TY - JOUR
T1 - SARS-CoV-2 Transmission Potential and Policy Changes in South Carolina, February 2020-January 2021
AU - Davies, Margaret R.
AU - Hua, Xinyi
AU - Jacobs, Terrence D.
AU - Wiggill, Gabi I.
AU - Lai, Po Ying
AU - Du, Zhanwei
AU - Debroy, Swati
AU - Robb, Sara Wagner
AU - Chowell, Gerardo
AU - Fung, Isaac Chun Hai
N1 - Publisher Copyright:
© 2022 The Author(s). Published by Cambridge University Press on behalf of Society for Disaster Medicine and Public Health.
PY - 2022/8/4
Y1 - 2022/8/4
N2 - INTRODUCTION: We aimed to examine how public health policies influenced the dynamics of coronavirus disease 2019 (COVID-19) time-varying reproductive number (
R
t
) in South Carolina from February 26, 2020, to January 1, 2021.
METHODS: COVID-19 case series (March 6, 2020, to January 10, 2021) were shifted by 9 d to approximate the infection date. We analyzed the effects of state and county policies on
R
t
using EpiEstim. We performed linear regression to evaluate if per-capita cumulative case count varies across counties with different population size.
RESULTS:
R
t
shifted from 2-3 in March to <1 during April and May.
R
t
rose over the summer and stayed between 1.4 and 0.7. The introduction of statewide mask mandates was associated with a decline in
R
t
(-15.3%; 95% CrI, -13.6%, -16.8%), and school re-opening, an increase by 12.3% (95% CrI, 10.1%, 14.4%). Less densely populated counties had higher attack rates (
P < 0.0001).
CONCLUSIONS: The
R
t
dynamics over time indicated that public health interventions substantially slowed COVID-19 transmission in South Carolina, while their relaxation may have promoted further transmission. Policies encouraging people to stay home, such as closing nonessential businesses, were associated with
R
t
reduction, while policies that encouraged more movement, such as re-opening schools, were associated with
R
t
increase.
AB - INTRODUCTION: We aimed to examine how public health policies influenced the dynamics of coronavirus disease 2019 (COVID-19) time-varying reproductive number (
R
t
) in South Carolina from February 26, 2020, to January 1, 2021.
METHODS: COVID-19 case series (March 6, 2020, to January 10, 2021) were shifted by 9 d to approximate the infection date. We analyzed the effects of state and county policies on
R
t
using EpiEstim. We performed linear regression to evaluate if per-capita cumulative case count varies across counties with different population size.
RESULTS:
R
t
shifted from 2-3 in March to <1 during April and May.
R
t
rose over the summer and stayed between 1.4 and 0.7. The introduction of statewide mask mandates was associated with a decline in
R
t
(-15.3%; 95% CrI, -13.6%, -16.8%), and school re-opening, an increase by 12.3% (95% CrI, 10.1%, 14.4%). Less densely populated counties had higher attack rates (
P < 0.0001).
CONCLUSIONS: The
R
t
dynamics over time indicated that public health interventions substantially slowed COVID-19 transmission in South Carolina, while their relaxation may have promoted further transmission. Policies encouraging people to stay home, such as closing nonessential businesses, were associated with
R
t
reduction, while policies that encouraged more movement, such as re-opening schools, were associated with
R
t
increase.
KW - COVID-19/epidemiology
KW - Humans
KW - Public Health
KW - Public Policy
KW - SARS-CoV-2
KW - South Carolina/epidemiology
UR - https://www.scopus.com/pages/publications/85136244540
U2 - 10.1017/dmp.2022.212
DO - 10.1017/dmp.2022.212
M3 - Article
C2 - 35924560
AN - SCOPUS:85136244540
SN - 1935-7893
VL - 17
JO - Disaster Medicine and Public Health Preparedness
JF - Disaster Medicine and Public Health Preparedness
IS - 10
M1 - e276
ER -
