[RESEARCH] How Hong Kong contained COVID-19 without total lockdown

Photo by Kate Trifo on Unsplash


A study recently published in The Lancet Public Health, reported on the impact of non-pharmaceutical interventions against COVID-19 in Hong Kong. As one of the most heavily affected countries during the severe acute respiratory syndrome (SARS) epidemic in 2003, Hong Kong has been prepared to respond to emerging infectious diseases such as COVID-19 by implementing a range of public health measures to reduce local transmission.

As of March 31, 2020, Hong Kong had 715 reported cases of COVID-19, including 94 asymptomatic infections, and 4 deaths in a population of around 7.5 million. Measures that were implemented including travel restrictions and bans, flexible working arrangements, and school closures from kindergartens up to tertiary and post-tertiary institutions, including tutorial centres. Religious services were also cancelled including many conferences and other local mass gatherings. Quarantine orders have been issued to the close contacts of individuals with confirmed infection, as well as travellers arriving from affected countries.

COVID-19 cases in Hong Kong by date of reporting (A) and date of symptom onset (B)

One of the main findings was the substantial decline in transmission after the implementation of social distancing measures and changes in population behaviours in late January. With the school closures, the marked reduction was measured by the daily effective reproduction number (Rt) from 1·28 to 0·72.

There have also been significant changes in the population behaviour. Over 99% of people were wearing face masks whilst going out, compared to 75% early in the epidemic. While the Hong Kong authorities did not enforce a stay at home order (apart from 14 days for people entering the Special Administrative Region), over 80% of people still reported staying at home as much as possible.

“Our findings strongly suggest that social distancing and population behavioural changes—that have a social and economic impact that is less disruptive than total lockdown—can meaningfully control COVID-19.”

Professor Benjamin Cowling from the University of Hong Kong

The study reported some limitations, mainly the inability to identify which measure was potentially the most effective – whether border restrictions, quarantine and isolation, social distancing, or behavioural changes are most important in containing COVID-19 transmission. However, the study acknowledged that each one is likely to play a role.

Source: “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 on Friday 17 April in The Lancet Public Health.

** All previous posts about COVID-19 here: https://sciencemediacentremalaysia.com/tag/covid-19/  

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