Paleoepidemiology of cribra orbitalia: Insights from early seventh millennium BP Con Co Ngua, Vietnam.

OBJECTIVES: We test the hypothesis that the condition(s) leading to the development of cribra orbitalia at Con Co Ngua, an early seventh millennium sedentary foraging community in Vietnam, effectively reduced the resilience of the population to subsequent health/disease impacts. An assessment of both the implications and potential etiology of cribra orbitalia in this specific population is carried out. METHODS: The effective sample included 141 adults aged ≥15 years (53 females, 71 males, and 17 unknown sex) and 15 pre-adults aged ≤14 years. Cribra orbitalia was identified by way of cortical bone porosity of the orbital roof initiated within the diplöic space, rather than initiated subperiosteally. The approach is also robust to the misidentification of various pseudo-lesions. Resultant data was analyzed using Kaplan-Meier survival analysis. RESULTS: Median survival is higher in adults aged ≥15 years without cribra orbitalia than those with this lesion. For the pre-adult cohort, the opposite pattern is seen where median survival is higher in those with cribra orbitalia than those without. CONCLUSION: Adults displayed increased frailty and pre-adults increased resilience with respect to cribra orbitalia. The differential diagnosis for a survival analysis of adults and pre-adults with and without cribra orbitalia included iron deficiency anemia and B12/folate deficiency, parasitism (including hydatid disease and malaria) in addition to thalassemia. The most parsimonious explanation for observed results is for both thalassemia and malaria being the chief etiological agents, while appreciating these conditions interact with, and can cause, other forms such as hematinic deficiency anemias.

Technical note: The use and misuse of threshold diagnostic criteria in paleopathology.

Weighted threshold diagnostic criteria approaches have emerged for diseases that involve skeletal/bony tissue that are readily diagnosed in the field of paleopathology such as Vitamin C deficiency (scurvy), Vitamin D deficiency (rickets) and treponemal disease. These criteria differ from traditional differential diagnosis in that they involve standardized inclusion criteria based on the lesion's specificity to the disease. Here I discuss the limitations and benefits of threshold criteria. I argue that while these criteria will benefit from further revision such as inclusion of lesion severity, and the incorporation of exclusion criteria, threshold diagnostic approaches have considerable value in the future of diagnosis in the field.

Climate change, human health, and resilience in the Holocene.

Climate change is an indisputable threat to human health, especially for societies already confronted with rising social inequality, political and economic uncertainty, and a cascade of concurrent environmental challenges. Archaeological data about past climate and environment provide an important source of evidence about the potential challenges humans face and the long-term outcomes of alternative short-term adaptive strategies. Evidence from well-dated archaeological human skeletons and mummified remains speaks directly to patterns of human health over time through changing circumstances. Here, we describe variation in human epidemiological patterns in the context of past rapid climate change (RCC) events and other periods of past environmental change. Case studies confirm that human communities responded to environmental changes in diverse ways depending on historical, sociocultural, and biological contingencies. Certain factors, such as social inequality and disproportionate access to resources in large, complex societies may influence the probability of major sociopolitical disruptions and reorganizations-commonly known as "collapse." This survey of Holocene human-environmental relations demonstrates how flexibility, variation, and maintenance of Indigenous knowledge can be mitigating factors in the face of environmental challenges. Although contemporary climate change is more rapid and of greater magnitude than the RCC events and other environmental changes we discuss here, these lessons from the past provide clarity about potential priorities for equitable, sustainable development and the constraints of modernity we must address.

Human femur morphology and histology variation with ancestry and behaviour in an ancient sample from Vietnam.

