학술논문
Magnitude and Determinants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Household Transmission: A Longitudinal Cohort Study
Document Type
article
Author
Kelly, J Daniel; Lu, Scott; Anglin, Khamal; Garcia-Knight, Miguel; Pineda-Ramirez, Jesus; Goldberg, Sarah A; Tassetto, Michel; Zhang, Amethyst; Donohue, Kevin; Davidson, Michelle C; Romero, Mariela; Diaz Sanchez, Ruth; Djomaleu, Manuella; Mathur, Sujata; Chen, Jessica Y; Forman, Carrie A; Servellita, Venice; Montejano, Rubi D; Shak, Joshua R; Rutherford, George W; Deeks, Steven G; Abedi, Glen R; Rolfes, Melissa A; Saydah, Sharon; Briggs-Hagen, Melissa; Peluso, Michael J; Chiu, Charles; Midgley, Claire M; Andino, Raul; Martin, Jeffrey N
Source
Clinical Infectious Diseases. 75(Supplement_2)
Subject
Language
Abstract
BackgroundHouseholds have emerged as important venues for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. Little is known, however, regarding the magnitude and determinants of household transmission in increasingly vaccinated populations.MethodsFrom September 2020 to January 2022, symptomatic nonhospitalized individuals with SARS-CoV-2 infection by RNA detection were identified within 5 days of symptom onset; all individuals resided with at least 1 other SARS-CoV-2-uninfected household member. These infected persons (cases) and their household members (contacts) were subsequently followed with questionnaire-based measurement and serial nasal specimen collection. The primary outcome was SARS-CoV-2 infection among contacts.ResultsWe evaluated 42 cases and their 74 household contacts. Among the contacts, 32 (43%) became infected, of whom 5 (16%) were asymptomatic; 81% of transmissions occurred by 5 days after the case's symptom onset. From 21 unvaccinated cases, 14-day cumulative incidence of SARS-CoV-2 infection among contacts was 18/40 (45% [95% confidence interval {CI}, 29%-62%]), most of whom were unvaccinated. From 21 vaccinated cases, 14-day cumulative incidence of SARS-CoV-2 infection was 14/34 (41% [95% CI, 25%-59%]) among all contacts and 12/29 (41% [95% CI, 24%-61%]) among vaccinated contacts. At least 1 comorbid condition among cases and 10 or more days of RNA detection in cases were associated with increased risk of infection among contacts.ConclusionsAmong households including individuals with symptomatic SARS-CoV-2 infection, both vaccinated-to-vaccinated and unvaccinated-to-unvaccinated transmission of SARS-CoV-2 to household contacts was common. Because vaccination alone did not notably reduce risk of infection, household contacts will need to employ additional interventions to avoid infection.