The 1918 to 1919 H1N1 influenza pandemic is among the most deadly events in recorded human history, having killed an estimated 50 to 100 million persons. Recent H5N1 avian influenza epizootics associated with sporadic human fatalities have heightened concern that a new influenza pandemic, one at least as lethal as that of 1918, could be developing. In early 2009, a novel pandemic H1N1 influenza virus appeared, but it has not exhibited unusually high pathogenicity. Nevertheless, because this virus spreads globally, some scientists predict that mutations will increase its lethality. Therefore, to accurately predict, plan, and respond to current and future influenza pandemics, we must first better-understand the events and experiences of 1918.
Although the entire genome of the 1918 influenza virus has been sequenced, many questions about the pandemic it caused remain unanswered. In this review, we discuss the origin of the 1918 pandemic influenza virus, the pandemic’s unusual epidemiologic features and the causes and demographic patterns of fatality, and how this information should impact our response to the current 2009 H1N1 pandemic and future pandemics. After 92 yrs of research, fundamental questions about influenza pandemics remain unanswered. Thus, we must remain vigilant and use the knowledge we have gained from 1918 and other influenza pandemics to direct targeted research and pandemic influenza preparedness planning, emphasizing prevention, containment, and treatment.

Early in September, 1918, the United States was invaded by a scourge of highly infectious and fatal disease, which spread with rapidity throughout the country, eventually infecting 500 million people worldwide, or about 27% of the world population, killing anywhere from 17 million to as many as 100 million, making it one of the deadliest epidemics in human history.
Known as Spanish Influenza, it was pandemic in its nature. No one seemed to know much about the disease or its treatment, and medical science and public health agencies were alike unprepared to cope with it.
Caught in the middle of this unfolding disaster was Wilkes-Barre, Pennsylvania, historian Oscar Jewell Harvey. In his little-known 1920 book “The Spanish Influenza Pandemic of 1918,” Harvey gives a first-hand account of how one middle-sized Pennsylvania city struggled to cope with the devastating plague which struck while America was preoccupied with fighting World War One.
In introducing his book, Harvey writes that “it certainly was a disconcerting fact that, at the very time when vast numbers of the people in widely-distributed localities had organized themselves, through the Red Cross and other wellknown and efficient mediums, to fight disease and prevent suffering and death, we should be smitten with a visitation which caused more casualties and deaths among the peaceful citizens in the homeland than the deadly missiles and poisonous gases of the enemy effected among the American Expeditionary Forces overseas in the great World War….”