Investigation of the link between visceral surface rib lesions and tuberculosis in a Medieval skeletal series from England using ancient DNA

The Evolution of Diagnostic Techniques in the Paleopathology of Tuberculosis: A Scoping Review

Tuberculosis (TB) is an ancient chronic infectious disease that remains a global health concern. In human remains, the most common and characteristic clinical signs are the skeletal modifications involving the spine, such as in Pott's disease. Diagnosing TB in ancient human remains is challenging. Therefore, in this systematic review, the authors investigated the studies assessing molecular diagnosis of Pott's disease in ancient human remains with the intention to survey the literature, map the evidence, and identify gaps and future perspectives on TB in paleopathology. Our systematic review offers a full contextualization of the history of Pott's disease in ancient times. Our search strategy was performed between August 2022 and March 2023. The authors initially identified 340 records, and 74 studies were finally included and assessed for qualitative analysis. Due to non-specific clinical signs associated with TB, how best to diagnose tuberculosis in human remains still represents a central point. Nevertheless, ancient DNA (aDNA) analysis, lipid biomarkers, and spoligotyping might be extremely useful tools in the study of TB in human remains. Moreover, we propose the extraction and study of immune response genes involved in innate and adaptive immunity versus Mycobacterium spp. as an innovative and vastly overlooked approach in TB paleopathology. Complementary methodologies should be integrated to provide the best approach to the study of TB in human remains.

The various meanings and uses of bone "remodeling" in biological anthropology: A review

OBJECTIVES

In modern bone biology, the term "remodeling" generally refers to internal bone turnover that creates secondary osteons. However, it is also widely used by skeletal biologists, including biological anthropologists as a catch-all term to refer to different skeletal changes. In this review, we investigated how "remodeling" is used across topics on skeletal biology in biological anthropology to demonstrate potential problems with such pervasive use of a generalized term.

METHODS

Using PubMed and Google Scholar, we selected and reviewed 205 articles that use the term remodeling to describe skeletal processes and have anthropological implications. Nine edited volumes were also reviewed as examples of collaborative work by different experts to demonstrate the diverse and extensive use of the term remodeling.

RESULTS

Four general meanings of bone "remodeling" were identified, namely, internal turnover, functional adaptation, fracture repair, and growth remodeling. Additionally, remodeling is also used to refer to a broad array of pathological skeletal changes.

DISCUSSION

Although we initially identified four general meanings of bone remodeling, they are not mutually exclusive and often occur in combination. The term "remodeling" has become an extensively used catch-all term to refer to different processes and outcomes of skeletal changes, which inevitably lead to misunderstanding and a loss of information. Such ambiguity and confusion are potentially problematic as the field of biological anthropology becomes increasingly multidisciplinary. Therefore, we advocate for precise, context-specific definitions and explanations of bone remodeling as it continues to be used across disciplines within and beyond biological anthropology.

A case of childhood tuberculosis from late mediaeval Somerset, England

BACKGROUND

The remains of a 3-5 year-old child from the late mediaeval cemetery serving the Priory of St. Peter and St. Paul, Taunton, Somerset, UK was the subject of an aDNA study.

OBJECTIVE

The aim was to distinguish between two differential diagnoses suggested by earlier osteological examination of the remains; either tuberculosis or Langerhans cell histiocytosis.

FINDINGS

The remains tested positive for MTB complex markers, corroborating this diagnosis reached on osteological grounds. Based on positivity for the mtp40 element and a deletion in the pks15/1 locus, we conclude that infection was due to a strain of the human pathogen M.tuberculosis belonging to lineage 4. Although DNA recovered from the case was heavily fragmented, sex determination by amelogenin PCR suggested these are the remains of a young male child. The findings are discussed considering additions to the literature since the original report.

CONCLUSIONS

Descriptions of tuberculosis in children from this period are rare and burial Sk2077 represents the first UK example of a pre-adolescent individual to have a molecular diagnosis combined with osteological pathology. This provides an important reference of childhood tuberculosis and insight into the likely presence of tuberculosis in the mediaeval adult population served by this cemetery.

