A migration-driven model for the historical spread of leprosy in medieval Eastern and Central Europe

A glimpse into the past of Hansen's disease - Re-evaluation and comparative analysis of cases with leprosy from the Avar period of the Trans-Tisza region, Hungary

Our knowledge of how society viewed leprosy and treated its victims in the past is still scarce, especially in geographical regions and archaeological periods from where no written sources are available. To fill in some research gaps, we provide the comparative analysis of five previously described, probable cases with leprosy from the Avar-period Trans-Tisza region (Hungary). The five skeletons were subject to a detailed macromorphological (re-)evaluation. Where possible, the biological and social consequences of having leprosy were reconstructed based on the observed bony changes and mortuary treatment, respectively. The retrospective, macromorphology-based diagnosis of leprosy could be established in three cases only. Based on the detected skeletal lesions, all of them suffered from near-lepromatous or lepromatous leprosy. The disease resulted in aesthetic repercussions and functional implications, which would have been disadvantageous for these individuals, and limited or changed their possibilities to participate in social situations. They could have even required heavy time investment from their respective communities. The analysis of the mortuary treatment of the confirmed leprosy cases revealed no evidence of a social stigma. These findings indicate that the afflicted have not been systematically expulsed or segregated, at least in death, in the Early Middle Ages of the Carpathian Basin.

A, Kis L, Király K, Varga S, Marcsik A, Schütz O, Török T, Hunt DR, Tihanyi B. White plague among the "forgotten people" from the Barbaricum of the Carpathian Basin-Cases with tuberculosis from the Sarmatian-period (3rd-4th centuries CE) archaeological site of Hódmezővásárhely-Kenyere-ér, Bereczki-tanya (Hungary)

Tuberculosis (TB) is a bacterial infection that is well-known in the palaeopathological record because it can affect the skeleton and consequently leaves readily identifiable macroscopic alterations. Palaeopathological case studies provide invaluable information about the spatio-temporal distribution of TB in the past. This is true for those archaeological periods and geographical regions from when and where no or very few TB cases have been published until now-as in the Sarmatian period (1st-5th centuries CE) in the Barbaricum of the Carpathian Basin. The aim of our paper is to discuss five newly discovered TB cases (HK199, HK201, HK225, HK253, and HK309) from the Sarmatian-period archaeological site of Hódmezővásárhely-Kenyere-ér, Bereczki-tanya (Csongrád-Csanád county, Hungary). Detailed macromorphological evaluation of the skeletons focused on the detection of bony changes likely associated with different forms of TB. In all five cases, the presence of endocranial alterations (especially TB-specific granular impressions) suggests that these individuals suffered from TB meningitis. Furthermore, the skeletal lesions observed in the spine and both hip joints of HK225 indicate that this juvenile also had multifocal osteoarticular TB. Thanks to the discovery of HK199, HK201, HK225, HK253, and HK309, the number of TB cases known from the Sarmatian-period Carpathian Basin doubled, implying that the disease was likely more frequent in the Barbaricum than previously thought. Without the application of granular impressions, the diagnosis of TB could not have been established in these five cases. Thus, the identification of TB in these individuals highlights the importance of diagnostics development, especially the refinement of diagnostic criteria. Based on the above, the systematic macromorphological (re-)evaluation of osteoarchaeological series from the Sarmatian-period Carpathian Basin would be advantageous to provide a more accurate picture of how TB may have impacted the ancestral human communities of the Barbaricum.

Professor David Minnikin Memorial Lecture: An era of the mycobacterial cell wall lipid biomarkers

This paper is dedicated to the memory of Professor David Ernest Minnikin (1939-2021). David was one of the key scientists who pioneered the field of Mycobacterium tuberculosis cell envelope research for over half a century. From the classification, identification, and extraction of the unusual lipids of the mycobacterial cell wall, to exploiting them as characteristic lipid biomarkers for sensitive detection, his ideas enlightened a whole world of possibilities within the tuberculosis (TB) field. In addition, his definition of the intricate models now forms a key milestone in our understanding of the M. tuberculosis cell envelope and has resolved many unanswered questions on the evolution of M. tuberculosis.

