16 Oct 2008

New TB clue in ancient bones

Scientists have discovered tuberculosis in 9 000 year-old human bones found submerged off Israel's coast - evidence the disease is at least 3 000 years older than previously thought.

The findings show how tuberculosis has evolved over thousands of years and provides a better understanding of ways it may change in the future, the researchers said.

"Examining ancient human remains for the markers of TB is very important because it helps to aid our understanding of prehistoric tuberculosis and how it evolved," said Mark Spigelman of University College, London, who worked on the study.

"This then helps us improve our understanding of modern TB and how we might develop more effective treatments."

TB kills 1.7 mil a year
Tuberculosis is an infectious bacterial disease typically attacking the lungs that newly affects about 9.2 million people each year and kills an estimated 1.7 million around the world.

The emergence and spread of drug-resistant germs makes treating it much harder and could make the disease even deadlier.

The international team, which also included researchers from Israel's Tel Aviv University, found the bones believed to be a mother and baby submerged off the coast of Haifa.

DNA analysis and bone lesions characteristic of tuberculosis showed that the skeletons from a 9 000 year-old Pre-Pottery Neolithic village were infected with the disease, the team said in the Public Library of Science journal PLoS One.

The village was located in a place that is now submerged.

Further tests showed that the strain was a type found only in humans and is similar to common bacteria that infects people with tuberculosis today.

Previously, the oldest confirmed human TB strain was from a group of Egyptians dating back to around 3 000 BC, said Helen Donoghue, a University College, London, researcher who worked on the study.

"We can tell that it was human because it was missing part of its DNA that is characteristic of the human lineage," she said in a telephone interview.

"The strain we have found as far as we can tell is identical to some of the bacteria that are going around and infecting people today," she added. – (Michael Kahn/Reuters Health)