Mask Effectiveness for Preventing Secondary Cases of COVID-19, Johnson County, Iowa, USA

In September of 2020, the Iowa Department of Public Health released guidance stating that persons exposed to someone with coronavirus disease (COVID-19) need not quarantine if the case-patient and the contact wore face masks at the time of exposure. This guidance differed from that issued by the Centers for Disease Control and Prevention. To determine the best action, we matched exposure information from COVID-19 case investigations with reported test results and calculated the secondary attack rates (SARs) after masked and unmasked exposures. Mask use by both parties reduced the SAR by half, from 25.6% to 12.5%. Longer exposure duration significantly increased SARs. Masks significantly reduced virus transmission when worn by both the case-patient and the contact, but SARs for each group were higher than anticipated. This finding suggests that quarantine after COVID-19 exposure is beneficial even if parties wore masks.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:28

Enthalten in:

Emerging infectious diseases - 28(2022), 1 vom: 12. Jan., Seite 69-75

Sprache:

Englisch

Beteiligte Personen:

Riley, Jacob [VerfasserIn]
Huntley, Jamie M [VerfasserIn]
Miller, Jennifer A [VerfasserIn]
Slaichert, Amelia L B [VerfasserIn]
Brown, Grant D [VerfasserIn]

Links:

Volltext

Themen:

2019 novel coronavirus disease
COVID-19
Contact tracing
Coronavirus disease
Iowa
Journal Article
Masks
Public health
Quarantine
Respiratory infections
SARS-CoV-2
Secondary attack rate
Severe acute respiratory syndrome coronavirus 2
USA
Viruses
Zoonoses

Anmerkungen:

Date Completed 24.12.2021

Date Revised 15.09.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.3201/eid2801.211591

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM331781891