SPANISH FLU

The 1918 flu pandemic, commonly referred to as the 'Spanish flu', was a category 5 influenza pandemic caused by an unusually severe and deadly Influenza A virus strain of subtype H1N1. Many of its victims were healthy young adults, in contrast to most influenza outbreaks which predominantly affect juvenile, elderly, or otherwise weakened patients.
The Spanish flu pandemic lasted from 1918 to 1919. Older estimates say it killed 40–50 million people The geography and mortality of the 1918 influenza pandemic., , KD, Patterson, Bull Hist Med., 1991 while current estimates say 50 million to 100 million people worldwide were killed. The Threat of Pandemic Influenza: Are We Ready? Workshop Summary (2005), , , , The National Academies Press, , This pandemic has been described as "the greatest medical holocaust in history" and may have killed as many people as the Black Death. A History of Influenza, , CW, Potter, J Appl Microbiol., 2006 This huge death toll was caused by an extremely high infection rate of up to 50% and the extreme severity of the symptoms, suspected to be caused by cytokine storms. Indeed, symptoms in 1918 were so unusual that initially influenza was misdiagnosed as dengue, cholera, or typhoid. One observer wrote, "One of the most striking of the complications was hemorrhage from mucous membranes, especially from the nose, stomach, and intestine. Bleeding from the ears and petechial hemorrhages in the skin also occurred." The majority of deaths were from bacterial pneumonia, a secondary infection caused by influenza, but the virus also killed people directly, causing massive hemorrhages and edema in the lung. Integrating historical, clinical and molecular genetic data in order to explain the origin and virulence of the 1918 Spanish influenza virus., , J, Taubenberger, Philos Trans R Soc Lond B Biol Sci, 2001

Chart of deaths in major cities

The 1918 flu pandemic was truly global, spreading even to the Arctic and remote Pacific islands. The unusually severe disease killed between 2 and 20% of those infected, as opposed to the more usual flu epidemic mortality rate of 0.1%. Another unusual feature of this pandemic was that it mostly killed young adults, with 99% of pandemic influenza deaths occurring in people under 65, and more than half in young adults 20 to 40 years old.^[1] This is unusual since influenza is normally most deadly to the very young (under age 2) and the very old (over age 70). The total mortality of the 1918–1919 pandemic is not known, but it is estimated that 2.5% to 5% of the world's population was killed. As many as 25 million may have been killed in the first 25 weeks; in contrast, HIV/AIDS has killed 25 million in its first 25 years.
The disease was first observed at Fort Riley, Kansas, U.S. on March 11, 1918. One researcher argues that the disease was found in Haskell County, Kansas as early as January of 1918.^[2] The Allies of World War I came to call it the Spanish Flu, primarily because the pandemic received greater press attention in Spain than in the rest of the world, as Spain was not involved in the war and had not imposed wartime censorship.
Scientists have used tissue samples from frozen victims to reproduce the virus for study.^[3] Given the strain's extreme virulence there has been controversy regarding the wisdom of such research. Among the conclusions of this research is that the virus kills via a cytokine storm, which explains its unusually severe nature and the unusual age profile of its victims.

Contents

History

Patterns of fatality

Devastated communities

Unaffected Locales

Further reading

External links

History

The difference between the influenza mortality age-distributions of the 1918 epidemic and normal epidemics. Deaths per 100,000 persons in each age group, United States, for the interpandemic years 1911–1917 (dashed line) and the pandemic year 1918 (solid line). 1918 Influenza: the mother of all pandemics., , J, Taubenberger, Emerg Infect Dis, 2006

The global mortality rate from the 1918/1919 pandemic is not known, but is estimated at 2.5 – 5% of the human population, with 20% or more of the world population suffering from the disease to some extent. Influenza may have killed as many as 25 million in its first 25 weeks; in contrast, AIDS killed 25 million in its first 25 years. Some estimates put the total killed at over twice that number, possibly even 100 million.
An estimated 17 million died in India, about 5% of India's population at the time. In the Indian Army, almost 22% of troops who caught the disease died of it. In the U.S., about 28% of the population suffered, and 500,000 to 675,000 died. In Britain as many as 250,000 died; in France more than 400,000. Entire villages perished in Alaska and southern Africa. In Australia an estimated 12,000 people died and in the Fiji Islands, 14% of the population died during only two weeks, and in Western Samoa 22%.
While World War I did not cause the flu, the close quarters and mass movement of troops quickened its spread. Researchers speculate that the soldiers' immune systems were weakened by the stresses of combat and chemical attacks, increasing their susceptibility to the disease.
A large factor in the spread of the disease was the increased amount of travel. The modernization of transportation made it easier for sailors to spread the disease more quickly and to a wider range of communities.

Patterns of fatality

The influenza strain was unusual in that this pandemic killed many young adults and otherwise healthy victims - typical influenzas kill mostly infants (aged 0-2 years), the old, and the immunocompromised. Another oddity was that this influenza outbreak struck hardest in summer and fall (in the Northern Hemisphere). Typically, influenza is worse in the winter months.
People without symptoms could be struck suddenly and within hours be too feeble to walk; many died the next day. Symptoms included a blue tint to the face and coughing up blood caused by severe obstruction of the lungs. In some cases, the virus caused an uncontrollable hemorrhaging that filled the lungs, and patients drowned in their body fluids.
In fast-progressing cases, mortality was primarily from pneumonia, by virus-induced consolidation. Slower-progressing cases featured secondary bacterial pneumonias, and there may have been neural involvement that led to mental disorders in a minority of cases. Some deaths resulted from malnourishment and even animal attacks in overwhelmed communities.