BACKGROUND: There is a genetic component to the minimum effective strain (MES)-a threshold which determines when bone will adapt to function-which suggests ancestry should play a role in bone (re)modelling. Further elucidating this is difficult in living human populations because of the high global genetic admixture. We examined femora from an anthropological skeletal assemblage (Mán Bac, Vietnam) representing distinct ancestral groups. We tested whether femur morphological and histological markers of modelling and remodelling differed between ancestries despite their similar lifestyles. METHODS: Static histomorphometry data collected from subperiosteal cortical bone of the femoral midshaft, and gross morphometric measures of femur robusticity, were studied in 17 individuals from the Mán Bac collection dated to 1906-1523 cal. BC. This assemblage represents agricultural migrants with affinity to East Asian groups, who integrated with the local hunter-gatherers with affinity to Australo-Papuan groups during the mid-Holocene. Femur robusticity and histology data were compared between groups of 'Migrant' (n = 8), 'Admixed' (n = 4), and 'Local' (n = 5). RESULTS: Local individuals had more robust femoral diaphyses with greater secondary osteon densities, and relatively large secondary osteon and Haversian canal parameters than the migrants. The Migrant group showed gracile femoral shafts with the least dense bone made up of small secondary osteons and Haversian canals. The Admixed individuals fell between the Migrant and Local categories in terms of their femoral data. However, we also found that measures of how densely bone is remodelled per unit area were in a tight range across all three ancestries. CONCLUSIONS: Bone modelling and remodelling markers varied with ancestral histories in our sample. This suggests that there is an ancestry related predisposition to bone optimising its metabolic expenditure likely in relation to the MES. Our results stress the need to incorporate population genetic history into hierarchical bone analyses. Understanding ancestry effects on bone morphology has implications for interpreting biomechanical loading history in past and modern human populations.

The role of dietary calcium in the etiology of childhood rickets in the past and the present.

For more than two centuries, lack of sunlight has been understood to cause vitamin D deficiency and documented as a primary cause of rickets. As such, evidence of rickets in the archeological record has been used as a proxy for vitamin D status in past individuals and populations. In the last decade, a clinical global consensus has emerged wherein it is recognized that dietary calcium deficiency also plays a role in the manifestation of rickets and classic skeletal deformities may not form if dietary calcium is normal even if vitamin D is deficient. This disease is now clinically called "nutritional rickets" to reflect the fact that rickets can take calcium deficiency-predominant or vitamin D deficiency-predominant forms. However, there are currently no paleopathological studies wherein dietary calcium deficiency is critically considered a primary etiology of the disease. We review here the interplay of calcium, vitamin D, and phosphorous in bone homeostasis, examine the role of dietary calcium in human health, and critically explore the clinical literature on calcium deficiency-predominant rickets. Finally, we report a case of rickets from the late Formative Period (~2500-1500 years ago) of the Atacama Desert and argue the disease in this infant is likely an example of calcium deficiency-predominant rickets. We conclude that most archeological cases of rickets are the result of multiple micronutrient deficiencies that compound to manifest in macroscopic skeletal lesions. For clinicians, these factors are important for implementing best treatment practice, and for paleopathologists they are necessary for appropriate interpretation of health in past communities.

Surgical amputation of a limb 31,000 years ago in Borneo.

The prevailing view regarding the evolution of medicine is that the emergence of settled agricultural societies around 10,000 years ago (the Neolithic Revolution) gave rise to a host of health problems that had previously been unknown among non-sedentary foraging populations, stimulating the first major innovations in prehistoric medical practices1,2. Such changes included the development of more advanced surgical procedures, with the oldest known indication of an 'operation' formerly thought to have consisted of the skeletal remains of a European Neolithic farmer (found in Buthiers-Boulancourt, France) whose left forearm had been surgically removed and then partially healed3. Dating to around 7,000 years ago, this accepted case of amputation would have required comprehensive knowledge of human anatomy and considerable technical skill, and has thus been viewed as the earliest evidence of a complex medical act3. Here, however, we report the discovery of skeletal remains of a young individual from Borneo who had the distal third of their left lower leg surgically amputated, probably as a child, at least 31,000 years ago. The individual survived the procedure and lived for another 6-9 years, before their remains were intentionally buried in Liang Tebo cave, which is located in East Kalimantan, Indonesian Borneo, in a limestone karst area that contains some of the world's earliest dated rock art4. This unexpectedly early evidence of a successful limb amputation suggests that at least some modern human foraging groups in tropical Asia had developed sophisticated medical knowledge and skills long before the Neolithic farming transition.

