The Great Influenza

by John M. Barry

  They also discussed overcrowding in hospitals and isolation of troops. Since 1916 the Canadian army had segregated all troops arriving in Britain for twenty-eight days, to prevent their infecting any trained troops ready to go to the front. Welch advised establishing similar 'detention camps for new recruits where men are kept for 10-14 days.'

  They all recognized the difficulty of convincing the army to do this, or of convincing the army to end the even more serious problem of overcrowding in barracks.

  Still, another army medical officer injected one piece of good news. He said that the problem of overcrowding in the hospitals themselves had been eliminated. Every hospital in the army had at least one hundred empty beds as of May 15, with a total of twenty-three thousand beds empty. Every single epidemiological statistic the army collected showed improved overall health. He insisted that facilities and training were adequate.

  Time would tell.

  *

  Man might be defined as 'modern' largely to the extent that he attempts to control, as opposed to adjust himself to, nature. In this relationship with nature, modern humanity has generally been the aggressor and a daring one at that, altering the flow of rivers, building upon geological faults, and, today, even engineering the genes of existing species. Nature has generally been languid in its response, although contentious once aroused and occasionally displaying a flair for violence.

  By 1918 humankind was fully modern, and fully scientific, but too busy fighting itself to aggress against nature. Nature, however, chooses its own moments. It chose this moment to aggress against man, and it did not do so prodding languidly. For the first time, modern humanity, a humanity practicing the modern scientific method, would confront nature in its fullest rage.

  Part IV

  IT BEGINS

  CHAPTER FOURTEEN

  IT IS IMPOSSIBLE to prove that someone from Haskell County, Kansas, carried the influenza virus to Camp Funston. But the circumstantial evidence is strong. In the last week of February 1918, Dean Nilson, Ernest Elliot, John Bottom, and probably several others unnamed by the local paper traveled from Haskell, where 'severe influenza' was raging, to Funston. They probably arrived between February 28 and March 2, and the camp hospital first began receiving soldiers with influenza on March 4. This timing precisely fits the incubation period of influenza. Within three weeks eleven hundred troops at Funston were sick enough to require hospitalization.

  Only a trickle of people moved back and forth between Haskell and Funston, but a river of soldiers moved between Funston, other army bases, and France. Two weeks after the first case at Funston, on March 18, influenza surfaced at both Camps Forrest and Greenleaf in Georgia; 10 percent of the forces at both camps would report sick. Then, like falling dominoes, other camps erupted with influenza. In total, twenty-four of the thirty-six largest army camps experienced an influenza outbreak that spring. Thirty of the fifty largest cities in the country, most of them adjacent to military facilities, also suffered an April spike in 'excess mortality' from influenza, although that did not become clear except in hindsight.

  At first it seemed like nothing to worry about, nothing like the measles outbreak with its pneumonic complications. Only in Haskell had influenza been severe. The only thing at all worrisome was that the disease was moving.

  As Macfarlane Burnet later said, 'It is convenient to follow the story of influenza at this period mainly in regard to the army experiences in America and Europe.'

  *

  After the pandemic, outstanding epidemiologists searched military and civilian health records in the United States for any signs of uncommon influenza activity prior to the Funston outbreak. They found none. (The warning published about Haskell misstated the date, incorrectly putting it after Funston.) In France there had been some localized flare-ups of influenza during the winter, but they did not seem to spread and behaved like endemic, not epidemic, disease.

  The first unusual outbreaks in Europe occurred in Brest in early April, where American troops disembarked. In Brest itself a French naval command was suddenly crippled. And from Brest the disease did spread, and quickly, in concentric circles.

  Still, although many got sick, these outbreaks were, like those in the United States, generally mild. Troops were temporarily debilitated, then recovered. For example, an epidemic erupted near Chaumont involving U.S. troops and civilians: of 172 marines guarding headquarters there, most fell ill and fifty-four required hospitalization - but all of them recovered.

