Digging into TB's history with genetics - DNA evidence from 1,000-year-old skeletons supports theory that tuberculosis was widespread in Europe during Middle Ages - Brief Article

Science News, June 3, 1995 by John Travis

Talk about a late diagnosis. Probing genetic fragments recovered from the skeletal remains of a man who died more than 1,000 years ago, two British researchers believe they have confirmed that he was afflicted with tuberculosis. In the process, they may have unearthed a way to resolve a medieval mystery surrounding the deadly disease.

From written records of the Middle Ages, researchers have concluded that tuberculosis ran rampant in Europe at that time. But the only physical evidence supporting this contention--namely, lesions and other bone

distortions often caused by tuberculosis--has come from analyses of skeletons taken from cemeteries of the period. The puzzle, says molecular biologist Ronald A. Dixon of the University of Bradford in England, is that "the historical record suggests a much larger number [of cases] than the cemeteries indicate."

So Dixon and his colleague Charlotte Roberts isolated bits of DNA from the bones of eight skeletons taken from a medieval graveyard in northern England. Then, with the same methods physicians routinely use today to diagnose tuberculosis, they amplified the fragments and studied the genetic sequences. For the one skeleton with lesions suggesting tuberculosis, they identified a stretch of DNA unique to Mycobacterium tuberculosis, the pathogen responsible for the disease.

The scientists, who plan to study more medieval skeletons, believe their method will uncover a higher incidence of medieval tuberculosis than bone studies have revealed. "We want to be useful to archaeologists," says Dixon.