A large COVID-19 outbreak occurred in Hong Kong in July after social distancing restrictions were loosened. In total, 617 confirmed cases in the community were reported from 5 to 21 July. A team of experts from HKUMed studied the whole genome of the virus from confirmed cases to trace its transmission path in this third wave of outbreak. Study results were published in Clinical Infectious Diseases.
Key takeaways from the study:
- A total of 53 genomes of SARS-CoV-2 from infected patients in the third wave were analysed.
- 33 specimens were locally acquired and 20 were imported.
- Two unique clusters, cluster HK1 and HK2, were identified among the locally acquired cases.
- Cluster HK1 and HK2 were closely related to imported cases from the Philippines and Kazakhstan, respectively.
- There were also important differences in the genomes between the locally acquired and imported cases, suggesting that the imported cases may not be the direct source of infection.
- Nonetheless, this suggested that cases from the third wave were unlikely to be related to asymptomatic patients from the earlier outbreaks.
More studies are needed to determine whether the environment or mutations to the viral genomes contributed to the third wave of COVID-19 in Hong Kong. Tighter controls at borders and the airport, wearing of facemasks and social distancing are needed to prevent further transmission in Hong Kong.
To read the original article published in Clinical Infectious Diseases, click here.
