History of Idea of Contagion and Germ Theory

Vipul Singh

Book Review

John Waller. The Discovery of the Germ: Twenty Years That Transformed the Way We Think About Disease, Cambridge: Icon Books, 2002. Pages 200.

ABSTRACT: Disease has surfaced as a key subject in environmental history especially after Alfred Crosby’s The Columbian Exchange. The book by John Waller deals extensively with the very notion of contagion. It tells us about the history of idea of distancing which originated because of a silent revolution in the form of germ theory between 1880 and 1900.

History has many lessons to teach us, if only we would try to learn from it. The President of United States, Donald Trump’s attempt to vilify China by calling Covid-19 as the ‘Chinese virus’ sounds erroneous because it is very difficult to trace the origin of a germ in such a globalised world. But many believe that China is at least responsible for the concealment of cases in the initial few months. Some researchers argue that it has led to the spread of the pandemic with such huge mortality, and is ultimately leading to delay in developing vaccine for coronavirus. John Waller in his The Discovery of the Germ provides us with long history of such concealments in the past.

Disease has surfaced as a key subject in environmental history especially after Alfred Crosby’s The Columbian Exchange. The book by John Waller though does not touch upon the issue of disease exchanges, but it deals extensively with the very notion of contagion. It tells us about the history of idea of distancing which originated because of a silent revolution between 1880 and 1900. It was in this short period of two decades that medical sciences underwent perhaps its greatest ever transformation. The central role of germs in producing illness was for the first time decisively demonstrated and Western doctors abandoned the earlier misconceived ideas about the causes and nature of disease that had persisted. The greatest contribution came from the German scientist Robert Koch, and a French, Louis Pasteur.

In the mid-nineteenth century, when there were outbreaks of the most deadly diseases it was often linked to the bad hygienic condition in which poor section of society lived. Their living in filthy environment was considered as reason of illness. The elites also looked at the epidemics as a measure of moral retribution for sins. By that time it had been well established that germs were mainly responsible for the diseases. The richer section of society was not ready to accept this. When tuberculosis became an epidemic in mid-nineteenth century it was blind to these perceived social distinctions. It did not discriminate between rich and poor, good and bad, old and young, male and female, and attacked everyone. The disease was taking between a tenth and a third of all European and American lives. Rapid weight loss was followed by severe respiratory problems and the coughing up of coloured sputum. As autopsies always revealed a mass of white granules in the cavities of the lungs, tuberculosis acquired a new name ‘The White Plague’. It was Robert Koch who solved this mystery of the diseases. He was the first scientist to discover that germs were mainly responsible for the epidemics.

This was also the time when the Suez canal was constructed in 1869 that allowed faster ship movements between Europe and the Asian colonies of the British. By 1880, almost 80 per cent of the tonnage passing through the Suez Canal was of the British. It also reduced the cost of transportation of raw material from India. This in turn also affected the cost of production of the British goods in world market. Thus the rapidity and cost-effectivity of her sailing ships was a critical factor in allowing Britain to maintain her economic lead. As the canal reduced the journey time between Britain and India by almost 50 per cent, its military as well as commercial importance was simply immense. It was during the same decade that cholera outbreak was witnessed in Bengal. There was a lot of pressure on Britain to quarantine the crew and the labour coming on British ships. They were forced to undergo long periods of quarantine on the ship itself before disembarking. The quarantine was costing Britain both in terms of time and money.

In 1882, Britain was able to make Egypt a protectorate of the Empire (p.145). The impact of this was also felt in Egypt as cholera hit Egypt in 1883. This put the British government in a very tight spot. The only way for Britain to evade the charges against her by other European countries was to show that cholera was not a communicable disease. Robert Koch’s theory that Cholera was caused by bacillus germ was completely ruled out by the British government. The government panel that appointed the British medical team was careful to avoid including anyone already sympathetic to the germ theory of cholera. Britain ensured that the team selected did not have experts in microscopy. As a consequence in Egypt inadequate microscopical studies of water supplies were done, and no attempt  was done to isolate specific microbes.
Britain was also able to negotiate with France that all ships coming from India to the Red Sea would be put into port for sanitary inspection at Aden. Britain promised that the infected person found on board would be disembarked immediately. The British doctors were working under Dr Guyer Hunter, and they all concluded that the epidemic was caused by unusual weather patterns. Such a conclusion was to suggest that cholera germs had been dormant in the Egyptian soil since the last outbreak in 1865. The recent cholera outbreak in Egypt, according to them, was because of the germ getting active again, and not because of the contagion from India coming on British ships. Dr.Guyer Hunter was immediately awarded for such theorisation and made a Knight Commander of the Order of St Michael and St George (p.146).

