Earlier this year a man in Central Florida was diagnosed with Hansen’s Disease. He is one of an increasing number of cases cropping up in the Southeastern United States in recent years.
Leprosy, also known as Hansen’s disease, is a bacterial infection caused by Mycobacterium leprae and the more recently discovered M. lepromatosis. It is a curable yet neglected tropical disease, entirely treatable with the right care, but nonetheless a disease that still occurs in more than 120 countries.
About 150 cases of leprosy are reported in the US each year. Unique strains of M. leprae have been detected in US patients, though most cases are people who have traveled from countries where leprosy is present or endemic.
Most people probably know of leprosy from the Bible stories they heard in Sunday school. In Luke Chapter 17, 10 lepers approach Jesus and ask him to heal them. Jesus heals the 10 and instructs them to present themselves to the priest. Only the priest had the legal authority to declare them disease free so they could re-enter society. The word “leper” has become synonymous with isolation as throughout history victims were often confined to leper colonies so as not to spread their disease to others.
Leprosy dates back at least 4,000 years. Nowadays it’s thought of as a tropical disease, but it wasn’t always that way. Between the 11th and 15th centuries leprosy was endemic in Europe, with about 1 in 30 Europeans infected. The disease was especially endemic in Southern Scandinavia. Yes, Denmark. The graves of people with leprosy have been explored in the United Kingdom, some date back to the 5th century AD. Some scholars wonder if leprosy didn’t originate in Europe.
Leprosy was more common among the poor, but kings were not immune. Baldwin IV, the Crusader King of Jerusalem died of leprosy at age 24 in 1185. He was a capable ruler. His premature death may have changed the course of history in the Middle East. He was portrayed in the movie Kingdom of Heaven. Robert I, King of the Scots died of leprosy at age 54 in 1329. Perhaps you remember him from the movie Braveheart. Robert the Bruce was the Scottish king who is most responsible for Scotland as an independent kingdom. It was later united with England rather than subjugated by it. Henry VII, King of Sicily and later King of Germany (1211 to 1242) and Alfonso II, King of Portugal (1185-1223) both had leprosy. Henry IV, King of England may have had leprosy (1367 – 1413). He had a disfiguring skin disease, but it also could have been psoriasis, syphilis, or something else.
Hansen’s Disease (i.e. leprosy) is not that difficult to cure nowadays. However, if is often not diagnosed early and the damage done to nerves and other tissue is permanent. Leprosy is not very contagious. A healthy immune system is usually enough.
More than 95% of people infected with Mycobacterium leprae don’t ever develop leprosy, because their immune system fights off the infection.
Leprosy began to quickly decline beginning in the 15th century and was mostly gone from Europe by the 1600s. By sequencing DNA of Mycobacterium leprae scientists found something amazing. The strains of bacteria found in the graves of people dating back 600 years or more were virtually the same strains found today. The pathogen has not changed. What changed was the hosts. That is, people changed. Increasingly people gained immunity to leprosy. Scientists theorize that when lepers were isolated into communities, they were less likely to reproduce. Over time they were partly selected out of the gene pool. Possible other reasons for leprosy dying out are better hygiene, better sanitation and better nutrition. Leprosy and tuberculosis (TB) are closely related diseases. People exposed to tuberculosis may have been better able to fight of leprosy.
Leprosy cases are on the rise in the US but doctors are not sur why. The bacteria are found in armadillos, and red squirrels to some degree. In the past most people with leprosy had traveled or were born abroad but many of the recent cases were contracted locally. There could be some type of natural reservoir of the pathogen that people are coming in contact with. Experts believe it comes from prolonged contact with an infected person.