key: cord-0907183-t6v88pqq authors: Qin, Gang; Zhang, Lei; Yu, Cheng-Jun title: Nonpharmaceutical interventions and epidemic intensity during the 2019 novel coronavirus disease pandemic date: 2020-04-13 journal: Clin Infect Dis DOI: 10.1093/cid/ciaa432 sha: a7c7e780f6a477a13945a3d85934ff9ac7b4ade8 doc_id: 907183 cord_uid: t6v88pqq nan nonpharmaceutical interventions (NPIs) for the COVID-19 epidemic in Wenzhou city, Zhejiang province, China ("Wenzhou anti-COVID-19 measures"). The reported epidemic dynamic in Wenzhou was comparable to the country-wide study performed by the national novel coronavirus pneumonia emergency response epidemiology team [2] . However, we believe that some of the implications may need rethinking. First, we question the level of synchrony of COVID-19 epidemics between Wenzhou and the three neighboring cities of Wuhan the epicenter ( Figure 1 ). The numbers of confirmed COVID-19 cases in cities were positively correlated to the emigration number from Wuhan [3] . Big data analysis revealed that Xiaogan, Huanggang and Jingzhou were the three cities of the largest influx of Wuhan passengers during Jan 10 th -23 rd , 2020, with approximately 690,000, 650,000 and 330,000 people respectively (according to online real-time map of migration at http://qianxi.baidu.com/), while Wenzhou had around 90,000 individuals returning from Wuhan. Moreover, although the symptom onset date of the first confirmed COVID-19 patient was Dec 1, 2019, the diagnostic PCR method was not established until Jan 10 th , 2020 [4] . The epidemic A c c e p t e d M a n u s c r i p t curves demonstrated in the article were constructed with dates of diagnosis report rather than symptom onset. In fact, the onset time of the outbreak in the three cities near Wuhan might be much earlier than that in Wenzhou. Second, the abrupt increases of reported cases in the three Hubei's cities on Feb 12 ("subsequent outbreaks" in the article) were more likely to be attributed to the change in the 5 th revision of the clinical diagnosis guideline for COVID-19 [5, 6] . The clinically diagnosed cases in Hubei province, but not applicable to the rest of the country, were regarded as confirmed cases if they fulfilled one epidemiological clue and had pneumonia-related computerized tomography (CT) scan results. Previously accumulated clinically-diagnosed cases that tested negative were reported as new confirmed cases afterwards. Third, the implemented NPIs in different Chinese cities may vary significantly nationwide [7] . Different cities had different risk factors and epidemic patterns, thus adding to the complexity of impact evaluation of public health interventions. Yangtze River Delta region is compromised by Shanghai, Jiangsu province and Zhejiang province ( Figure 1 ). Nantong city, with similar geographic characteristics, population size (7.3 million) and an influx of Wuhan passengers (650,000 people according to http://qianxi.baidu.com/), might be a better comparison than cities in Hubei province. It reported 40 confirmed COVID-19 cases, significantly lower than the average level of Jiangsu province (0.55 vs. 0.81 per 100,000 persons, P = 0.016). Shanghai, the New measures for COVID-19 response: a lesson from the Wenzhou experience The epidemiological characteristics of an outbreak of 2019 novel coronavirus diseases (COVID-19) in China Distribution of the COVID-19 epidemic and correlation with population emigration from wuhan, China Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China China's Hubei reports jump in new cases of COVID-19 after diagnosis criteria revision. Xiahua News National Health Commission C. Clinical diagnosis and treatment guidelines for COVID-19 (5th revision version) fcaf1e3e13a/files/ab6bec7f93e64e7f998d802991203cd6.pdf?ich_args2=464-07164809053935_c917f79e3cf56aa586d6161ea039bb89_10001002_9c896c2ad5c7f8d2963 3518939a83798_0ea02ed9e3018a6ee0986e4206568fcd Report of WHO-China joint mission on COVID-19 A c c e p t e d M a n u s c r i p t A c c e p t e d M a n u s c r i p t