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A Need for Data-driven Public Health Responses to COVID-19

Twa, Michael D.

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Optometry and Vision Science: April 2020 - Volume 97 - Issue 4 - p 227-228
doi: 10.1097/OPX.0000000000001511
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On January 22, 2020, Netflix released a six-part documentary series titled “Pandemic: How to Prevent an Outbreak.” This series describes current emerging disease surveillance systems around the world, spotlights current clinical practices for dealing with seasonal flu, and provides perspectives on the social and economic impact of the 1918 Spanish Flu Pandemic. It makes clear that there is a thin line of dedicated individuals who have an impossible responsibility to protect public health on a global scale. This documentary further elucidates the social and economic impact that a contemporary major public health outbreak could have—a prescient release, now that we are living in the reality of the COVID-19 global pandemic. An important and hotly debated question is: How best to respond to this health threat? Taking lessons from current global outcomes, there are three interesting cases to consider: China, Italy, and Singapore.


On December 26, 2019, COVID-19 emerged and began working its way through the citizens in Hubei, China. By January 22, 547 official cases were known, and more than 1500 additional cases existed but were not yet detected. On January 23, China imposed an unprecedented quarantine on 11 million people in the city of Wuhan (site of the initial infections) and 15 other cities, effectively isolating nearly 50 million people. The quarantine required in-home isolation and ceased all transit within and between the 16 cities. At the time the quarantine was announced, it drew strong criticism related to China's previous heavy-handed social policies. Critics warned it could backfire and that it would not end the crisis. These restrictions have drastically reduced the number of new infections and are only now (March 21) beginning to ease.

What we have learned so far from China's experience is that this new virus seems to be highly transmissible (R0 between 2 and 3),1 meaning that each infected person will likely infect between 2 and 3 people. What we also learned is that estimates for the case fatality rate are about 2.2%.1 The passage of time has made clear that China's relatively slow, but strong move to impose wide quarantines effectively reduced the spread of infection and saved lives. If this action had been taken sooner and if individuals raising alarm had not been silenced, even more lives could have been saved.


Singapore has a strong central government structure and in 2002 and 2003 was caught underprepared for the severe acute respiratory syndrome outbreak. Since then, Singapore has invested in preparations that have paid off during the COVID-19 pandemic. The primary response to the severe acute respiratory syndrome outbreak was to address resource shortfalls and to strengthen public health system practices based on what worked well. These changes included building and designating specific isolation hospitals and additional capacity for negative-pressure rooms. They also created stronger penalties for breaking quarantine orders. Some of the most effective changes were community transmission control measures such as the following:

  • maintaining a broad and sensitive surveillance system;
  • conducting rapid, aggressive, and effective contact tracing;
  • low thresholds for enforced quarantine of patients and their contacts; and
  • providing clear and consistent public guidance from public health officials.

Singapore's surveillance system has provided exceptional data on the incidence and prevalence of the virus, allowing public officials to make rational decisions about broader social restrictions informed by public health officials with deep local information about their population and environment. As of March 21, Singapore has 432 reported cases and two deaths, well below the infection rates elsewhere in the world.


In comparison with Singapore, Italy has had a slow and relatively weak public health response to the COVID-19 pandemic. Unlike Singapore, they had no call to action from the previous severe acute respiratory syndrome outbreak in 2002 to 2003. As of March 21, there are more than 53,000 confirmed COVID-19 infections.2 Yesterday, Italy surpassed China in the number of lives lost because of COVID-19 illness (currently 4825). There has been limited population testing, and only recently has the country imposed quarantine restrictions. The total population of Italy is about 60 million people, and approximately 50% of those are older than 45 years. Hospital capacity is overrun, and there are not enough resources available for those who require life support. It is a tragedy. We are seeing just how quickly and widely the virus can spread, how it affects older populations, and how devastating the demand for supplies, personnel, and facilities can be.


As of March 21, 2020, more than 300,000 cases of infection are known, and more than 13,000 deaths have been attributed to COVID-19 worldwide. In the United States, there are more than 25,000 cases of infection and more than 280 deaths; more will follow over the coming months. The R0 estimate for this virus is 2.28,1,3 almost twice that of the average seasonal flu (R0 = 1.3), which means that the spread of infections will be much faster. Symptoms, if they are visible, show after an average of 5.1 days and include fever, cough, chills, runny nose, and gastrointestinal symptoms. The time between infection and the onset of severe symptoms was 2 to 8 weeks.3 The virus normally infects close partners, for example, spouse or close family members. Reportedly, 81% of cases of infection are mild and recover without incident.1 This means that COVID-19 is less deadly but more transmissible than severe acute respiratory syndrome or Middle East respiratory syndrome. Those at greatest risk of serious illness are older and males. Case fatality rates are considerably higher among older patients: 14.8% in patients 80 years or older and 8.0% for patients 70 to 79 years old. Overall, the case fatality rate is estimated to be between 2.3 and 3.6%.1

What remains to be learned is how this new pathogen will settle into the population. Will it become an endemic seasonal concern? Will it behave like the four other coronaviruses endemic in humans, causing upper respiratory illnesses ranging from the common cold to pneumonia? What is clear is that success in battling this pandemic disease relies on sound information applied to rational policies designed to address the public health concerns. It is unhelpful to worry first about the economic or political ramifications before the health matters are addressed. First and foremost, we should be responding to this pandemic like the public health challenge that it is. If we want to be successful, we will need leaders who communicate effectively and make public health priorities a clear and consistent priority. We will need wide and aggressive public health surveillance, with effective tracing and exposure controls. The varied responses to the spread of COVID-19 around the globe underscore the difference that effective leadership and a strong public health infrastructure can have on the impact of this disease in our communities.

Michael D. Twa

Editor in Chief Houston, TX


1. Wu Z, McGoogan JM. Characteristics of and Important Lessons from the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72 314 Cases from the Chinese Center for Disease Control and Prevention. JAMA 2020; doi: 10.1001/jama.2020.2648. [Epub ahead of print].
2. Johns Hopkins University Coronavirus Resource Center. Available at: Accessed March 21, 2020.
3. Baud D, Qi X, Nielsen-Saines K, et al. Real Estimates of Mortality Following COVID-19 Infection. Lancet Infect Dis 2020; doi: 10.1016/S1473-3099(20)30195-X. [Epub ahead of print].
© 2020 American Academy of Optometry