Human intestinal parasites in the past: new findings and a review

Paleoparasitology research on ancient helminth eggs and larvae in the Republic of Korea

Paleoparasitology is a discipline that applies existing conventional and molecular techniques to study parasites found in ancient ruins. This review focuses on the history of the discovery of parasites (mostly helminth eggs and larvae) in archaeological soil samples and mummies in Korea from the Three Kingdoms Period to the Joseon Dynasty (100 BCE-1910 CE). We also briefly review important milestones in global paleoparasitology. The helminth species reported so far in Korea included Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis (larva), Trichostrongylus sp. (larva), Paracapillaria philippinensis (syn. Capillaria philippinensis), Enterobius vermicularis, Fasciola hepatica, dicrocoeliids, Paragonimus westermani, Clonorchis sinensis, Metagonimus yokogawai, Pygidiopsis summa, Gymnophalloides seoi, Isthmiophora hortensis, Dibothriocephalus nihonkaiensis (syn. Diphyllobothrium nihonkaiense), and Taenia spp. tapeworms. The findings obtained by Korean paleoparasitologists/archaeologists have brought about deep insight into the status of helminthic infections in Korea's past populations. Continued paleoparasitological research is essential for further understanding of ancient parasites and parasitic diseases in Korea.

The eukaryome of African children is influenced by geographic location, gut biogeography, and nutritional status

Eukaryotes have historically been studied as parasites, but recent evidence suggests they may be indicators of a healthy gut ecosystem. Here, we describe the eukaryome along the gastrointestinal tract of children aged 2-5 years and test for associations with clinical factors such as anaemia, intestinal inflammation, chronic undernutrition, and age. Children were enrolled from December 2016 to May 2018 in Bangui, Central African Republic and Antananarivo, Madagascar. We analyzed a total of 1104 samples representing 212 gastric, 187 duodenal, and 705 fecal samples using a metabarcoding approach targeting the full ITS2 region for fungi, and the V4 hypervariable region of the 18S rRNA gene for the overall eukaryome. Roughly, half of all fecal samples showed microeukaryotic reads. We find high intersubject variability, only a handful of taxa that are likely residents of the gastrointestinal tract, and frequent co-occurrence of eukaryotes within an individual. We also find that the eukaryome differs between the stomach, duodenum, and feces and is strongly influenced by country of origin. Our data show trends towards higher levels of Fusarium equiseti, a mycotoxin producing fungus, and lower levels of the protist Blastocystis in stunted children compared to nonstunted controls. Overall, the eukaryome is poorly correlated with clinical variables. Our study is of one of the largest cohorts analyzing the human intestinal eukaryome to date and the first to compare the eukaryome across different compartments of the gastrointestinal tract. Our results highlight the importance of studying populations across the world to uncover common features of the eukaryome in health.

Deciphering Diets and Lifestyles of Prehistoric Humans through Paleoparasitology: A Review

Parasites have affected and coevolved with humans and animals throughout history. Evidence of ancient parasitic infections, particularly, reside in archeological remains originating from different sources dating to various periods of times. The study of ancient parasites preserved in archaeological remains is known as paleoparasitology, and it initially intended to interpret migration, evolution, and dispersion patterns of ancient parasites, along with their hosts. Recently, paleoparasitology has been used to better understand dietary habits and lifestyles of ancient human societies. Paleoparasitology is increasingly being recognized as an interdisciplinary field within paleopathology that integrates areas such as palynology, archaeobotany, and zooarchaeology. Paleoparasitology also incorporates techniques such as microscopy, immunoassays, PCR, targeted sequencing, and more recently, high-throughput sequencing or shotgun metagenomics to understand ancient parasitic infections and thus interpret migration and evolution patterns, as well as dietary habits and lifestyles. The present review covers the original theories developed in the field of paleoparasitology, as well as the biology of some parasites identified in pre-Columbian cultures. Conclusions, as well as assumptions made during the discovery of the parasites in ancient samples, and how their identification may aid in better understanding part of human history, ancient diet, and lifestyles are discussed.

Human and Animal Fascioliasis: Origins and Worldwide Evolving Scenario

Fascioliasis is a plant- and waterborne zoonotic parasitic disease caused by two trematode species: (i) Fasciola hepatica in Europe, Asia, Africa, the Americas, and Oceania and (ii) F. gigantica, which is restricted to Africa and Asia. Fasciolid liver flukes infect mainly herbivores as ruminants, equids, and camelids but also omnivore mammals as humans and swine and are transmitted by freshwater Lymnaeidae snail vectors. Two phases may be distinguished in fasciolid evolution. The long predomestication period includes the F. gigantica origin in east-southern Africa around the mid-Miocene, the F. hepatica origin in the Near-Middle East of Asia around the latest Miocene to Early Pliocene, and their subsequent local spread. The short postdomestication period includes the worldwide spread by human-guided movements of animals in the last 12,000 years and the more recent transoceanic anthropogenic introductions of F. hepatica into the Americas and Oceania and of F. gigantica into several large islands of the Pacific with ships transporting livestock in the last 500 years. The routes and chronology of the spreading waves followed by both fasciolids into the five continents are redefined on the basis of recently generated knowledge of human-guided movements of domesticated hosts. No local, zonal, or regional situation showing disagreement with historical records was found, although in a few world zones the available knowledge is still insufficient. The anthropogenically accelerated evolution of fasciolids allows us to call them "peridomestic endoparasites." The multidisciplinary implications for crucial aspects of the disease should therefore lead the present baseline update to be taken into account in future research studies.