The Human Bone Collection of the Faculty of Dentistry at the University of Hong Kong: History and description of cranial and postcranial skeletal remains

OBJECTIVES

The present work describes the status and contents of The Human Bone Collection of the Faculty of Dentistry at the University of Hong Kong.

MATERIALS AND METHODS

The Collection originates from the 1980s and became officially established in 2017 for teaching and research purposes. Most of the Collection consists of unclaimed human remains of southern Chinese individuals exhumed from local cemeteries and donated to the Faculty in the last few decades. The demographic information was provided largely from burial records and forensic estimations. Since 2016, the Collection has undergone a process of reorganization into cranial and postcranial remains, followed by preservation procedures that included cleaning and classification.

RESULTS

The Collection currently consists of remains belonging to about 368 individuals (243 males, 54 females, 71 unknown), with ages ranging from 0.8 to 90 years (mean 57.4 years). It comprises cranial remains belonging to 260 individuals (169 males, 39 females, 52 unknown), and postcranial remains belonging to 248 individuals (180 males, 42 females, 26 unknown). The preservation status ranges from poor to good, with the cranial remains better preserved than the postcranial elements. For a large number of individuals, ear ossicles, soil samples, and other materials are also available.

DISCUSSION

The Collection is accessible to local and international institutions for teaching and research.

Advances in the molecular detection of tuberculosis in pre-contact Andean South America

Andean paleopathological research has significantly enhanced knowledge about the geographical distribution and evolution of tuberculosis (TB) in pre-Columbian South America. In this paper, we review the history and progress of research on ancient tuberculosis (TB) in the Andean region, focusing on the strengths and limitations of current approaches for the molecular detection of ancient pathogens, with special attention to TB. As a case study, we describe a molecular screening approach for the detection of ancient Mycobacterium tuberculosis in individuals from Late Intermediate Period (1000-1400 CE) contexts at the site of Huari, Peru. We evaluate 34 commingled human vertebrae and combine morphological assessments of pathology with high throughput sequencing and a non-selective approach to ancient pathogen DNA screening. Our method enabled the simultaneous detection of ancient M. tuberculosis DNA and an evaluation of the environmental microbial composition of each sample. Our results show that despite the dominance of environmental DNA, molecular signatures of M. tuberculosis were identified in eight vertebrae, six of which had no observable skeletal pathology classically associated tuberculosis infection. This screening approach will assist in the identification of candidate samples for downstream genomic analyses. The method permits higher resolution disease identification in cases where pathology may be absent, or where the archaeological context may necessitate a broad differential diagnosis based on morphology alone.

The association between skeletal lesions and tuberculosis diagnosis using a probabilistic approach

Sensitivity and specificity estimates for 18 skeletal lesions were generated from modern skeletons for future paleoepidemiological analyses of tuberculosis prevalence in archaeological samples. A case-control study was conducted using 480 skeletons from 20^th century American skeletal collections. One-half of the skeletons were documented tuberculosis cases (Terry Collection). The remaining age and sex-matched skeletons were controls (Bass Collection). The association between 18 candidate skeletal lesions and tuberculosis was established by comparing lesion distributions in case and control groups. Lesion indicators at six locations - visceral surface of ribs, ventral vertebral bodies, lateral part of ilium, acetabular fossa, iliac auricular surface, and ulna olecranon process - occurred significantly more often among cases than in controls, and were associated with one another. The most useful indicator proved to be a bony reaction on ventral thoracic and lumbar vertebral bodies. Its presence means a 53.3% probability of a true tuberculosis diagnosis. Because of the nature of the reference sample - 20th century American cases - sensitivity and specificity estimates will better estimate disease prevalence in archaeological samples from cultural settings where pulmonary tuberculosis predominated. The general approach of this proof-of-concept study is applicable to other diseases that occur commonly and affect bone.

