (p=0.0047; OR 4.25; CI95% (1.02-17.69).
The frequency of COVID-19 cases among the years analyzed 2020, 2021 and 2022 was 7.5% (23/307), 3.5% (27/762) and 9.3% (51/545), respectively.
In the analyses between years in relation to COVID-19 infection, it shows that in 2020 and 2022 there was a significant association in relation to 2021. (Table 1) That is, children hospitalized in 2020 and 2022 had 2.2 and 2.8 times more chances of this infection occurring than those hospitalized in 2021.
The frequency of cases of viral coinfection during this period was 11% (11/101). Only three of these pathogens were detected. RSV received 64% (7/11), four cases (< 1 year), one case (2 -| 5 years), and two cases (> five years). HRV was detected in three cases, 27% (3/11), when the children were seven months old, and the detection of Flu-A was 9% (1/11) the child was two years old.
The following graph (figure 1) shows positive cases of age groups and their monthly distribution since the beginning of the pandemic. The peaks of cases in children younger than five years correspond to the emergence and spread of new variants in Brazil, while in children older than five years, beyond these peaks, there is a continuous detection for all these periods.