On the increasing incidence of SARS-CoV- 2 in older adolescents and younger adults during the epidemic in Mexico

OBJECTIVE: To estimate temporary changes in the inciden-ce of SARS-CoV-2-confirmed hospitalizations (by date of symptom onset) by age group during and after the national lockdown. MATERIALS AND METHODS: For each age group g, we computed the proportion E(g) of individuals in that age group among all cases aged 10-59y during the early lock-down period (April 20-May 3, 2020), and the corresponding proportion L(g) during the late lockdown (May 18-31, 2020) and post-lockdown (June 15-28, 2020) periods and computed the prevalence ratio: PR(g)=L(g)/E(g). RESULTS: For the late lockdown and post-lockdown periods, the highest PR values were found in age groups 15-19y (late: PR=1.69, 95%CI 1.05,2.72; post-lockdown: PR=2.05, 1.30,3.24) and 20-24y (late: PR=1.43, 1.10,1.86; post-lockdown: PR=1.49, 1.15,1.93). These estimates were higher in individuals 15-24y compared to those ≥30y. CONCLUSIONS: Adolescents and younger adults had an increased relative incidence of SARS-CoV-2 during late lockdown and post-lockdown periods. The role of these age groups should be considered when implementing future pandemic response efforts.