April 17, 2020

expert reaction to paper assessing the impact of non- pharmaceutical interventions against COVID-19 in Hong Kong

A study, published in the Lancet Public Health, reports on the the impact of non- pharmaceutical interventions against COVID-19 in Hong Kong.

Prof Paul Hunter, Professor in Medicine, UEA, said:

“This is an important paper and represents one of the first good quality population based studies of COVID-19.  The methods are sound though the assumption “that 99% of imported cases and 80% of local cases would be detected” seems optimistic to me. The main finding was the marked reduction in infectivity as measured by R_t from 1.28 to 0.72 associated with school closures. This does not necessarily mean that the school closures were the only cause of this decline as other control measures and behavioural changes occurred such as civil servants working from home, and over 97% of people were wearing face masks whilst going out, compared to 74.5% early in the epidemic. The Hong Kong authorities do not seem to have enforced a stay at home order, other than for 14 days for people entering the Special Administrative Region. Nevertheless over 80% of people reported staying at home as much as possible.

“To me this paper is very timely and provides important evidence that should influence our own plans for moving away from lock-down. Although one cannot always extrapolate from an Asian to a European country, the Hong Kong approach could provide us with a way of easing the severity of the lockdown without risking case numbers increasing again. It is not possible from the available data to quantify the impact that the different policy and behavioural changes will have had on the transmissibility of the infection. For example, it is not possible to say how much of the reduced transmissibility of COVID19 could be due to the almost universal wearing of face masks. However, we should not reject any of the changes in Hong Kong without further review and analysis.”

“Impact assessment of non-pharmaceutical interventions against coronavirus disease 2019 and influenza in Hong Kong: an observational study” by Benjamin J Cowling et al. was published in Lancet Public Health at 23:30 UK time Friday 17 April.

All our previous output on this subject can be seen at this weblink: www.sciencemediacentre.org/tag/covid-19

Declared interests

None received.