But in 2008, scientists discovered that a similar species, M. lepromatosis, can cause it, too.
Leprosy from M. lepromatosis appears to be rarer than the former, with cases predominantly found in North and South America.
And though M. leprae still causes the majority of leprosy cases worldwide, its less famous cousin certainly has the potential to become a bigger threat.
“Given its diversity and spread, M. lepromatosis could be an emerging pathogen with dynamics different from M. leprae,” Rascovan said.
They now believe that a strain of M. lepromatosis was brought over to the British Isles sometime in the 19th century, where it still infects red squirrels today.
The history of one of the oldest diseases in the world is even more complicated than one might think. A type of leprosy was raging throughout the Americas long before European settlers arrived, according to recent research.
The study was carried out by a sizable international team of scientists and was published in Science on Thursday. DNA evidence was discovered by the researchers that Mycobacterium lepromatosis, a recently identified species of leprosy-causing bacteria, was present in North and South America more than 1,000 years ago, before European colonization. The results disprove the widely held notion that leprosy was brought to the New World by Europeans.
The Bible makes repeated references to leprosy because of its notorious reputation for destroying people (though some of these references may have been about other conditions). Even though symptoms like lesions and sores might not show up for years, these bacteria can cause a chronic infection of our skin and nerve cells. The infection can gradually and irreversibly harm these cells if antibiotics are not taken, which could result in major side effects and lifetime impairments.
Mycobacterium leprae bacteria are the main cause of leprosy, also known as Hansen’s disease. However, in 2008, researchers found that it can also be caused by a related species called M. lepromatosis. M. lepromatosis leprosy seems to be less common than the former, with most cases occurring in North and South America. Due in part to the difficulty of cultivating both species in the lab (like viruses, leprosy-causing bacteria can only multiply by taking over our cells from the inside), we also know very little about it.
After discovering something of their own, study author Nicolas Rascovan, who focuses on the evolution of human diseases, and his team decided to investigate the bacteria further.
“When we unexpectedly found M. lepromatosis DNA in the remains of an ancient individual in North America, we became interested,” Rascovan, a researcher at the Pasteur Institute in Paris, France, told Gizmodo. This led us to inquire about the pathogen’s duration of circulation on the continent, its extent of spread prior to European contact, and its potential diversity today. “.”.
Both ancient DNA samples recovered from people in the Americas prior to European contact and hundreds of samples taken from contemporary individuals (mostly recent leprosy patients) were examined by the team. The researchers discovered that three of these ancient samples, which came from people who lived in what is now Argentina and Canada, tested positive for the bacteria.
M. leprae is an example of leprosy, which has long been thought to have been introduced to the Americas by Europeans. Our research, however, indicates that at least one of the two species responsible—M. Rascovan clarified that lepromatosis—had existed for centuries before and had most likely developed locally for thousands of years. In essence, this modifies our understanding of the history of the disease in the Americas. “.”.
In many parts of the world, leprosy is uncommon due to antibiotics and better sanitation; in the United States, there are only 200 recorded cases. A. annual). More than 200,000 cases are reported worldwide each year, but in some nations, it continues to be a public health concern. Furthermore, the results of the study could make leprosy’s past and future more complicated.
Although the majority of contemporary cases of M. lepromatosis were associated with a single, recently expanded clade of the bacteria, the team also discovered older clades that have probably been evolving separately in the Americas for more than 9,000 years. Accordingly, these bacteria may have been hiding in as yet unidentified animal hosts (in the U.S. S. Occasionally, exposure to armadillos has been connected to the classic form of leprosy. Furthermore, although M. leprae continues to be the primary cause of leprosy cases globally, its less well-known cousin undoubtedly has the capacity to grow into a more serious threat.
“Mdot lepromatosis may be a new pathogen with distinct dynamics from M. leprae, considering its diversity and dissemination,” Rascovan stated.
As is frequently the case in science, the team’s work has left them with even more questions to address. They want to track the bacteria’s path from the Americas to other regions of the world, for example, and find the animal reservoirs where it may have been circulating for so long. They now think that some time in the 19th century, a strain of M. lepromatosis was introduced to the British Isles, where red squirrels are still infected. However, we still don’t know how it got to Asia, where there have been reported cases.
According to Rascovan, “all of this suggests that this is not just a neglected disease, but a neglected pathogen—one whose history and spread are only now beginning to be understood.”.
