The term influenza is derived from the Italian word for “influence” and dates from 1357. Italian astrologers of that time believed influenza was the result of the influence of celestial bodies. Influenza is commonly known today as the flu. It is an infectious disease that affects both birds and mammals. Influenza has been at the center of many debates between private and government scientists and within the government itself, and these debates have become an obstacle to medical scientists and physicians seeking to discover an effective treatment and vaccine.
There are many different strains of influenza, some more dangerous than others, but all are caused by an RNA virus from the Orthomyxoviridae family. Influenza is not a disease natural to humans; it is believed to have originated in birds and spread to humans during the last ice age. There are three types of influenza viruses, classified as A, B, and C. Type C rarely causes disease in humans, and type B causes illness but not epidemics. Only type A is capable of producing an epidemic or pandemic. Individuals suffering from seasonal influenza generally recover in two weeks, with 20,000 to 50,000 individuals dying of influenza viral infections annually within the United States.
I. The Great Influenza Pandemic of 1918–1919
II. Influenza in More Recent Decades
III. Swine Flu and Bird Flu
The Great Influenza Pandemic of 1918–1919
Although influenza has been known for centuries, it became infamous during the Great Influenza Pandemic of 1918–1919, also known as the Spanish flu (type A, H1N1). Interestingly, it received the name Spanish flu simply because the Spanish newspapers were the first to report it, even though it had appeared in the United States months before. This strain of influenza was particularly lethal and is thought to have originated in Haskell County, Kansas. Although this influenza might have died out, the political state of the country at the time helped to spread it worldwide. America had just entered the Great War (1914–1918) and was preparing to ship thousands of soldiers to France. Before this could be done, the soldiers had to be trained. This training took place in cantonments throughout the country, with each cantonment holding tens of thousands of young men in cramped quarters, and influenza spread rapidly among the soldiers and support staff on the base. The movement of troops between U.S. bases, forts, and cantonments ensured that almost no American community went untouched by the disease.
Shipping men overseas helped to promote the spread of influenza throughout Europe and eventually the world, with cases appearing as far away as the Arctic and on remote islands in the South Pacific. Nearly all residents of Western Samoa contracted influenza, and 7,500 were killed—roughly 20 percent of the total population. As surgeon general of the army, William Gorgas was responsible for ensuring the effective and successful performance of military medicine. But although Gorgas was known internationally as an expert on public health, in reality he was given little authority by the U.S. government. Gorgas recommended that drafts be postponed and that the movement of soldiers between cantonments and overseas cease. President Wilson, however, continued to transfer soldiers from bases throughout the country and to ship them overseas, creating strained relations between the president and his military medical advisers.
Because the natural home of influenza is birds and because influenza can survive in pigs, the survival of humans is not necessary in order for influenza to survive. As a result, mortality rates in humans can reach extremely high numbers. Contemporary estimates suggest that 50 to 100 million individuals were killed worldwide during the Great Influenza Pandemic—2.5 to 5 percent of the world’s population—and 65 percent of those infected in the United States died.
A second battle was being fought during the Great War, this one between the scientists and influenza itself. It was no mystery that disease followed war, and on the eve of the United States’ entrance into this war, the military recruited the top medical minds in the United States. These included William Welch, founder of Johns Hopkins University; Victor Vaughan, dean of the Michigan medical school; Simon Flexner, Welch’s protege; Paul Lewis from Penn; Milton Rosenau from Harvard; and Eugene Opie at Washington University. Eventually the entire Rockefeller Institute was incorporated into the army as Army Auxiliary Laboratory Number One by Surgeon General of the Army William Gorgas. As the pandemic raged on, scientists found themselves in a race against time. They worked night and day, at times around the clock, in an attempt to develop a treatment and a vaccine or antiserum for influenza. The risk was great, as more than one scientist was struck down by the disease itself.
The cause of influenza was not known at this time, and two camps emerged: those who believed influenza to be a virus and those who believed that the bacterium B. influenzae caused the disease. During this time a number of medical discoveries were made, such as a treatment for three different types of pneumonia. Unfortunately, no true progress toward creating an influenza vaccine was made until 1944, when Thomas Francis Jr. was able to develop a killed-virus vaccine. His work was expanded on by Frank MacFarlane Burnet, who, with U.S. Army support, created the first successful influenza vaccine.
The American Red Cross was another principal player. Given the tremendous number of both civilian and military deaths due to influenza and the cost of the war overseas, the government could not put together the necessary funds and personnel to care for matters on the home front. Assistance was needed, and when it became apparent that this influenza had reached the scale of a pandemic, the Red Cross created the Red Cross National Committee on Influenza to coordinate a national response. The Red Cross proved invaluable. The Red Cross National Committee took charge of recruiting, supplying, and paying all nursing personnel and was responsible for providing emergency hospital supplies when local authorities were unable to do so and for distributing doctors through the U.S. Public Health Service to wherever they were needed. The shortage of medical personnel created by the war meant that the Red Cross was more or less single-handedly responsible for coordinating the movement of medical personnel throughout the country. Between September 14 and November 7, 1918, the Red Cross recruited over 15,000 women with varying degrees of medical training to serve in military and civilian posts. By spring of the following year, the Red Cross had spent more than $2 million in services.