  The first appearance in the French army came April 10. Influenza struck Paris in late April, and at about the same time the disease reached Italy. In the British army the first cases occurred in mid-April, then the disease exploded. In May the British First Army alone suffered 36,473 hospital admissions and tens of thousands of less serious cases. In the Second Army, a British report noted, 'At the end of May it appeared with great violence' . The numbers affected were very great' . A brigade of artillery had one-third of its strength taken ill within forty-eight hours, and in the brigade ammunition column only fifteen men were available for duty one day out of a strength of 145.' The British Third Army suffered equally. In June troops returning from the Continent introduced the disease into England.

  But again the complications were few and nearly all the troops recovered. The only serious concern (and it was serious indeed) was that the disease would undermine the troops' ability to fight.

  That seemed the case in the German army. German troops in the field suffered sharp outbreaks beginning in late April. By then German commander Erich von Ludendorff had also begun his last great offensive - Germany's last real chance to win the war.

  The German offensive made great initial gains. From near the front lines Harvey Cushing, Halsted's protegé, recorded the German advance in his diary: 'They have broken clean through' .''The general situation is far from reassuring' . 11 P.M. The flow of men from the retreating Front keeps up.' 'Haig's most disquieting Order to the Army' ends as follows: 'With our backs to the wall, and believing in the justice of our cause, each one of us must fight to the end. The safety of our homes and the freedom of mankind depend alike upon the conduct of every one of us at this moment.''

  But then Cushing noted, 'The expected third phase of the great German offensive gets put off from day to day.' 'When the next offensive will come off no one knows. It probably won't be long postponed. I gather that the epidemic of grippe which hit us rather hard in Flanders also hit the Boche worse, and this may have caused the delay.'

  Ludendorff himself blamed influenza for the loss of initiative and the ultimate failure of the offensive: 'It was a grievous business having to listen every morning to the chiefs of staff's recital of the number of influenza cases, and their complaints about the weakness of their troops.'

  Influenza may have crippled his attack, stripped his forces of fighting men. Or Ludendorff may have simply seized upon it as an excuse. British, French, and American troops were all suffering from the disease themselves, and Ludendorff was not one to accept blame when he could place it elsewhere.

  In the meantime, in Spain the virus picked up its name.

  *

  Spain actually had few cases before May, but the country was neutral during the war. That meant the government did not censor the press, and unlike French, German, and British newspapers (which printed nothing negative, nothing that might hurt morale) Spanish papers were filled with reports of the disease, especially when King Alphonse XIII fell seriously ill.

  The disease soon became known as 'Spanish influenza' or 'Spanish flu,' very likely because only Spanish newspapers were publishing accounts of the spread of the disease that were picked up in other countries.

  It struck Portugal, then Greece. In June and July, death rates across England, Scotland, and Wales surged. In June, Germany suffered initial sporadic outbreaks, and then a full-fledged epidemic swept across all the country. Denmark and Norway began suffering in July, Holland and Sweden in August.

  The earliest
cases in Bombay erupted on a transport soon after its arrival May 29. First seven police sepoys who worked the docks were admitted to the police hospital; then men who worked at the government dockyard succumbed; the next day employees of the Bombay port fell ill, and two days later men who worked at a location that 'abuts on the harbor between the government dockyard and Ballard Estate of the Port Trust.' From there the disease spread along railroad lines, reaching Calcutta, Madras, and Rangoon after Bombay, while another transport brought it to Karachi.

  Influenza reached Shanghai toward the end of May. Said one observer, 'It swept over the whole country like a tidal wave.' A reported half of Chungking lay ill. It jumped to New Zealand and then Australia in September; in Sydney it sickened 30 percent of the population.

  But if it was spreading explosively, it continued to bear little resemblance to the violent disease that had killed in Haskell. Of 613 American troops admitted to the hospital during one outbreak in France, only one man died. In the French army, fewer than one hundred deaths resulted from forty thousand hospital admissions. In the British fleet, 10,313 sailors fell ill, temporarily crippling naval operations, but only four sailors died. Troops called it 'three-day fever.' In Algeria, Egypt, Tunisia, China, and India it was 'everywhere of a mild form.'