Inflammatory periosteal reaction on ribs associated with lower respiratory tract disease: A method for recording prevalence from sites with differing preservation

Objectives

Inflammatory periosteal reaction (IPR) on the visceral surfaces of the ribs has been used in bioarchaeology as an indicator of lower respiratory tract disease. This article presents a detailed method for recording IPR on the ribs, even those in severely fragmented states, with the objectives of increasing the consistency of recording and producing true prevalence rates for skeletons so as to improve data comparability between future bioarchaeological studies of lower respiratory tract disease.

Materials and methods

The presence and prevalence of respiratory‐related IPR were recorded from three different Sudanese cemetery sites using a detailed method for identifying and recording IPR. Sites with variable preservation were chosen to test the applicability of the method. A flowchart to aid in identification of bony changes is presented. The method requires the recording of IPR on three separate sections of the rib (neck, angle, and shaft) and the allocation of ribs into rib cage regions of upper, upper‐middle, middle, lower‐middle, and lower.

Results

Results demonstrate differences in the distribution of IPR between sites and verify the method's applicability to archeological sites with various levels of skeletal preservation.

Discussion

While crude prevalence rates can indicate the number of individuals experiencing lower respiratory tract disease within a site, this method can provide information about the distribution of IPR within the rib cage. This should lead to new ways of distinguishing respiratory diseases within archeological populations. This method also allows for comparability between well‐preserved and lesser‐preserved sites by accommodating for rib fragmentation.

Life on a Napoleonic battlefield: A bioarchaeological analysis of soldiers from the Battle of Aspern, Austria

On the 21st-22nd of May 1809, French and Austrian soldiers engaged in battle near the village of Aspern on the outskirts of Vienna. This battle, the first defeat of Napoleon's army on land, was one of the largest and deadliest encounters during the Napoleonic Wars (1798-1815). Salvage excavations between 2009 and 2016 have revealed several battlefield burial sites in Aspern. The remains of 30 individuals were evaluated for a series of pathological conditions which develop during childhood and adulthood to elucidate the impact of Napoleonic military conditions on health. Statistical comparisons were conducted of stature estimates and frequencies of pathological conditions between the Aspern soldiers, several contemporaneous military, and two civilian samples of differing socioeconomic status. These data were compared to test the hypothesis that military conscripts had 'healthy' childhoods, but then experienced deteriorating health as a result of military conditions. The analysis revealed comparatively high mean stature, but also a high prevalence of enamel hypoplastic defects, indicating that the childhood health of the military recruits was more varied than was initially expected. High frequencies of carious lesions, dental calculus, active maxillary sinusitis and pleuritis and osteoarthritis were recorded, demonstrating the deleterious effects of military life on health.

Introduction: Scientific rigor in paleopathology

This introductory chapter to the Special Issue on "Scientific Rigor in Paleopathology" serves to orient and introduce the chapters that follow through a detailed consideration of paleopathology as a 21^st century intellectual field. In this vein, we first make the significant point that paleopathology is a profoundly interdisciplinary endeavor, encompassing aspects of the biomedical science, the humanities, and the social sciences. Thus, we suggest that no one practitioner can personally command the range of skills necessary for a 21^st century paleopathologist. To maintain rigor in differential diagnosis, we emphasize collaborations and consider key concepts that illustrate the basic knowledge from each of these fields that any paleopathologist should command. We then address the manner in which disease diagnosis should proceed as a scientific endeavor. To illustrate scientific rigor in differential diagnosis, we present two case studies drawn from 1970s contributions by Cook and by Buikstra. Finally, we introduce Chapters 2-6, which address differential diagnosis in contexts ranging from specific conditions (scurvy, trepanation) to broader field-wide considerations (paleoparasitology, historical paleopathology, imaging, animal paleopathology).

