Evidence and characteristics of human-to-human transmission of SARS-CoV-2

Abstract

Background: On December 31, 2019, an outbreak of COVID-19 in humans was reported in Wuhan, and then spread fast to other provinces, China. We analyzed data from field investigations and genetic sequencing to describe the evidence and characteristics of human-to-human transmission in Guangdong Province. Methods: A confirmed COVID-19 case was defined if a suspected case was verified with positive of SARS-CoV-2 in throat swabs, nasal swabs, bronchoalveolar lavage fluid (BALF), or endotracheal aspirates by real-time reverse transcriptase polymerase chain reaction assay (RT-PCR) or genetic sequencing. Field investigations were conducted for each confirmed case. Clinical and demographic data of confirmed cases were collected from medical records. Exposure and travel history were obtained by interview. Results: A total of 1,151 confirmed cases were identified as of February 10, 2020 in Guangdong Province, China. Of them, 697 (60.1%) cases were from 234 cluster infections. Two hundred and fourteen (18.6%) were secondary cases, in which 144 cases were from family cluster infections. With the epidemic continuing, although familial cluster events were dominated, community cluster events increased with a nosocomial event. The whole genomes within the same family cluster infections were identical, and presented a few unique single nucleotide variants (SNVs) compared with SARS-CoV-2 identified on December 2019 in Wuhan. Conclusions: We observed evident human-to-human transmissions of SARS-CoV-2 in Guangdong, China. Although most of them were from family cluster infections, community and nosocomial infections were increasing. Our findings indicate that human-to-human transmission risks are transferring from family to community in Guangdong Province.

The impact of vital signs on the death of patients with new coronavirus pneumonia: A systematic review and meta-analysis

“…Novel coronavirus disease (COVID-19) is another serious threat to public health after SARS, Ebola, and avian flu. Owing to its fast transmissibility through respiratory droplets and close contact, the virus is extremely infectious and pathogenic [28][29] , thereby making COVID-19 a global concern within a short period. This article mainly conducts a meta-analysis of the impact of vital signs on the death of patients with COVID-19, and evaluates the impact of vital signs on the prognosis of COVID-19.…”

“…Thereafter, 119 articles were excluded by the titles and abstracts, and 43 of the remaining 56 articles were deleted for various reasons, and we were left with 13 articles. According to the literature quality evaluation, 12 articles of 3493 patients [16][17][18][19][20][21][22][23][24][25][26][27][28] were ultimately selected for the meta-analysis ( Figure 1). All these selected studies were published in 2020 with varying sample sizes ranging from 20 to 7614 patients.…”

COVID-19: Epidemiology, Evolution, and Cross-Disciplinary Perspectives

“…The second phase started on January 13, marked by rapid expansion and spread of the virus within hospitals (nosocomial infection) and by family transmission (close-contact transmission). In this phase the epidemic spread from Wuhan to other areas [12][13][14][15][16][17][18]. The first case outside of China was reported in Thailand on January 13, caused by a Wuhan resident travelling to this country.…”

Identification of Common Deletions in the Spike Protein of Severe Acute Respiratory Syndrome Coronavirus 2

“…The first COVID-19 clinical case (sample 014, Table 1) in Guangdong, China, was reported on 19 January, with illness onset on 1 January (11). A bronchoalveolar lavage fluid (BALF) sample from this patient was collected and inoculated on Vero-E6 cells.…”