Discussion
In this cross-sectional study, the characteristics of the population of children up to 12 years of age hospitalized and diagnosed with COVID-19 in HSP were evaluated. It is noteworthy that patients treated and hospitalized in the HSP are very complex. In this analysis, it was found that a portion of the population was eligible to be vaccinated, but none had completed vaccination during hospitalization. vaccination for children between 5 and 11 years of age had not been approved until the beginning of 2022 and for children between 6 months and four years of age until the end of last year. Since the onset of this pandemic, children have not been as susceptible to the virus as adults or the last pandemic in 2009, which was caused by the H1N1 influenza virus and severely affected children at the time. (5).
However, this scenario has changed, possibly due to the high vaccination coverage in the adult and elderly population, immunization of children older than 12 years until the end of 2021, the end of quarantine and the emergence of new variants.
In this new context, our study children up to 11 years of age became more susceptible to the new circulating variant of omicron. A recent study reported a change in the current pandemic scenario, showing a significant increase in the proportion of pediatric cases after the emergence of the Omicron variant, rising from > 2% at the beginning of the pandemic to 25% by March 2022 (4).
As observed in our study, most patients were hospitalized for other causes or underlying diseases with an influenza-like illness. Only a few cases required more intensive treatment or had a more severe clinical outcome.
Other studies, such as Zhu’s, report that although most cases are lighter, children with underlying conditions are at higher risk of developing severe symptoms of the disease. (4) In Brazil, one study reported that approximately 40% of the pediatric population had at least one chronic condition, 14.6% (associated with neurological conditions) and 14.2% of children diagnosed with two or more chronic conditions as a risk factor for COVID-19. (5)
Evaluating this population, our findings show that the most affected individuals were children older than five years of age. As age increases, so does the likelihood of infection. This is consistent with other studies, such as Siegel et al., which have shown over time that children aged 12 to 17 years are more susceptible to this infection, followed by the age group of 5 to 11 years and those under four years of age. (6) In the United States, the percentage of general hospitalizations related to COVID-19 in children was 36%, with the highest rate in the > 2 age group (32.7%), followed by 2 to 4 years (8.7%), 5 to 11 years (16.8%). The highest rate was in the age group from 12 to 17 years (41.8%). The rate of ICU admissions was approximately 33%, with only one death. (7)
Data released by the CDC in March of this year through the COVID-NET network, which conducts surveillance of hospitalizations in the United States, show an increase in hospitalizations in the 0-4 age group, with 85% of these cases attributable to COVID -19. Among these cases, 37% had one or more underlying conditions. (8) This differs from our data, which showed that detection was more common in the < 5 age group, and the incidence of underlying disease or comorbidities was approximately 69%.
The cases of coinfection we presented were low (11%) compared with other studies. Wu et al. analyzed COVID -19 coinfections in 74 confirmed children positive for this pathogen. As a result, 34 (45.95%) patients were positive for the cold virus, and 19 (51.35%) had coinfection with pathogens other than SARS-CoV-2. (9).
Our study showed that children older than five years are more likely to test positive for COVID-19. The group with the lowest frequency of this infection was between 1 -| 2 years old. Kolla’s study et.al. 2022, suggests that, in children between these ages, vaccines against the tuna virus may confer a protective factor against other viruses, such as SARS-CoV-2, so this probably influenced the lower frequency of cases. The main aged virus vaccines used in this range are quadrivalent viral and poliomyelitis 1 and 3. (10)
Results in the literature usually show a lighter form of the disease in most cases. However, it is worth mentioning that additional research is needed in this population, as the number of cases has changed significantly from the beginning of this pandemic to the current scenario. With the natural evolution of SARS-CoV-2, due to evolutionary pressure, the emergence of new variants and subtypes and the increase in cases among children, such as what happened after the Omicron variant. Therefore, it is difficult to predict the impact of this disease on children over time and its effect on the seasonality of other respiratory viruses and epidemiological control in this population.”
In conclusion, after the evolution of SARS-CoV-2, children were finally impacted, as expected compared to other respiratory viruses. We demonstrated that most of the hospitalized cases presented with comorbidities especially patients with sickle cell anemia, a group that was frequently readmitted suggesting that those children should be contemplated with strong program of immunization. Omicron variant caused the highest rate of hospitalization which is implicated in the best formulation should be used among children. In this sense, the new monovalent vaccine with Ômicron XBB, may be the best options for them particularly for those with comorbidities.