Leprosy is a terror of the past. Right?

First published in newsGP 17 September 2018

What is leprosy?

The historic leper hospital, or lazaret, on Peel Island, just off the coast of Brisbane. (Image: State Library of Queensland)

Western Australia has had 20 new cases of leprosy in the past five years. The disease disproportionately affects Aboriginal and Torres Strait Islander communities.

So what is leprosy? And why isn’t it a thing of the past?

Leprosy is a rare mycobacterial infection that affects the skin, nerves and respiratory tract. The disease leads to chronic numbness, which in turn leads to deformity and disability. It is transmitted by droplet spread but, despite folklore and common misconception, is not very contagious.

Leprosy has a long incubation period, usually between three and five years, and sometimes up to 20 years. This meant that until science eventually provided an explanation, a person with leprosy – a leper – seemed to always appear out of nowhere, adding to the mythical nature of the illness.

The earliest recorded account of a disease resembling leprosy appears in an Egyptian papyrus document from 1550 BC. Indian writings also mention a similar illness in 600 BC. Genomic studies support the hypothesis that leprosy first originated in Africa, spreading out with successive human migrations. This is further supported by analysis of 2000-year-old human remains.

The disease remained relatively rare in Australia until the late 1800s. It mainly afflicted Chinese immigrants, from where it spread to the Aboriginal and Torres Strait Islander community and then became more common in the white community, as commercial ships brought more visitors to Australian shores.

Shunning and separation has been the most common way to deal with lepers throughout history. Australia’s approach was no different.

Several leper colonies, or lazarets, existed throughout Australia. Notable examples included Peel Island, off the coast of Brisbane, Fantome island, near Townsville (exclusively for Aboriginal patients), and Mud Island and Channel Island, in the Northern Territory.

Then, as now, Aboriginal and Torres Strait Islander and immigrant communities, primarily Chinese, were disproportionately affected. Unfortunately for these groups, access to treatment and facilities was much worse compared to white patients. Western Australia even instituted what was known as a ‘leper line’, with Aboriginal and Torres Strait Islander patients sent above the 25th parallel and white patients housed in much better facilities in Perth.

Various treatments have been used for leprosy over the centuries with no success. The list includes arsenic, mercury, elephant’s teeth, snake venom, bee stings, scarification, castration, blood as a beverage or a bath, chaulmoogra oil injected (painfully), and prayer. None were particularly efficacious.

By the 1900s in Australia, segregation and mistreatment was order of the day. Patients were taken forcibly from their families to the lazarets, often in chains, and left there in poor conditions.

In 1873, Norwegian Dr Gerhard Hansen discovered that leprosy was caused by a bacteria called mycobacterium leprae. As it so happens, this is also the first bacteria to be identified as causing disease in humans and was three years prior to Robert Koch’s definitive study.

The discovery was shrouded in several conflicts, the first over who made the discovery. Dr Hansen first saw rod-like structures in tissue but did not identify them as bacteria (this work was ultimately conducted by another scientist, Dr Albert Ludwig Sigesmund Neisser) and by experimentation conducted on humans without consent.

Once leprosy was known to have an infectious cause, an effective treatment was possible. However, it took until 1908 and the arrival of sulphonimides for something that was finally, sort of, active. But this did not really become widespread in Australia until the 1940s and most of the lazarets and policies of separation stayed active until that point.

Today, a multi-drug treatment is required, often for up to a year, which in many communities can be quite tricky. And, like many things, treatment is threatened by increasing antibiotic resistance. The stigma of leprosy, however, continues.

Leprosy, it seems, isn’t quite done with us yet.

Author: Dr Gillian Riley