Leprosy, does it still exist?

Today leprosy is most prominent in three countries: India, Brazil, and Indonesia account for around 80% of all new cases globally. Overall leprosy is mostly found in Asia, Africa and South America. One can get the impression that leprosy is a tropical disease based of the geography of these countries, but in fact leprosy has not always been considered a tropical disease.

Leprosy existed in Europe in the Middle Ages. Archaeologists and historians have investigated leprosy in medieval times through bioarcheology on human remains in cemeteries, the structures of leprosy hospitals and churches, and medieval texts. The first evidence of leprosy in Europe dates back to the fourth century.

Leprosy hospitals were established throughout Europe from the second half of the eleventh century, around 320 establishments in England alone. The hospitals were mostly run as Christian institutions; Christianity and leprosy are strongly intertwined. Several chapters from the book Leprosy and Identity in the Middle Ages (2021) argue that leprosy was not as stigmatized as later writers made it appear, and there was a rather fine line between integration and segregation.[1] People were moved into leprosaria, but most likely not in a violent or forceful way. The leprous communities were a part of the wider society, and not completely segregated. Archaeological evidence shows that many people with leprosy were buried following standard practices rather than being treated differently from others. Many leprosaria shared chapels with the local communities, and therefore shared their places of worship. At some hospitals the inmates received money to pray on others’ behalf. The leprosaria depended on donations from these donors and travellers in need of somewhere to pray.

Fewer and fewer leprosy cases appeared during the sixteenth and seventeenth century, leading to hospitals being shut down. The decreasing case numbers could be due to persons affected by leprosy dying from other diseases such as tuberculosis and the bubonic plague resulting in fewer people with leprosy to spread the disease.

Even though leprosy cases had declined on mainland Europe by the end of the Middle Ages, there was still leprosy in Europe. Norway is famous for its leprosy history, as Gerhard Armauer Hansen discovered the bacteria causing leprosy in 1873 in Bergen, Norway.[2] During the 1800s, there was a noticeable increase of leprosy cases in Norway, especially in coastal communities. But there was a decline of cases in the 1900s, which might be explained by multiple different factors, including the various health campaigns Norway launched or the overall improvement of living conditions. [3]

So why is leprosy no longer prevalent in Europe, but rather in Asia, Africa and South America? Many countries in these regions have much higher poverty rates than in modern Europe. According to the World Bank’s poverty statics, high income countries (like most European countries), only have 0.3 % of their population in extreme poverty, whereas over 10% of the population in low- and middle-income countries live in extreme poverty.[4] Poverty creates an environment in which leprosy can spread more easily. This is partly due to social determinants, nutrition status and physical conditions they are forced to live in, and the fact that it is more difficult to access proper health care. This also means that statistics about people with leprosy can be incorrect, because a lack of access to healthcare prevents people from being diagnosed.

Leprosy also exacerbates the cycle of poverty. People who have lower education and worse living conditions are more susceptible to leprosy. Subsequently, having leprosy can lead to disabilities and losing one’s job. This creates a cycle that must be solved through aiding those in poverty.

Leprosy is not inherently a tropical disease. Leprosy prevalence is dependent on socio-economic conditions in a country, and therefore disproportionally affects underprivileged populations.

Voluntarily written for nlrinternational.org by Marion Jørgensen. Opinions stated in the article are on personal title of the author and do not necessarily express NLR’s views. 

Sources

[1] Brenner, E. & Touati, F. O. (Eds). (2021). Leprosy and identity in the Middle Ages. Manchester University Press. https://manchesteruniversitypress.co.uk/9781526127419/

[2] See Marion Jørgensen, 150th anniversary of the discovery of the Leprosy Bacillus, https://nlrinternational.org/blogs/blog-150th-anniversary-of-the-discovery-of-the-leprosy-bacteria/

[3] Abraham Meima, Lorentz M Irgens, Gerrit J van Oortmarssen, Jan H Richardus, J Dik F Habbema. (2002). Disappearance of leprosy from Norway: an exploration of critical factors using an epidemiological modelling approach. International Journal of Epidemiology, 31(5), 991-1000. https://doi.org/10.1093/ije/31.5.991

[4] https://data.worldbank.org/indicator/SI.POV.DDAY?locations=XO-XD