Pre-Columbian tuberculosis in Tierra del Fuego? Discussion of the paleopathological and molecular evidence

This work contributes to ongoing discussions about the nature of tuberculosis in the Western Hemisphere prior to the time of European contact. Our example, from the extreme south of South America was, at the time of our study, without firm temporal association or molecular characterization. In Tierra del Fuego, Constantinescu (1999) briefly described vertebral bone lesions compatible with TB in an undated skeleton from Myren 1 site (Chile). The remains of Myren are estimated to represent a man between 18 and 23 years old at the time of death. The objectives of this research are to extend this description, to present molecular results, to establish a radiocarbon date, and to report stable isotopic values for the remains. We provide further description of the remains, including tuberculosis-like skeletal pathology. Radiocarbon dating of 640±20 years BP attributes this individual to the precontact fourteenth-fifteenth centuries. Isotopic ratios for nitrogen and carbon from bone collagen suggest a mixed diet. Molecular results were positive for the rpoB quantitative PCR (qPCR) assays but negative for two independent IS6110 and IS1081 qPCR assays. Further testing using genomic methods to target any mycobacteria for specific identification are needed.

Paleopathological Study of Dwarfism-Related Skeletal Dysplasia in a Late Joseon Dynasty (South Korean) Population

Skeletal dysplasias related to genetic etiologies have rarely been reported for past populations. This report presents the skeletal characteristics of an individual with dwarfism-related skeletal dysplasia from South Korea. To assess abnormal deformities, morphological features, metric data, and computed tomography scans are analyzed. Differential diagnoses include achondroplasia or hypochondroplasia, chondrodysplasia, multiple epiphyseal dysplasia, thalassemia-related hemolytic anemia, and lysosomal storage disease. The diffused deformities in the upper-limb bones and several coarsened features of the craniofacial bones indicate the most likely diagnosis to have been a certain type of lysosomal storage disease. The skeletal remains of EP-III-4-No.107 from the Eunpyeong site, although incomplete and fragmented, provide important clues to the paleopathological diagnosis of skeletal dysplasias.

An analysis of the alleged skeletal remains of Carin Göring

In 1991, treasure hunters found skeletal remains in an area close to the destroyed country residence of former Nazi leader Hermann Göring in northeastern Berlin. The remains, which were believed to belong to Carin Göring, who was buried at the site, were examined to determine whether it was possible to make a positive identification. The anthropological analysis showed that the remains come from an adult woman. The DNA analysis of several bone elements showed female sex, and a reference sample from Carin's son revealed mtDNA sequences identical to the remains. The profile has one nucleotide difference from the Cambridge reference sequence (rCRS), the common variant 263G. A database search resulted in a frequency of this mtDNA sequence of about 10% out of more than 7,000 European haplotypes. The mtDNA sequence found in the ulna, the cranium and the reference sample is, thus, very common among Europeans. Therefore, nuclear DNA analysis was attempted. The remains as well as a sample from Carin's son were successfully analysed for the three nuclear markers TH01, D7S820 and D8S1179. The nuclear DNA analysis of the two samples revealed one shared allele for each of the three markers, supporting a mother and son relationship. This genetic information together with anthropological and historical files provides an additional piece of circumstantial evidence in our efforts to identify the remains of Carin Göring.

Osteological and molecular identification of Brucellosis in ancient Butrint, Albania

Ancient skeletal remains can harbor unique information about past civilizations at both the morphological and molecular levels. For instance, a number of diseases manifest in bone, some of which have been confirmed through DNA analysis, verifying their presence in ancient populations. In this study, anthropological analysis of skeletal remains from the ancient Albanian city of Butrint identified individuals with severe circular lytic lesions on their thoracic and lumbar vertebrae. Differential diagnosis suggested that the lesions resulted from pathologies known to affect these skeletal regions, such as tuberculosis (TB) or brucellosis. Relevant bones of two adolescent males from the 10th to 13th century AD that displayed the lesions, along with unaffected individuals, were collected in the field. Genetic screening of the skeletal samples for TB was repeatedly negative, thus additional testing for Brucella spp.-bacteria of livestock and the causative agent of brucellosis in humans-was conducted. Two Brucella DNA markers, the IS6501 insertion element and Bcsp31 gene, amplified from the affected vertebrae and/or ribs, whereas all unaffected individuals and control samples were negative. Subsequent DNA sequencing confirmed the presence of the brucellar IS6501 insertion element. On the basis of the skeletal lesions, negative tests for TB, and positive Brucella findings, we report a confirmed occurrence of brucellosis in archaeologically recovered human bone. These findings suggest that brucellosis has been endemic to the area since at least the Middle Ages.

