Does Covid-19 differ in its incidence and clinical presentation among children and adults in a household? To find out the answer to this question, a study published in JAMA Network Open recruited 690 participants from 175 households from end of November 2020 through to mid-October 2021.¹ During this time, the Alpha and Delta SARS-CoV-2 variants were prevalent.

Among the participants selected for the study, 245 were in the age group 0 to 4 years, 100 in the age group 5-17 years and there were 334 adults aged 18-74 years. Every week, the participants were assigned symptom questionnaires to check for symptoms and submitted self-collected nasal swabs for SARS-CoV-2 RT PCR test.

At the end of the study, 7.8% (n = 54) of the participants developed SARS-CoV-2 infection. These included 8.6% (22/256) of children aged 0-4 years, 11% (11/100) children aged 5-17 years and 6.3% adults. Asymptomatic infections were most common among the 0-17-year age group (36.7%;11/30) versus adults (14.3%; 3/21). Of note was the finding that compared to infected adults, children aged 0-4 years were more than twice as likely to be asymptomatic (14.3% vs 36.8%).

A significant association was observed between the number of symptoms and viral loads among adults but not in children. The median viral load was highest among patients infected with the Delta variant (4.4 log10 copies/mL) compared to those infected with Alpha variant (2.6 log10 copies/mL) or other variants not of interest/concern (1.9 log10 copies/mL). While adults with high viral loads had more severe symptoms, this was not the case in young children.

According to this study, children younger than 4 years of age are quite often asymptomatic. Unlike in adults, no correlation of viral load with symptoms was noted in this age group suggesting that even asymptomatic children could still be infectious and spread the infection to others. Relying on symptoms alone for screening could miss many asymptomatic, but contagious cases among young children. Children exposed to Covid-19 should be considered for testing, even if they do not have any symptoms. Besides following Covid-appropriate behavior, everyone in the family, including children must be updated with the vaccination, as per their eligibility.

Reference

1. Ruth A Karron, et al; SEARCH Study Team. Assessment of clinical and virological characteristics of SARS-CoV-2 infection among children aged 0 to 4 years and their household members. JAMA Netw Open. 2022 Aug 1;5(8):e2227348. doi: 10.1001/jamanetworkopen.2022.27348.