Robert Koch was not convinced at all. He himself arrived in Calcutta and tried to investigate his postulation that there was some microbial culprit behind the disease (p.148). His anatomical studies proved that cholera is an intestinal disease. There were distinctive microbes in the intestine in the form of a comma-shaped bacillus in the mucus lining of the intestinal tract. But by the time it was being further investigated to develop a vaccine, the epidemic death curve flattened. Robert Koch then had to return back to Germany.

It took many more years to develop a vaccine for Cholera because of the British concealment of fact. Later, a Russian-born scientist Waldemar Haffkine, was able to develop a vaccine based on Koch’s early research on Cholera. Haffkine first injected himself with his attenuated bacilli that he had developed in his laboratory. He felt alright and had mild fever for few days. He was then convinced that his vaccine would work well on infected people. Haffkine came to India in 1893 with the support of the former viceroy of India Lord Dufferin. In Calcutta, he vaccinated 116 of the 200 residents of a locality where cholera had spread. His vaccine was a huge success as all 116 vaccinated people escaped the epidemic, whereas several of the unvaccinated people died (p.157). In Assam too his vaccine had a huge success.

In eighteenth century, the medical profession relied on plausible but almost wholly mistaken ideas about the causes of infectious illness. Disease was seen as result of  a disharmony  between air, food, drink, movement, sleeping, waking, excretion and person’s state of mind (p.10). The cause and the cure of ill health all rested on a fundamental belief that disease results from a disharmony between the individual’s physiological state and their mode of life. Sicknesses was diagnosed based on symptoms, and it was‘correlated with the production, expulsion and retention of rather unpleasant bodily fluids. If you vomit as a consequence of food poisoning, the body expels bile with the offending material’(p.17). If one had tuberculosis, he or she would cough up bloody sputum. If one had plague, large lymph-filled buboes would develop under the arms and in the region of the groin.

John Waller takes us down the memory lane of ancient world before telling us the story of the origin of germ theory. In ancient times it was believed that environmental factors such as weather, seasons, altitude and wind direction caused illness. Two of the most popular works of early times are Charak Samhit, written around the 2^ndcentury BC,and Hippocrates –Airs, Waters and Places, written in the 5th century BC. Waller has although mentioned only Hippocrates while talking about ancient disease diagnosis. Charak Samhita  is one of the earliest works that speculated on genetic basis of disease. Hippocrates singled out the towns located near stagnant stretches of water or marshy ground as the places most prone to disease. It was generally believed that the wind carried deadly fumes to those living in the vicinity. Such noxious gases were loosely defined. In ancient world, there was also a generalised fear of sickness because of swallowing foul substances. So people used to wash their hands before meals and vigorously scrub their faces with coarse cloths(p.26).

In the eighteenth century hygiene began to be taken more seriously in Europe as Industrialisation had led to polluting environment, and growth of large, insanitary towns and devastating epidemic diseases. Many British doctors began to argue that the air contains minute, inorganic particles, often emanating from the ground, that can induce illness. By the mid-eighteenth century, this ‘miasmatic theory’ of disease had become extremely popular. ‘Contagionism’ gained further momentum with the introduction of syphilis from the New World. That this new and deadly illness spread by sexual contact was quickly demonstrated. Yet, as sufferers became more and more stigmatised, it came to be believed that syphilis could also be caught from the breath, clothes, utensils and even the breast-milk of sufferers. Smallpox provided the most compelling evidence of person-to-person transmission. However, concept of inoculation, and with it clear evidence of the contagiousness of smallpox, didn’t make its way to Western Europe until the eighteenth century. Waller, however, forgets to mention that British doctor J.Z. Holwell was able to learn from the Indians about inoculation. He observed that people in Bengal were inoculating the non-infected people with the puss of infected person.

