Ancient bones may hold clues to TB - various

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Ancient bones may hold clues to TB

 

Ori Lewis

Reuters

 

Tuesday, 15 July 2008

 

A team of German, Israeli and Palestinian researchers is studying ancient bones

found in the biblical city of Jericho for clues that could help scientists

combat tuberculosis.

 

" We see a re-emerging wave of tuberculosis all over the world and ... perhaps

learning from the past will help us understand the present, " says Professor

Andreas Nerlich from Ludwig-Maximilians University in Munich.

Nerlich and other researchers in the team have begun studying 6000-year-old

bones unearthed in Jericho more than a half-century ago by British

anthropologist Dr Kathleen Kenyon, in what is now the occupied West Bank.

Chance find

Professor Mark Spigelman from Jerusalem's Hebrew University, came across the

long-forgotten bones while examining mummies at Sydney University's Nicholson

Museum.

 

" They told me they had lots of boxes of bones and didn't know what they were

because they'd been deposited there fifty years earlier by an anthropologist

who'd worked with Dr Kathleen Kenyon who'd been excavating at Jericho, "

Spigelman says.

 

" When I examined them, I recognised that these were the bones from Jericho, and

I told them not throw them out. "

Disease of crowds

Tuberculosis, also known as TB, is a deadly infectious bacterial disease that

usually attacks the lungs. Acknowledged as a disease of crowds, it is

transmitted from human to human living in close contact.

 

Many of the bones show signs of tuberculosis, suggesting the disease afflicted a

significant proportion of the population of the ancient world.

Experts believe the infectious bacterial disease, which usually attacks the

lungs, could have originated about 10,000 years ago in the first villages and

small towns in an area stretching from the Persian Gulf through to the Nile

delta.

 

Researchers say preliminary work suggests there is sufficient DNA in the bone

samples to provide clues to how tuberculosis evolves and help experts find new

ways to fight it.

 

Spigelman says knowing how a disease evolves helps us understand what it will do

as it continues to evolve, and will ultimately alter the practice of public

health officials in combating it.

 

Professor Ziad Abdeen, a Palestinian who heads the nutrition and health research

institute at al-Quds University near Jerusalem, says the project shows how

Israeli and Palestinian academics had learned to cooperate.

 

http://www.abc.net.au/science/articles/2008/07/15/2303953.htm?topic=health

 

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TB may be among oldest human diseases

 

Rossella Lorenzi

Discovery News

 

Wednesday, 31 August 2005

 

Our hominid ancestors suffered from tuberculosis, according to new genetic

research that traces the origins of the bacteria that causes it to 3 million

years ago in East Africa. After infecting early, small-brained hominids, the

lung disease commonly known as TB may have spread around the world with waves of

human migration out of Africa, the French researchers say. Dr Veronique Vincent

and colleagues at the Pasteur Institute in Paris will report their research in

September in the journal PLoS Pathogens. TB has long been thought to have

emerged only a few tens of thousands of years ago. Scientists came to this

conclusion because members of the Mycobacterium tuberculosis complex, the agents

responsible for TB, represent one of the most extreme examples of genetic

homogeneity. Analysis of this complex shows the bacteria have few mutations and

nearly identical DNA, pointing to a relatively recent origin of TB. The lack of

mutations suggests that current

strains would have originated from a single successful ancestor about 20,000 to

35,000 years ago. But Vincent says the M. tuberculosis complex is only " the

visible tip of a much broader progenitor species " , whose living representatives

are tubercle bacilli recovered from patients in Djibouti, East Africa. The

researchers studied cases of TB from Djibouti, in the Horn of Africa, in which

unusual bacteria strains form colonies physically different from anything seen

before. Genetic analysis shows the Djibouti strains, as well as the more common

strains, descend from an ancient M.

prototuberculosis species. Vincent and colleagues estimate that the necessary

time needed to accumulate the observed mutations in the Djibouti strains is some

3 million years. " Tuberculosis could thus be much older than the plague, typhoid

fever or malaria, and might have affected early hominids, " the researchers

conclude. They suggest that similar to humans, TB bacteria emerged in Africa and

then underwent diversification as early humans left that continent. The genetic

diversity of the African strain and the uniform worldwide M. tuberculosis

complex would reflect the distribution of human genetic diversity among the

world population, with larger genetic diversity observed among living Africans.

