Cholera

The Deadliest Epidemic in Belgian History

By Sophie Van Wambeke & Sarah Heynssens

Imagine a disease so deadly that nearly half of those it touched would not survive.

In 19th-century Belgium, cholera swept through cities and countryside multiple times, leaving devastation in its wake.

The poor suffered the most, but the severity of the disease meant that the wealthier social classes could not escape its grasp.

Was it simply bad luck, or did deeper patterns of inequality determine who lived and who died?

Image: Cholera as the Grim Reaper, drawing from “L’espiègle: Journal Satirique, Politique, Artistique et Littéraire”, Brussel, 1866. (© Public Domain)

What Is Cholera?

What is cholera?

Cholera is a waterborne disease caused by the bacterium Vibrio cholerae, typically acquired through the consumption of contaminated water. Symptoms include severe watery diarrhoea, vomiting, muscle cramps, and rapid dehydration which can lead to death.

Where does it occur?

The bacterium Vibrio cholerae is native to coastal waters of the Indian subcontinent but it can spread to other parts of the world through infected people and in contexts with poor sanitation.

Diagnosis and treatment

Today, cholera is diagnosed with stool tests and treated with oral or intravenous rehydration and antibiotics. In the 19th century, diagnosis relied on symptoms, and effective treatment was unavailable.

Prevention and control

Efficient separation of sewage and consumption water is central to cholera prevention. A vaccine exists since the 1990s but it is not routinely recommended.

Cholera in Europe

Cholera entered Europe in the early 19th century, during the first global outbreak. The disease began spreading westward from Asia in the 1810s, carried by trade routes and the movement of armies and migrants. By 1831, cholera had reached the eastern edges of Europe, quickly moving through Russia and then into the heart of the continent.

The arrival of cholera marked a new era, as countries faced repeated and deadly outbreaks. Outbreaks were driven by increased global travel and rapid urbanization during the 19th century. As more people moved to cities, especially in industrializing regions, living conditions for the poor deteriorated, creating an environment where the disease could spread quickly.

For a long time, it was thought that bad odors, so-called “miasms”, caused the disease. Those smelly gasses rose from the numerous polluted waterways, or canals and streams in the cities, which often functioned as dumping grounds for human and animal waste.

Cholera Today

Today, cholera is estimated to cause over 2 million cases and 90,000 deaths globally each year. The disease remains a challenge in areas where infrastructure for water and sewage is inexistent, insufficient or not functioning.

The WHO estimates that over 1.5 billion people don’t have access to safe sanitation, and 1.7 billion people consume water contaminated with faeces.

In reality, cholera outbreaks were mainly caused by contaminated drinking water. Before the late 1800s, most people used shared wells and rivers for water.

In the 1850s, the English physician John Snow identified unsafe water as a source of contamination. However, the disease was not fully understood until 1884 when Robert Koch discovered that it is caused by the bacteria Vibrio cholerae. From then on, the transmission could be clarified.

Cholera is a waterborne bacterial infectious disease and is accompanied by symptoms such as vomiting and diarrhoea, which can result in death from dehydration. Victims often develop a bluish skin colour, making the disease known as the “blue death” (figure 1).

Figure 1: Cholera or the "Blue Death"

Cholera in Belgium

In Belgium, cholera caused seven big outbreaks, which exposed severe urban poverty and claimed many lives. In between these major outbreaks, the disease remained present yet claimed few victims yearly.

In 1832 and 1833, the disease caused the first epidemic in Belgium killing 7,984 people.

In 1848 and 1849, the country was hit by a second, particularly severe epidemic that struck a population already weakened by food crises. It killed 23,027 people.

The deadliest outbreak occurred in 1866, resulting in a devastating loss of over 43,000 lives.

Four additional epidemics in the 19th and early 20th centuries were less severe and caused significantly fewer deaths compared to the two major outbreaks.

Figure 2: Cholera epidemics in Belgium

Source:  Documents statistiques 1857-1869; Annuaire statistique, 1870-1885; State Archives Belgium, Mouvement de la population, 1886-1930.

The Outbreak of 1866

The outbreak of 1866 accounted for nearly 1 in 3 of all recorded deaths that year. 

Cholera entered the country in March from different directions and claimed many victims until early December, with the highest numbers in the summer. 

Figure 3 shows that the disease predominantly affected people living in the cities. The metropolitan area around Brussels forms a dark stain on the map. Indeed, 40% of the disease cases were in the big cities, places with 20,000 inhabitants or more, such as Brussels, Mons, Ghent, Antwerp, Verviers, Liège and Namur. 

Nearly 70% of deaths occurred in smaller cities, places with at least 5,000 inhabitants. La-Roche-en-Ardennes and Geraardsbergen had particularly high numbers of casualties, with respectively 86% and 73% of all deaths in the year 1866 being caused by cholera.

While most villages in the countryside were spared, some were also affected heavily, particularly the villages on the Luxemburg border such as Aubange, Messancy and Bleid.

The 1866 outbreak is by far the deadliest epidemic in Belgian history. But was it as deadly for everybody? Or were some more vulnerable to the disease?

Explore the number of deaths per municipality in our interactive map.

Figure 3: Cholera deaths by municipality in Belgium during the 1866 epidemic

The 1866 Epidemic in Brussels

Figure 4: Cholera deaths in Brussels

Source: Ghent University, Quetelet Center

As figure 3 above shows, the city of Brussels was hit hard. In Brussels, 3,469 people died of cholera, which corresponds to 45% of all deaths in the year 1866. 21 per 1,000 inhabitants died of cholera.

What do we learn when we zoom in on the epidemic in Brussels? Where did it start? And who did it kill? The video on the right (figure 4) represents the total number of deaths in the city from cholera in 1866.