  In fact, its mildness made some physicians wonder if this disease actually was influenza. One British army report noted that the symptoms 'resembled influenza' but 'its short duration and absence of complications' created doubt that it was influenza. Several different Italian doctors took a stronger position, arguing in separate medical journal articles that this 'febrile disease now widely prevalent in Italy [is] not influenza.' Three British doctors writing in the journal The Lancet agreed; they concluded that the epidemic could not actually be influenza, because the symptoms, though similar to those of influenza, were too mild, 'of very short duration and so far absent of relapses or complications.'

  That issue of The Lancet was dated July 13, 1918.

  *

  In March and April in the United States, when the disease began jumping from army camp to army camp and occasionally spreading to adjacent cities, Gorgas, Welch, Vaughan, and Cole showed little concern about it, nor did Avery commence any laboratory investigation. Measles was still lingering, and had caused many more deaths.

  But as influenza surged across Europe, they began to attend to it. Despite the articles in medical journals about its generally benign nature, they had heard of some worrisome exceptions, some hints that perhaps this disease wasn't always so benign after all, that when the disease did strike hard, it was unusually violent - more violent than measles.

  One army report noted 'fulminating pneumonia, with wet hemorrhagic lungs' (i.e., a rapidly escalating infection and lungs choked with blood) 'fatal in from 24 to 48 hours.' Such a quick death from pneumonia is extraordinary. And an autopsy of a Chicago civilian victim revealed lungs with similar symptoms, symptoms unusual enough to prompt the pathologist who performed the autopsy to send tissue samples to Dr. Ludwig Hektoen, a highly respected scientist who knew Welch, Flexner, and Gorgas well and who headed the John McCormick Memorial Institute for Infectious Diseases. The pathologist asked Hektoen 'to look at it as a new disease.'

  And in Louisville, Kentucky, a disturbing anomaly appeared in the influenza statistics. There deaths were not so few, and (more surprisingly) 40 percent of those who died were aged twenty to thirty-five, a statistically extraordinary occurrence.

  In France in late May, at one small station of 1,018 French army recruits, 688 men were ill enough to be hospitalized and forty-nine died. When 5 percent of an entire population (especially of healthy young adults) dies in a few weeks, that is frightening.

  By mid-June, Welch, Cole, Gorgas, and others were trying to gather as much information as possible about the progression of influenza in Europe. Cole could get nothing from official channels but did learn enough from such people as Hans Zinsser, a former (and future) Rockefeller investigator in the army in France, to become concerned. In July, Cole asked Richard Pearce, a scientist at the National Research Council who was coordinating war-related medical research, to make 'accurate information concerning the influenza prevailing in Europe' a priority, adding, 'I have inquired several times in Washington at the Surgeon General's office' (referring to civilian Surgeon General Rupert Blue, head of the U.S. Public Health Service, not Gorgas) 'but no one seems to have any definite information in regard to the matter.' A few days later Cole showed more concern when he advised Pearce to put more resources into related research.

  In response Pearce contacted several individual laboratory scientists, such as Paul Lewis in Philadelphia, as well as clinicians, pathologists, and epidemiologists, asking if they could begin new investigations. He would act as a clearinghouse for their findings.

  *

  Between June 1 and August 1, 200,825 British soldiers in France, out of two million, were hit hard enough that they could not report for duty even in the midst of desperate combat. Then the disease was gone. On August 10, the British command declared the epidemic over. In Britain itself on August 20, a medical journal stated that the influenza epidemic 'has completely disappeared.'

  The Weekly Bulletin of the Medical Service of the American Expeditionary Force in France was less willing than the British to write off the influenza epidemic entirely. It did say in late July, 'The epidemic is about at an end' and has been throughout of a benign type, though causing considerable noneffectiveness.'

  But it went on to note, 'Many cases have been mistaken for meningitis' . Pneumonias have been more common sequelae in July than in April.'

