Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent behind the ongoing coronavirus disease 2019 (COVID-19) pandemic.
Population-based surveys on COVID-19 prevalence have helped establish the epidemiology of infection and allowed more accurate decision-making regarding re-opening policies.
The susceptibility of adolescents (10-19 years) and youth (15-24 years) to COVID-19 have been a controversial topic ever since the pandemic declaration.
According to the WHO, adolescents fall in the 10-19 age group, and youth belong to the 15-24 age group. Early studies performed in Hunan province, China, reported the infection rate in 0-14-year-olds as 6.2% compared to an infection rate of 8.6% in 15-64-year-olds and 16.3% in individuals 65 years and above.
Several other studies have also reported that adolescents are significantly less prone to COVID-19 compared to older adults. As per these results, older adults were deemed significantly more susceptible to COVID-19 than adolescents and youth.
Statistical analyses to compare COVID-19 prevalence in adolescents and youth to older adults
In an attempt to replicate the results of previous studies, a team of researchers from the New York Medical College, Touro College & University System, SUNY Downstate College of Medicine, and Icahn School of Medicine at Mount Sinai, New York, USA, performed statistical analyses on COVID-19 prevalence data from the U.S. to compare the number of cases in adolescents and youth to that in older adults. Their work is published on the preprint server medRxiv*.
The researchers analyzed data from 6 U.S. states experiencing an increase in the number of COVID-19 cases to determine the prevalence of COVID-19 and two other parameters pertaining to COVID-19 prevalence in youth and adolescents to older adults. The 2 parameters were (% of cases observed in a given age group) ÷ (% of cases expected based on population demographics); and percentage deviation or [(% observed - % expected)/ % expected] x 100.
COVID-19 prevalence in adolescence significantly greater than in older adults
As per the results obtained, the prevalence of COVID-19 in adolescents and youth was considerably higher than that in older adults (p < .00001), as was % observed ÷ % expected (p < .005).
"Our findings in the six U.S. states are contrary to those of Zhang et al. in China who found that the infection rate in older adults, ages 65+, exceeded that in adolescents and youth, and to those of Wu et al., who found that of 44,672 confirmed cases of COVID in mainland China, only 1% were in adolescents ages 10-19 years of age."
The % deviation was significantly higher in adolescents/youth compared to that in older adults
(p < 0.00001) when observed cases were more than the expected numbers and significantly less when observed numbers were fewer than expected (p < 0.00001).
"We found that the prevalence of COVID-19 in adolescence was significantly greater than in older adults, and similarly for the two other prevalence-related measures."
High susceptibility of adolescents and youth to COVID-19 highlights the need for masks and social distancing in schools
The study results did not agree with the findings of previous studies that concluded adolescents are less susceptible to COVID-19 than older adults. This work's findings indicate a similar infection rate for all the age groups, which can have crucial implications for the re-opening of schools.
Students in middle and high schools, college, and the first two years of professional / graduate schools fall in the age groups of 10-19 and 15-24. The high prevalence of COVID-19 in these age groups indicates the need for an abundance of caution while making decisions regarding school re-openings. In countries where schools have already re-opened, the high prevalence of COVID-19 in these age groups emphasizes the necessity of students, teachers, and staff using masks, following social distancing, and regular sanitizing and washing hands.
"In places where schools have nevertheless re-opened, the high prevalence of COVID-19 highlights the necessity of students, faculty, and staff wearing masks, social distancing, and washing hands regularly."
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.