Devastated communities

Street car conductor in Seattle not allowing passengers aboard without a mask in 1918.

While in most places less than one-third of the population was infected, only a small percentage of whom died, in a number of towns in several countries entire populations were wiped out.
Even in areas where mortality was low, those incapacitated by the illness were often so numerous as to bring much of everyday life to a stop. Some communities closed all stores or required customers not to enter the store but place their orders outside the store for filling. There were many reports of places with no health care workers to tend the sick because of their own ill health and no able-bodied grave diggers to bury the dead. Mass graves were dug by steam shovel and bodies buried without coffins in many places.

Unaffected Locales

In Japan, 257,363 deaths were attributed to influenza by July 1919, giving an estimated 0.425% mortality rate, much lower than nearly all other Asian countries for which data are available. The Japanese government severely restricted maritime travel to and from the home islands when the pandemic struck. The only sizeable inhabited place with no documented outbreak of the flu in 1918–1919 was the island of Marajó at the mouth of the Amazon River in Brazil. In the Pacific, American Samoa Influenza of 1918 (Spanish Flu) and the US Navy
and the French colony of New Caledonia
Nonpharmaceutical interventions for pandemic influenza, international measures., World Health Organization Writing Group, , , Centers for Disease Control and Prevention (CDC) Emerging Infectious Diseases (EID) Journal, 2006
also succeeded in preventing even a single death from influenza through effective quarantines.

Further reading

★ The Great Influenza: The Epic Story of the Greatest Plague in History, , John M., Barry, Viking Penguin, 2004,

★ America's Forgotten Pandemic: The Influenza of 1918, , Alfred W., Crosby, Cambridge University Press, 1990,

★ Britain and the 1918-19 Influenza Pandemic: A Dark Epilogue, , Niall, Johnson, Routledge, 2006,

★ Measuring a pandemic: Mortality, demography and geography, , Niall, Johnson, Popolazione e Storia, 2003

★ Scottish ’flu – The Scottish mortality experience of the “Spanish flu, , Niall, Johnson, Scottish Historical Review, 2003

★ Updating the accounts: global mortality of the 1918–1920 ‘Spanish’ influenza pandemic, , Niall, Johnson, Bulletin of the History of Medicine, 2002

★ If I Die Before I Wake: The Flu Epidemic Diary of Fiona Macgregor, Toronto, Ontario, 1918, , Jean, Little, Scholastic Canada, 2007,

★ The 1918 Influenza Epidemic's Effects on Sex Differentials in Mortality in the United States, , Andrew, Noymer, Population and Development Review, 2000

★ World War I may have allowed the emergence of "Spanish" influenza, Oxford JS, Sefton A, Jackson R, Innes W, Daniels RS, Johnson NP, , , The Lancet infectious diseases, 2002

★ Who's that lady?, Oxford JS, Sefton A, Jackson R, Johnson NP, Daniels RS, , , Nat. Med., 1999

★ The Spanish Flu Pandemic of 1918: New Perspectives, , Howard, Phillips, Routledge, 2003,

★ Pandemic Influenza in Japan, 1918-1919: Mortality Patterns and Official Responses, , Geoffrey W., Rice, Journal of Japanese Studies, 1993

★ Black November: the 1918 Influenza Pandemic in New Zealand, , Geoffrey W., Rice, , 2005,

★ Existing antivirals are effective against influenza viruses with genes from the 1918 pandemic virus, Tumpey TM, García-Sastre A, Mikulasova A, ''et al'', , , Proc. Natl. Acad. Sci. U.S.A., 2002

External links

★ Video from Expert Panel Discussion on Avian Flu

★ ''Nature'' "Web Focus" on 1918 flu, including new research

★ Influenza Pandemic on stanford.edu

★ Article: The Deadliest Fall

★ Influenza 1918 in the United States on pbs.org

★ Secrets of the Dead: Killer Flu (PBS)

★ Flu by Eileen A. Lynch. The devastating effect of the Spanish flu in the city of Philadelphia, PA, USA

★ Dialog: An Interview with Dr. Jeffery Taubenberger on Reconstructing the Spanish Flu

★ The Deadly Virus - The Influenza Epidemic of 1918, by the National Archives and Records Administration (see actual pictures and records of the time).

★ The 1918 Influenza Pandemic in New Zealand - includes recorded recollections of people who lived through it

★ Experts Unlock Clues to Spread of 1918 Flu Virus - ''The New York Times''

★ PBS - recovery of flu samples from Alaskan flu victims

★ An Avian Connection as a Catalyst to the 1918-1919 Influenza Pandemic

★ Alaska Science Forum - Permafrost Preserves Clues to Deadly 1918 Flu

★ Pathology of Influenza in France, 1920 Report

★ "Deadly secret of 1918 flu virus unmasked", ''Cosmos'' magazine, September 2006

★ Yesterday's News blog, 1918 newspaper account on impact of flu on Minneapolis

★ "Lethal secrets of 1918 flu virus" BBC News, January 2007

★ "Study uncovers a lethal secret of 1918 influenza virus" University of Wisconsin - Madison, January 17, 2007

★ "The site of origin of the 1918 influenza pandemic and its public health implications" Journal of Translational Medicine, January 20, 2004