本研究結取2020/1/4~2/24中國湖北以外50省分的新聞稿,武漢肺炎確診病例數,再經由模式推導潛伏期。經推算,武漢肺炎潛伏期約5.1天(95% CI=4.5-5.8天),97.5%的患者會在11.5天內出現症狀(95% CI=8.2-15.6天)。若以發燒定義潛伏期,則潛伏期約為5.7天(95% CI=4.9-6.8天),97.5%的患者會在12.5天內發燒(95% CI=8.2-17.7天)。經過換算,若主動監測隔離期為14天,每10,000名患者中,會漏掉101名感染者(99th percentile:482名)。但本模型未考慮無症狀感染。有鑑於目前已有無症狀傳染之案例,由感染至具傳染性的潛伏期(latent period)應小於出現症狀的潛伏期(incubation period)。研究結果大致支持目前隔離14天的政策,但在極端狀況中,可能需要考慮更長的隔離期。

(財團法人國家衛生研究院 莊淑鈞博士摘要整理)

Background:A novel human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified in China in December 2019. There is limited support for many of its key epidemiologic features, including the incubation period for clinical disease (coronavirus disease 2019 [COVID-19]), which has important implications for surveillance and control activities.
Objective:To estimate the length of the incubation period of COVID-19 and describe its public health implications.
Design:Pooled analysis of confirmed COVID-19 cases reported between 4 January 2020 and 24 February 2020.
Setting:News reports and press releases from 50 provinces, regions, and countries outside Wuhan, Hubei province, China.
Participants:Persons with confirmed SARS-CoV-2 infection outside Hubei province, China.
Measurements:Patient demographic characteristics and dates and times of possible exposure, symptom onset, fever onset, and hospitalization.
Results:There were 181 confirmed cases with identifiable exposure and symptom onset windows to estimate the incubation period of COVID-19. The median incubation period was estimated to be 5.1 days (95% CI, 4.5 to 5.8 days), and 97.5% of those who develop symptoms will do so within 11.5 days (CI, 8.2 to 15.6 days) of infection. These estimates imply that, under conservative assumptions, 101 out of every 10 000 cases (99th percentile, 482) will develop symptoms after 14 days of active monitoring or quarantine.
Limitation:Publicly reported cases may overrepresent severe cases, the incubation period for which may differ from that of mild cases.

Author:Stephen A. Lauer, Kyra H. Grantz, BA, Qifang Bi, MHS, et al.
原文連結:https://is.gd/jPygMM