Analysis: Spanish Flu Pandemic Proves Social Distancing Works

As Americans enter their second month of homebound social-distancing, politicians and other public health officials are pondering the question of just how long it will be necessary to cancel public gatherings. Some have wondered aloud whether long-term isolation is even necessary to stop the spread of the coronavirus disease 2019 (COVID-19).

In a new paper published in the Journal of the American Society of Cytopathology, Stefan E. Pambuccian, MD, MIAC, a professor and vice chair of the department of pathology and laboratory medicine at Loyola University Chicago’s Stritch School of Medicine attempts to answer those questions using the “Spanish Influenza” pandemic of 1918-1919 as a model.

In short, his answer to the question of whether social distancing works is: yes.

"The stricter the isolation policies, the lower the mortality rate," Pambuccian said, in a press release.

The 1918-1919 pandemic eventually killed an estimated 50 million people around the world, and some 675,000 people in the United States. That’s despite the fact that many countries, including the US, outlawed large public gatherings, canceled school, and required masks and other protective gear in certain situations. However, just as is the case today, Pambuccian said part of the problem was that the adoption of precautions was not universal.

“[T]hese measures were not implemented at the same time or for the same duration in different cities, nor were they uniformly followed,” he writes.

In his paper, Pambuccian reviews existing scientific literature about the earlier pandemic, and compares it with known facts and projects related to the current pandemic.

Cities like San Francisco, St. Louis, Milwaukee, and Kansas City were proactive in their safety measures, Pambuccian writes, and it is believed that their swift action cut transmission by as much as 30-50%. Those cities also had lower peak mortality and lower total mortality.

“The duration that these ‘social distancing’ measures were kept in place correlated with a reduced total mortality burden,” he writes. “Although we still have no known effective therapy or vaccine prevention for this coronavirus, and the world is a quite different place than it was 100 years ago, the efficacy of the measures instituted during the 1918-19 pandemic gives us hope that the current measures will also limit the impact of the COVID-19 pandemic.”

One key difference between the 1918-1919 pandemic and the current one is the benefit of hindsight. Pambuccian noted that there remain many questions about the current disease, and as a result healthcare professionals will need to be particularly cautious and open to new information.

In his paper, Pambuccian, a cytologist, also examines steps that can be taken in the cytology laboratory to minimize the risk associated with SARS-CoV-2, the virus that causes COVID-19.

Many of those steps echo the work being done by all health care workers, such as ensuring staffing is adequate to match needs, and also making sure staff take proper precautions to protect themselves and to limit the risk of transmission if the worker becomes sick. From a diagnostic standpoint, he said the cytology lab can mainly help remove potential conflicting evidence.

“The role of the cytology laboratory in a patient with known COVID-19 is limited,” he wrote. “In analogy to the role of the cytology laboratory in SARS, it is mainly to rule out superimposed pulmonary infections in sputum and other respiratory specimens.”

Pambuccian also said it is incumbent upon laboratory professionals to stay abreast of the rapidly evolving situation, including following the latest guidelines from the US Centers for Disease Control and Prevention and the World Health Organization.