Early-Life Mebendazole Exposure Increases the Risk of Adult-Onset Ulcerative Colitis: A Population-Based Cohort Study

INTRODUCTION

According to the hygiene hypothesis, exposure to parasites may protect against inflammatory bowel disease (IBD). Our aim was to examine the risk of IBD with childhood exposure to mebendazole, a broad-spectrum antihelminthic agent.

METHODS

We conducted a population-based cohort study using prospectively collected historical data of all individuals born in Denmark between 1995 and 2018. We identified mebendazole exposure at age younger than 18 years and during early life (younger than 5 years). We performed adjusted Cox proportional hazards regression analysis to determine the risk of IBD, ulcerative colitis (UC), and Crohn's disease with mebendazole exposure after adjusting for potential confounders.

RESULTS

Of 1,520,290 individuals in the cohort, 615,794 had childhood or adolescence mebendazole exposure. One thousand five hundred fifty-five and 1,499 individuals were subsequently diagnosed with pediatric-onset and adult-onset IBD, respectively. On multivariable analysis, mebendazole exposure at age younger than 18 years did not affect pediatric-onset or adult-onset IBD risk (adjusted hazard ratio [aHR] 0.97, 95% confidence interval [CI] 0.87, 1.07, and 1.08, 95% CI 0.97, 1.19, respectively). On limiting mebendazole exposure to age younger than 5 years while there was no association with pediatric-onset IBD (aHR 0.98, 95% CI 0.87, 1.11), adult-onset IBD risk was increased (aHR 1.17, 95% CI 1.04, 1.31). This increase in risk was driven by UC (aHR 1.32, 95% CI 1.12, 1.55), but not Crohn's disease (1.03, 95% CI 0.87, 1.22).

DISCUSSION

Early-life mebendazole exposure is associated with an increase in the risk of adult-onset UC. These findings suggest the importance of early-life exposures in shaping the risk of IBD later in life.

Paleoproteomics

Paleoproteomics, the study of ancient proteins, is a rapidly growing field at the intersection of molecular biology, paleontology, archaeology, paleoecology, and history. Paleoproteomics research leverages the longevity and diversity of proteins to explore fundamental questions about the past. While its origins predate the characterization of DNA, it was only with the advent of soft ionization mass spectrometry that the study of ancient proteins became truly feasible. Technological gains over the past 20 years have allowed increasing opportunities to better understand preservation, degradation, and recovery of the rich bioarchive of ancient proteins found in the archaeological and paleontological records. Growing from a handful of studies in the 1990s on individual highly abundant ancient proteins, paleoproteomics today is an expanding field with diverse applications ranging from the taxonomic identification of highly fragmented bones and shells and the phylogenetic resolution of extinct species to the exploration of past cuisines from dental calculus and pottery food crusts and the characterization of past diseases. More broadly, these studies have opened new doors in understanding past human-animal interactions, the reconstruction of past environments and environmental changes, the expansion of the hominin fossil record through large scale screening of nondiagnostic bone fragments, and the phylogenetic resolution of the vertebrate fossil record. Even with these advances, much of the ancient proteomic record still remains unexplored. Here we provide an overview of the history of the field, a summary of the major methods and applications currently in use, and a critical evaluation of current challenges. We conclude by looking to the future, for which innovative solutions and emerging technology will play an important role in enabling us to access the still unexplored "dark" proteome, allowing for a fuller understanding of the role ancient proteins can play in the interpretation of the past.

Population genomics of ancient and modern Trichuris trichiura

The neglected tropical disease trichuriasis is caused by the whipworm Trichuris trichiura, a soil-transmitted helminth that has infected humans for millennia. Today, T. trichiura infects as many as 500 million people, predominantly in communities with poor sanitary infrastructure enabling sustained faecal-oral transmission. Using whole-genome sequencing of geographically distributed worms collected from human and other primate hosts, together with ancient samples preserved in archaeologically-defined latrines and deposits dated up to one thousand years old, we present the first population genomics study of T. trichiura. We describe the continent-scale genetic structure between whipworms infecting humans and baboons relative to those infecting other primates. Admixture and population demographic analyses support a stepwise distribution of genetic variation that is highest in Uganda, consistent with an African origin and subsequent translocation with human migration. Finally, genome-wide analyses between human samples and between human and non-human primate samples reveal local regions of genetic differentiation between geographically distinct populations. These data provide insight into zoonotic reservoirs of human-infective T. trichiura and will support future efforts toward the implementation of genomic epidemiology of this globally important helminth.

Unique genetic structure of the human tapeworm Dibothriocephalus latus from the Alpine lakes region - a successful adaptation?

Dibothriocephalus latus is the most frequent causative agent of fish-borne zoonosis (diphyllobothriosis) in Europe, where it is currently circulating mainly in the Alpine lakes region (ALR) and Russia. Three mitochondrial genes (cox1, cob and nad3) and 6 microsatellite loci were analysed to determine how is the recently detected triploidy/parthenogenesis in tapeworms from ALR displayed at the DNA level. A geographically distant population from the Krasnoyarsk Reservoir in Russia (RU-KR) was analysed as a comparative population. One or 2 alleles of each microsatellite locus was detected in plerocercoids from RU-KR, corresponding to the microsatellite pattern of a diploid organism. In contrast, 1–3 alleles were observed in tapeworms from ALR, in accordance with their triploidy. The high diversity of mitochondrial haplotypes in D. latus from RU-KR implied an original and relatively stable population, but the identical structure of mitochondrial genes of tapeworms from ALR was probably a consequence of a bottleneck typical of introduced populations. These results indicated that the diploid/sexually reproducing population from RU-KR was ancestral, located within the centre of the distribution of the species, and the triploid/parthenogenetically reproducing subalpine population was at the margin of the distribution. The current study revealed the allelic structure of the microsatellite loci in the triploid tapeworm for the first time.