The first fatality was 66-year-old widow Catherine Ravaiau on 26 May 1866. She was a textile worker who lived with her sister in a very modest house at the Vieux Marché 32. The building was located near the river Senne and housed several families.

In the following days, several sick people were reported in nearby houses, which led the mayor to have all the residents of the alley evacuated.

From this working-class neighbourhood, the disease quickly spread to the South and Southwest of Brussels. In mid-June, working-class areas in the North and around the Chaussée d’Etterbeek in the very Eastern part of the city followed.  The death toll in the city rose rapidly.

The hospitals in Brussels faced a shortage of staff and the police had to step in to transport sick people and corpses.

From mid-June there were about 15 cholera deaths a day, a month later this number had already tripled. In July, the disease became more prevalent in neighbourhoods with a higher average cadastral income. The epidemic claimed victims in all sections of the population, but in the more affluent neighbourhoods, it took several weeks before the disease hit hard.

The epidemic reached its peak on 25 and 26 August, with 62 deaths each day. The mortality then decreased gradually from early September.

By mid-November, almost half a year after the first death, the epidemic had burned itself out in Brussels. The final victim was Nathalie Pollenus, the 59-year-old wife of François Lasne, a lawyer and real estate expert; she died on 16 November in their home, a townhouse at the Rue Royal 150. The epidemic had been raging in the city for nearly six months at that point.

Figure 5: Victims day-by-day, from late May until mid-November

Source: based on data from the City Archives Brussels, Police Archives, red series 83-86, processed by the author.

Who Were the Victims?

Figure 6: Number of cholera deaths by age, Brussels 1866.

Source: based on the data from the City Archives Brussels, Police Archives, red series 83-86, processed by the author.

The cholera outbreak in Brussels of 1866 caused many deaths among children below age 10 and among adults aged 20 to 49. However, this can partly be explained by the fact that these were the biggest age groups in the population at that time. When we adjust for the number of people in each age group, a clearer pattern appears (figure 6). 

The people with the highest risk of dying were young children and older adults (60 and above). Teenagers had the lowest risk. Men were a bit more at risk than women, except among those aged 60 to 79.

Which social backgrounds were most vulnerable? 

When we look at the number of deaths per neighbourhood, we see that those neighbourhoods with an average lower cadastral income, so the poorer neighbourhoods, were hit particularly bad during the epidemic.

Figure 7 shows a clear relationship between the social categories (poor to low income to high income to rich neighbourhoods) and the number of deaths per category in those areas over time. Higher numbers of cholera deaths occurred in poorer neighbourhoods. The richest neighbourhoods counted the least victims.

During the month of June and July, most victims fell in neighbourhoods with low and very low average incomes. The epidemic reached a peak in the beginning of August. In the neighbourhoods with high and very high incomes, the peek occurred later, in September, and was much lower.

Figure 7: Number of cholera deaths per social group over time, Brussels 1866

Number of Cholera deaths in Brussel per neighbourhood per average cadastral income class; Source: based on data from the Quetelet Center, POPPKAD-Database, processed by the author.

How Did the Disease Spread?

Figure 8: Location of buildings with more than one death, Brussels 1866

Today we know cholera spreads through infected water. In 1866, Brussels possessed Belgium’s first public water supply network, which had been built in 1856. Although the city was a pioneer in this regard, access to clean water remained unevenly distributed in 1866. Certain neighbourhoods still struggled with shortages and pollution. Workers homes and alleys were connected much more slowly and remained dependent on public fountains and wells. Those were often polluted by infiltrations from nearby cesspits or the heavily polluted river Senne.

On figure 8 we see houses were multiple people died of cholera with several days in between. The longer the period of time in between contaminations, the bigger the circle. The timing apart between the different infections within these houses is longer than the incubation period of cholera. So rather than spreading directly from person to person within the home, this map shows that the disease was introduced into these households multiple times.

In blue, we see the zones of the city that were in proximity (less then 50 metres away) from buildings without piped water. In these zone’s people were more likely to use contaminated water from wells and fountains.

This diffusion pattern points to the challenges poorer households with limited access to clean drinking water faced in avoiding repeated exposure to the disease. Even if a family managed to avoid infection during one outbreak, they could still become infected during a subsequent wave as the disease returned. Crowded living conditions amplified the risk, with households being repeatedly exposed and different family members falling ill over time, making it difficult to avoid contagion.

However, these observations call for an important nuance. The data also shows that the entire city was affected by cholera: deaths were recorded everywhere in the city, and in all socio-economic groups, and all neighbourhoods

The Cost of Inequality?

Figure 9: Cholera as the grim reaper

Source: Cholera as the Grim Reaper, drawing from “L’espiègle: Journal Satirique, Politique, Artistique et Littéraire”, Brussel, 1866.

The cholera epidemics that ravaged Belgium in the 19th century did not strike indiscriminately. Although no social class was entirely spared, it was the urban poor who bore the brunt of the suffering and mortality. Cramped housing, unsanitary conditions, and limited access to clean water made working-class neighbourhoods especially vulnerable to the disease. In cities like Charleroi and Brussels, cholera deaths were concentrated in overcrowded quarters, near open sewers and contaminated canals. In this way, cholera revealed and reinforced deep social inequalities, forcing public attention to the realities of urban poverty.

Data Sources

Annuaire statistique de la Belgique, 1870-1885
Documents statistiques de la Belgique,1857-1869
State Archives Belgium, Mouvement de la population et de l’Etat civil, 1886-1930
City Archives Brussels, Police Archives, red series 83-86
Ghent University, Quetelet Center, HISSTER-, LOKSTAT- , POPPKAD- and S.O.S. Antwerp-Databases.