Transmission dynamics of SARS-CoV-2 Omicron variant infections in Hangzhou, Zhejiang, China, January-February 2022.
Int J Infect Dis
; 126: 132-135, 2023 Jan.
Article
in English
| MEDLINE | ID: covidwho-2086293
ABSTRACT
OBJECTIVES:
We aimed to explore the transmission dynamics of the Omicron BA.1.1 variant in an outbreak in China.METHODS:
We constructed 113 transmission pairs based on the time of exposure and symptom onset for identified infectors and infectees, using the epidemiological data collected during an outbreak in Hangzhou, Zhejiang province, China, between January and February 2022. The key epidemiological parameters were estimated.RESULTS:
The mean estimates of the incubation period and latent period distributions were 3.8 days (95% credible interval 3.5, 4.1) and 3.1 days (2.8, 3.5), respectively. The overall transmission risk peaked at symptom onset, and we estimated that 33.6% (24.8, 42.5) of transmission occurred before symptom onset. The forward generation time decreased from 5.2 days (4.7, 5.7) at the start of the outbreak to 2.2 days (2.0, 2.5) by the end. Allowing this variation over time in the generation time distribution, we estimated that the reproduction number dropped rapidly from 9.5 (3.5, 18.4) to 0.8 (0.3, 1.5) over the outbreak.CONCLUSION:
Shorter incubation period and latent period were estimated for the Omicron BA.1.1 variant. Stringent public health measures prevented a large epidemic by reducing transmission, as indicated by the shortened generation time.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
SARS-CoV-2
/
COVID-19
Type of study:
Observational study
/
Prognostic study
Topics:
Variants
Limits:
Humans
Country/Region as subject:
Asia
Language:
English
Journal:
Int J Infect Dis
Journal subject:
Communicable Diseases
Year:
2023
Document Type:
Article
Affiliation country:
J.ijid.2022.10.033
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