Occurrence of Taeniidae in a Middle Pleistocene speleothem of the Bàsura cave (Toirano, Liguria, Italy)

OBJECTIVE

This study aims to (i) analyse whether speleothems may contain fossil parasitic worm eggs and, if so, (ii) identify the pathogens involved, and (iii) place them in geological, palaeontological, and chronological contexts to know the zoonoses that could affect human and animal populations during the Middle Pleistocene.

MATERIALS

A sample of calcite dated to the beginning of MIS 9 and MIS 8 from the Bàsura cave (Liguria, Italy) was analysed.

METHODS

The chemical protocol applied is characterised using hydrochloric acid, the reduction of hydrofluoric acid application time, and by the absence of the use of base, dense liquor or acetolysis.

RESULTS

An embryophore of a taeniid was recovered.

CONCLUSIONS

Endoparasitic worm eggs can be found in speleothems. A taeniid embryophore was found in a calcite level dated to MIS 9. Zoonoses related to the Taeniidae family existed 300,000 years ago in the northern Mediterranean region and may have affected Middle Pleistocene predators, carnivores, or humans. Speleothems are good tools for paleoparasitological studies.

SIGNIFICANCE

This is the oldest taeniid recovered and identified.

LIMITATIONS

A more precise determination of the genus of this taeniid is not possible in the absence of more precise palaeontological data.

SUGGESTIONS FOR FURTHER RESEARCH

An application of this approach to other Pleistocene speleothems could broaden the spectrum of parasites and their zoonoses over remote Pleistocene periods.

Back to basics: Could simple experiments resolve important parasitology enigmas? The rarity of Ascaris eggs compared with Trichuris eggs in archeology and other contexts

Most parasitologists face a conundrum throughout their careers: 'which parasite eggs are more resistant to environmental stress, Ascaris spp. or Trichuris spp.?' In this analysis, our experimental and statistical analyses demonstrated that Trichuris sp. is more resistant than Ascaris sp. We highlight that desiccation exerts a major effect on the conservation of Ascaris eggs, and this may result in an underestimation of Ascaris eggs in paleoparasitological records. This observation can be extrapolated to more modern scenarios, for example, parasitological research in animal feces from semiarid environments, where whipworms are more common than roundworms. Similarly, this could be a plausible explanation for the higher frequency and abundance of whipworms than roundworms, when other hypotheses are unsupported.

Reconstructing the history of helminth prevalence in the UK

Intestinal helminth parasites (worms) have afflicted humans throughout history and their eggs are readily detected in archaeological deposits including at locations where intestinal parasites are no longer considered endemic (e.g. the UK). Parasites provide valuable archaeological insights into historical health, sanitation, hygiene, dietary and culinary practices, as well as other factors. Differences in the prevalence of helminths over time may help us understand factors that affected the rate of infection of these parasites in past populations. While communal deposits often contain relatively high numbers of parasite eggs, these cannot be used to calculate prevalence rates, which are a key epidemiological measure of infection. The prevalence of intestinal helminths was investigated through time in England, based on analysis of 464 human burials from 17 sites, dating from the Prehistoric to Industrial periods. Eggs from two faecal-oral transmitted nematodes (Ascaris sp. and Trichuris sp.) and the food-derived cestodes (Taenia spp. and Diphyllobothrium latum syn Dibothriocephalus latus) were identified, although only Ascaris was detected at a high frequency. The changing prevalence of nematode infections can be attributed to changes in effective sanitation or other factors that affect these faecal-oral transmitted parasites and the presence of cestode infections reflect dietary and culinary preferences. These results indicate that the impact of helminth infections on past populations varied over time, and that some locations witnessed a dramatic reduction in parasite prevalence during the industrial era (18^th-19^th century), whereas other locations continued to experience high prevalence levels. The factors underlying these reductions and the variation in prevalence provide a key historical context for modern anthelmintic programs.

Parasitic worms (helminths) cause many health problems in poorer countries, particularly those in tropical and sub-tropical regions. In modern Europe these infections are very rare and mostly found in those travelling from endemic areas but this wasn’t always the case. Archaeological studies have detected eggs of parasitic helminths in numerous European sites. Key questions include how prevalent these infections were in past communities and whether (or when) these patterns changed over time? This paper addresses both of these questions using a large number of single grave samples from archaeological sites in England dating between Prehistoric and Industrial periods. Helminth infections were detected across all periods but the overall prevalence rates changed over time, being highest in the Roman and Late-Medieval periods. The Industrial period was interesting in that two of the three sites contained very few (or no) parasites whereas the third, London, contained high levels of infection. We discuss factors that may have contributed to the changing parasite landscape and how understanding these factors may influence efforts to control helminth infections in modern endemic areas.