Until the late nineteenth century, doubt remained as to whether epidemic diseases such as cholera, typhoid, typhus and diphtheria could also pass from person to person. In 1800, a Scottish doctor William Cullen wrote that plague, syphilis and smallpox caused by ‘contagious effluvia’ that spread through inter-personal contact (p.34). He also observed that they had a marked peculiarity i.e. they always produce the identical disease in those to whom they spread. Thus, contagion had emerged as an concept in the Middle Ages in an atmosphere of widespread outbreak of plague, but ‘divine displeasure, strange celestial movements and freak weather conditions’ were still the dominant concepts. With plague becoming pandemic in Europe in early modern times it was now well realised that plague was contagious, and therefore, ‘plague victims were isolated and their houses boarded up, and practice of quarantining ships’ crews became common (p.31).

By the end of the eighteenth century, just after the French revolution, huge metropolitan hospitals were established, each with a permanent staff of qualified doctors. Patients were stripped, felt, prodded and examined as closely as the doctor felt necessary for effective diagnosis. The dissection of human bodies now became a central part of medical training and research (p.46). Fresh bodies had always been a rare treat for the medical student. Earlier, surgeons had traditionally loitered around sites of public execution in the hope of purchasing the bodies of the condemned for anatomy instruction. As doctors sliced, sectioned and minutely inspected the organs of the human body, they began distinguishing between illnesses with new precision. Pierre-Fidèle Bretonneau, for instance, discovered that fevers with very similar symptoms can be associated with quite different kinds of damage inside the patient. Following Bretonneau, many other doctors found clear correlations between certain diseases and lesions located in particular parts of the body. Within a few decades, many of the new metropolitan hospitals had become centres for rigorous experimentation in which this kind of question could be addressed. Plenty of hospital doctors now had the time, money and resources to put medical theories to the test and utilise ever-improving microscope technology in investigating disease. Governments began allocating substantial funds to scientific and medical research. While France became the pioneers in hospitals, by the late 1830s the Germans assumed the lead by establishing an exceptional collection of research laboratories.

If germs could cause meat to rot and wine to turn sour, the researchers began to think whether they might also produce deadly reactions inside the human body. Louis Pasteur and Joseph Lister were two such scientist who began to think on those lines. In 1847, Ignaz Semmelweis, a doctor in Vienna did a very interesting observation of two maternity wards which had very different death rates of mothers (p.63). In the first ward, the mortality rate was as high as 29 per cent, whereas in the second ward it was just 3 per cent. Semmelweis could observe that the births in the first ward were handled by medical students who often went straight from the autopsy room to the maternity ward. But only midwifery students worked in the second ward and their hands were free of cadaverous matter. Semmelweis realised that the doctors were routinely, if unknowingly, transferring lethal material from the dead to the living in a wretched, ongoing cycle. Semmelweis ordered his staff to wash their hands in chlorinated water before deliveries. Deaths from childbed fever were suddenly and spectacularly reduced. Similarly, in 1854, when London cholera epidemic spread, Dr John Snow showed that deaths from the disease in one neighbourhood of Soho clustered around Broad Street’s water-pump was caused by a specific germ and that it is released in the stools of the infected. According to him, it was a water borne disease, but during those years no one was ready to listen to his germ arguement.

In mid 1850s Louis Pasteur observed that tartaric acid often formed during wine making and the fermentation therein required the action of microbes (p.76). Then he proved that the yeast used in the process of fermentation comprises micro-organisms. He was also able to show that wines, beers and vinegars contain micro-organisms that vary in appearance, and he leapt to the conclusion that different germs have different effects. Emperor Napoleon III invited him to investigate the ‘wine diseases’ that bedevilled viniculture (p.80). He set up a laboratory in his home town of Arbois. Within weeks, he had shown the presence of contaminating bacteria in a batch of yeast that had produced sour wine. Isolating the bacteria and sowing them in other wine barrels caused these to turn bad as well. Pasteur had shown how vintners could use the microscope to identify which barrels were contaminated. Their contents could then be poured down the drain instead of wasting yet more time and money. Better still, Pasteur revealed that controlled heat could be used as a means of destroying harmful bacteria in the finished wine. ‘Pasteurisation’, made yet more famous in the processing of milk, was born.

