Variability in transmission risk of SARS-CoV-2 in close contact settings: A contact tracing study in Shandong Province, China.
Epidemics
; 39: 100553, 2022 06.
Article
em En
| MEDLINE
| ID: mdl-35287110
ABSTRACT
BACKGROUND:
Understanding the relative transmissibility of SARS-CoV-2 virus across different contact settings and the possibility of superspreading events is important for prioritizing disease control. Such assessment requires proper consideration of individual level exposure history, which is made possible by contact tracing.METHODS:
The case-ascertained study in Shandong, China including 97 laboratory-confirmed index cases and 3158 close contacts. All close contacts were quarantined after their last exposure of index cases. Contacts were tested for COVID-19 regularly by PCR to identify both symptomatic and asymptomatic infections. We developed a Bayesian transmission model to the contact tracing data to account for different duration of exposure among individuals to transmission risk in different settings, and the heterogeneity of infectivity of cases.RESULTS:
We estimate secondary attack rates (SAR) to be 39% (95% credible interval (CrI) 20-64%) in households, 30% (95% CrI 11-67%) in healthcare facilities, 23% (95% CrI 7-51%) at workplaces, and 4% (95% CrI 1-17%) during air travel. Models allowing heterogeneity of infectivity of cases provided a better goodness-of-fit. We estimated that 64% (95% CrI 55-72%) of cases did not generate secondary transmissions, and 20% (95% CrI 15-26%) cases explained 80% of secondary transmissions.CONCLUSIONS:
Household, healthcare facilities and workplaces are efficient setting for transmission. Timely identification of potential superspreaders in most transmissible settings remains crucial for containing the pandemic.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
SARS-CoV-2
/
COVID-19
Tipo de estudo:
Etiology_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Humans
País/Região como assunto:
Asia
Idioma:
En
Revista:
Epidemics
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
China