Tsuchiura Public Health Center of Ibaraki Prefectural Government, Tsuchiura 300-0812, Japan.
Fujiidera Public Health Center of Osaka Prefectural Government, Fujiidera 583-0024, Japan.
Int J Environ Res Public Health. 2021 Mar 24;18(7):3377. doi: 10.3390/ijerph18073377.
Long diagnostic delays (LDDs) may decrease the effectiveness of patient isolation in reducing subsequent transmission of coronavirus disease 2019 (COVID-19). This study aims to investigate the correlation between the proportion of LDD of COVID-19 patients with unknown transmission routes and the subsequent doubling time. LDD was defined as the duration between COVID-19 symptom onset and confirmation ≥6 days. We investigated the geographic correlation between the LDD proportion among 369 confirmed COVID-19 patients with symptom onset between the 9th and 11th week and the subsequent doubling time for 717 patients in the 12th-13th week among the six prefectures. The doubling time on March 29 (the end of the 13th week) ranged from 4.67 days in Chiba to 22.2 days in Aichi. Using a Pearson's product-moment correlation (-value = 0.00182) and multiple regression analyses that were adjusted for sex and age (correlation coefficient -0.729, 95% confidence interval: -0.923--0.535, -value = 0.0179), the proportion of LDD for unknown exposure patients was correlated inversely with the base 10 logarithm of the subsequent doubling time. The LDD for unknown exposure patients was correlated significantly and inversely with the subsequent doubling time.
长诊断延迟（LDD）可能会降低患者隔离在减少随后的 2019 年冠状病毒病（COVID-19）传播中的效果。本研究旨在调查 COVID-19 患者未知传播途径的 LDD 比例与随后倍增时间之间的相关性。LDD 定义为 COVID-19 症状发作和确诊之间的持续时间≥6 天。我们调查了在第 9 周至第 11 周期间出现症状的 369 例确诊 COVID-19 患者中 LDD 比例与第 12 周至第 13 周期间六个县的 717 例患者的随后倍增时间之间的地理相关性。3 月 29 日（第 13 周结束）的倍增时间范围从千叶的 4.67 天到爱知的 22.2 天。使用 Pearson 积矩相关（-值=0.00182）和调整了性别和年龄的多元回归分析（相关系数-0.729，95%置信区间：-0.923--0.535，-值=0.0179），未知暴露患者的 LDD 比例与随后倍增时间的以 10 为底的对数呈负相关。未知暴露患者的 LDD 与随后的倍增时间呈显著负相关。