The Technological Advance and Application of Coprolite Analysis

Coprolites (mummified or fossilized feces), belonging to the group of ichnofossils, are fossilized remains of feces produced by animals. Various types of data from coprolites provide detailed evidence of the producer’s condition, like diet, intestinal microbiome, virus infection and parasites diseases. In addition, the palaeoenvironment information relevant to producers’ ecological niche can be drawn from taphonomy details the coprolites mirrored. At present, the phylogenetic clues of the producer’s population can be determined by advanced molecular biotechnologies. With the integration of multiple methods and techniques, coprolite has been widely accepted as an ideal material to study the diet, evolution, and palaeoenvironment of producers. In this paper, we reviewed the history of coprolite research, enumerated and interpreted the data recovered from coprolites, and explained their research value to palaeocoprology and evolutionary biology. Finally, we summarized the current directions of coprolite research and looked into its future prospects.

Ups and downs of infections with the broad fish tapeworm Dibothriocephalus latus in Europe from 1900 to 2020: Part I

The broad fish tapeworm, Dibothriocephalus latus (Diphyllobothriidea), is the most frequent causative agent of diphyllobothriosis, a fish-borne zoonosis, in Europe. Diphyllobothriosis is characterized by the transmission of D. latus larvae to humans via the consumption of raw, marinated, smoked or inadequately cooked fish products. The most important European foci of diphyllobothriosis have been Fennoscandia, the Baltic region, the Alpine lakes region, the Danube River region, and several endemic regions in Russia. This review provides basic data on the biology, life cycle, host specificity, methods of identification of D. latus, and a detailed summary of its occurrence in intermediate and definitive hosts in Fennoscandia and the Baltic, Alpine, and Danube regions during the last 120 years (1900-2020). Deeper insight into the unique pattern of distribution of D. latus in endemic regions is provided. The numbers of records are associated with several milestones of particular time periods. The first milestone (historical), which influenced studies on D. latus in Europe, was the period during and after World War II (1941-1950). The second milestone (epidemiological) was the decade 1981-1990, when previous massive health campaigns led to a marked decline of diphyllobothriosis in Europe and less published data on D. latus. Based on recent data, the broad fish tapeworm is either absent or present at very low prevalences in Fennoscandia and the Baltic and Danube regions, but the Alpine lakes region represents a continuous ongoing circulation of the parasite in the natural environment and humans.

Risk of Trypanosoma cruzi transmission in southern Minas Gerais, Brazil - Data from 2014 to 2020

Trypanosoma cruzi, the etiologic agent of Chagas disease, is widely distributed in the Americas and is transmitted through vectorial, transfusional, and oral routes. This study aimed to evaluate the risk of vectorial transmission of Chagas disease in municipalities located in southern Minas Gerais, Brazil, by analyzing triatomine specimens collected from 2014 to 2020. All 1522 hematophagous triatomines were identified as Panstrongylus megistus, and were subjected to parasitological and molecular examinations. From 2014 to 2016, approximately 10% of insects were positive in the microscopic analysis of intestinal content, and 27% were positive as detected by the quantitative polymerase chain reaction (qPCR) of the same sampling. However, in the last investigated years, an increase in infected triatomines was observed in microscopic analysis (22%) and qPCR methods (41%). This corroborates the findings of acute human Chagas disease cases, which have increased in the study area from a maximum of 2 cases in previous years to 20 cases in 2019, and 17 cases in 2020 through June. Additionally, bloodmeal sources of infected triatomines were investigated; human blood was detected in up to 85.7% of the samples. Moreover, canine blood was also detected in triatomine intestinal content in recent years, reaching 91% of analyzed insects in 2018. Data on bloodmeal sources have demonstrated human-vector contact and have suggested the participation of dogs in the parasite transmission cycle. These results indicate the risk of T. cruzi vectorial transmission in Southern Minas Gerais and São Paulo owing to the boundary between these states. Thus, enhanced surveillance and vector control of Chagas disease are highly recommended in these areas.

First report in pre-Columbian mummies from Bolivia of Enterobius vermicularis infection and capillariid eggs: A contribution to Paleoparasitology studies

OBJECTIVE

This study was designed to search for ancient parasites in abdominal content and coprolites from Bolivian mummies.

MATERIALS

Twelve mummified individuals from the Andean highlands, housed at the National Museum of Archaeology (MUNARQ) in La Paz, Bolivia.

METHODS

Microscopic analysis of rehydrated samples (coprolites and abdominal content), following Lutz's spontaneous sedimentation technique.

RESULTS

Eggs of Enterobius vermicularis were identified in coprolites from one mummy, and capillariid eggs in the organic abdominal content from another individual.

CONCLUSIONS

This is the first evidence of ancient intestinal parasites in Bolivian mummies.

SIGNIFICANCE

This pioneering study focused on the search of ancient intestinal parasites in human remains of the Bolivian Andes and contributes to greater knowledge of paleoparasitology in South America.

LIMITATIONS

All mummies in the MUNARQ belonged to the Andean Bolivian highlands (post-Tiwanaku era or Late Intermediate Period), although the exact provenance of the material and the associated contexts are not well recorded.

SUGGESTIONS FOR FURTHER RESEARCH

Considering the great number of well-known archaeological sites and other unexplored sites in Bolivia, in addition to large collections in museums, further paleopathological and paleoparasitological molecular studies in mummies and skeletons are called for.

