By Associate Prof Dr Nirmala Bhoo Pathy

The World Health Organization (WHO) has attributed the rapid spread of COVID-19 to "alarming levels of inaction" by many countries. Although social distancing measures such as working from home, closure of educational institutes, and banning of public events are essential components in mitigating the impact of the COVID-19 pandemic, there appears to be a delay in adoption of these measures in many of the affected countries even in affluent settings, some in fear of 'over-reacting' and 'hurting the economy'. Opponents to some of these public health measures such as closure of schools have argued a lack of evidence to support their implementation. Central to this issue, is the question of whether a really old lesson from 100 years ago can be applied to contemporary pandemic mitigation measures?  

An archival research that was published more than a decade ago had elegantly highlighted that an early, sustained, and multi-layered public health response to a pandemic was strongly associated with better outcomes such as lower death rates. In this study, researchers in the United States (US) had examined whether city-to-city variation in mortality during the 1918-1919 influenza pandemic was associated with the timing, duration, and combination of public health actions that were taken in 43 US cities? 

Results revealed that school closure and public gathering bans that were activated concurrently represented the most common combination implemented in 34 cities (79%). Overall, it took between 1 to 10 weeks from the onset of the epidemic before these cities adopted the above measures, with 50% of cities implementing them in 4 weeks. What was striking was that while all the US cities eventually implemented some public health interventions, the timing of activation, duration, and choice or combination of these interventions were key determinants in their success or failure. Delay in execution of public health gatherings for instance appeared to lead to very high death rates in Pittsburgh whereas much lower death rates were observed in St Louis, where a timely and comprehensive public health response including school closure and cancellation of public gatherings were sustained for close to 10 weeks. Notably, the cities that had implemented earlier public health interventions also had greater delays in reaching peak mortality, and attained lower peak mortality rates.

In the above study, the US researchers had conducted an archival study where historical data on public health interventions including school closures, cancellation of public gatherings, and isolation and quarantine that were implemented in 43 US cities during the 1918-1919 influenza pandemic were retrieved from popular newspapers, municipality records, etc. This was examined in relation to excess deaths from pneumonia and influenza covering the 24 weeks from September 8, 1918, through February 22, 1919 for the 43 US cities, in comparison with weekly deaths from pneumonia and influenza occurring between 1910-1916, before the influenza pandemic. 

While this archival research offers valuable lessons for the modern day pandemic management, it is acknowledged that we live in a modern era where other factors such as better understanding of infectious diseases among the public, ease of access to internet/ knowledge, advances in medical technology, and not forgetting the ease of flow of information, goods, and people across political and geographic boundaries also need consideration. 

Nonetheless, this study serves to remind the global citizens; politicians, health professionals, senior management teams, and the public alike that a suite of classic public health interventions that are implemented in a timely and sustained manner can lead to success in mitigating a pandemic by flattening the epidemic curve (delaying the spread of the disease) that in turn may reduce the strain on healthcare systems, and also by reducing the number of deaths. When else can we not adopt this than now, while we are facing the threat of COVID-19?

Reference:

JAMA Network: Non-pharmaceutical interventions implemented by US cities during the 1918-1919 influenza pandemic

(Associate Prof Dr Nirmala Bhoo Pathy is Public Health Physician/Epidemiologist at the Department of Social and Preventive Medicine, Faculty of Medicine, Universiti Malaya.)