Influenza in More Recent Decades
The severity of the 1918–1919 epidemic was not forgotten; since then, influenza has been a concern for physicians, scientists, and policy makers. With the exclusion of recent avian viruses passed directly from bird to human, all type A influenza viruses globally have originated from the 1918 H1N1 virus. In the early 1930s, scientist Richard Shope proved that the feared H1N1 virus was alive and thriving in the country’s pig population. This is particularly feared because the pig can act as an intermediary animal, allowing avian flu strains to adapt to mammals and then be passed onto humans. This strain of the H1N1 virus in the pig population is often referred to as swine flu. In 1957 the threat of another pandemic appeared. Government and medical officials feared the return of the H1N1 virus, or swine flu. That was not the case. Although the virus killed upward of a million individuals, it was not the H1N1 virus and instead became known as the Asian flu, an H2N2 virus. An earlier, and much less documented, influenza virus had occurred between 1889 and 1890. This pandemic was known as the Asiatic (Russian) flu. The Asiatic flu killed roughly one million individuals, and it is suspected that it too was an H2N2 virus. The most recent pandemic occurred from 1968 to 1969. Known as the Hong Kong virus (H3N2), it infected many, but the mortality rate was low. It was responsible for 750,000 to 1,000,000 deaths. Although there has not been a pandemic since the Hong Kong flu, public officials, hypersensitive to the threat of a flu epidemic, were concerned for the potential of a swine flu epidemic in 1976 and Asiatic flu pandemic in 1977.
In 1976, at Fort Dix, New Jersey, an 18-year-old private, feeling the symptoms of influenza, decided to join his platoon on a night march anyway. A few hours into the hike, he collapsed. He was dead by the time he reached the base hospital. Although the young private’s death was the only suspicious death to occur, it was a reminder of the 1918–1919 virus’s ability to kill young adults quickly, and officials feared another epidemic was at hand. Simultaneously, a young boy living on a Wisconsin farm contracted swine flu, surviving thanks to the antibodies produced by handling pigs, which were infected with Shope’s swine flu virus. Overwhelmed by the potential consequences of being wrong, medical and government officials chose to prepare themselves for the worst and declared the potential for an epidemic. Dr. David J. Sencer, director of the Centers for Disease Control, requested a $134 million congressional allocation for developing and distributing a vaccine. Following a dramatic televised speech given by the President Gerald Ford, Congress granted $135 million toward vaccine development and distribution in a last-minute vote. The president signed Public Law 94–266, allocating funds for the flu campaign on national television, stating that the Fort Dix virus was the cause of the 1918–1919 pandemic. The epidemic never surfaced. The American flu campaign was criticized on both a national and an international level, and Sencer was removed from his position at the CDC in 1977.
Swine Flu and Bird Flu
The most recent influenza scares have centered on swine flu (H1N1) and avian flu (H5N1). Avian influenza, also known as bird flu, is an extremely virulent virus that generally infects only birds. In recent years, however, it has been documented as infecting pigs and most recently, humans. Since April 2009, CDC has received reports of 338 pediatric deaths from the strain, 282 due to H1N1. Both spread rapidly though animal and human populations and can produce a mortality rate of 100 percent within 48 hours. In 1997 the H5N1 virus spread directly from chickens to humans and killed 16 out of 18 infected. It is this particular virus to which the term avian influenza most commonly refers. After this incident, all chickens in Hong Kong (1.2 million) were slaughtered in an effort to contain the virus. This protective measure failed because the virus had been able to spread to the wild bird population. In 2003 two more people were infected with avian flu, and one died. When scientists first tried to develop a vaccine for avian flu using the traditional vaccine growth medium, chicken eggs, they found that the virus was too lethal; the virus was killing the eggs in which it was being grown. A vaccine for avian flu now exists, but it took more than a year to develop, and it has not been stockpiled should a pandemic arise. All of those who caught the virus were infected directly by chickens, and the virus did not develop the ability to spread from human to human.
The potential for creation of a new, lethal virus exists, however. If one of the individuals who caught the avian flu had simultaneously been infected with a human influenza strain, it would have been possible for the two different strains of influenza to separate and recombine, using the human individual as an incubator to create a new strain of avian flu capable of being spread through human-to-human contact. It took a year to develop an avian flu vaccine. Should the virus mutate once more, it would have done the majority of its damage by the time a new vaccine could be developed by scientists. In an effort to stem this possibility, the World Health Organization (WHO) established a formal monitoring system for influenza viruses in 1948. Eighty-two countries and 110 laboratories participate by collecting information, which is then processed by four collaborating WHO laboratories. Any mutations in existing viruses are documented and are then used to adjust the next year’s vaccine. The surveillance system also actively searches for any signs of a new influenza strain, especially one with the potential to mutate into the next pandemic.
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- Centers for Disease Control, Key Flu Indicators, 2009, http://www.cdc.gov/h1n1flu/update.htm
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- Gregor, Michael, Bird Flu: A Virus of Our Own Hatching. New York: Lantern Books, 2006.
- Taubenberger, Jeff ery, and David M. Morens, “1918 Influenza: The Mother of All Pandemics.” Emerging Infectious Diseases 12, no. 1 (2006). http://wwwnc.cdc.gov/eid/article/12/1/05-0979_article.htm
- World Health Organization, “Influenza.” Epidemic and Pandemic Alert and Response (EPR). http://www.who.int/influenza/en/