Abstract
Background: Social distancing and stringent hygiene seem to be effective in reducing the number of transmitted virus particles, and therefore the infectivity, of coronavirus disease 2019 (COVID-19) and could alter the mode of transmission of the disease. However, it is not known if such practices can change the clinical course in infected individuals.
Methods: We prospectively studied an outbreak of COVID-19 in Switzerland among a population of 508 predominantly male soldiers with a median age of 21 years. We followed the number of infections in 2 spatially separated cohorts with almost identical baseline characteristics with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) before and after implementation of stringent social distancing.
Results: Of the 354 soldiers infected prior to the implementation of social distancing, 30% fell ill from COVID-19, while no soldier in a group of 154, in which infections appeared after implementation of social distancing, developed COVID-19 despite the detection of viral RNA in the nasal and virus-specific antibodies within this group.
Conclusions: Social distancing not only can slow the spread of SARS-CoV-2 in a cohort of young, healthy adults but it can also prevent the outbreak of COVID-19 while still inducing an immune response and colonizing nasal passages. Viral inoculum during infection or mode of transmission may be a key factor determining the clinical course of COVID-19.
Keywords: COVID-19; SARS-CoV-2; cohort study; social distancing; viral inoculum.
【저자키워드】 COVID-19, SARS-CoV-2, social distancing, cohort study, viral inoculum., 【초록키워드】 coronavirus disease, Coronavirus disease 2019, coronavirus, immune response, antibody, social distancing, Infection, Transmission, nasal, severe acute respiratory syndrome Coronavirus, cohort study, Spread, Cohort, Clinical course, Viral, outbreak, implementation, male, Viral RNA, respiratory, Switzerland, nasal passages, hygiene, acute respiratory syndrome, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, baseline characteristics, mode, infected individuals, median age, virus particles, key factor, viral inoculum, Alter, Prevent, effective, healthy, transmitted, the disease, reducing, separated, prospectively studied, 【제목키워드】 clinical, Comparative,