The origins of leprosy are more strange than we thought

One of the oldest diseases in the world has a more complex history than expected. Research reveals today that a form of leprosy was chasing people in the Americas a long time before the Europeans arrived.

A large international team of scientists conducted the study, Published Thursday in science. The researchers found the DNA guide from Pakistor-A kind of bacteria has been discovered recently-in North and South America more than 1,000 years ago, from the foregoing European colonialism. The results of the prevailing belief that the Europeans were responsible for the front of leprosy for the new world.

Leprosy The reputation of human destruction is so bad that it was indicated again and again in the Bible (some of these references may be about Other conditionsNevertheless). These bacteria can cause a chronic infection of our skin cells and neurons, although it may take years for symptoms such as pests and sores. If it is not treated with antibiotics, the infection can harm these cells gradually and permanently, which leads to lifelong disabilities and other serious complications.

The leprosy, which is also called Hansen’s disease, is the result of it in the first place Mycobacterium Leprae Bacteria. But in 2008, scholars find out That a similar type, M. lepromatosisIt can cause this, too. Leprosy M. lepromatosis It seems rare from before, as there are mostly cases in North and South America. We know very little about it, partly because both types are not easy to culture in the laboratory (very similar to viruses, leprosy bacteria can only be repeated by kidnapping our cells from the inside).

The author of the study, Nicholas Raskovan, who specializes in the development of human diseases, and his team decided to take a closer look at bacteria after their discovery.

“Our interest started when we discovered unexpectedly M. lepromatosis “We have pushed Rasvan, a researcher at the Paris Institute in Paris, France, to what was there before European contact, what it might have today.”

The team analyzed hundreds of samples collected from contemporary people (most of them are new leprosy patients), as well as old DNA samples that were recovered from people in the Americas before European communication. The researchers have found three of these ancient samples positive for bacteria, from people who live in Canada and Argentina now.

“The leprosy has long been a disease that the Europeans brought to the Americas, which applies to a condition M. But our study shows that at least one of the two types causes it –M. lepromatosis“It was already centuries ago, and may have evolved locally for thousands of years. This mainly changes how we understand the history of the disease in the Americas,” Raskovan said.

Thanks to antibiotics and sanitation improvement, leprosy in most of the world (only 200 cases documented In the United States every year). But it still represents a public health issue in some countries, with more than 200,000 cases I mentioned Annually worldwide. The results of the researchers may complicate the past and the future of leprosy.

While most modern cases M. lepromatosis It has been linked to one specific company, or Klum, from the recently expanded bacteria, the team also identified the old birth that is likely to develop independently in the Americas for more than 9000 years. This indicates that these bacteria were hiding in mysterious animal hosts (in the United States, the classic shape of leprosy Sometimes it was associated with exposure to Armadilo). And in spite of M Leprosy He still causes most of the leprosy cases around the world, as his lesser cousin definitely has the ability to become a greater threat.

“Given its diversity and spread, M. lepromatosis The emerging nurse with dynamics can be different from MRaskovan said.

As often in science, the team’s work raised more questions for them to answer. They hope to discover animal tanks that bacteria are likely to revolve throughout this time, for example, and follow their journey from the Americas to other parts of the world. They now believe that a strain M. lepromatosis It was brought to the British islands at some point in the nineteenth century, where it still affects the red squirrels today. But we are still in the dark about how it reached Asia, where cases were documented.

“All of this indicates that this is not just a neglected disease, but rather the causes of neglected diseases – those whose history began and spread now only in its understanding.”