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1918 REVISITED: LESSONS AND SUGGESTIONS FOR FURTHER INQUIRY

John M. Barry

Distinguished Visiting Scholar

Center for Bioenvironmental Research at Tulane and Xavier Universities

The 1918–1919 influenza pandemic killed more people in absolute numbers than any other disease outbreak in history. A contemporary estimate put the death toll at 21 million, a figure that persists in the media today, but understates the real number. Epidemiologists and scientists have revised that figure several times since then. Each and every revision has been upward. Frank Macfarlane Burnet, who won his Nobel Prize for immunology but who spent most of his life studying influenza, estimated the death toll as probably 50 million, and possibly as high as 100 million. A 2002 epidemiologic study also estimates the deaths at between 50 and 100 million (Johnson and Mueller, 2002).

The world population in 1918 was only 28 percent of today's population. Adjusting for population, a comparable toll today would be 175 to 350 million. By comparison, at this writing AIDS has killed approximately 24 million, and an estimated 40 million more people are infected with the virus.

A letter from a physician at one U.S. Army camp to a colleague puts a more human face on those numbers:

These men start with what appears to be an ordinary attack of LaGrippe or Influenza, and when brought to the Hosp. they very rapidly develop the most vicious type of Pneumonia that has ever been seen … and a few hours later you can begin to see the Cyanosis extending from their ears and spreading all over the face, until it is hard to distinguish the colored men from the white. It is only a matter of a few hours then until death comes…. It is horrible. One can stand it to see one, two or twenty men die, but to see these poor devils dropping like flies…. We have been averaging about 100 deaths per day…. Pneumonia means in about all cases death…. We have lost an outrageous number of Nurses and Drs. It takes special trains to carry away the dead. For several days there were no coffins and the bodies piled up something fierce…. It beats any sight they ever had in France after a battle. An extra long barracks has been vacated for the use of the Morgue, and it would make any man sit up and take notice to walk down the long lines of dead soldiers all dressed and laid out in double rows…. Good By old Pal, God be with you till we meet again (Grist, 1979).

That letter reflected a typical experience in American Army cantonments. The civilian experience was not much better.

In preparing for another pandemic, it is useful to examine events of 1918 for lessons, warnings, and areas for further inquiry.

The Virus Itself

The pandemic in 1918 was hardly the first influenza pandemic, nor was it the only lethal one. Throughout history, there have been influenza pandemics, some of which may have rivaled 1918's lethality. A partial listing of particularly violent outbreaks likely to have been influenza include one in 1510 when a pandemic believed to come from Africa “attacked at once and raged all over Europe not missing a family and scarce a person” (Beveridge, 1977). In 1580, another pandemic started in Asia, then spread to Africa, Europe, and even America (despite the fact that it took 6 weeks to cross the ocean). It was so fierce “that in the space of six weeks it afflicted almost all the nations of Europe, of whom hardly the twentieth person was free of the disease” and some Spanish cities were “nearly entirely depopulated by the disease” (Beveridge, 1977). In 1688, influenza struck England, Ireland, and Virginia; in all these places “the people dyed … as in a plague” (Duffy, 1953). A mutated or new virus continued to plague Europe and America again in 1693 and Massachusetts in 1699. “The sickness extended to almost all families. Few or none escaped, and many dyed especially in Boston, and some dyed in a strange or unusual manner, in some families all were sick together, in some towns almost all were sick so that it was a time of disease” (Pettit, 1976). In London in 1847 and 1848, more people died from influenza than from the terrible cholera epidemic of 1832. In 1889 and 1890, a great and violent worldwide pandemic struck again (Beveridge, 1977).

But 1918 seems to have been particularly violent. It began mildly, with a spring wave. In fact, it was so mild that some physicians wonder if this disease actually was influenza. Typically, several Italian doctors argued in separate journal articles that this “febrile disease now widely prevalent in Italy [is] not influenza” (Policlinico, 1918). British doctors echoed that conclusion; a Lancet article in July 1918 argued that the spring epidemic was not influenza because the symptoms, though similar to influenza, were “of very short duration and so far absent of relapses or complications” (Little et al., 1918).