Intestinal helminths as a biomolecular complex in archaeological research

Enteric helminths are common parasites in many parts of the world and in the past were much more widespread both geographically and socially. Many enteric helminths are relatively long-lived in the human host, often benign or of low pathogenicity while producing large numbers of environmentally resistant eggs voided in the faeces or found associated with individual remains (skeletons and mummies). The combination of helminth characters offers opportunities to the field of historical pathogen research that are quite different to that of some of the more intensively studied high impact pathogens. Historically, a wealth of studies has employed microscopic techniques to diagnose infection using the morphology of the helminth eggs. More recently, various ancient DNA (aDNA) approaches have been applied in the archaeoparasitological context and these are revolutionizing the field, allowing much more specific diagnosis as well as interrogating the epidemiology of helminths. These advances have enhanced the potential for the field to provide unique information on past populations including using diseases to consider many aspects of life (e.g. sanitation, hygiene, diet, culinary practices and other aspects of society). Here, we consider the impact of helminth archaeoparasitology and more specifically the impact and potential for application of aDNA technologies as a part of the archaeologists' toolkit. This article is part of the theme issue 'Insights into health and disease from ancient biomolecules'.

Epidemiological insights from a large-scale investigation of intestinal helminths in Medieval Europe

Helminth infections are among the World Health Organization's top neglected diseases with significant impact in many Less Economically Developed Countries. Despite no longer being endemic in Europe, the widespread presence of helminth eggs in archaeological deposits indicates that helminths represented a considerable burden in past European populations. Prevalence of infection is a key epidemiological feature that would influence the elimination of endemic intestinal helminths, for example, low prevalence rates may have made it easier to eliminate these infections in Europe without the use of modern anthelminthic drugs. To determine historical prevalence rates we analysed 589 grave samples from 7 European sites dated between 680 and 1700 CE, identifying two soil transmitted nematodes (Ascaris spp. and Trichuris trichiura) at all locations, and two food derived cestodes (Diphyllobothrium latum and Taenia spp.) at 4 sites. The rates of nematode infection in the medieval populations (1.5 to 25.6% for T. trichiura; 9.3-42.9% for Ascaris spp.) were comparable to those reported within modern endemically infected populations. There was some evidence of higher levels of nematode infection in younger individuals but not at all sites. The genetic diversity of T. trichiura ITS-1 in single graves was variable but much lower than with communal medieval latrine deposits. The prevalence of food derived cestodes was much lower (1.0-9.9%) than the prevalence of nematodes. Interestingly, sites that contained Taenia spp. eggs also contained D. latum which may reflect local culinary practices. These data demonstrate the importance of helminth infections in Medieval Europe and provide a baseline for studies on the epidemiology of infection in historical and modern contexts. Since the prevalence of medieval STH infections mirror those in modern endemic countries the factors affecting STH decline in Europe may also inform modern intervention campaigns.

Pre-Columbian zoonotic enteric parasites: An insight into Puerto Rican indigenous culture diets and life styles

The pre-Columbian Huecoid and Saladoid cultures were agricultural ethnic groups that supplemented their diets by fishing, hunting and scavenging. Archaeological deposits associated to these cultures contained a variety of faunal osseous remains that hinted at the cultures' diets. The present study identified zoonotic parasites that may have infected these two cultures as a result of their diets. We used metagenomic sequencing and microscopy data from 540-1,400 year old coprolites as well as the zooarchaeological data to recreate the possible interactions between zoonotic parasites and their hosts. Microscopy revealed Diphyllobothrium spp. and Dipylidium caninum eggs along with unidentified cestode and trematode eggs. DNA sequencing together with functional prediction and phylogenetic inference identified reads of Cryptosporidium spp., Giardia intestinalis and Schistosoma spp. The complimentary nature of the molecular, microscopy and zooarchaeology data provided additional insight into the detected zoonotic parasites' potential host range. Network modeling revealed that rodents and canids living in close proximity to these cultures were most likely the main source of these zoonotic parasite infections.

Intestinal parasites in six Islamic medieval period latrines from 10th-11th century Córdoba (Spain) and 12th-13th century Mértola (Portugal)

OBJECTIVE

To investigate the types of intestinal parasites that infected people living in Islamic period southern Iberia (al-Andalus), and compare with other regions of Europe.

MATERIALS

Four cesspits from 10^th-11^th century CE Córdoba (Spain), and two from 12^th-13^th century Mértola (Portugal).

METHODS

Sediment from each cesspit was analyzed using digital light microscopy and enzyme-linked immunosorbent assay (ELISA).

RESULTS

Analysis revealed eggs of roundworm (Ascaris lumbricoides) in every cesspit analyzed, but no evidence of other species of helminth or protozoal parasites.

CONCLUSION

Differences were noted between parasite species found in Mediterranean Europe and northern Europe, where a range of zoonotic parasites were endemic alongside sanitation-related parasites. We suggest that the scarcity of zoonotic parasites in southern Europe in the medieval period may reflect contrasts in climate between northern and southern Europe.

SIGNIFICANCE

The repeated identification of roundworm eggs suggests that al-Andalus was less hygienic than historically depicted. We did not note a difference between parasites found in Muslim and Christian regions of Iberia, and the predominance of parasites spread by fecal contamination of food is consistent with past research.

LIMITATIONS

The eggs of some species of parasite are fragile, so may theoretically have been present in the population but did not survive for us to identify them.

SUGGESTIONS FOR FURTHER RESEARCH

To further investigate the role of climate upon the parasites that affected past human populations.

