When a man sleepwalks and falls out of his hotel window on the second floor, that's odd. When two men sleepwalk and fall out of the windows of their rooms on the second floor of the same hotel, that's very odd. But when three men in three years sleepwalk and fall out of their windows on the second floor of the same hotel, that's a mystery.
The influenza pandemic of 1918-1919, also known as Spanish Flu, claimed the lives of 675,000 Americans and as many as 40 million people worldwide. The roll among U.S. servicemen during WW1 was especially severe. "Of the U.S. soldiers who died in Europe, half of them fell to the influenza virus and not to the enemy. An estimated 43,000 servicemen died of influenza." No part of America escaped this pandemic. Yet, each community in America was affected by, and reacted to, this disease in a unique way. This paper is an examination of the 1918 Influenza epidemic in Cumberland County, Pennsylvania and a comparison with the findings of other historians on the effects of the epidemic in Philadelphia, San Francisco and Los Angeles. Particular attention will be given to the measures taken to curb the epidemic by the Board of Health in each of these cities. The effectiveness of these measures, and the controversies that arose in response to them, will also be examined.
The Spanish Flu of 1918 was caused by the H1N1 Influenza A Virus. The Influenza A virus is an RNA virus that contains 8 genes within a lipid shell (Appendix A). Inserted into this shell are proteins called hemaglutinin (HA) and neuraminidase (NA). It is the properties of these proteins that are used to classify the different subtypes of influenza A virus. Three subtypes of influenza A have caused pandemics (world-wide epidemic) in the past one hundred years: H1N1- Spanish Flu of 1918, H2N2- Asian Flu of 1957, and H3N2- Hong Kong Flu of 1968.
When a person is infected with a virus, his or her body mobilizes its immune system to form antibodies to the virus. If all goes well, these antibodies will enable the immune system to clear the virus from the body. Once antibodies have been formed and the virus cleared, that individual will never again be susceptible to infection with the exact same virus. Many viruses have developed ways to deceive the immune system's memory. In the case of influenza A, subtle changes frequently occur in the HA and NA proteins (antigens) contained in the virus' outer shell. This is called "antigenic drift" and forms the basis for the nearly biannual reoccurrence of low-grade influenza epidemics. Once every several years, with no predictability and with no periodicity, a replacement occurs in one of the genes that comprise the core of the influenza virus. This causes the virus to produce markedly different proteins in its outer shell, proteins to which no human has previously been exposed. This is called "antigenic shift" and forms the basis for global pandemics. Once an antigenic shift occurs in the influenza virus, it causes a major pandemic and then remains in circulation for many years until the next antigenic shift occurs. For example, the H1N1 shift caused the pandemic of 1918 (Spanish Flu). That virus remained in circulation until the H2N2 shift occurred, causing the pandemic of 1957 (Asian Flu).
The consequence of the 1918 H1N1 antigenic shift in the Influenza A virus for the citizens of Pennsylvania is clearly illustrated in Table 1. Note that the number of deaths from influenza in 1918 was 26 times greater than in 1917. All data were obtained from the United States Bureau of the Census.
There are several questions about the 1918 influenza pandemic that remain unanswered. One question concerns the origin of the pandemic. As recently as 2001 one scientist posited that the pandemic may have originated in France. In "The so-called Great Spanish Influenza Pandemic of 1918 may have originated in France in 1916," J.S. Oxford notes several localized epidemics of influenza that occurred in Britain and France in 1916. Most historians agree that, in the United States, the pandemic originated in the military and that the most virulent form of the 1918 Influenza A virus was carried from the United States to the rest of the world. Most historians also agree that the 1918 influenza pandemic occurred in three waves: the first in the Spring of 1918, the second in the Autumn of 1918, and the third in the Winter of 1919.