Leprosy: The age-old companion of humans - Re-evaluation and comparative analysis of Avar-period cases with Hansen's disease from the Danube-Tisza Interfluve, Hungary

In recent years, our knowledge of leprosy in the past has substantially been enriched. Nonetheless, much still remains to be discovered, especially in regions and periods from where no written sources are available. To fill in some research gaps, we provide the comparative analysis of eight Avar-period leprosy cases from the Danube-Tisza Interfluve (Hungary). In every case, to reconstruct the biological consequences of leprosy, the detected bony changes were linked with palaeopathological and modern medical information. To reconstruct the social consequences of being affected by leprosy, conceptualisation of the examined individuals' treatment in death was conducted. In every case, the disease resulted in deformation and disfigurement of the involved anatomical areas (rhinomaxillary region, feet, and/or hands) with difficulties in conducting certain physical activities. These would have been disadvantageous for the examined individuals and limited or changed their possibilities to participate in social situations. The most severe cases would have required continuous support from others to survive. Our findings indicate that, despite their very visible disease and associated debility, the examined communities did not segregate leprosy sufferers but provided and cared for them, and maintained a strong enough social network that made their survival possible even after becoming incapable of self-sufficiency.

The two extremes of Hansen’s disease—Different manifestations of leprosy and their biological consequences in an Avar Age (late 7th century CE) osteoarchaeological series of the Duna-Tisza Interfluve (Kiskundorozsma–Daruhalom-dűlő II, Hungary)

To give an insight into the different manifestations of leprosy and their biological consequences in the Avar Age of the Hungarian Duna-Tisza Interfluve, two cases from the 7^th-century-CE osteoarchaeological series of Kiskundorozsma–Daruhalom-dűlő II (Hungary; n = 94) were investigated. Based on the macromorphology of the bony changes indicative of Hansen’s disease, KD271 (a middle-aged male) and KD520 (a middle-aged female) represent the two extremes of leprosy. KD271 appears to have an advanced-stage, long-standing near-lepromatous or lepromatous form of the disease, affecting not only the rhinomaxillary region but also both upper and lower limbs. This has led to severe deformation and disfigurement of the involved anatomical areas of the skeleton, resulting in his inability to perform the basic activities of daily living, such as eating, drinking, grasping, standing or walking. The skeleton of KD520 shows no rhinomaxillary lesions and indicates the other extreme of leprosy, a near-tuberculoid or tuberculoid form of the disease. As in KD271, Hansen’s disease has resulted in disfigurement and disability of both of the lower limbs of KD520; and thus, the middle-aged female would have experienced difficulties in standing, walking, and conducting occupational physical activities. KD271 and KD520 are amongst the very few published cases with leprosy from the Avar Age of the Hungarian Duna-Tisza Interfluve, and the only examples with detailed macromorphological description and differential diagnoses of the observed leprous bony changes. The cases of these two severely disabled individuals, especially of KD271 –who would have required regular and substantial care from others to survive–imply that in the Avar Age community of Kiskundorozsma–Daruhalom-dűlő II there was a willingness to care for people in need.

Creating communities of care: Sex estimation and mobility histories of adolescents buried in the cemetery of St. Mary Magdalen leprosarium (Winchester, England)

Objectives

This study examines the biological sex and geographical origins of adolescents buried at the St Mary Magdalen leprosarium (Winchester, UK). The data are combined with archaeological and palaeopathological evidence to broaden the understanding of mobility and its relationship to leprosy and leprosaria in Medieval England.

Materials and Methods

Nineteen individuals (~10–25 at death) with skeletal lesions diagnostic of leprosy were analyzed using standard osteological methods. Amelogenin peptides were extracted from five individuals whose biological sex could not be assessed from macroscopic methods. Enamel samples were analyzed to produce ⁸⁷Sr/⁸⁶Sr and δ¹⁸O values to explore mobility histories.

Results

Amelogenin peptides revealed three males and two females. Tooth enamel samples provided an ⁸⁷Sr/⁸⁶Sr ratio range from 0.7084 to 0.7103 (mean 0.7090, ±0.0012, 2σ). δ¹⁸O_P values show a wide range of 15.6‰–19.3‰ (mean 17.8 ± 1.6‰ 2σ), with corresponding δ¹⁸O_DW values ranging from −9.7‰ to −4.1‰ (mean −6.3 ± 2.4‰ 2σ).

