TY - JOUR
T1 - Estimating the Instantaneous Asymptomatic Proportion With a Simple Approach
T2 - Exemplified With the Publicly Available COVID-19 Surveillance Data in Hong Kong
AU - Li, Chunyu
AU - Zhao, Shi
AU - Tang, Biao
AU - Zhu, Yuchen
AU - Ran, Jinjun
AU - Li, Xiujun
AU - He, Daihai
N1 - Funding Information:
XL was supported by the National Natural Science Foundation of China (Grant No. 81673238), the COVID-19 Emergency Research Project of Shandong University (Grant No. 2020XGC01), and the National Key Research and Development Program of China (Grant Nos. 2019YFC1200500, 2019YFC1200502). DH was supported by General Research Fund (Grant No. 15205119) of the Research Grants Council (RGC) of Hong Kong, China, and an Alibaba (China) Co. Ltd. Collaborative Research grant.
Publisher Copyright:
© Copyright © 2021 Li, Zhao, Tang, Zhu, Ran, Li and He.
PY - 2021/5/3
Y1 - 2021/5/3
N2 - Background: The asymptomatic proportion is a critical epidemiological characteristic that modulates the pandemic potential of emerging respiratory virus, which may vary depending on the nature of the disease source, population characteristics, source–host interaction, and environmental factors. Methods: We developed a simple likelihood-based framework to estimate the instantaneous asymptomatic proportion of infectious diseases. Taking the COVID-19 epidemics in Hong Kong as a case study, we applied the estimation framework to estimate the reported asymptomatic proportion (rAP) using the publicly available surveillance data. We divided the time series of daily cases into four stages of epidemics in Hong Kong by examining the persistency of the epidemic and compared the rAPs of imported cases and local cases at different stages. Results: As of July 31, 2020, there were two intermittent epidemics in Hong Kong. The first one was dominated by imported cases, accounting for 63.2% of the total cases, and the second one was dominated by local cases, accounting for 86.5% of the total cases. The rAP was estimated at 23.1% (95% CI: 10.8–39.7%) from January 23 to July 31, and the rAPs were estimated at 22.6% (95% CI: 11.1–38.9%) among local cases and 38.7% (95% CI: 9.0–72.0%) among imported cases. Our results showed that the rAPs of local cases were not significantly different between the two epidemics, but increased gradually during the first epidemic period. In contrast, the rAPs of imported cases in the latter epidemic period were significantly higher than that in the previous epidemic period. Conclusion: Hong Kong has a high rAP of imported COVID-19 cases and should continue to strengthen the detection and isolation of imported individuals to prevent the resurgence of the disease.
AB - Background: The asymptomatic proportion is a critical epidemiological characteristic that modulates the pandemic potential of emerging respiratory virus, which may vary depending on the nature of the disease source, population characteristics, source–host interaction, and environmental factors. Methods: We developed a simple likelihood-based framework to estimate the instantaneous asymptomatic proportion of infectious diseases. Taking the COVID-19 epidemics in Hong Kong as a case study, we applied the estimation framework to estimate the reported asymptomatic proportion (rAP) using the publicly available surveillance data. We divided the time series of daily cases into four stages of epidemics in Hong Kong by examining the persistency of the epidemic and compared the rAPs of imported cases and local cases at different stages. Results: As of July 31, 2020, there were two intermittent epidemics in Hong Kong. The first one was dominated by imported cases, accounting for 63.2% of the total cases, and the second one was dominated by local cases, accounting for 86.5% of the total cases. The rAP was estimated at 23.1% (95% CI: 10.8–39.7%) from January 23 to July 31, and the rAPs were estimated at 22.6% (95% CI: 11.1–38.9%) among local cases and 38.7% (95% CI: 9.0–72.0%) among imported cases. Our results showed that the rAPs of local cases were not significantly different between the two epidemics, but increased gradually during the first epidemic period. In contrast, the rAPs of imported cases in the latter epidemic period were significantly higher than that in the previous epidemic period. Conclusion: Hong Kong has a high rAP of imported COVID-19 cases and should continue to strengthen the detection and isolation of imported individuals to prevent the resurgence of the disease.
KW - COVID-19
KW - epidemic
KW - Hong Kong
KW - instantaneous asymptomatic proportion
KW - likelihood-based framework
UR - http://www.scopus.com/inward/record.url?scp=85106065992&partnerID=8YFLogxK
U2 - 10.3389/fpubh.2021.604455
DO - 10.3389/fpubh.2021.604455
M3 - Journal article
C2 - 34012950
AN - SCOPUS:85106065992
SN - 2296-2565
VL - 9
SP - 1
EP - 6
JO - Frontiers in Public Health
JF - Frontiers in Public Health
M1 - 604455
ER -