Evolution of human tuberculosis: a systematic review and meta-analysis of paleopathological evidence

Tuberculosis is a re-emerging disease and is a major problem in both developing and developed countries today. An estimated one third of the world's population is infected and almost two million people die from the disease each year. Bone lesions occur in 3-5% of active tuberculosis cases and can be used to diagnose the disease in ancient skeletal remains. A meta-analysis was conducted on 531 palaeopathological tuberculosis cases from 221 sites (7250 BCE to 1899) on all continents for the purpose of testing two hypotheses; (1) the frequency of bone lesions does not change through time and (2) the distribution of lesions throughout the skeleton does not change over time. The frequency of bone lesions was found to significantly decrease over time (P<0.05). The distribution of bone lesions was found to change from mainly spinal in earlier time periods to include more cases in other regions of the skeleton (long bones, joints, hands, feet) in later time periods. This difference in distribution was evaluated using a Chi-squared test and found to be significant (P<0.01). These findings are an important addition to the current knowledge of the evolution of the disease and the Mycobacterium tuberculosis.

A search for β thalassemia mutations in 4000 year old ancient DNAs of Minoan Cretans

Ancient DNA methodologies can be applied in the investigation of the genetics of extinct populations. A search for beta thalassemia mutations was performed on 49 Minoan individuals from the Bronze Age who were living in the island of Crete approximately 4000 Years Before Present (YBP). Standard precautionary measures were employed in the laboratory to ensure authenticity of the DNA extracted from the ancient bones, resulting in the successful analysis of DNA of 24 Minoans. DNA sequencing focused on the Intervening Sequence 1 (IVS-1) of the beta globin gene and its splicing junctions. 63% of the thalassemia mutations observed among modern Cretans reside in beta IVS-1. None of the Minoan individuals carried one of the IVS-1 mutations known to cause beta thalassemia; however, only one was expected to be observed if the average frequency of beta thalassemia heterozygotes in the Minoan population was the same with that of modern day Cretans (7.6%). One individual contained a C to G substitution in position 91 of the IVS-1, located 40 bp 5' to the intron 1/exon 2 junction. Functional studies indicated that the mutation did not affect mRNA splicing or stability, and most likely represented an innocent single nucleotide polymorphism.

Museums and disease: using tissue archive and museum samples to study pathogens

Molecular studies of archival and fossil samples have traditionally focused on the nucleic acids derived from the host species. However, there has recently been an increase in ancient DNA research on the identification and characterization of infectious agents within the hosts. The study of pathogens from the past provides great opportunities for discovering the causes of historical infection events, characterizing host-microorganism co-evolution and directly investigating the evolution of specific pathogens. Several research teams have been able to isolate and characterize a variety of different bacterial, parasite and viral microorganisms. However, this emerging field is not without obstacles. The diagenetic processes that make ancient DNA research generally difficult are also impediments to ancient pathogen research and perhaps more so given that their DNA may represent an even rarer proportion of the remaining nucleic acids in a fossil sample than host DNA. However, studies performed under controlled conditions and following stringent ancient DNA protocols can and have yielded reliable and often surprising results. This article reviews the advantages, problems, and failures of ancient microbiological research.

Tuberculosis and leprosy in perspective

Two of humankind's most socially and psychologically devastating diseases, tuberculosis and leprosy, have been the subject of intensive paleopathological research due to their antiquity, a presumed association with human settlement and subsistence patterns, and their propensity to leave characteristic lesions on skeletal and mummified remains. Despite a long history of medical research and the development of effective chemotherapy, these diseases remain global health threats even in the 21st century, and as such, their causative agents Mycobacterium tuberculosis and M. leprae, respectively, have recently been the subject of molecular genetics research. The new genome-level data for several mycobacterial species have informed extensive phylogenetic analyses that call into question previously accepted theories concerning the origins and antiquity of these diseases. Of special note is the fact that all new models are in broad agreement that human TB predated that in other animals, including cattle and other domesticates, and that this disease originated at least 35,000 years ago and probably closer to 2.6 million years ago. In this work, we review current phylogenetic and biogeographic models derived from molecular biology and explore their implications for the global development of TB and leprosy, past and present. In so doing, we also briefly review the skeletal evidence for TB and leprosy, explore the current status of these pathogens, critically consider current methods for identifying ancient mycobacterial DNA, and evaluate coevolutionary models.

