The ۱۹۱۸ Spanish Influenza Pandemic: Epidemiological Characteristics and Its Lasting Influence on Public Health Infrastructure

The ۱۹۱۸ influenza pandemic, commonly known as the Spanish flu, was one of the most devastating global health events of the twentieth century. Occurring between ۱۹۱۸ and ۱۹۲۰, it infected approximately one third of the world’s population and caused an estimated ۴۰–۵۰ million deaths worldwide. This study aimed to examine the epidemiological characteristics of the ۱۹۱۸ pandemic and to analyze its impact on the development of modern public health systems. A narrative historical review was conducted using published literature from major scientific databases. Findings indicate that the pandemic occurred in three waves, with the second wave being the most lethal. An unusual W shaped age specific mortality pattern was observed, with high mortality among young adults aged ۲۰–۴۰ years. Rapid global spread was facilitated by World War I troop movements, overcrowding, and limited healthcare infrastructure. In the absence of vaccines or antiviral therapies, non pharmaceutical interventions such as isolation, quarantine, school closures, and mask mandates were widely implemented, and earlier interventions were associated with reduced mortality in several cities. The pandemic exposed significant weaknesses in disease surveillance, reporting systems, and healthcare capacity, prompting structural reforms in public health administration and infectious disease research. These reforms contributed to the foundation of modern epidemiological surveillance systems and international health cooperation. The lessons learned from the ۱۹۱۸ influenza pandemic continue to inform contemporary strategies for pandemic preparedness and response.

کلیدواژه ها:

۱۹۱۸ influenza pandemic ، Spanish flu ، epidemiology ، public health history ، non pharmaceutical interventions ، disease surveillance