Discussion

Amelogenin peptide data reveal the presence of adolescent females with bone changes of leprosy, making them the youngest confirmed females with leprosy in the archaeological record. Results also show at least 12 adolescents were local, and seven were from further afield, including outside Britain. Since St. Mary Magdalen was a leprosarium, it is possible that these people traveled there specifically for care. Archaeological and palaeopathological data support the notion that care was provided at this facility and that leprosy stigma, as we understand it today, may not have existed in this time and place.

A probable case of leprosy from colonial period St. Vincent and the Grenadines, Southeastern Caribbean

OBJECTIVE

To document and differentially diagnose facial pathology found in an isolated skull from St. Vincent and the Grenadines, southeastern Caribbean. To directly date this individual using radiocarbon dating.

MATERIALS

Isolated skull recovered from Petite Mustique Island.

METHODS

Describe facial pathology occurring in this individual and compare with known diseases or disease processes that impact the craniofacial complex.

RESULTS

Features of the rhinomaxillary syndrome are present, indicating a diagnosis of leprosy. Dating places the time of death to the late 18th or early 19th centuries.

CONCLUSIONS

Analysis of the rhinomaxillary syndrome produces a diagnosis of early-stage leprosy in an individual that correlates with the apparent attempt to locate a leprosarium on Petite Mustique Island in the first decade of the 19th century.

SIGNIFICANCE

Location and time corroborate historical records of at least one attempt to locate a leprosarium on Petite Mustique Island. Only directly dated individual with leprosy in the western hemisphere and possibly the earliest yet recorded.

LIMITATIONS

This is an isolated find that is archaeologically unprovenienced.

SUGGESTIONS FOR FURTHER RESEARCH

Professional archaeological survey of Petite Mustique.

Life and death of a leprosy sufferer from the 8th-century-CE cemetery of Kiskundorozsma–Kettőshatár I (Duna-Tisza Interfluve, Hungary)—Biological and social consequences of having Hansen’s disease in a late Avar Age population from Hungary

The aim of our paper is to demonstrate a middle-aged male (KK61) from the 8^th-century-CE cemetery of Kiskundorozsma–Kettőshatár I (Duna-Tisza Interfluve, Hungary), who appears to represent the lepromatous form of Hansen’s disease. Leprosy has affected not only the rhinomaxillary region of his face but also his lower limbs, with severe deformation and disfigurement of the involved anatomical areas (saddle-nose and flat-foot deformity, respectively). Consequently, he would have experienced disability in performing the basic activities of daily living, such as eating, drinking, standing or walking; and thus, he would have required regular and substantial care from others to survive. Despite his very visible disease and associated debility, it seems that KK61 was accepted as a member of the community in death, since he has been buried within the cemetery boundaries, among others from his community. In addition, his grave has conformed to the mortuary practices characteristic of the Kiskundorozsma–Kettőshatár I cemetery (e.g., burial orientation, position of the body in the grave, and type and quantity of accompanying grave goods). Although distinction or segregation in life do not preclude normative treatment in death, the long-lasting survival of KK61 with Hansen’s disease implies that he would not have been abandoned but cared for by others. KK61 is one of the few published historic cases with leprosy from the Avar Age of the Hungarian Duna-Tisza Interfluve. His case gives us a unique insight into the biological consequences of living with Hansen’s disease and illustrates the social attitude toward leprosy sufferers in early mediaeval Hungary.

Badania kopalnego DNA – możliwości i ograniczenia

Ostatnie cztery dekady przyniosły znaczący rozwój archeologii molekularnej i badania nad kopalnym DNA (aDNA). Nowatorskie metody uwzględniają szeroki zakres badań, począwszy od sekwencjonowania niewielkich fragmentów mitochondrialnego DNA po wielkoskalowe badania całych populacji, łączące sekwencjonowanie genomów mitochondrialnych, genów podlegających doborowi naturalnemu, jak i całych genomów jądrowych. Postęp, zwłaszcza w dziedzinie technologii sekwencjonowania DNA, umożliwił pozyskanie informacji ze szczątków paleontologicznych i materiału archeologicznego, umożliwiając zbadanie związków filogenetycznych między wymarłymi i współczesnymi gatunkami. Dzięki zastosowaniu technologii sekwencjonowania nowej generacji możliwe stało się poznanie sekwencji DNA nie tylko bezpośrednio ze szczątków ludzkich lub zwierzęcych, ale także z osadów sedymentacyjnych z głębin jezior oraz jaskiń. W artykule przedstawiono możliwości i ograniczenia występujące w badaniach nad kopalnym DNA ludzi, zwierząt czy bakterii z podkreśleniem wkładu polskich badaczy w rozwój tej dziedziny nauki.

