Identification of a Super-Spreading Chain of Transmission Associated with COVID-19 at the Early Stage of the Disease Outbreak in Wuhan
Author(s): Ke Hu, Yang Zhao, Mengmei Wang, Qiqi Zeng, Xiaorui Wang, Ming Wang, Zhishui Zheng, Xiaochen Li, Yunting Zhang, Tao Wang, Shaolin Zeng, Yan Jiang, Dan Liu, Wenzhen Yu, Fang Hu, Hongyu Qin, Jingcan H
Background: The super-spreading events were associated with the outbreaks of SARS and MERS, but their association with the outbreak of COVID-19 was unknown before we first published a report in medRxiv preprint in March 2020. Here, we reported a super-spreading transmission chain of SARS-CoV-2 involving an index patient, seven cancer patients, 40 health care workers and four family members.
Methods: We conducted a retrospective study to identify the index patient and the exposed individuals linked to a chain of transmission associated with COVID-19. We collected and analyzed the data on demographic features, exposure history, clinical presentation, laboratory investigation, radiological examination, and disease outcome of these patients.
Results: We identified the index patient and another presumptive “super-spreader”, who initiated and amplified a super-spreading transmission chain associated with COVID-19, respectively. There were 31 female and 21 male patients in this cohort, and the median age was 37 years (range: 22-79 years). Each of them had an exposure history with the index patient or his close contacts. Approximately 87% (45/52) of the patients had fever or other symptoms, 96% (50/52) had abnormal chest CT-scan findings, 86% of the tested patients (39/45) were positive for SARS-CoV-2 in the nasopharyngeal or throat swab specimen, 85% of the tested patients (29/34) were positive for SARS-CoV-2-specific IgM and/or IgG, 15% of the RT-PCR positive patients were tested negative for the specific IgM and/or IgG at the convalescent phase, and 15% of the RT-PCR negative patients were tested positive for the specific IgM and/or IgG. The severe patients experienced a significant decrease in oximetry saturation, lymphocyte, and platelet counts, along with a significant increase in C-reactive protein, D-dimer, and lactate dehydrogenase. All six fatal cases had comorbidities and five of the seven cancer patients (71%) died within 2-20 days of the disease onset.
Conclusions: Our findings suggested that the super-spreading events associated with COVID-19 took place at the early stage of the disease outbreak in Wuhan. The cancer patients appeared to be highly vulnerable to SASR-CoV-2 infection.