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.

An Umbrella Review of the Evidence of Sex Determination Procedures in Forensic Dentistry.

Sex determination in forensic dentistry is a major step towards postmortem profiling. The most widely recognized method is DNA, yet its application in the dental field of forensic sciences is still impractical. Depending on the conditions of the remains, teeth are often the only surviving organ. Some systematic reviews (SRs) have been recently produced; hence this umbrella review critically assesses their level of evidence and provides an overall comprehensive view. An electronic database search was conducted in four databases (PubMed, Cochrane, Web of Science, and LILACS) and three grey search engines up to December 2021, focusing on SRs of sex determination through forensic dentistry procedures. The methodological quality of the SRs was analyzed using the measurement tool to assess SRs criteria (AMSTAR2). Five SRs were included, two of critically low quality and three of low quality. The SRs posited that canines are the most dimorphic teeth; oral tissue remnants are a rich source for sex determination by DNA tracing; and artificial intelligence tools demonstrate high potential in forensic dentistry. The quality of evidence on sex determination using dental approaches was rated as low. Well-designed clinical trials and high standard systematic reviews are essential to corroborate the accuracy of the different procedures of sex determination in forensic dentistry.

Validation of the Third Molar Maturation Index (I3M) to assess the legal adult age in the Portuguese population.

Age estimation is a major step in forensic and legal procedures. Its relevance has been increasing due to growing society issues, such as identification of missing people, crimes against minors or lack of valid identification papers from locals or foreigners. Evaluation of the cut-off value of the Third Molar Maturation Index (I3M) = 0.08 for discriminating minors from adults in the Portuguese population. The left lower third molars were analysed by applying a specific cut-off value of 0.08 determined by Cameriere et al. in 2008. A sample of 778 digital panoramic radiographs of a representative Portuguese sample (442 females and 336 males), in the age range of 12-24 years (mean age 17.7 ± 2.98 years in females and 18.1 ± 3.0 years in males), was retrospectively evaluated. I3M decreased as the real age gradually increased in both sexes. The 0.08 cut-off score was valuable in discriminating adults from minors. According to the pooled results, the accuracy, by means of area under the curve, was 92.8% (95% confidence interval (CI) 91.0-94.6%). The proportion of correctly classified subjects (sensitivity) was 90.7% (95% CI 88.7-92.8%) and the specificity was 94.9% (95% CI 93.3-96.4%). The results show that I3M is a valuable method to differentiate minors from adults in the Portuguese population.

Extracapsular fracture of the femur in an elderly male from the Church of Nossa Senhora da Anunciada (Setúbal, Portugal).

In modern populations, hip fractures in older people are associated with high morbidity and mortality. Their incidence is rising; notwithstanding, fractures of the proximal femur are still relatively uncommon in archeological contexts. This case study represents a well-healed hip fracture in an aged male skeleton from Church of Nossa Senhora da Anunciada (16th-19th centuries AD) in Setúbal (Portugal). The individual was also diagnosed with diffuse idiopathic skeletal hyperostosis. Fractures of the proximal femur are usually associated with bone loss but in this case other causes are proposed, including the anatomy of the proximal femur, and the potential combined effect of diffuse idiopathic skeletal hyperostosis, cardiovascular disease, diabetes mellitus and falls.

Toxocara eggs in an 18th century Franciscan from Portugal. The challenge of differentiating between parasitism and chance in Paleoparasitology.

In 2005, an adult male was excavated in the cloister of the former Convent of the Holy Spirit, in the Franciscan Province of Holy Mary of Arrábida, Lisbon district. From the anterior part of the sacrum, a darker organic agglomeration was collected and studied for intestinal parasites. Samples were rehydrated with Lycopodium tablets in a Na3PO4 5% solution for 72h, followed by the swirl technique. Organic material was concentrated at 2500rpm. At least 20 slides of each sample were examined using a light/polarized microscope. A control sample from outside the pelvis revealed no biological remains. A sample collected inside the pelvic girdle was positive for pollen grains, other plant remains and Toxocara eggs, perhaps T. cati (2766 eggs/gram sediment). This finding, although exciting, cannot be explained in a simple way because humans are not definitive hosts for Toxocara species. Ingestion of feces-contaminated food or water, geophagy, or true infection are hypotheses considered in this study, which demonstrates the difficulty of interpreting the presence of animal parasites in human remains. This is the first time Toxocara eggs are found associated with human remains.