Mycobacterium leprae diversity and population dynamics in medieval Europe from novel ancient genomes

BACKGROUND

Hansen's disease (leprosy), widespread in medieval Europe, is today mainly prevalent in tropical and subtropical regions with around 200,000 new cases reported annually. Despite its long history and appearance in historical records, its origins and past dissemination patterns are still widely unknown. Applying ancient DNA approaches to its major causative agent, Mycobacterium leprae, can significantly improve our understanding of the disease's complex history. Previous studies have identified a high genetic continuity of the pathogen over the last 1500 years and the existence of at least four M. leprae lineages in some parts of Europe since the Early Medieval period.

RESULTS

Here, we reconstructed 19 ancient M. leprae genomes to further investigate M. leprae's genetic variation in Europe, with a dedicated focus on bacterial genomes from previously unstudied regions (Belarus, Iberia, Russia, Scotland), from multiple sites in a single region (Cambridgeshire, England), and from two Iberian leprosaria. Overall, our data confirm the existence of similar phylogeographic patterns across Europe, including high diversity in leprosaria. Further, we identified a new genotype in Belarus. By doubling the number of complete ancient M. leprae genomes, our results improve our knowledge of the past phylogeography of M. leprae and reveal a particularly high M. leprae diversity in European medieval leprosaria.

CONCLUSIONS

Our findings allow us to detect similar patterns of strain diversity across Europe with branch 3 as the most common branch and the leprosaria as centers for high diversity. The higher resolution of our phylogeny tree also refined our understanding of the interspecies transfer between red squirrels and humans pointing to a late antique/early medieval transmission. Furthermore, with our new estimates on the past population diversity of M. leprae, we gained first insights into the disease's global history in relation to major historic events such as the Roman expansion or the beginning of the regular transatlantic long distance trade. In summary, our findings highlight how studying ancient M. leprae genomes worldwide improves our understanding of leprosy's global history and can contribute to current models of M. leprae's worldwide dissemination, including interspecies transmissions.

Syndemics and the history of disease: Towards a new engagement

Historians of medicine and disease have yet to think through a syndemic lens. This commentary aims to point out why they should. Although there are several hurdles to overcome, our histories of disease and our understanding of current syndemics both stand to gain should historians begin to explore episodes of cooccurring diseases that share root causes.

Evolutionary history of Mycobacterium leprae in the Pacific Islands

As one of the oldest known human diseases, leprosy or Hansen's disease remains a public health concern around the world with over 200 000 new cases in 2018. Most human leprosy cases are caused by Mycobacterium leprae, but a small number of cases are now known to be caused by Mycobacterium lepromatosis, a sister taxon of M. leprae. The global pattern of genomic variation in M. leprae is not well defined. Particularly, in the Pacific Islands, the origins of leprosy are disputed. Historically, it has been argued that leprosy arrived on the islands during nineteenth century colonialism, but some oral traditions and palaeopathological evidence suggest an older introduction. To address this, as well as investigate patterns of pathogen exchange across the Pacific Islands, we extracted DNA from 39 formalin-fixed paraffin-embedded biopsy blocks dating to 1992-2016. Using whole-genome enrichment and next-generation sequencing, we produced nine M. leprae genomes dating to 1998-2015 and ranging from 4-63× depth of coverage. Phylogenetic analyses indicate that these strains belong to basal lineages within the M. leprae phylogeny, specifically falling in branches 0 and 5. The phylogeographical patterning and evolutionary dating analysis of these strains support a pre-modern introduction of M. leprae into the Pacific Islands. This article is part of the theme issue 'Insights into health and disease from ancient biomolecules'.