The discovery could have important future implications in the diagnosis and

treatment of the disease, which claims 3 million lives a year. Tuberculosis

researcher Professor Gunnar Bjune from the international health department at

Norway's University of Oslo,

says the implication that " people today living in the area where Lucy was

excavated are closer to the source of tubercle bacilli is primitive and rather

unscientific " . " The claim that Lucy and her Homo afarensis family suffered from

tuberculosis is not completely proven. As is often the case in such papers, the

emphasis is on the genetic studies. Very little information is given on the

clinical picture of the Djibouti patient, " Bjune says. " Nevertheless, this is a

very important study. The finding is not totally unexpected, given the strange

ability of mycobacteria to keep their genome in shape through thousands of

years, but it teaches us an important evolutionary lesson. "

 

http://www.abc.net.au/science/articles/2005/08/31/1450010.htm

 

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TB may have led to leprosy decline

 

Rossella Lorenzi

Discovery News

 

Monday, 14 February 2005

 

The spread of tuberculosis may have killed off leprosy in Europe in the Middle

Ages, according to research into the shrouded body of a man who lived around the

time of Christ.

 

Discovered by Israeli archaeologist Dr Shimon Gibson in a rock-carved niche

covered with a stone, the shrouded body remained undisturbed for 2000 years.

 

At that time, burial customs prescribed wrapping the body in a shroud, then

returning after a suitable time and reburying the bones in an ossuary.

 

" But the shrouded body had not been re-buried. We thought there must have been a

reason for this, so we decided to look for signs of leprosy, a cause of fear and

stigma at the time, in addition to the tuberculosis [TB] which we had already

found to be present, " says infectious disease expert Dr Mark Spigelman, one of

the University College London's scientists who carried out the study.

 

Indeed, the man's body turned out to also bear DNA traces of infection with the

leprosy bacteria.

 

Leprosy, which causes trademark skin lesions, nerve damage and loss of

sensation, was a widespread, much-feared disease in the Middle Ages. But at that

time it unaccountably declined around the same time that TB began to spread

across Europe.

 

TB went on to become a major long-term epidemic, with one-third of the world's

population infected and more than eight million new cases in 2000.

 

Infected human remains

 

To investigate the relationship between the two diseases, Spigelman and his

colleague Dr Helen Donoghue analysed two dozen skeletons dating from the first

to the 16th century, from across Europe and the Middle East.

 

Surprisingly, the DNA of the bacteria behind TB and leprosy was detected in 42%

of the samples examined, the researchers write in the Royal Society journal

Proceedings B.

 

" We realised that we were looking at a fairly common, previously unrecognised

phenomenon of co-infection, " Donoghue says.

 

The finding would disprove the belief that TB, caused by the bacterium

Mycobacterium tuberculosis, might cross-immunise sufferers from leprosy, caused

by the related M. leprae.

 

" Our findings suggest a different explanation. A weakening of the immune system

following infection by leprosy, coupled with the stress, poverty and

malnutrition associated with the social isolation and stigma of living with the

disease, could have paved the way for opportunistic co-infection by TB, which

brought a speedier death. In time this would reduce the number of individuals

suffering from leprosy, leading to its overall decline, " Donoghue says.

 

Not everyone's convinced

 

According to Norwegian researcher Professor Gunnar Bjune, from the University of

Oslo, the study is " stimulating to read " , but doesn't give enough evidence for

TB being responsible for leprosy's decline.

 

" It is not correct to say that TB would have killed people suffering from both

diseases before they had a chance to pass on leprosy. The transmission of M.

leprae is still debated, but most evidence points against leprosy patients

playing a role at all, " Bjune says.

 

" Most probably, the bacilli are spread from healthy carriers who have M. leprae

in their nasal secretion. I think that if susceptibility is linked to one or a

few genes in humans, then selection from death amplified by the much stronger

force of avoiding marriage with families with leprosy could explain the

decline. "

 

Striking an estimated 500,000 people a year, leprosy remains a threat today in

places like Central and South America, the Caribbean and the Indian

subcontinent.

 

http://www.abc.net.au/science/articles/2005/02/14/1302419.htm

 

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