Prevalence, intensity and associated risk factors of soil transmitted helminth infections: A comparison between Negritos (indigenous) in inland jungle and those in resettlement at town peripheries

BACKGROUND

Formerly known as the Malaysian hunter gatherers, the Negrito Orang Asli (OA) were heavily dependent on the forest for sustenance and early studies indicated high prevalence of intestinal parasitism. Initiation of a redevelopment program in the 1970s aimed to demarginalize the OA was expected to reduce soil transmitted helminth (STH) infections. Gradually, the OA were relocated to new resettlement areas at the peripheries. The aim of this study was to compare STH infections between Negritos who are still living in the inland jungle with those living in resettlements.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 416 Negrito participants were grouped into two categories of communities based on location; Inland Jungle Villages (IJV); and Resettlement Plan Scheme (RPS). Iodine wet mount, formalin-ether sedimentation, modified Trichrome and modified Ziehl-Neelsen staining and Kato-Katz methods were performed on stool samples. A questionnaire was used to collect information regarding demographic, socioeconomic, environmental and hygiene behaviors. Prevalence of STH was significantly higher in IJV (91.3%) versus RPS (83.1%) (P = 0.02). However, the percentage of individuals with severe intensity of Trichuris trichiura infections was significantly higher in the RPS (17.2%) compared to IJV (6.5%) (P = 0.01). Severe Ascaris lumbricoides infection was observed at 20.0% amongst RPS Negritos and 15.0% amongst IJV (P = 0.41). Whilst for hookworm infection, both prevalence and individuals with moderate to severe infections were higher in the IJV (26.2%, 41.0%) versus RPS (18.7%, 24.0%) (P values = 0.08, 0.09), accordingly. The prevalence other intestinal parasitic infections (e.g. Entamoeba sp., Blastocystis and flukes) was also higher in IJV versus RPS. Apart from poor hygienic behaviors as significant risk factors in both communities, low socio-economic status was highly associated with STH infections in RPS (P<0.001) but not significantly associated in IJV.

CONCLUSIONS

The findings showed that ex situ development plan by RPS has not profoundly contributed to the STH reduction among the OA. Conversely, burden rate of T. trichiura infections increased due to their extreme poverty and poor hygienic behaviors. Here, we are suggesting biannual mass albendazole intervention (triple dose regimens in RPS, but a single dose in IJV) and community empowerment to both communities. For a long-term and better uptake, these strategies must be done together with the community input and participation, respecting their traditional customs and accompanied by recruitment of more OA people in the health-care taskforce.

Parasitic infections and resource economy of Danish Iron Age settlement through ancient DNA sequencing

In this study, we screen archaeological soil samples by microscopy and analyse the samples by next generation sequencing to obtain results with parasites at species level and untargeted findings of plant and animal DNA. Three separate sediment layers of an ancient man-made pond in Hoby, Denmark, ranging from 100 BC to 200 AD, were analysed by microscopy for presence of intestinal worm eggs and DNA analysis were performed to identify intestinal worms and dietary components. Ancient DNA of parasites, domestic animals and edible plants revealed a change in use of the pond over time reflecting the household practice in the adjacent Iron Age settlement. The most abundant parasite found belonged to the Ascaris genus, which was not possible to type at species level. For all sediment layers the presence of eggs of the human whipworm Trichuris trichiura and the beef tapeworm Taenia saginata suggests continuous disposal of human faeces in the pond. Moreover, the continuous findings of T. saginata further imply beef consumption and may suggest that cattle were living in the immediate surrounding of the site throughout the period. Findings of additional host-specific parasites suggest fluctuating presence of other domestic animals over time: Trichuris suis (pig), Parascaris univalens (horse), Taenia hydatigena (dog and sheep). Likewise, alternating occurrence of aDNA of edible plants may suggest changes in agricultural practices. Moreover, the composition of aDNA of parasites, plants and vertebrates suggests a significant change in the use of the ancient pond over a period of three centuries.

Ancient DNA from latrines in Northern Europe and the Middle East (500 BC-1700 AD) reveals past parasites and diet

High-resolution insight into parasitic infections and diet of past populations in Northern Europe and the Middle East (500 BC- 1700 AD) was obtained by pre-concentration of parasite eggs from ancient latrines and deposits followed by shotgun sequencing of DNA. Complementary profiling of parasite, vertebrate and plant DNA proved highly informative in the study of ancient health, human-animal interactions as well as animal and plant dietary components. Most prominent were finding of soil-borne parasites transmitted directly between humans, but also meat-borne parasites that require consumption of raw or undercooked fish and pork. The detection of parasites for which sheep, horse, dog, pig, and rodents serves as definitive hosts are clear markers of domestic and synanthropic animals living in closer proximity of the respective sites. Finally, the reconstruction of full mitochondrial parasite genomes from whipworm (Ascaris lumbricoides) and roundworm species (Trichuris trichiura and Trichuris muris) and estimates of haplotype frequencies elucidates the genetic diversity and provides insights into epidemiology and parasite biology.

DNA barcoding of ancient parasites

Ancient samples present a number of technical challenges for DNA barcoding, including damaged DNA with low endogenous copy number and short fragment lengths. Nevertheless, techniques are available to overcome these issues, and DNA barcoding has now been used to successfully recover parasite DNA from a wide variety of ancient substrates, including coprolites, cesspit sediment, mummified tissues, burial sediments and permafrost soils. The study of parasite DNA from ancient samples can provide a number of unique scientific insights, for example: (1) into the parasite communities and health of prehistoric human populations; (2) the ability to reconstruct the natural parasite faunas of rare or extinct host species, which has implications for conservation management and de-extinction; and (3) the ability to view in ‘real-time’ processes that may operate over century- or millenial-timescales, such as how parasites responded to past climate change events or how they co-evolved alongside their hosts. The application of DNA metabarcoding and high-throughput sequencing to ancient specimens has so far been limited, but in future promises great potential for gaining empirical data on poorly understood processes such as parasite co-extinction.

