Higher Viral Load Drives Infrequent Severe Acute Respiratory Syndrome Coronavirus 2 Transmission Between Asymptomatic Residence Hall Roommates.
J Infect Dis
; 224(8): 1316-1324, 2021 10 28.
Article
in English
| MEDLINE | ID: covidwho-1493825
ABSTRACT
BACKGROUND:
The coronavirus disease 2019 pandemic spread to >200 countries in <6 months. To understand coronavirus spread, determining transmission rate and defining factors that increase transmission risk are essential. Most cases are asymptomatic, but people with asymptomatic infection have viral loads indistinguishable from those in symptomatic people, and they do transmit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, asymptomatic cases are often undetected.METHODS:
Given high residence hall student density, the University of Colorado Boulder established a mandatory weekly screening test program. We analyzed longitudinal data from 6408 students and identified 116 likely transmission events in which a second roommate tested positive within 14 days of the index roommate.RESULTS:
Although the infection rate was lower in single-occupancy rooms (10%) than in multiple-occupancy rooms (19%), interroommate transmission occurred only about 20% of the time. Cases were usually asymptomatic at the time of detection. Notably, individuals who likely transmitted had an average viral load approximately 6.5-fold higher than individuals who did not (mean quantification cycle [Cq], 26.2 vs 28.9). Although students with diagnosed SARS-CoV-2 infection moved to isolation rooms, there was no difference in time to isolation between cases with or without interroommate transmission.CONCLUSIONS:
This analysis argues that interroommate transmission occurs infrequently in residence halls and provides strong correlative evidence that viral load is proportional to transmission probability.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Viral Load
/
Asymptomatic Infections
/
SARS-CoV-2
/
COVID-19
Type of study:
Diagnostic study
/
Observational study
/
Prognostic study
Limits:
Adult
/
Humans
/
Young adult
Language:
English
Journal:
J Infect Dis
Year:
2021
Document Type:
Article
Affiliation country:
Infdis
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