Diet, tuberculosis, and the paleopathological record

Osseous manifestation of infectious disease is of paramount importance to paleopathologists seeking to interpret ancient health, but the relationships among infectious agent exposure, development of disease, and skeletal involvement are complex. The outcome of an exposure strongly depends on multiple factors, including ecology, diet, nutrition, immune function, and the genetics of pathogen and host. Mycobacterial diseases are often studied in ancient remains but also are especially influenced by these factors; individual and population differences in severity and course are apparent following onset of active disease. The osteological record for these diseases represents the complex interplay of host and pathogen characteristics influencing within- and among-individual skeletal lesion prevalence and distribution. However, many of these characteristics may be assessed independently through the archaeological record. Here, we explore the contributions of dietary protein and iron to immune function, particularly the course and outcome of infection with Mycobacterium tuberculosis. We emphasize how nutrition may influence the dissemination of bacilli to the skeleton and subsequent formation of diagnostic lesions. We then generate models and hypotheses informed by this interplay and apply them to four prehistoric New World areas. Finally, discrepancies between our expectations and the observed record are explored as a basis for new hypotheses.

PCR diagnostics of Mycobacterium tuberculosis in historic human long bone remains from 18th century burials in Kaiserebersdorf, Austria

Background

In the present pilot study we applied recently published protocols for detecting Mycobacterium tuberculosis in human remains. We screened long bones from an 18^th century cemetery and skulls from the anatomical "Weisbach collection" (19^th century). In addition, besides the study of abundance of tuberculosis in inmates of the poorhouse itself, we were interested to test whether in this particular instance tuberculosis can be identified from cortical bones, which are rarely affected by tuberculosis, but mostly better preserved than the vertebral bodies or epiphyses.

Method

The DNA extractions from the bone samples were obtained following established ancient DNA protocols. Subsequently extracts were subjected to a series of PCR amplifications using primer pairs published previously [1,2]. PCR products of the expected size were subsequently sequenced.

Results

Only primers targeting the repetitive IS6110 insertion sequence yielded PCR products of appropriate size. In one sample only (skull sample WB354 of the "Weisbach collection") sequence analysis revealed an authentic M. tuberculosis sequence that matched to a reference sequence from GenBank.

Conclusion

With a variety of established PCR approaches we failed to detect M. tuberculosis DNA in historic human femurs from an 18^th century cemetery relating to a poor house in Kaiserebersdorf, Austria. Our data may indicate that in this particular case, thoracic or lumbar vertebrae, i.e. bones that are severely affected by the disease, would be more suitable for molecular diagnostics than long bones. However, the unpredictable state of DNA preservation in bones from museum collections does not allow any general recommendation of any type of bone.

Tuberculosis in the New World: a study of ribs from the Schild Mississippian population, West-Central Illinois

Vertebral lesions have been the main evidence for infection by the Mycobacterium tuberculosis complex (MTC) in paleopathology. Skeletal involvement is expected in a small percentage of infected individuals. Recently, several authors report a correlation between rib lesions and tuberculosis (TB) complex infection. This study tests the hypothesis that rib lesions can serve as a useful marker for MTC infection within the Mississippian Schild skeletal collection from West-Central Illinois. Ribs from 221 adults and juveniles were examined, and affected individuals were tested for TB complex infection. DNA from rib samples of affected individuals was amplified with primers targeting the IS6110 insertion element, which is common to all members of the TB complex. Although it cannot allow discrimination between different species of TB, IS6110 is present in many copies within their genomes, and its presence is thus an indication of MTC infection. The results support the use of rib lesions as a marker for TB infection. Additionally, we demonstrate that MTC DNA can be recovered from ribs that lack lesions in individuals who have lesions of other bones. We recommend that an examination of ribs be incorporated into investigations for TB.

