A familial cluster of pneumonia associated with COVID- 2019 indicating person-to-person transmission
A familial cluster of pneumonia associated with COVID- 2019 indicating person-to-person transmission Spencer EA, Heneghan C.
Published on July 27, 2020
Transmission Dynamics of COVID-19
||Chan JF, Yuan S, Kok KH, et al. A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster. Lancet. 2020;395(10223):514-523. doi:10.1016/S0140-6736(20)30154-9
||The Shaw Foundation Hong Kong, Respiratory Viral Research Foundation Limited, the Hong Kong Hainan Commercial Association South China Microbiology Research Fund, Sanming Project of Medicine (Shenzhen), and High Level-Hospital Program (Guangdong Health Commission).
||Close contact, person to person, asymptomatic, orofecal
This very early study established the likelihood of person to person transmission of SARS-CoV-2, in hospital and family settings. It also highlighted the possibility of transmission from asymptomatic carriers.
Of six family members who had travelled to Wuhan and presented with symptoms, five were identified as infected with the novel coronavirus [SARS-CoV-2]. Additionally, one family member, who did not travel to Wuhan, became infected with the virus after several days of contact with four of the family members.
The two children in the family were asymptomatic, and tested negative for the novel coronavirus, although the asymptomatic 10-year-old child was found to show radiological ground-glass lung opacities. None of the family members had had contacts with Wuhan markets or animals, although two had visited a Wuhan hospital.
All respiratory samples were negative on two point-of-care multiplex PCR systems for 18 respiratory viral and four bacterial targets. The two faecal samples from patients 3 and 4 who had preceding diarrhoea were negative on a multiplex PCR assay for common diarrhoeal viruses, bacteria, and parasites.
Five patients tested positive for genetic markers indicative of SARS-CoV-2. One additional patient was considered infected with the novel virus despite testing negative, because of clinical symptoms and radiological evidence of lung effects
Phylogenetic analysis of these five patients’ RT-PCR amplicons and two full genomes by next-generation sequencing showed that this is a novel coronavirus [SARS-CoV-2]. Only one serum sample tested positive. All other patients’ serum, urine, and faecal samples were negative for SARS-CoV-2.
What did they do?
The study reports the epidemiological, clinical, laboratory, radiological, and microbiological findings of five patients in a family cluster who presented with unexplained pneumonia after returning to Shenzhen, Guangdong province, China, after a visit to Wuhan, and an additional family member who did not travel to Wuhan. Phylogenetic analysis of genetic sequences from these patients was done.
On 10th January 2020, two patients who initially presented to The University of Hong Kong-Shenzhen Hospital (Shenzhen, Guangdong province, China) with fever, respiratory symptoms, or diarrhoea, and pulmonary infiltrates on chest radiographs were asked to join the study. Subsequently, between 11th and 15th January 2020, five other members of this family also presented to our hospital for the assessment of their health conditions.
These six individuals had travelled to Wuhan from Shenzhen between 29th December 2019 and 4th January 2020.
This was a thorough report of the clinical and genetic investigations for a small number of patients, and needs replication.
|Clearly defined setting
||Demographic characteristics described
||Follow-up length was sufficient
||Transmission outcomes assessed
||Main biases are taken into consideration
What else should I consider?
An early study published in The Lancet, 24th January 2020.
About the authors
Carl is Professor of EBM & Director of CEBM at the University of Oxford. He is also a GP and tweets @carlheneghan. He has an active interest in discovering the truth behind health research findings
Dr Elizabeth Spencer; MMedSci, PhD. Epidemiologist, Nuffield Department for Primary Care Health Sciences, University of Oxford.