Children with Omicron infection reporte lower respiratory tract symptoms more frequently than was reported with any of the other variants

A new study involving 14 Canadian pediatric Emergency Departments (ED) in hospitals across the country has found that the SARS-CoV-2 Omicron is causing more health issues in children that previously thought.

The study findings were published in the peer reviewed journal: JAMA Network Open. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2802161

Among children positive for SARS-CoV-2 who presented for care in pediatric EDs across Canada, symptom profiles differed based on etiologic variants. Children with the Alpha variant had the fewest number of presenting symptoms, while those with the Delta variant had the greatest number of symptoms.

While the latter group of children were most likely to report conjunctivitis and upper respiratory tract symptoms, they were also most likely to have codetection of an additional virus.

The symptoms of COVID-19 in children can vary widely and may depend on a variety of factors, including the age of the child, any underlying health conditions, and the severity of the infection.

While some children infected with the Omicron variant of COVID-19 may be asymptomatic or experience mild symptoms, others may experience more severe symptoms that require medical attention.

Some of the common symptoms of COVID-19 in children that have been reported with the Omicron variant include:

• Fever
• Coughing
• Sore throat
• Runny or stuffy nose
• Shortness of breath or difficulty breathing
• Fatigue
• Headache
• Muscle or body aches
• Loss of taste or smell
• Nausea or vomiting
• Diarrhea

Although the characteristics of presenting symptoms changed as the SARS-CoV-2 virus evolved, unlike in adults where mortality declined in subsequent waves,25 the proportions of infected children experiencing undesirable outcomes in our study remained stable.

Children with Omicron infection are nearly twice as likely to experience fever as those with original-type SARS-CoV-2 infection and 1.5 times more likely to report a cough. Although Omicron has been associated with croup,13 we did not find that upper respiratory tract symptoms were more common in children with Omicron infection when compared with other variants.

However, croup and stridor were not specific data fields in our study, which may have led to underreporting of upper respiratory tract symptoms.

Our results show that children with Omicron infection reported lower respiratory tract symptoms (eg, shortness of breath, chest pain, wheezing, or sputum) more frequently than was reported with any of the other variants.

Additionally, systemic manifestations such as apnea, irritability, lethargy, and drowsiness were more commonly reported by children with Omicron infection than among those with earlier variants.

Although anosmia and ageusia were rare complaints in participants with Omicron infection,26 participants infected by Omicron most commonly had core COVID-19 symptoms.19 While several reports described Omicron as being responsible for less severe disease than prior variants,27 particularly among adults,28,29 we found that children with Omicron infection received more interventions and were more likely to experience ED revisits. Our findings are not unique, as they align with other pediatric studies that report higher pediatric hospitalization rates30-32 during the Omicron period.

Similar to earlier studies,33,34 fever and cough were the most common presenting symptoms in our cohort irrespective of infecting variant, being reported by over half of the children in our cohort.

This is confounded, however, by the fact that fever and/or cough were commonly used indications for SARS-CoV-2 testing in study institutions. Our results align with previous reports of how symptom patterns evolved with the Delta and Omicron variants,35 both of which led to fever, congestion, and cough becoming more common presenting symptoms, while the prevalence of myalgias, anosmia, and ageusia declined.

This may reflect changes in testing patterns over time, with hospitals moving from a “test all” approach to a more selective strategy testing only those who are more unwell or with core COVID-19 symptoms. Further, the higher prevalence of respiratory symptoms in the Omicron and Delta groups may reflect coinfections that, as we report, became more common later in the pandemic as seasonal respiratory viruses resurfaced.36

Children infected with the Omicron strain consumed significant resources, being most likely to have chest radiography performed, to have intravenous fluids and corticosteroids administered, and to revisit the ED within 14 days. This may reflect several factors, including the selective testing of more unwell children, changes in parental thresholds for seeking ED care, higher rates of coinfection, more lower respiratory tract and systemic symptoms, and the younger age of children with Omicron infection.

Although the overall proportions of participants experiencing severe disease was lower than has been previously reported,37 they are consistent with previous reports from our hospital network.38

This may reflect the fact that our study did not capture children transported from referral hospitals directly to our ICU and that in Canada, the EDs often served as a SARS-CoV-2 testing location due to testing capacity limitations elsewhere.

Nonetheless, the rates of hospitalization,39 ICU admission, and total health care provider revisits did not differ between variants. Thus, unlike in adults, it does not appear that children are being less severely affected by emerging variants, and understanding the clinical presentation of COVID-19 in children is needed to design therapeutic trials on this population.

Moreover, as the pediatric COVID-19 clinical phenotype shift occurs over time, clinicians should remain alert to its possible presence, test when clinically indicated, and treat when appropriate (eg, corticosteroids in children hospitalized with COVID-19–associated pneumonia).40