Molecular epidemiology of leprosy: An update

Molecular epidemiology investigations are notoriously challenging in the leprosy field mainly because the inherent characteristics of the disease as well as its yet uncultivated causative agents, Mycobacterium leprae and M. lepromatosis. Despite significant developments in understanding the biology of leprosy bacilli through genomic approaches, the exact mechanisms of transmission is still unclear and the factors underlying pathological variation of the disease in different patients remain as major gaps in our knowledge about leprosy. Despite these difficulties, the last two decades have seen the development of genotyping procedures based on PCR-sequencing of target loci as well as by the genome-wide analysis of an increasing number of geographically diverse isolates of leprosy bacilli. This has provided a foundation for molecular epidemiology studies that are bringing a better understanding of strain evolution associated with ancient human migrations, and phylogeographical insights about the spread of disease globally. This review discusses the advantages and drawbacks of the main tools available for molecular epidemiological investigations of leprosy and summarizes various methods ranging from PCR-based genotyping to genome-typing techniques. We also describe their main applications in analyzing the short-range and long-range transmission of the disease. Finally, we summarise the current gaps and challenges that remain in the field of molecular epidemiology of leprosy.

Archival, paleopathological and aDNA-based techniques in leprosy research and the case of Father Petrus Donders at the Leprosarium 'Batavia', Suriname

OBJECTIVE

We assessed whether Petrus Donders (died 1887), a Dutch priest who for 27 years cared for people with leprosy in the leprosarium Batavia, Suriname, had evidence of Mycobacterium (M.) leprae infection. A positive finding of M. leprae ancient (a)DNA would contribute to the origin of leprosy in Suriname.

MATERIALS

Skeletal remains of Father Petrus Donders; two additional skeletons excavated from the Batavia cemetery were used as controls.

METHODS

Archival research, paleopathological evaluation and aDNA-based testing of skeletal remains.

RESULTS

Neither archives nor inspection of Donders skeletal remains revealed evidence of leprosy, and aDNA-based testing for M. leprae was negative. We detected M. leprae aDNA by RLEP PCR in one control skeleton, which also displayed pathological lesions compatible with leprosy. The M. leprae aDNA was genotyped by Sanger sequencing as SNP type 4; the skeleton displayed mitochondrial haplogroup L3.

CONCLUSION

We found no evidence that Donders contracted leprosy despite years of intense leprosy contact, but we successfully isolated an archaeological M. leprae aDNA sample from a control skeleton from South America.

SIGNIFICANCE

We successfully genotyped recovered aDNA to a M. leprae strain that likely originated in West Africa. The detected human mitochondrial haplogroup L3 is also associated with this geographical region. This suggests that slave trade contributed to leprosy in Suriname.

LIMITATIONS

A limited number of skeletons was examined.

SUGGESTIONS FOR FURTHER RESEARCH

Broader review of skeletal collections is advised to expand on diversity of the M. leprae aDNA database.

Revisiting the tuberculosis and leprosy cross-immunity hypothesis: Expanding the dialogue between immunology and paleopathology

OBJECTIVE

Our primary objective is to re-visit the tuberculosis and leprosy cross-immunity. hypothesis through the careful integration of immunology and paleopathology.

METHODS

Using an integrated theoretical analysis that evaluates clinical literature on human innate immunological responses, paleomicrobiology, bioarchaeology, and paleopathology, we develop a multifactorial model.

RESULTS

Past populations do not represent homogeneous immunological landscapes, and therefore it is likely that leprosy in Medieval Europe did not uniformly decline due to cross-immunity.

CONCLUSIONS

We recommend that bioarchaeological reconstructions of past disease experience take into consideration models that include variation in immune function based on past environments and social contexts. This provides a unique opportunity to conduct comprehensive analyses on complex immunological processes.

SIGNIFICANCE

Extrapolating results from experimental immunology to larger populations elucidates complexities of disease cross-immunity and highlights the importance of synthesizing archaeological, social, paleopathological and biological data as a means of understanding disease in the past.

LIMITATIONS

All extrapolations from data produced from in vitro studies to past populations, using living donors, pose significant limitations where, among other factors, the full reconstruction of past environmental and social contexts can frequently be sparse or incomplete.

SUGGESTIONS FOR FUTURE RESEARCH

To reduce the limitations of integrating experimental immunology with bioarchaeological reconstructions (i.e. how to use skeletal samples to reconstruct inflammatory phenotypes), we propose that osteoimmunology, or the study of the interplay between immune cells and bone cells, should be considered a vital discipline and perhaps the foundation for the expansion of paleoimmunology.

