Tuberculosis in Dr Granville’s mummy
‘Dr Granville's mummy’ was described to the Royal Society of London in 1825 and was the first ancient Egyptian mummy to be subjected to a scientific autopsy. The remains are those of a woman, Irtyersenu, aged about 50, from the necropolis of Thebes and dated to about 600 BC. Augustus Bozzi Granville (1783–1872), an eminent physician and obstetrician, described many organs still in situ and attributed the cause of death to a tumour of the ovary.
However, subsequent histological investigations indicate that the tumour is a benign cystadenoma. Histology of the lungs demonstrated a potentially fatal pulmonary exudate and earlier studies attempted to associate this with particular disease conditions. Palaeopathology and ancient DNA analyses show that tuberculosis was widespread in ancient Egypt, so a systematic search for tuberculosis was made, using specific DNA and lipid biomarker analyses.
Clear evidence for Mycobacterium tuberculosis complex DNA was obtained in lung tissue and gall bladder samples, based on nested PCR of the IS6110 locus. Lung and femurs were positive for specific M. tuberculosis complex cell-wall mycolic acids, demonstrated by high-performance liquid chromatography of pyrenebutyric acid–pentafluorobenzyl mycolates. Therefore, tuberculosis is likely to have been the major cause of death of Irtyersenu.
Origins of Human Malaria
In today's MBE, Origins of Human Malaria: Rare Genomic Changes and Full Mitochondrial Genomes Confirm the Relationship of Plasmodium falciparum to Other Mammalian Parasites but Complicate the Origins of Plasmodium vivax (doi:10.1093/molbev/msn069):
Despite substantial work, the phylogeny of malaria parasites remains debated. The matter is complicated by concerns about patterns of evolution in potentially strongly selected genes as well as the extreme AT bias of some Plasmodium genomes. Particularly contentious has been the position of the most virulent human parasite Plasmodium falciparum, whether grouped with avian parasites or within a larger clade of mammalian parasites. Here, we study 3 classes of rare genomic changes, as well as the sequences of mitochondrial ribosomal RNA (rRNA) genes.
We report 3 lines of support for a clade of mammalian parasites:
1) we find no instances of spliceosomal intron loss in a hypothetical ancestor of P. falciparum and the avian parasite Plasmodium gallinaceum, suggesting against a close relationship between those species;
2) we find 4 genomic mitochondrial indels supporting a mammalian clade, but none grouping P. falciparum with avian parasites; and
3) slowly evolving mitochondrial rRNA sequences support a mammalian parasite clade with 100% posterior probability.We further report a large deletion in the mitochondrial large subunit rRNA gene, which suggests a subclade including both African and Asian parasites within the clade of closely related primate malarias. This contrasts with previous studies that provided strong support for separate Asian and African clades, and reduces certainty about the historical and geographic origins of Plasmodium vivax. Finally, we find a lack of synapomorphic gene losses, suggesting a low rate of ancestral gene loss in Plasmodium.
Blocking the cultural transmission of violence
The NY Times has a fascinating article by Alex Kotlowitz on how organisations like CeaseFire are having success at reducing gang violence in Chicago by treating it like a disease:
CeaseFire’s founder, Gary Slutkin, is an epidemiologist and a physician who for 10 years battled infectious diseases in Africa. He says that violence directly mimics infections like tuberculosis and AIDS, and so, he suggests, the treatment ought to mimic the regimen applied to these diseases: go after the most infected, and stop the infection at its source. “For violence, we’re trying to interrupt the next event, the next transmission, the next violent activity,” Slutkin told me recently. “And the violent activity predicts the next violent activity like H.I.V. predicts the next H.I.V. and TB predicts the next TB.” Slutkin wants to shift how we think about violence from a moral issue (good and bad people) to a public health one (healthful and unhealthful behavior). (More at NYT)
Tuberculosis much, much older than originally thought
A new Homo erectus find has shown that Tuberculosis is much older than originally thought. Previously, the earliest definite proof of TB's existence dates to around 18,000 years in fossilised Buffalo, but this new skull shows small lesions that are characteristic of Tb and dates to around 500,000 years ago. This suggests that TB has a long history of infecting not just humans, but other hominins too.
The paper, First Homo erectus from Turkey and implications for migrations into temperate Eurasia, is available in the American Journal of Physical Anthropology, and the abstract says -
Remains of fossil hominins from temperate regions of the Old World are rare across both time and space, but such specimens are necessary for understanding basic issues in human evolution including linkages between their adaptations and early migration patterns. We report here the remarkable circumstances surrounding the discovery of the first fossil hominin calvaria from Turkey. The specimen was found in the Denizli province of western Turkey and recovered from within a solid block of travertine stone as it was being sawed into tile-sized slabs for the commercial natural stone building market. The new specimen fills an important geographical and temporal gap and displays several anatomical features that are shared with other Middle Pleistocene hominins from both Africa and Asia attributed to Homo erectus.
It also preserves an unusual pathology on the endocranial surface of the frontal bone that is consistent with a diagnosis of Leptomeningitis tuberculosa (TB), and this evidence represents the most ancient example of this disease known for a fossil human. TB is exacerbated in dark-skinned peoples living in northern latitudes by a vitamin D deficiency because of reduced levels of ultraviolet radiation (UVR). Evidence for TB in the new specimen supports the thesis that reduced UVR was one of the many climatic variables presenting an adaptive challenge to ancient hominins during their migration into the temperate regions of Europe and Asia.