Pandemic influenza and socioeconomic disparities: Lessons from 1918 Chicago
The 1918 "Spanish" influenza pandemic holds a particular place in medical history; it wiped out an estimated ~1% of the global population, or ~20 50 million deaths worldwide, and earned the dubious honor of being coined the "mother of all pandemics" (1) Fortunately, important strides have been made in elucidating the emergence of novel pandemic influenza viruses and their impact on human populations since the 1918 pandemic. The field of archeo epidemiology has been particularly active in recent years, thanks to coordinated interdisciplinary efforts involving epidemiologists, virologists, demographers, and medical historians. Their work has paid off to unearth, digitize, and analyze archival disease records sitting in dusty old books, providing a careful description of the mortality and transmissibility patterns of the 1918 influenza pandemic in several areas of the world where little prior quantitative information existed (e.g. refs. 2| 5) In PNAS, Grantz et al. (6) contribute to the growing interest in applying modern analytical tools to epidemiological archives, through the lens of socioeconomic disparities affecting the 1918 influenza pandemic. The role of socioeconomic factors on influenza mortality and morbidity goes back to the early work of Robert Pearl in the years immediately following the 1918 pandemic (7) but has only regained traction among epidemiologists and sociologists in the last decade. In 2006, a seminal study revealed more than 30 fold variation in 1918 pandemic excess mortality rates across a sample of 20 countries, with socioeconomic factors explaining a significant fraction of the observed variation (2) In Latin America, pandemic excess mortality rates varied from 0.4 to 2.9% in national and province level data, a greater than sevenfold variation (4, 8, 9) In contrast, United States and European populations fared relatively well during the pandemic, despite intense disruption at the end of World War I (excess mortality rates of [1]1To whom correspondence should be addressed. Email: gchowell{at}gsu.edu. [1] #xref corresp 1 1
Proceedings of the National Academy of Sciences