The 19th Century’s Main Killer: Tuberculosis
Authors: Valentin Charlier, Sophie Van Wambeke
La miseria, 1886, painting by Cristóbal Rojas (© Public Domain)
What did Queen Louise d’Orléans, George Orwell, Frédéric Chopin, Franz Kafka, and Thérèse of Lisieux have in common?
They all died from tuberculosis, as did so many people from all walks of life and regions of the world, so many that tuberculosis is likely the biggest killer in human history.
In Belgium, tuberculosis was an important killer for a long time, but especially in the 19th century, when living conditions degraded substantially for urban dwellers. But where all Belgians equally affected by tuberculosis? Let’s take a look.
What is tuberculosis?
WHAT?
Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis that affects primarily lungs, but can also affect other organs, and is associated with coughing, fever, weight loss and fatigue among other symptoms.
WHERE?
Tell-tale signs of tuberculosis have been found in bones dating from ancient times, so that it is a very old companion of humankind. Today, tuberculosis is still associated to crowded living conditions and poverty but is also a frequent co-infection for AIDS patients. Today, TB remains a leading cause of death globally with 1.25 million deaths (2023; WHO ).
DIAGNOSIS AND TREATMENT
Several innovations have been key to diagnosis, such as the stethoscope and the chest X-ray, which remain widely used in large detection and treatment programs where tuberculosis is prevalent. While rest and good food where widely used, since 1943, antibiotics have been able to cure tuberculosis, although the rise of resistance to antibiotics is a great concern.
PREVENTION AND CONTROL
Tuberculosis was always associated with crowded, unsanitary conditions as well as nutritional deficiencies – thus solving these issues has been key in limiting the prevalence of TB. Preventing new infections remains a high priority globally especially with the rise of multidrug-resistant strains. Access to treatment remains problematic for a large fraction of patients.
Tuberculosis in Europe and in Belgium
In many European countries, the industrial revolution was associated to rapid growth of urban populations. Belgium, as a country industrialising early on, is no exception. Influx of people in cities or industrial areas was often associated to crowded living conditions in unsanitary housing. This laid a perfect bed for infectious diseases, especially for poor working classes. Inadequate public health measures were unable to contain epidemic and endemic diseases. Throughout the 19th century, infectious diseases caused about 40% of deaths.
Respiratory diseases were very important among infectious diseases, including tuberculosis. Tuberculosis mostly affected adults, and among them, affected males more badly than females. Tuberculosis mortality was already declining during the 19th century, in the context of the mortality transition but this accelerated during the 20th century as living conditions for workers and poor city dwellers improved, and that more proactive public health measures were put in place, including through opening of institutions dedicated to patient isolation and treatment, the sanatoria. Prevention was also important in emphasizing hygiene, cleaner living conditions, and improved nutrition. Several events temporarily slowed the decrease, including mechanisation in the mines with the advent of the jackhammer (which creates much finer and more abundant dust), as well as both World Wars.
As tuberculosis was gradually better prevented and treated, mortality gradually shifted from the general population to specific populations in the mining and industrial basins where it eventually decreased. Today, tuberculosis can still be found in Belgium although it is generally associated to people originating from countries where tuberculosis is still prevalent.
Spatial Evolution
From 1889 to 1950, TB-related mortality was higher in Flanders than in Wallonia. This disparity can be linked to two main factors:
First, there were significant socio-economic differences between the regions at the beginning of the 20th century. Flanders remained impoverished until the 1960s, undergoing delayed industrialization following the collapse of the rural linen industry in the 19th century. The arrival of cheap grain from the New World—the so-called “agricultural invasion”—led to widespread unemployment, with the exception of Antwerp, which benefited from port expansion and rail connections to Wallonia’s industrial basins. In contrast, Wallonia experienced considerable prosperity due to the rise of coal and steel industries, positioning it as a major European industrial center until the early 20th century [Buyst, 2009]. However, this industrial boom came at a cost to workers’ health and was followed by socio-economic decline after the collapse of heavy industry [Buyst, 2009].
Second, differences in health-related behaviours and infrastructure may also explain the regional gap. Wallonia had a more developed health infrastructure [Eggerickx & Tabutin, 1994], while in Flanders, lower rates of breastfeeding and the use of poor-quality water for infant feeding may have weakened immunity and increased susceptibility to measles [Van Rossem et al., 2018].
Still, the Walloon industrial basin is visible on the map, and it did concentrate more deaths from tuberculosis in the final years of our analysis – the tail end of tuberculosis as a major cause of death in Belgium.
In Belgium, as in other European countries at the time, before the causes, prevention and treatment were fully understood, tuberculosis affected the population broadly. But our maps make it clearshow that some areas were particularly badly affected, which can be related to agricultural crisis as well as the urban transition related to the industrial revolution.
Tuberculosis and scientific innovation: Koch’s postulates
For a long time, ill-health was not well understood, in particular infectious diseases, which were sometimes assumed to result from “miasma” (or foul air of some kind), or a form of godly punishment – the implication of which sometimes being that poor morals were at play. During the 19th century, many scientists began to think differently and investigated possible causes in the form of micro-organisms. However, microscopes were still poor, and actually, observing the presence of a micro-organisms does not necessarily designate it as a culprit. For example, Haemophilus influenzae, a bacterium that is found to live in the throat of many people, was believed to cause influenza for a while before viruses (which are much smaller than bacteria) could be identified and eventually observed. Haemophilus influenzae can sometimes cause disease, and a vaccine against it is recommended for babies.
Scientists like Louis Pasteur and Robert Koch started thinking about the conditions under which one could designate a microorganism as the culprit for a disease, and experimenting with inoculation.
Thus Koch, who discovered Mycobacterium tuberculosis as the cause of tuberculosis, proposed his postulates:
- Find it: The germ should always be found in people (or animals) who have the disease — but not in healthy ones.
- Isolate it: Take the germ out of the sick person’s body and grow it in a lab (so you have only that germ, nothing else).
- Test it: Give the germ to a healthy person or animal — they should get the same disease.
- Prove it: Take the germ out of this newly sick person or animal — it should be the exact same germ you started with.
Today, our understanding of infectious diseases shows that Koch’s postulates do not quite apply to all (many infections actually do not lead to disease, some bacteria cannot be grown in the lab, …) but they can still inspire us to apply rigour in research.
Conclusion
Tuberculosis was once the leading cause of death in Europe and a defining feature of 19th-century urban life. Its decline , driven by better living conditions, public health reform, and scientific discovery , marks one of humanity’s great public health successes.
Yet the story is far from over. Tuberculosis continues to thrive where poverty, overcrowding, and limited healthcare persist. Understanding its history reminds us how deeply health is shaped by social and economic conditions, and how progress against disease depends not only on medicine, but also on equity.
Sources and Literature
Eggerickx & Tabutin, 1994;
Van Rossem et al., 2018]
WHO 2023
Buyst 2009