In 1870s Denmark’s A. Stadfelt was effective at bringing down death rates in his Copenhagen lying-in hospital (p.92). Before taking part in a delivery, midwives were placed in a room in which they breathed fresh air through a tube while their bodies and clothes were exposed to sulphuric acid fumes for fifteen minutes. Then, before and after each delivery, hands, instruments and catheters were carefully disinfected. Mortality from childbed fever fell by more than two- thirds. As a result of such findings, by 1880s in many German hospitals, surgeons were now forbidden from attending post-mortems or infectious patients for 24 hours prior to performing surgery. In addition, outside clothing was either removed or covered with clean aprons before operations began; hands and arms were washed with carbolic acid; and a nailbrush was used to scrub the hands and arms as well as the nails. Prior to surgery, both operating theatres and patients were liberally soaked in antiseptic. Operating tables were constructed of a single slab of glass so they could easily be washed. And surgical instruments were manufactured from solid pieces of metal so that germs were unable to collect in the gaps between the handle and the blade (p.93).

Among the livestock, anthrax had for long been a mystery and was the reasons for huge number of deaths. It used to appear suddenly and destroyed entire flocks that had had no apparent contact with other anthracic sheep. That means the standard models of contagion just didn’t apply to the sheep. A German scientist Davaine had read Pasteur’s work on fermentation. In 1863, he hypothesised that the corpuscles were the sole cause of the disease. Seeking to confirm his hunch, he transferred blood from an infected sheep to healthy rats and rabbits(p.104). Three days later he found that all the animals were dead of anthrax. He also found that the higher the concentration of stick-shaped corpuscles, the faster the animals died. He was, however, still not able to explain the most curious feature of the disease’s epidemiology and the way flocks of perfectly healthy animals could be wiped out almost overnight by anthrax, despite their never having coming into contact with other infected animals.

Robert Koch had a home-made laboratory in East Germany. He was among the many who felt that Davaine’s work remained unfinished. Koch later was able to identified six specific bacteria that always caused identical deadly infections in their hosts. What made this work especially significant was that all six closely resembled human diseases. The author argues that Robert Koch’s research marks a major turning point of disease study. Before 1880, germ theory was considered as a loose conjecture, and was dismissed as fanciful by almost the entire medical establishment. Most doctors had always assumed that each disease could be caused in a variety of different ways, and people succumbed to exactly the same illnesses but for entirely different reasons. Therefore, the doctors often ignored to look for specific disease-causing agents. With Robert Koch’s new theorisation germ suddenly came to be considered as a central tenet of modern medicine. It was realised for the first time that coughs and sneezes really do spread diseases. It was after this that the stage was set for the emergence of antibiotic medicine. It was after this that doctors like Ronald Ross could figure out in late 1890s that anopheles mosquitoes are the vector that transmit malarial fever in humans, and hewas able to mobilized funds from the British government for his laboratory in Calcutta. He recommended for the consumption of Quinine as a precautionary drug to stop the spread of Malaria, and Quinine began to be distributed and consumed in prisons, cantonments, schools and government offices in India.

The germ theory established three things. First, that microbes cause illnesses within the body. Second, they spread from one person to another. And, third, for each form of infectious disease there is a specific microbial agent. In other words, the same microbe always produce the same disease in susceptible hosts. And all these are still so relevant when coronavirus has come as pandemic, and researchers are working on developing a vaccine for it.

In larger framework of disease history, The Discovery of the Germ is quite an engaging book. The author keeps the readers glued to his beautiful narration of long history of vaccines. It is written more for the general readers to understand how the germ theory profoundly changed the way we view disease today. Perhaps, speaking something on how this conceptualisation led to increased traffic between the worlds of business, vernacular markets, colonial governance and scientific knowledge would have made the book much more relevant in terms of historical debates on colonialism because over the last two decades, disease has emerged as an important part of study in environmental history with analysis of the social and material changes that contribute to outbreaks.

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