Tuberculosis and leprosy associated with historical human population movements in Europe and beyond - an overview based on mycobacterial ancient DNA

Context: Tuberculosis and leprosy are readily recognised in human remains due to their typical palaeopathology. Both Mycobacterium tuberculosis (MTB) and Mycobacterium leprae (ML) are obligate pathogens and have been detected in ancient human populations. Objective: To demonstrate historical tuberculosis and leprosy cases in Europe and beyond using molecular methods, as human populations are associated with different mycobacterial genotypes. Methods: MTB and ML ancient DNA (aDNA) has been detected by DNA amplification using PCR, or by whole genome sequencing. Mycobacterial cell wall lipids also provide specific markers for identification. Results: In 18th century Hungary, the European indigenous MTB genotype 4 strains have been found. However, many individuals were co-infected with up to three MTB sub-genotypes. In 8th-14th century Europe significant differences in ML genotypes were found between northwest Europe compared with central, southern, or eastern Europe. In addition, several co-infections of MTB and ML were detected in historical samples. Conclusion: Both MTB and ML strain types differ between geographically separate populations. This is associated with ancient human migration after an evolutionary bottleneck and clonal expansion. The absence of indigenous leprosy in Europe today may be due to the greater mortality of tuberculosis in individuals who are co-infected with both organisms.

Ancient genomes reveal a high diversity of Mycobacterium leprae in medieval Europe

Studying ancient DNA allows us to retrace the evolutionary history of human pathogens, such as Mycobacterium leprae, the main causative agent of leprosy. Leprosy is one of the oldest recorded and most stigmatizing diseases in human history. The disease was prevalent in Europe until the 16th century and is still endemic in many countries with over 200,000 new cases reported annually. Previous worldwide studies on modern and European medieval M. leprae genomes revealed that they cluster into several distinct branches of which two were present in medieval Northwestern Europe. In this study, we analyzed 10 new medieval M. leprae genomes including the so far oldest M. leprae genome from one of the earliest known cases of leprosy in the United Kingdom-a skeleton from the Great Chesterford cemetery with a calibrated age of 415-545 C.E. This dataset provides a genetic time transect of M. leprae diversity in Europe over the past 1500 years. We find M. leprae strains from four distinct branches to be present in the Early Medieval Period, and strains from three different branches were detected within a single cemetery from the High Medieval Period. Altogether these findings suggest a higher genetic diversity of M. leprae strains in medieval Europe at various time points than previously assumed. The resulting more complex picture of the past phylogeography of leprosy in Europe impacts current phylogeographical models of M. leprae dissemination. It suggests alternative models for the past spread of leprosy such as a wide spread prevalence of strains from different branches in Eurasia already in Antiquity or maybe even an origin in Western Eurasia. Furthermore, these results highlight how studying ancient M. leprae strains improves understanding the history of leprosy worldwide.

Ancient DNA study reveals HLA susceptibility locus for leprosy in medieval Europeans

Leprosy, a chronic infectious disease caused by Mycobacterium leprae (M. leprae), was very common in Europe till the 16th century. Here, we perform an ancient DNA study on medieval skeletons from Denmark that show lesions specific for lepromatous leprosy (LL). First, we test the remains for M. leprae DNA to confirm the infection status of the individuals and to assess the bacterial diversity. We assemble 10 complete M. leprae genomes that all differ from each other. Second, we evaluate whether the human leukocyte antigen allele DRB1*15:01, a strong LL susceptibility factor in modern populations, also predisposed medieval Europeans to the disease. The comparison of genotype data from 69 M. leprae DNA-positive LL cases with those from contemporary and medieval controls reveals a statistically significant association in both instances. In addition, we observe that DRB1*15:01 co-occurs with DQB1*06:02 on a haplotype that is a strong risk factor for inflammatory diseases today.

Leprosy, caused by infection with Mycobacterium leprae, was common in Europe in the Middle Ages. Here, Krause-Kyora et al. analyze ancient DNA from a medieval Danish leprosarium to assemble 10 complete bacterial genomes and perform association analysis of the DRB1*15:01 allele with risk of leprosy infection.

