How did leprosy spread across the ancient world?

Over the past five weeks two new studies have been released that are giving scholars new clues as to how leprosy became a global scourge.

The first, and most dramatic, find came out at the end of May and reported on the analysis of a 4,000 year old skeleton from the site of Balathal, a Harappa site, in India. The analysis detected the presence of leprosy, making it, by far, the oldest case known. (For comparison the next oldest cases date to nearly 2,500 years ago)

This study means that the troops of Alexander the Great might well have spread the disease after they returned home from their campaign in India a popular idea given historical accounts that describe a disease that sounds like leprosy coming in their wake.

It also makes it possible that the 3,500 year old Ebers Papyrus, in Ancient Egypt, did in fact discuss leprosy.

The second study wasreleased just a weekago online in the Journal of Archaeological Science. Itoffers a possible reason why such virulent outbreaks occurred in the 4th century Byzantine World, and then Middle Ages Europe.

The team was led by G. Michael Taylor of the Centre for Infectious Diseases and International Health at University College, London.

In it the scientists analyze the skeleton of an adult female found in Uzbekistan dating from the 1st 4th century A.D and find that she had leprosy.

Now,while there are other cases of leprosy known inCentral Asia, what is specialaboutthis case isthat the scientists were able to identify the type she had.It turned out that genetically its the same type (type 3) as those that pop up in Europe and in afew instances, China.

This isnt likely to be a coincidence.

You see at the end of the second century B.C. China opened its export market for silk. This quickly mothballed into what we call the Silk Road linking China, Central Asia and Europe in an ancient long-distance trade route. The scientists theorize that this trade route may have aided the spread of leprosy westward to Europe.

The idea certainly seems plausible. Just look at this timeline of the history of leprosy and you can see the overlap between outbreaks in East Asia and Europe.

Type 3 strains have also been reported in China and it is possible that leprosy may have reached Uzbekistan and other regions of Central Asia through the movement of peoples and trade westwards and southwards, eventually reaching Europe, theteam says in the journal article.

This is supported by the observation of (type 3) strains in Iran and some regions of Turkey.

These discoveries leave some important questions to be answered of course.

Why hasnt there been skeletal remains found of someone with leprosy for the period between 2,000 500 B.C? Did the disease die out between them? Or have we simply not found them yet?

Also, are there more “type 3” cases waiting to be found in Central Asia that can solidly prove a Silk Road avenue of spread?