Discussion
In our study, patients with COVID-19 were older than those with ORP infections. This findings were similar to the results of Melé et al.: median age 16.9 years old for SARS-CoV-2 versus 3.5 years for non-SARS-CoV-2(p=0.004).(7)
We also demonstrated that fever, headache, anosmia, dysgeusia, myalgia and rash were more prevalent in the SARS-CoV-2 group, while cough was more frequent in Group 2. Melé et al., on the other hand indicated similar clinical findings between groups.(7)
Radiographic examinations were more often altered in the SARS-CoV-2 group in our study, which contraposed the findings of the Spanish team, where radiographic results were similar between groups.(7)
Considering outcomes and greater demand of clinical support, we found that pediatric COVID-19 was more severe when compared to other virus. In the Spanish study, COVID-19 patients also needed more cardiovascular support.(7)
However, rhinovirus comprises 84% of all respiratory virus excluding SARS-CoV-2 in our study. Due to this selection bias inherent to the world’s epidemiological status, we are unable to suggest that these differences are applicable to other respiratory viruses such as influenza or RSV.
Trenholme et al. reported stable rhinovirus infection rates in 2020, as opposed to reduced RSV and influenza infection rates. In agreement, we showed that the rhinovirus seems to be the main circulating virus besides SARS-CoV-2 in 2020, so much so that rhinovirus was the only virus to present as a coinfection with SARS-CoV-2.(1) Zhang et al. showed a Rhinovirus/SARS-CoV-2 coinfection rate of 23,3%.(2)
Comparing SARS-CoV-2 and influenza infection, Piroth et al. observed that in the pediatric population: (a) influenza infection was more significantly frequent than COVID-19, (b) COVID-19 patients had worse outcomes (higher PICU admission and in-hospital mortality), which confirmed with our findings; and (c) COVID-19 patients had more underlying conditions (hypertension, respiratory disease, heart failure and obesity) than patients with influenza.(8)
Alvares compared children with solely SARS-CoV-2 infection versus SARS-CoV-2/RSV coinfection, and demonstrated longer hospitalizations in the coinfection group.(9) Here, coinfection rates of SARS-CoV-2 were low, likewise reported in other studies.(2,7,10)
The limitations to our study were selection bias and we only assessed patients from a single high complexity center, mainly including pediatric chronic conditions, and with a limited time frame.
Our data reinforces differences in clinical presentation, laboratory abnormalities and outcomes between pediatric COVID-19 and rhinovirus infections. Further studies are required to better understand SARS-CoV-2 and its role within the myriad of pediatric respiratory infections.
Acknowledgement: we thank Lucas Ruiter Kanamori, Lucia Maria Mattei de Arruda Campos, Nadia E. Aikawa, Mayra de Barros Dorna, Ana Paula Beltran Moschione, Antonio Carlos Pastorino, Ana Cristina Aoun Tannuri, Uenis Tannuri, Ricardo Katsuya Toma, Andreia Watanabi, Aurora Rosaria Pagliara Waetge, Sonia Regina Testa da Silva Ramos, Mariana Nutti de Almeida Cordon, Vera Aparecida dos Santos. Pediatric COVID HC-FMUSP Study Group: Adriana Pasmanik Eisencraft, Alfio Rossi Jr, Dr. Artur Figueiredo Delgado, Gabriela Nunes Leal, Maria Augusta Cicaroni Gibelli, Patricia Palmeira Daenekas Jorge, Neusa Keico Sakita, Emilly Henrique dos Santos, Mussya Cisotto Rocha, Kelly Aparecida Kanunfre, Magda Carneiro-Sampaio, Werther Brunow de Carvalho.