OMG, oldest TB evar!

This is one of those weeks where there is SO much to blog about and so little time to do it in! How shall I ever get to it all! This article actually came out on Tuesday, which means of course that others have now been there before me, but I like this paper a LOT and so I’m going to cover it anyway.

Hershkovitz et al. “Detection and molecular characterization of 9000-year-old mycobacterium tubuerculosis from a neolithic settlement in the eastern mediterranean”. PLoS ONE, 3(10), 2008.

If you’re a history geek like myself (and I assume some of you reading this blog must me, and if you are, I salute you!), there’s a few diseases that really pop into your mind when you think of big diseases in history. The Black Death, smallpox, the Influenza epidemic of 1918, polio, etc. And you can’t forget tuberculosis. Formerly referred to as “consumption”, tuberculosis (or TB) has been found in humans since antiquity. There are Egyptian mummies with evidence of TB. A form of TB which infected the lymphatic system used to be known as scrofula, “the king’s evil”, and in the middle ages, kings and queens would hold touchings where they would touch scrofula victims in order to heal them. There are tons of references to TB in literature and film. In the film Moulin Rouge, Nicole Kidman dies of consumption, and I always remember those books I used to read as a child that had ghosts in them of children who had died of TB in the Victorian era. And of course where would literature be if it weren’t for the delicate consumptive Romantic poets. Even now TB is pretty common, everyone in my department has to get TB tests twice a year at least in order to conduct animal research.
TB is a bacterial disease caused by the Mycobacterium tuberculosis. Nowadays it can be treated with antibiotics, but there is also a vaccine. The main symptoms are a cough that brings up blood, fever, night sweats, and weight loss. There are various forms of TB, the most common of which affect the lungs (pulmonary TB). Sometimes TB can progress outside the lungs, where it is less contagious (it’s airborne), but very dangerous, of course, to the person who has it. Generally, only 10% of those exposed to TB will become infect, but if untreated, the death rate from TB is 50%.
Egyptian mummies had TB, and the Greeks named the disease, but until recently, it was not know HOW old the disease was. Scientists thought it had originated from the very similar cattle TB, but it appears that bovine TB is more recent and not, in fact, all that similar. But it didn’t have to come from cattle, there’s evidence of TB in animals that is up to 20,000 years old. However, TB is not all that deadly when it’s transmitted from cows to humans, and so the researchers here hypothesized that TB might have taken off in humans when they moved from a hunter-gathered lifestyle to a settled agrarian life, and it is only coincidental that they also started domesticating cattle around this time.
So the scientists looked at skeletons found at a prehistoric village off the coast of Israel, near Haifa. The site is called Alit-Yam, and it is one of the oldest sites in the world where agriculture and animal domestication have been known to take place. I can only imagine how hard data collection must have been, the site is now underwater, though luckily only about 8m under sea level. It was presumably submerged when the ice melted after the last Ice Age, which was apparently pretty soon after it was abandoned for the last time.

From the site, they took the skeletons of a mother and her 1-year-old child who had been buried together and analyzed the bones. They found that the bones of both the mother and infant showed lesions characteristic of TB. The authors used a lot of words like “hypertrophic osteoarthropathy” and “epiphyseal ring ankylosis”, but dude, the bones are full of holes and little engravings which indicate chronic lung problems. No need for long words.

Not only did they look at the bones, they were able to yank the DNA! They found evidence of TB bacterium DNA in the bones themselves, so it’s probable that the woman and her son died of TB. This is the earliest report of the disease in humans, and provides a little more evidence that we probably didn’t get the disease from cattle, as they were just being domesticated at this time, and may not have had their own form of TB.
I think what really geeked me out about this paper was that they were able to pull the very DNA from the well-preserved bones, and find not only the human DNA, but the bacteria as well! It’s only a matter of time before we’re making dinosaurs from preserved mosquitoes. 🙂
Israel Hershkovitz, Helen D. Donoghue, David E. Minnikin, Gurdyal S. Besra, Oona Y-C. Lee, Angela M. Gernaey, Ehud Galili, Vered Eshed, Charles L. Greenblatt, Eshetu Lemma, Gila Kahila Bar-Gal, Mark Spigelman, Niyaz Ahmed (2008). Detection and Molecular Characterization of 9000-Year-Old Mycobacterium tuberculosis from a Neolithic Settlement in the Eastern Mediterranean PLoS ONE, 3 (10) DOI: 10.1371/journal.pone.0003426