Respiratory specimens were collected from identified suspected cases. Then, infected persons, their close contacts, and their healthcare teams were interviewed for epidemiological field reports. Detailed exposure and contact histories were traced and recorded. 

Sources of Data for Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus-Infected Pneumonia.

Until January 18th:
A suspected novel coronavirus-infected pneumonia (NCIP) case was defined as a case that fulfilled all of the following criteria:
"fever, with or without recorded temperature; radiographic evidence of pneumonia; low or normal white-cell count or low lymphocyte count; and no reduction in symptoms after antimicrobial treatment for 3 days, following standard clinical guidelines "
OR was linked to Huanan Seafood Wholesale Market or contact with other patients with similar symptoms and fulfilled the first three criteria above.

January 18th and later:
Cases were determined by a travel history to Wuhan or direct contact with patients from Wuhan who had fever or respiratory symptoms, within 14 days before illness onset. A confirmed case was "a case with respiratory specimens that tested positive for the 2019-nCoV by at least one of the following three methods: isolation of 2019-nCoV or at least two positive results by real-time reverse-transcription–polymerase-chain-reaction (RT-PCR) assay for 2019-nCoV or a genetic sequence that matches 2019-nCoV."



Case Definitions for Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus-Infected Pneumonia.

- Sources of Data
- Case Definitions
- Laboratory Testing
- Statistical Analyses

University of Michigan - Ann Arbor

Study of 425 laboraory-confirmed cases of novel coronavirus-infected pneumonia (NCIP) with mean incubation period of 5.2 days (95% confidence interval: [4.1, 7.0]). 

Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus-Infected Pneumonia.

Li, Q., Guan, X., Wu, P., Wang, X., Zhou, L., Tong, Y., ... & Xing, X. (2020). Early transmission dynamics in Wuhan, China, of novel coronavirus–infected pneumonia. New England Journal of Medicine.
doi: 10.1056/NEJMoa2001316.
https://www.nejm.org/doi/full/10.1056/NEJMoa2001316

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