Ancient Soil-Transmitted Parasite Eggs Detected from the Sixth Century Three Kingdom Period Silla Tomb

The parasitic infection patterns of the Joseon period have begun to be revealed in a series of paleoparasitological studies. However, parasitism prevailing during or before the Three Kingdom period is still relatively unexplored. In the present study, we therefore conducted parasitological examinations of soil and organic-material sediments precipitated upon human hipbone and sacrum discovered inside an ancient Mokgwakmyo tomb dating to the Silla Dynasty (57 BCE-660 CE). Within the samples, we discovered ancient Ascaris lumbricoides (eggs per gram [EPG], 46.6-48.3) and Trichuris trichiura (EPG, 32.8-62.1) eggs, the species commonly detected among Korean populations until just prior to the 1970s. These findings show that soil-transmitted parasitic infection among the Silla nobility might not have been uncommon. This is the first-ever report on the presence of ancient parasite eggs in the samples obtained from a Three Kingdom period tomb; and it also presents the earliest positive results for any of the ancient South Korean tombs paleoparasitologically examined to date.

New paleoparasitological investigations from the pre-inca to hispanic contact period in northern Chile

Paleoparasitological studies have demonstrated that changes in environment or culture are reflected in the patterns of parasitic infection diseases in populations worldwide. The advent of agriculture and animal domestication, with its accompanying reduction in human mobility and expanding population involves changes in or emergence of, parasites, the so-called first epidemiological transition. Cultural processes related to territory occupation contribute to both loss and acquisition of parasites. The archaeological site Lluta 57 in the Lluta Valley, Chile, provides a chronology of the transition from the pre-Inca or Late Intermediate Period (LIP), through the Late or Inca Period (LP), to the Hispanic Contact Period (HCP), providing the possibility of evaluating this epidemiological transition. The aim of this study was to conduct a paleoparasitological investigation of to gain insight into the dynamics of parasitism in Lluta people throughout the Inca expansion. Fourteen human coprolites from the three periods were rehydrated, submitted to spontaneous sedimentation, and examined by light microscopy for the presence of intestinal parasite eggs, pollen grains, and micro-remains. Eggs of four parasites: Enterobius vermicularis, Trichostrongylus sp., Trichuris sp., and Eimeria macusaniensis were recovered. Frequency, diversity, and number of parasite eggs per sample increased over the studied time period. Trichostrongylus sp. and E. macusaniensis were recorded in the region for the first time. Enterobius vermicularis eggs, absent in the LIP, were present as a hyper-infection in LP. The presence of E. macusaniensis is likely related to exploitation of llamas, which were used for food and transport and as sacrificial offerings. The paleobotanical analysis revealed ten families of pollen grains, as well as phytoliths and floral remains. In contrast to parasitological results, a diachronic pattern was not detected. Evolution of the settlements, with the advent of larger, more densely populated, villages, could have influenced the emergence and intensification of transmission of parasites in the region. The study showed that the Inca expansion influenced host-parasite-environment relationships in the Lluta Valley.

Of dogs and hookworms: man's best friend and his parasites as a model for translational biomedical research

We present evidence that the dog hookworm (Ancylostoma caninum) is underutilised in the study of host-parasite interactions, particularly as a proxy for the human-hookworm relationship. The inability to passage hookworms through all life stages in vitro means that adult stage hookworms have to be harvested from the gut of their definitive hosts for ex vivo research. This makes study of the human-hookworm interface difficult for technical and ethical reasons. The historical association of humans, dogs and hookworms presents a unique triad of positive evolutionary pressure to drive the A. caninum-canine interaction to reflect that of the human-hookworm relationship. Here we discuss A. caninum as a proxy for human hookworm infection and situate this hookworm model within the current research agenda, including the various 'omics' applications and the search for next generation biologics to treat a plethora of human diseases. Historically, the dog hookworm has been well described on a physiological and biochemical level, with an increasing understanding of its role as a human zoonosis. With its similarity to human hookworm, the recent publications of hookworm genomes and other omics databases, as well as the ready availability of these parasites for ex vivo culture, the dog hookworm presents itself as a valuable tool for discovery and translational research.

Reestablishing rigor in archaeological parasitology

Archaeological parasitology originated in the mid-twentieth century with interdisciplinary teams of specialists directed by archaeologists. The goals of such studies were detailed analyses of dietary, medicinal, and environmental factors that shaped the patterns of infection. By the 1970s, a cadre of unique coprolite analysts was trained to analyze macroscopic and microscopic remains for integrated reconstructions of the cultural determinants of parasitism. During these first phases of research, diagnostic rigor was maintained by direct training of specialists in parasitology and archaeology sub-disciplines including archaeobotany and archaeopalynology. Near the end of the twentieth century, however, "paleoparasitology" was defined as a separate field focusing on defining parasite distribution through time and space. Ironically, this focus resulted in an increase in misdiagnosis, especially prominent after 2000. Paleoparasitology does not explicitly include other specialized studies in it research design. Thus, dietary, environmental and medicinal inferences have been neglected or lost as samples were destroyed solely for the purpose of parasitological analysis. Without ancillary archaeological studies, paleoparasitology runs the risk of separation from archaeological context, thereby reducing its value to the archaeologists who recover samples for analysis.

