Tuberculosis occurred much earlier than previously thought
So far, researchers suspected that the tuberculosis pathogen originated in the Neolithic period. Studies of a roughly 500,000-year-old fossil of an early human from Turkey showed that the infectious disease probably occurred much earlier in human history than previously thought in the world of researchers. The skull of a homo erectus showed signs of meningitis caused by tuberculosis.
Tuberculosis leads to death statistics for bacterial infections Tuberculosis (TBC, or formerly called consumption) is one of the most widespread bacterial infections, which is caused by a number of different bacteria from a bacterial strain. In most cases, the germs affect the human lung tissue. According to statistics from the World Health Organization (WHO), tuberculosis is one of the most common deadly infectious diseases worldwide. According to a WHO evaluation in 2009, around 1.8 million people died in 2008 from the sequelae of the disease.
Find of skull shows signs of meningeal infection An international team of researchers, led by the "Department of Anthropology" at the University of Texas, Austin, succeeded in 2004 with the help of an analysis of the skull that was found to show that the serious illness was very likely to have occurred much earlier, than previously thought. Until then, scientists were of the opinion that the TBC only first spread to humans a few thousand years ago. However, the find could refute previous assumptions, so that the first early humans had infections for the first time around 500,000 years ago. According to the experts from the University Medical Center Göttingen (UMG), the analyzed skull of a Homo erectus showed traces of a persistent meningitis, which usually occurs as a result of tuberculosis. The scientists now assume that the skull found belonged to a dark-skinned person from Africa who, unlike light-skinned people, can produce significantly less vitamin D through skin exposure to the sun. As a result, people with dark skin tones are particularly prone to tuberculosis.
However, the assumption has not yet been fully confirmed, which is why a team led by Prof. Dr. Michael Schultz, paleopathologist at UMG, examined the replica of the 500,000-year-old skull for signs of tuberculosis. "From a purely morphological point of view, it is likely that the 'dimples' and notches on the inside of the front skull are remnants of a meningitis caused by tuberculosis," explains the Göttingen paleopathologist. If the assumption is correct, then the Turkish find is "the only evidence worldwide of meningeal tuberculosis in humans from the fossil era", says Schultz.
Tuberculosis pathogens affect the lungs and the brain Tuberculosis affects the lungs in most cases, but can also spread to other internal organs. Accordingly, the brain is often also affected, which is why meningitis develops. Therefore, the studies that are currently being carried out serve to diagnose the skull. Clear grooves and cusp structures on the front of the front cranial fossa can provide valuable information. Based on the size and shape of the eyebrow bones, the researchers estimate the age of the person between the ages of 18 and 30 at the time. The pieces of the skull were found in the travertine rock in a stone factory in western Turkey.
The morphological discovery relates to an identical cast of the discovered skull. Together with the US researcher Prof. John Kappelmann, the paleopathologist in Göttingen wants to examine the skull section microscopically. The anthropologist Kappelmann from the University of Austin in Texas is a member of the research group that is leading the early man's finds. The original skull is still in Turkey. In summer 2012, further analyzes with a light microscope and a scientific endoscopy are to follow. According to the expert, these could confirm or reject the morphological assumptions.
It is already certain that the one to two millimeter disruption of the anatomical structure on the top of the skull arose when man was still alive. The characteristics are typically indications of a meningeal infection. “Above all, the exact shape and placement of the lesions on the skull are very characteristic of a specific form of tuberculosis. It is known as tuberculosa leptomeningitis, ”adds Prof. John Kappelmann.
Further examinations should confirm acceptance "The paleopathological examinations provide a new basis for interpreting the evolution and history of tuberculosis," says Schultz. If the previous assumptions are confirmed, the skull find would be of "extraordinary importance for the historical classification of TBC". The first point in time of the occurrence of the infectious disease in human history would then have to be corrected.
Today, TBC can usually be treated well with antibiotic drugs. However, spread cannot be prevented, particularly in poorer regions of the world. About nine million new cases occur every year. The number of deaths has flattened much less in recent decades than the number of new cases. Since the pathogen can also lie dormant in the body of an otherwise physically stable infected person for years without there being any recognizable symptoms, it is still difficult, among other things, to completely stop the spread. All previous study results can be found in the "American Journal of Physical Anthropology" (135: 110-116, 2008). (sb)
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Photo: Kappelmann, UMG: The notches and grooves on the inside of the skull of Homo erectus can be seen with the naked eye. Image: Kappelmann