Phylogenomics and antimicrobial resistance of the leprosy bacillus Mycobacterium leprae

Leprosy is a chronic human disease caused by the yet-uncultured pathogen Mycobacterium leprae. Although readily curable with multidrug therapy (MDT), over 200,000 new cases are still reported annually. Here, we obtain M. leprae genome sequences from DNA extracted directly from patients’ skin biopsies using a customized protocol. Comparative and phylogenetic analysis of 154 genomes from 25 countries provides insight into evolution and antimicrobial resistance, uncovering lineages and phylogeographic trends, with the most ancestral strains linked to the Far East. In addition to known MDT-resistance mutations, we detect other mutations associated with antibiotic resistance, and retrace a potential stepwise emergence of extensive drug resistance in the pre-MDT era. Some of the previously undescribed mutations occur in genes that are apparently subject to positive selection, and two of these (ribD, fadD9) are restricted to drug-resistant strains. Finally, nonsense mutations in the nth excision repair gene are associated with greater sequence diversity and drug resistance.

Leprosy is caused by the yet-uncultured pathogen Mycobacterium leprae. Here, Benjak et al. obtain M. leprae genome sequences from DNA extracted from patients' skin biopsies and, by analysing 154 genomes from 25 countries, provide insight into the pathogen’s evolution and antimicrobial resistance.

Possible cases of leprosy from the Late Copper Age (3780-3650 cal BC) in Hungary

At the Abony-Turjányos dűlő site, located in Central Hungary, a rescue excavation was carried out. More than 400 features were excavated and dated to the Protoboleráz horizon, at the beginning of the Late Copper Age in the Carpathian Basin, between 3780-3650 cal BC. Besides the domestic and economic units, there were two special areas, with nine-nine pits that differed from the other archaeological features of the site. In the northern pit group seven pits contained human remains belonging to 48 individuals. Some of them were buried carefully, while others were thrown into the pits. The aim of this study is to present the results of the paleopathological and molecular analysis of human remains from this Late Copper Age site. The ratio of neonates to adults was high, 33.3%. Examination of the skeletons revealed a large number of pathological cases, enabling reconstruction of the health profile of the buried individuals. Based on the appearance and frequency of healed ante- and peri mortem trauma, inter-personal (intra-group) violence was characteristic in the Abony Late Copper Age population. However other traces of paleopathology were observed on the bones that appear not to have been caused by warfare or inter-group violence. The remains of one individual demonstrated a rare set of bone lesions that indicate the possible presence of leprosy (Hansen's disease). The most characteristic lesions occurred on the bones of the face, including erosion of the nasal aperture, atrophy of the anterior nasal spine, inflammation of the nasal bone and porosity on both the maxilla and the bones of the lower legs. In a further four cases, leprosy infection is suspected but other infections cannot be excluded. The morphologically diagnosed possible leprosy case significantly modifies our knowledge about the timescale and geographic spread of this specific infectious disease. However, it is not possible to determine the potential connections between the cases of possible leprosy and the special burial circumstances.

Leprosy in a Lombard-Avar cemetery in central Italy (Campochiaro, Molise, 6th-8th century AD): ancient DNA evidence and demography

BACKGROUND

The study of past infectious diseases increases knowledge of the presence, impact and spread of pathogens within ancient populations.

AIM

Polymerase chain reaction (PCR) was used to examine bones for the presence of Mycobacterium leprae ancient DNA (aDNA) as, even when leprosy is present, bony changes are not always pathognomonic of the disease. This study also examined the demographic profile of this population and compared it with two other populations to investigate any changes in mortality trends between different infectious diseases and between the pre-antibiotic and antibiotic eras.

SUBJECTS AND METHODS

The individuals were from a site in Central Italy (6th-8th CE) and were examined for the presence of Mycobacterium leprae aDNA. In addition, an abridged life mortality table was constructed.

RESULTS

Two individuals had typical leprosy palaeopathology, and one was positive for Mycobacterium leprae aDNA. However, the demographic profile shows a mortality curve similar to that of the standard, in contrast to a population that had been subjected to bubonic plague.

CONCLUSIONS

This study shows that, in the historical population with leprosy, the risk factors for health seem to be constant and distributed across all age classes, similar to what is found today in the antibiotic era. There were no peaks of mortality equivalent to those found in fatal diseases such as the plague, probably due to the long clinical course of leprosy.

