A forgotten enemy: pandemics of the past

How quickly we forget the past and how little we seem to have learnt from major encounters with infectious disease. Australia’s history is littered with examples of epidemics and pandemics of infectious disease which caused havoc and incredible fear and terror. Many of these we have now totally forgotten, and we continue to ignore the lessons learnt and the immense suffering that confronted hundreds of thousands of Australians.

 One hundred years ago a new infectious disease swept the world and by 1918 had reached down to invade Australia. But who now remembers the pandemic of Sleepy Sickness or Encephalitis Lethargica which emerged in Vienna in the winter of 1916-17 and spread rapidly around the world? A good example of a slow pandemic it affected more than five million people and hung around for more than 12 years and then mysteriously disappeared.

The incidence of the disease peaked in Europe in 1920 and then gradually petered out. About 30% of people infected died from respiratory complications or other causes, about 33% recovered and the rest remained in a semi-comatose state characterised by fever, lethargy, eye movement disturbances, tremor, delirium and the inability to coordinate movements, psychosis and stupor. Many were destined to spend the rest of their lives in a frozen state consigned to special hospitals or asylums. Those who died did so in the acute stages of the sleeping sickness, in states of coma so deep that arousal proved impossible or in states of sleeplessness so intense as to preclude sedation. In the 1920s and for the next 70 years the disease was poorly understood, no cure emerged and at least 100,000 people were destined to remain in a frozen state in care facilities all their lives.

 The cause of the disease remained a total mystery and because it overlapped with the 1918-19 flu pandemic suspicion fell on the influenza disease. Encephalitis Lethargica reached Australia as early as 1917 but was not officially reported until some years later and thereafter remained an issue for more than 12 years. Between 1917 and 1935 many Australians caught the disease and there were more than 1,000 deaths and possibly 15,000-20,000 cases. In Australia as elsewhere in the world, large numbers of children and young adults were struck down by the disease. Overall, some cases ran a rapid mild course ending in about two or three weeks with apparently complete recovery. Others ran a more stormy course terminating in death after a few days, while some showed a slow convalescence extending into months and leaving the individual permanently incapacitated with unsteady gait, general weakness, a masked face, paralysis of the limbs, speech difficulties and mental and emotional instability.

But what was it and where did it come from? Well, towards the end of 1916, wards in Vienna’s Psychiatric Clinic contained a number of patients exhibiting a strange variety of symptoms. Many seemed to be suffering from a mild lethargy combined with disturbances of their eye muscles. Constantin von Economo later detailed how these patients represented the beginnings of a pandemic which would sweep the world. Dr Von Economo the first person to describe the emerging infection recalled the nona epidemic of 1890-91 which followed the flu pandemic of 1889-90 in Europe. Nona was an epidemic of somnolence that closely followed the flu outbreak. But as von Economo pointed out, Encephalitis Lethargica seemed to have been closely associated with flu epidemics in Europe on at least 10 occasions between 1580 and 1918-19. But there had never been a pandemic to compare with what swept around the world between 1917 and 1930. After 1918 the disease spread in waves across the world. First recognised in Australia in 1917 in would persist for more than 12 years during which time more than 1,000 Australians died of the disease and thousands caught the disease.

 In the 1920s, the Medical Journal of Australia was full of detailed case reports but little was known about the disease and the symptoms of those stricken with the disease were so varied and so complex that the medical profession had no real idea what they were confronting. Countless reasons were advanced ranging from epidemic delirium, epidemic schizophrenia, brain fever, botulism, epidemic Parkinsonism and atypical poliomyelitis. In Australia doctors initially pointed their finger at “X” Disease which had appeared in 1917 throughout parts of NSW. Largely affecting young children “X” Disease was marked by an abrupt onset, headaches, convulsions, rigidity with varying degrees of paralysis, mental confusion, coma and for many sufferers death within a few days. Given such symptoms it is not surprising that members of the health profession thought that it was linked to Encephalitis Lethargica, Like Encephalitis Lethargica, “X” Disease remained unidentified for more than 25 years until the early 1950s when it was finally revealed to be Murray Valley Encephalitis.

In Australia the Commonwealth Department of Health and all State Health Departments showed little concern or interest in the outbreak of the disease. Perhaps they were still struggling to get over the flu pandemic of 1919 or perhaps they did not believe the new infection to be that threatening. Finally, in 1926 the Federal Government declared Encephalitis Lethargica to be an infectious disease under the Public Health Act. By this date the epidemic in Australia was drawing to a close and more than 700 deaths and 10,000 cases had occurred. Over the next nine years a further 400 deaths and thousands of cases would be recorded.

Interestingly in the 1960s an American neurologist Oliver Sacks administered the drug L-Dopa, used for people suffering from Parkinson’s Disease, to a number of people suffering from Encephalitis Lethargica who had been in a frozen state for more than 40 years. Some recovered and begin to walk and talk haltingly. But quickly the drug became less and less effective and despite the dose being increased the patients sank back into stupor. It would be another 30 years before the nature of the disease began to be unravelled.

But is Encephalitis Lethargica ever likely to reappear? Well, in 1993 a 23-year-old woman in the UK suddenly became ill and was diagnosed with the disease. Since 1993 there have been a number of cases most of which started with a sore throat and doctors discovered a rare form of streptococcus bacteria which had mutated into a much more severe form and had triggered attacks of Encephalitis Lethargica. Given this discovery two UK doctors returned to evidence available from cases of Encephalitis Lethargica in the 1920s and discovered that many sufferers had presented with sore throats and that there were references to a certain bacteria, notably diplococcus, a form of streptococcus bacteria. For the first time in more than 70 years we have edged closer to understanding the nature of Encephalitis Lethargica. Even so, we still do not really know why the disease erupted so violently in 1917 and then after 10-12 years apparently almost disappeared.

The Encephalitis Lethargica pandemic which embraced Australia after 1917 was an important point in Australia’s epidemiological history. The pandemic stunned the medical community with its virulence and high mortality and the fact that it left thousands of sufferers in a frozen state for more than 50 years and was largely ignored by the Federal Government. It should not be forgotten.