Was there an association of public health interventions with improved control of the
COVID-19 outbreak in Wuhan, China? In this cohort study that included 32 583 patients
with laboratory-confirmed COVID-19 in Wuhan from December 8, 2019, through March 8,
2020, the institution of interventions including cordons sanitaire , traffic restriction,
social distancing, home quarantine, centralized quarantine, and universal symptom
survey was temporally associated with reduced effective reproduction number of SARS-CoV-2
(secondary transmission) and the number of confirmed cases per day across age groups,
sex, and geographic regions. A series of multifaceted public health interventions
was temporally associated with improved control of the COVID-19 outbreak in Wuhan
and may inform public health policy in other countries and regions. Coronavirus disease
2019 (COVID-19) has become a pandemic, and it is unknown whether a combination of
public health interventions can improve control of the outbreak. To evaluate the association
of public health interventions with the epidemiological features of the COVID-19 outbreak
in Wuhan by 5 periods according to key events and interventions. In this cohort study,
individual-level data on 32 583 laboratory-confirmed COVID-19 cases reported between
December 8, 2019, and March 8, 2020, were extracted from the municipal Notifiable
Disease Report System, including patients’ age, sex, residential location, occupation,
and severity classification. Nonpharmaceutical public health interventions including
cordons sanitaire , traffic restriction, social distancing, home confinement, centralized
quarantine, and universal symptom survey. Rates of laboratory-confirmed COVID-19 infections
(defined as the number of cases per day per million people), across age, sex, and
geographic locations were calculated across 5 periods: December 8 to January 9 (no
intervention), January 10 to 22 (massive human movement due to the Chinese New Year
holiday), January 23 to February 1 ( cordons sanitaire , traffic restriction and home
quarantine), February 2 to 16 (centralized quarantine and treatment), and February
17 to March 8 (universal symptom survey). The effective reproduction number of SARS-CoV-2
(an indicator of secondary transmission) was also calculated over the periods. Among
32 583 laboratory-confirmed COVID-19 cases, the median patient age was 56.7 years
(range, 0-103; interquartile range, 43.4-66.8) and 16 817 (51.6%) were women. The
daily confirmed case rate peaked in the third period and declined afterward across
geographic regions and sex and age groups, except for children and adolescents, whose
rate of confirmed cases continued to increase. The daily confirmed case rate over
the whole period in local health care workers (130.5 per million people [95% CI, 123.9-137.2])
was higher than that in the general population (41.5 per million people [95% CI, 41.0-41.9]).
The proportion of severe and critical cases decreased from 53.1% to 10.3% over the
5 periods. The severity risk increased with age: compared with those aged 20 to 39
years (proportion of severe and critical cases, 12.1%), elderly people (≥80 years)
had a higher risk of having severe or critical disease (proportion, 41.3%; risk ratio,
3.61 [95% CI, 3.31-3.95]) while younger people (<20 years) had a lower risk (proportion,
4.1%; risk ratio, 0.47 [95% CI, 0.31-0.70]). The effective reproduction number fluctuated
above 3.0 before January 26, decreased to below 1.0 after February 6, and decreased
further to less than 0.3 after March 1. A series of multifaceted public health interventions
was temporally associated with improved control of the COVID-19 outbreak in Wuhan,
China. These findings may inform public health policy in other countries and regions.
This population epidemiology study examines associations between phases of nonpharmaceutical
public health interventions (social distancing, centralized quarantine, home confinement,
and others) and rates of laboratory-confirmed COVID-19 infection in Wuhan, China,
between December 2019 and early March 2020.