Another new and really interesting paper on #SarsCoV2 clusters and superspreading by @gmleunghku, @bencowling88 and others: “we estimated that approximately 20% of cases were responsible for 80% of all #SarsCoV2 transmission in Hong Kong” https://twitter.com/gmleunghku/status/1264368142895083521

“Overall, the majority (51.9%; 539/1,038) of #SARSCoV2 infections in Hong Kong have been associated with at least one of 135 known clusters. The median cluster size was two and the largest involved 106 local cases.”

That large cluster “traced back to multiple social exposures among a collection of bars across Hong Kong. Evidence suggested this “bar and band” cluster originated in Lan Kwai Fong among a few staff and customers before being spread to additional venues by a number of musicians”

Authors say their results indicate 5-7 superspreading events in Hong Kong and they estimate k to be 0,45 indicating ”potential for future superspreading, albeit less than SARS-CoV and MERS-CoV”. Caveat: This was with some #PhysicalDistancing measures already in place.

“Overall there is substantial potential for SSEs in #COVID19, but less so than for SARS and MERS. In the absence of non-pharmaceutical interventions such as physical distancing implemented in Hong Kong, the potential for SSEs is likely greater than observed in our study.”

Conclusions? “Our results show that the number of individual secondary cases was significantly higher within social settings such as bars and restaurants compared to family or work exposures. This is certainly due to the greater numbers of contacts expected in such settings.”

“Targeted interventions should therefore focus on reducing extreme numbers of social contacts at high-risk venues such as bars, nightclubs and restaurants, which also appear at increased risk of SSEs, either via closures or physical distancing policies...”