Secondary infection risks were lower for primary cases aged 12 to 17 years compared with those aged 18 to 49 years
MONDAY, Feb. 28, 2022 (HealthDay News) — Children and adults within a household can transmit and are susceptible to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), according to a study published online Feb. 23 in Pediatrics.
Huong Q. McLean, Ph.D., M.P.H., from the Marshfield Clinic Research Institute in Wisconsin, and colleagues enrolled households between April 2020 and April 2021 that included people with SARS-CoV-2 infection in Nashville, Tennessee, and Central and Western Wisconsin and their household contacts, who were followed for 14 days for examination of symptoms and secondary transmission events. Secondary infection risks (SIR) were estimated by the age of the primary case and contacts.
The researchers identified 198 secondary SARS-CoV-2 infections among 404 household contacts following the 226 primary cases. Among contacts, the age group-specific SIR varied from 36 to 53 percent, with no differences by age. Primary cases aged 12 to 17 years had lower SIR than those aged 18 to 49 years (risk ratio, 0.42). Among primary case-contact pairs in the same versus different age groups, SIRs were 55 and 45 percent, respectively. The highest SIR was seen among primary case-contact pairs aged 65 years or older and 5 to 11 years (76 and 69 percent, respectively). Nineteen percent of the secondary SARS-CoV-2 infections were asymptomatic, with no variation in the frequency of asymptomatic infections by age group.
“We observed that both children and adults of all ages can transmit and are susceptible to SARS-CoV-2 infection,” the authors write. “There were no significant differences in susceptibility to SARS-CoV-2 by age group, from preschool-aged children to older adults. Further research is needed to understand age-related interactions and behaviors in households as it relates to the probability of transmission by age.”
One author disclosed financial ties to the pharmaceutical industry.
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