Hydatid disease (Echinococcosis granulosis) diagnosis from skeletal osteolytic lesions in an early seventh-millennium BP forager community from preagricultural northern Vietnam.

OBJECTIVES: Con Co Ngua is a complex, sedentary forager site from northern Vietnam dating to the early seventh millennium BP. Prior research identified a calcified Echinococcus granulosis cyst, which causes hydatid disease. Osteolytic lesions consistent with hydatid disease were also present in this individual and others. Hydatid disease is observed in high frequencies in pastoralists, and its presence in a hunter-gatherer community raises questions regarding human-animal interaction prior to farming. The objective of this article is to identify and describe the epidemiology of hydatid disease in the human skeletal assemblage at Con Co Ngua. MATERIALS AND METHODS: One hundred and fifty-five individuals were macroscopically assessed for lesions. Of these, eight individuals were radiographed. Hydatid disease was diagnosed using a new threshold criteria protocol derived from clinical literature, which prioritizes lesions specific to the parasite. RESULTS: Twenty-two individuals (14.2%) presented with osteolytic lesions consistent with hydatid disease, affecting the distal humerus, proximal femur and forearm, and pelvis. Seven individuals radiographed (4.5%) had multilocular cystic lesions strongly diagnostic for hydatid disease. All probable cases had lesions of the distal humerus. The remaining lesions were macroscopically identical to those radiographed and were considered possible cases. DISCUSSION: While hydatid disease has previously been found in pre-agricultural communities, the high prevalence at Con Co Ngua is non-incidental. We propose that the presence of wild canids and management of wild buffalo and deer increased the risk of disease transmission. These findings further reveal subsistence complexity among hunter-gatherers living millennia prior to the adoption of farming in Southeast Asia.

Forager and farmer evolutionary adaptations to malaria evidenced by 7000 years of thalassemia in Southeast Asia.

Thalassemias are inherited blood disorders that are found in high prevalences in the Mediterranean, Southeast Asia and the Pacific. These diseases provide varying levels of resistance to malaria and are proposed to have emerged as an adaptive response to malaria in these regions. The transition to agriculture in the Holocene has been suggested to have influenced the selection for thalassemia in the Mediterranean as land clearance for farming encouraged interaction between Anopheles mosquitos, the vectors for malaria, and human groups. Here we document macroscopic and microscopic skeletal evidence for the presence of thalassemia in both hunter-gatherer (Con Co Ngua) and early agricultural (Man Bac) populations in northern Vietnam. Firstly, our findings demonstrate that thalassemia emerged prior to the transition to agriculture in Mainland Southeast Asia, from at least the early seventh millennium BP, contradicting a long-held assumption that agriculture was the main driver for an increase in malaria in Southeast Asia. Secondly, we describe evidence for significant malarial burden in the region during early agriculture. We argue that the introduction of farming into the region was not the initial driver of the selection for thalassemia, as it may have been in other regions of the world.

Sensationalism and speaking to the public: Scientific rigour and interdisciplinary collaborations in palaeopathology.

OBJECTIVES: In this brief communication we discuss issues concerning scientific rigour in palaeopathological publications, particularly studies published in clinical or general science journals, that employ skeletal analysis to elucidate the lives and deaths of historical figures or interpret "mysterious" assemblages or burials. We highlight the relationship between poor methodological rigour and lack of interdisciplinary communication, and discuss how this can result in scientifically weak, sensational narratives being presented to the public. CONCLUSIONS: Although most high profile publications involving analysis of archaeological human remains are methodologically sound and well interpreted, others have suffered from poor scientific rigour stemming from an apparent lack of awareness of anthropological methods and ethics. When these publications are highlighted by the press, sensationalistic narratives are perpetuated which may reflect poorly on our discipline and give the public unrealistic expectations about our work. SUGGESTIONS FOR FUTURE RESEARCH: We suggest that best practice in high-profile paleopathological research include recruitment of a range of authors and reviewers from clinical sciences, anthropology, and the humanities, consideration of the ethical issues surrounding retrospective diagnosis, and transparency with the press in regards to the limitations inherent in this kind of work.