Within a few weeks of that Lancet article appearing, a second pandemic wave swept around the world. It also initially caused investigators to doubt that the disease was influenza—but this time because it was so virulent. It was followed by a third wave in 1919, and significant disease also struck in 1920. (Victims of the first wave enjoyed significant resistance to the second and third waves, offering compelling evidence that all were caused by the same virus. It is worth noting that the 1889–1890 pandemic also came in waves, but the third wave seemed to be the most lethal.)

The 1918 virus, especially in its second wave, was not only virulent and lethal, but extraordinarily violent. It created a range of symptoms rarely seen with the disease. After H5N1 first appeared in 1997, pathologists reported some findings “not previously described with influenza” (To et al., 2001). In fact, investigators in 1918 described every pathological change seen with H5N1 and more (Jordon, 1927: 266–268).

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” (Ireland, 1928: 57). A German investigator recorded “hemorrhages occurring in different parts of the interior of the eye” with great frequency (Thomson and Thomson, 1934b). An American pathologist noted: “Fifty cases of subconjunctival hemorrhage were counted. Twelve had a true hemotypsis, bright red blood with no admixture of mucus…. Three cases had intestinal hemorrhage” (Ireland, 1928: 13). The New York City Health Department's chief pathologist said, “Cases with intense pain look and act like cases of dengue … hemorrhage from nose or bronchi … paresis or paralysis of either cerebral or spinal origin … impairment of motion may be severe or mild, permanent or temporary … physical and mental depression. Intense and protracted prostration led to hysteria, melancholia, and insanity with suicidal intent” (Jordon, 1927: 265).

The 1918 virus also targeted young adults. In South African cities, those between the ages of 20 and 40 accounted for 60 percent of the deaths (Katzenellenbogen, 1988). In Chicago the deaths among those aged 20 to 40 nearly quintupled deaths of those aged 41 to 60 (Van Hartesveldt, 1992). A Swiss physician “saw no severe case in anyone over 50.”1 In the “registration area” of the United States—those states and cities that kept reliable statistics—the single greatest number of deaths occurred in the cohort aged 25 to 29, the second greatest in those aged 30 to 34, and the third in those aged 20 to 24. More people died in each one of those 5-year groups than the total deaths among all those over age 60, and the combined deaths of those aged 20 to 34 more than doubled the deaths of all those over 50 (U.S. Bureau of the Census, 1921). The single group most likely to die if infected were pregnant women. In 13 studies of hospitalized pregnant women during the 1918 pandemic, the death rate ranged from 23 to 71 percent (Jordon, 1927: 273). Of the pregnant women who survived, 26 percent lost the child (Harris, 1919). (As far back as 1557, people connected influenza with miscarriage and the death of pregnant women.)

The case mortality rate varied widely. An overall figure is impossible to obtain, or even estimate reliably, because no solid information about total cases exists. In U.S. Army camps where reasonably reliable statistics were kept, case mortality often exceeded 5 percent, and in some circumstances exceeded 10 percent. In the British Army in India, case mortality for white troops was 9.6 percent, for Indian troops 21.9 percent.

In isolated human populations, the virus killed at even higher rates. In the Fiji islands, it killed 14 percent of the entire population in 16 days. In Labrador and Alaska, it killed at least one-third of the entire native population (Jordan, 1927; Rice, 1988).

But perhaps most disturbing and most relevant for today is the fact that a significant minority—and in some subgroups of the population a majority—of deaths came directly from the virus, not from secondary bacterial pneumonias.

In 1918, pathologists were intimately familiar with the condition of lungs of victims of bacterial pneumonia at autopsy. But the viral pneumonias caused by the influenza pandemic were so violent that many investigators said the only lungs they had seen that resembled them were from victims of poison gas.

Then, the Army called them “atypical pneumonias.” Today we would call this atypical pneumonia Acute Respiratory Distress Syndrome (ARDS). The Army's pneumonia board judged that “more than half” of all the deaths among soldiers came from this atypical pneumonia (Ireland, 1928).

One cannot extrapolate from this directly to the civilian population. Army figures represent a special case both in terms of demographics and environment, including overcrowded barracks.

Even so, the fact that ARDS likely caused more than half the deaths among young adults sends a warning. ARDS mortality rates today range from 40 to 60 percent, even with support in modern intensive care units (ICUs). In a pandemic, ICUs would be quickly overwhelmed, representing a major challenge for public health planners.

https://www.ncbi.nlm.nih.gov/books/NBK22148/