Evaluating bacterial pathogen DNA preservation in museum osteological collections

Reports of bacterial pathogen DNA sequences obtained from archaeological bone specimens raise the possibility of greatly improving our understanding of the history of infectious diseases. However, the survival of pathogen DNA over long time periods is poorly characterized, and scepticism remains about the reliability of these data. In order to explore the survival of bacterial pathogen DNA in bone specimens, we analysed samples from 59 eighteenth and twentieth century individuals known to have been infected with either Mycobacterium tuberculosis or Treponema pallidum. No reproducible evidence of surviving pathogen DNA was obtained, despite the use of extraction and PCR-amplification methods determined to be highly sensitive. These data suggest that previous studies need to be interpreted with caution, and we propose that a much greater emphasis is placed on understanding how pathogen DNA survives in archaeological material, and how its presence can be properly verified and used.

Anatomy of a serial killer: Differential diagnosis of tuberculosis based on rib lesions of adult individuals from the Coimbra identified skeletal collection, Portugal

The role of new bone formation on visceral surfaces of ribs in the diagnosis of tuberculosis (TB) in past human populations has been explored by many researchers, using both skeletal remains with known causes of death and archaeological samples. This study focuses, firstly, on adult skeletons from the Coimbra Identified Skeletal Collection in Portugal and investigates the skeletal manifestations of individuals known to have died from TB; secondly, this study focuses on the role of rib lesions in the diagnostic criteria for TB. One hundred and fifty-seven males and 106 females aged between 22-87 years were examined; causes of death were assigned as pulmonary TB, extrapulmonary TB, and pulmonary non-TB; a control group, extrapulmonary non-TB, was selected from the remaining individuals. Of individuals with rib lesions, 85.7% (69/81) had pulmonary or extrapulmonary TB as an assigned cause of death, while 17.8% (16/90) of individuals with rib lesions had a non-TB cause of death. Rib lesions were significantly more common in individuals who had died from TB, although the lesions cannot be considered pathognomonic for TB. In individuals dying from pulmonary TB, ribs in the central part of the rib cage were most affected, at their vertebral ends. The lower part of the rib cage may be a marker for peritoneal TB, and "coral-like" new bone formation on ribs may be an indicator of neoplastic disease. Further work on rib involvement in TB in clinical contexts, and the study of further documented skeletal collections, are recommended.

Palaeomicrobiology: current issues and perspectives

Palaeomicrobiology is an emerging field that is devoted to the detection, identification and characterization of microorganisms in ancient remains. Data indicate that host-associated microbial DNA can survive for almost 20,000 years, and environmental bacterial DNA preserved in permafrost samples has been dated to 400,000-600,000 years. In addition to frozen and mummified soft tissues, bone and dental pulp can also be used to search for microbial pathogens. Various techniques, including microscopy and immunodetection, can be used in palaeomicrobiology, but most data have been obtained using PCR-based molecular techniques. Infections caused by bacteria, viruses and parasites have all been diagnosed using palaeomicrobiological techniques. Additionally, molecular typing of ancient pathogens could help to reconstruct the epidemiology of past epidemics and could feed into current models of emerging infections, therefore contributing to the development of appropriate preventative measures.

Tuberculosis: from prehistory to Robert Koch, as revealed by ancient DNA

During the past 10 years palaeomicrobiology, a new scientific discipline, has developed. The study of ancient pathogens by direct detection of their DNA has answered several historical questions and shown changes to pathogens over time. However, ancient DNA (aDNA) continues to be controversial and great care is needed to provide valid data. Here we review the most successful application of the technology, which is the study of tuberculosis. This has provided direct support for the current theory of Mycobacterium tuberculosis evolution, and suggests areas of investigation for the interaction of M tuberculosis with its host.