  In the United States, influenza had neither swept through the country, as it had in Western Europe and parts of the Orient, nor had it completely died out.

  Individual members of the army's pneumonia commission had dispersed to perform studies in several locations, and they still saw signs of it. At Fort Riley, which included Camp Funston, Captain Francis Blake, was trying to culture bacteria from the throats of both normal and sick troops. It was desultory work, far less exciting than what he was accustomed to, and he hated Kansas. He complained to his wife, 'No letter from my beloved for two days, no cool days, no cool nights, no drinks, no movies, no dances, no club, no pretty women, no shower bath, no poker, no people, no fun, no joy, no nothing save heat and blistering sun and scorching winds and sweat and dust and thirst and long and stifling nights and working all hours and lonesomeness and general hell - that's Fort Riley Kansas.' A few weeks later, he said it was so hot they kept their cultures of bacteria in an incubator so the heat wouldn't kill them. 'Imagine going into an incubator to get cool,' he wrote.

  He also wrote, 'Have been busy on the ward all day - some interesting cases'. But most of it influenza at present.'

  Influenza was about to become interesting.

  For the virus had not disappeared. It had only gone underground, like a forest fire left burning in the roots, swarming and mutating, adapting, honing itself, watching and waiting, waiting to burst into flame.

  CHAPTER FIFTEEN

  THE 1918 INFLUENZA PANDEMIC, like many other influenza pandemics, came in waves. The first spring wave killed few, but the second wave would be lethal. Three hypotheses can explain this phenomenon.

  One is that the mild and deadly diseases were caused by two entirely different viruses. This is highly unlikely. Many victims of the first wave demonstrated significant resistance to the second wave, which provides strong evidence that the deadly virus was a variant of the mild one.

  The second possibility is that a mild virus caused the spring epidemic, and that in Europe it encountered a second influenza virus. The two viruses infected the same cells, 'reassorted' their genes, and created a new and lethal virus. This could have occurred and might also explain the partial immunity some victims of the first wave acquired, but at least some scientific evidence directly contradicts this hypothesis, and most influenza experts today do not believe this happened.

 
The third explanation involves the adaptation of the virus to man.

  *

  In 1872 the French scientist C. J. Davaine was examining a specimen of blood swarming with anthrax. To determine the lethal dose he measured out various amounts of this blood and injected it into rabbits. He found it required ten drops to kill a rabbit within forty hours. He drew blood from this rabbit and infected a second rabbit, which also died. He repeated the process, infecting a third rabbit with blood from the second, and so on, passing the infection through five rabbits.

  Each time he determined the minimum amount of blood necessary to kill. He discovered that the bacteria increased in virulence each time, and after going through five rabbits a lethal dose fell from 10 drops of blood to 1/100 of a drop. At the fifteenth passage, the lethal dose fell to 1/40,000 of a drop of blood. After twenty-five passages, the bacteria in the blood had become so virulent that less than 1/1,000,000 of a drop killed.

  This virulence disappeared when the culture was stored. It was also specific to a species. Rats and birds survived large doses of the same blood that killed rabbits in infinitesimal amounts.

  Davaine's series of experiments marked the first demonstration of a phenomenon that became known as 'passage.' This phenomenon reflects an organism's ability to adapt to its environment. When an organism of weak pathogenicity passes from living animal to living animal, it reproduces more proficiently, growing and spreading more efficiently. This often increases virulence.

  In other words, it becomes a better and more efficient killer.

  Changing the environment even in a test tube can have the same effect. As one investigator noted, a strain of bacteria he was working with turned deadly when the medium used to grow the organism changed from beef broth to veal broth.

  But the phenomenon is complex. The increase in killing efficiency does not continue indefinitely. If a pathogen kills too efficiently, it will run out of hosts and destroy itself. Eventually its virulence stabilizes and even recedes. Especially when jumping species, it can become less dangerous instead of more dangerous. This happens with the Ebola virus, which does not normally infect humans. Initially Ebola has extremely high mortality rates, but after it goes through several generations of human passages, it becomes far milder and not particularly threatening.