Paleomicrobiology of Leprosy

The use of paleomicrobiological techniques in leprosy has the potential to assist paleopathologists in many important aspects of their studies on the bones of victims, solving at times diagnostic problems. With Mycobacterium leprae, because of the unique nature of the organism, these techniques can help solve problems of differential diagnosis. In cases of co-infection with Mycobacterium tuberculosis, they can also suggest a cause of death and possibly even trace the migratory patterns of people in antiquity, as well as explain changes in the rates and level of infection within populations in antiquity.

Paleopathology of Human Infections: Old Bones, Antique Books, Ancient and Modern Molecules

Paleopathology studies the traces of disease on human and animal remains from ancient times. Infectious diseases have been, for over a century, one of its main fields of interest. The applications of paleogenetics methods to microbial aDNA, that started in the 90s combined to the recent development of new sequencing techniques allowing 'paleogenomics' approaches, have completely renewed the issue of the infections in the past. These advances open up new challenges in the understanding of the evolution of human-pathogen relationships, integrated in "One Health" concept.In this perspective, an integrative multidisciplinary approach combining data from ancient texts and old bones to those of old molecules is of great interest for reconstructing the past of human infections. Despite some too optimistic prediction of their eradication in the late 20th century, some of these ancient human diseases, such as plague, leprosy or tuberculosis, are still present and continue their evolution at the beginning of this 21rst century. Better know the past to predict a part of the future of human diseases remains, more than ever, the motto of the paleopathological science.

Red squirrels in the British Isles are infected with leprosy bacilli

Leprosy, caused by infection with Mycobacterium leprae or the recently discovered Mycobacterium lepromatosis, was once endemic in humans in the British Isles. Red squirrels in Great Britain (Sciurus vulgaris) have increasingly been observed with leprosy-like lesions on the head and limbs. Using genomics, histopathology, and serology, we found M. lepromatosis in squirrels from England, Ireland, and Scotland, and M. leprae in squirrels from Brownsea Island, England. Infection was detected in overtly diseased and seemingly healthy animals. Phylogenetic comparisons of British and Irish M. lepromatosis with two Mexican strains from humans show that they diverged from a common ancestor around 27,000 years ago, whereas the M. leprae strain is closest to one that circulated in Medieval England. Red squirrels are thus a reservoir for leprosy in the British Isles.

Changes in North Atlantic Oscillation drove Population Migrations and the Collapse of the Western Roman Empire

Shifts in the North Atlantic Oscillation (NAO) from 1-2 to 0-1 in four episodes increased droughts on the Roman Empire's periphery and created push factors for migrations. These climatic events are associated with the movements of the Cimbri and Teutones from 113-101 B.C., the Marcomanni and Quadi from 164 to 180 A.D., the Goths in 376 A.D., and the broad population movements of the Migration Period from 500 to 600 A.D. Weakening of the NAO in the instrumental record of the NAO have been associated with a shift to drought in the areas of origin for the Cimbri, Quadi, Visigoths, Ostrogoths, Huns, and Slavs. While other climate indices indicate deteriorating climate after 200 A.D. and cooler conditions after 500 A.D., the NAO may indicate a specific cause for the punctuated history of migrations in Late Antiquity. Periodic weakening of the NAO caused drought in the regions of origin for tribes in antiquity, and may have created a powerful push factor for human migration. While climate change is frequently considered as a threat to sustainability, its role as a conflict amplifier in history may be one of its largest impacts on populations.

Molecular studies on ancient M. tuberculosis and M. leprae: methods of pathogen and host DNA analysis

Humans have evolved alongside infectious diseases for millennia. Despite the efforts to reduce their incidence, infectious diseases still pose a tremendous threat to the world population. Fast development of molecular techniques and increasing risk of new epidemics have resulted in several studies that look to the past in order to investigate the origin and evolution of infectious diseases. Tuberculosis and leprosy have become frequent targets of such studies, owing to the persistence of their molecular biomarkers in ancient material and the characteristic skeletal lesions each disease may cause. This review examines the molecular methods used to screen for the presence of M. tuberculosis and M. leprae ancient DNA (aDNA) and their differentiation in ancient human remains. Examples of recent studies, mainly from Europe, that employ the newest techniques of molecular analysis are also described. Moreover, we present a specific approach based on assessing the likely immunological profile of historic populations, in order to further elucidate the influence of M. tuberculosis and M. leprae on historical human populations.