Non-pharmaceutical Interventions Against Coronavirus Disease, Do They Work? What Evidence is There?
A study performed in Hong Kong looked at the use of aggressive public health measures including massive mobility restrictions, universal fever screenings in all settings and neighbourhood based household focussed social distancing enforced by teams of community workers as well as the deployment of artificial intelligence based social media applications to review whether these measures prevented Coronavirus spread.
Would these measures be acceptable in western societies?
Hong Kong suffered greatly during the SARS epidemic of 2003 and this community was prepared to respond to emerging infectious diseases with harsh measures.
In March 2020, there was intense surveillance for infections in incoming travellers and also in the local community.
Once individuals were identified to be positive for COVID-19 they were isolated into hospitals until they recovered and ceased viral shedding.
Their close contacts were traced and quarantined in special facilities.
Because not every infected patient or person can be identified, containment measures only work if social distancing or behavioural change is used to reduce silent transmission in the community as a whole.
This study found that the border entry restrictions, quarantine and isolation of cases and contacts and social distancing measures and personal protective measures that Hong Kong implemented since late January 2020 was associated with a reduced spread of COVID-19.
It was found that in the 10 weeks following the first known individual with COVID-19 in Hong Kong showing symptoms there had been little sustained local transmission of the disease.
This study strongly suggested that social distancing and population behavioural change that may have a social and economic impact which is less destructive than a total lockdown can meaningfully control COVID-19.
There has been an increasing number of imported infections into Hong Kong in March and this increase has occurred at the same time as a relaxation of some voluntary avoidance behaviours in the general community. It is suggested that a strengthening of social distancing measures is required in order to prevent local infection.
It is also suggested that travel measures, testing, tracing and treated efforts are particularly important in maintaining suppression. It was also found in this study that the various measures involved coincided with a substantial reduction in influenza transmission in early February 2020. Interestingly, there was an estimated 44% reduction in influenza transmission in the general community in February 2020 which was much greater than the estimated 10 to 15% reduction in transmission without these measures.
The London General Practice