Intestinal parasites from the 2nd-5th century AD latrine in the Roman Baths at Sagalassos (Turkey)

The aim of this research was to determine the species of intestinal parasite present in a Roman Imperial period population in Asia Minor, and to use this information to improve our understanding of health in the eastern Mediterranean region in Roman times. We analyzed five samples from the latrines of the Roman bath complex at Sagalassos, Turkey. Fecal biomarker analysis using 5β-stanols has indicated the feces were of human origin. The eggs of roundworm (Ascaris) were identified in all five samples using microscopy, and the cysts of the protozoan Giardia duodenalis (which causes dysentery) were identified multiple times in one sample using ELISA. The positive G. duodenalis result at Sagalassos is particularly important as it represents the earliest reliable evidence for this parasite in the Old World (i.e. outside the Americas). As both these species of parasite are spread through the contamination of food and water by fecal material, their presence implies that Roman sanitation technologies such as latrines and public baths did not break the cycle of reinfection in this population. We then discuss the evidence for roundworm in the writings of the Roman physician Galen, who came from Pergamon, another town in western Asia Minor.

Pathogenic helminths in the past: Much ado about nothing

Despite a long tradition on the extent to which Romanisation has improved human health, some recent studies suggest that Romanisation in general, and Roman sanitation in particular, may not have made people any healthier, given that in Roman times gastrointestinal parasites were apparently widespread, whilst in the present day such parasites rarely cause diseases. Unfortunately, this novel claim neglects the empirical evidence that worldwide infections in over 1.5 billion people are caused by ubiquitous foodborne nematodes. Therefore, many may wonder if fossil remains of soil-transmitted helminths have been reported in ancient sanitation infrastructures. Beneficial access to improved sanitation should always be prioritized, hence how can historical sanitation efforts have ever been harmful? In this short article, a strong plea for caution is given, asking for an augmented nematological record and showing that there is not any evidence against Roman sanitation, neither in the past nor in the present.

Gut Protozoa: Friends or Foes of the Human Gut Microbiota?

The importance of the gut microbiota for human health has sparked a strong interest in the study of the factors that shape its composition and diversity. Despite the growing evidence suggesting that helminths and protozoa significantly interact with gut bacteria, gut microbiome studies remain mostly focused on prokaryotes and on populations living in industrialized countries that typically have a low parasite burden. We argue that protozoa, like helminths, represent an important factor to take into account when studying the gut microbiome, and that their presence - especially considering their long coevolutionary history with humans - may be beneficial. From this perspective, we examine the relationship between the protozoa and their hosts, as well as their relevance for public health.

Palaeoparasitology and palaeogenetics: review and perspectives for the study of ancient human parasites

While some species of parasites can be identified to species level from archaeological remains using microscopy (i.e.Enterobius vermicularis,Clonorchis sinensis), others can only be identified to family or genus level as different species produce eggs with similar morphology (i.e.Tæniasp. andEchinococcussp.). Molecular and immunological approaches offer the possibility to provide more precise determination at the species level. They can also identify taxa when classic parasite markers such as eggs or cysts have been destroyed over time. However, biomolecules can be poorly preserved and modern reference DNA is available only for a limited number of species of parasites, leading to the conclusion that classic microscopic observation should be combined with molecular analyses. Here we present a review of the molecular approaches used over the past two decades to identify human pathogenic helminths (Ascarissp.,Trichurissp.,E. vermicularis,Fasciolasp. etc.) or protists (Giardiasp.,Trypanosomasp.,Leishmaniasp. etc.). We also discuss the prospects for studying the evolution of parasites with genetics and genomics.

Human spiruridiasis due to Physaloptera spp. (Nematoda: Physalopteridae) in a grave of the Shahr-e Sukhteh archeological site of the Bronze Age (2800-2500 BC) in Iran

Evidence of rare human helminthiasis in paleoparasitological records is scarce. we report here the finding of Physaloptera spp. eggs in a soil sample collected in the pelvic and sacrum bones area of a skeleton excavated from a grave of Shahr-e Sukhteh archeological site dating back to the Bronze Age. The site is located in southeastern Iran and has attracted the attention of numerous archeological teams owing to its vast expanse and diverse archeological findings since 1997. The spirurid nematodes Physaloptera spp. are rarely the cause of human helminthiasis nowadays, but this infection might not have been so rare in ancient populations such as those in the Shahr-e Sukhteh. Out of 320 skeletons analyzed in this study, only one parasitized individual was detected. This surprising result led us to suspect the role of nematophagous fungi and other taphonomic processes in possible false-negative results. This is the first paleoparasitological study on human remains in this archeological site and the first record of ancient human physalopterosis in the Middle East.

Immunomodulation by helminths: Similar impact on type 1 and type 2 diabetes?

The incidence of both type 1 (T1D) and type 2 diabetes (T2D) is drastically increasing, and it is predicted that the global prevalence of diabetes will reach almost 600 million cases by 2035. Even though the pathogenesis of both types of diabetes is distinct, the immune system is actively involved in both forms of the disease. Genetic and environmental factors determine the risk to develop T1D. On the other hand, sedentary life style, surplus of food intake and other lifestyle changes contribute to the increase of T2D incidence. Improved sanitation with high-quality medical treatment is such an environmental factor that has led to a continuous reduction of infectious diseases including helminth infections over the past decades. Recently, a growing body of evidence has implicated a negative association between helminth infections and diabetes in humans as well as animal models. In this review, we discuss studies that have provided evidence for the beneficial impact of helminth infections on T1D and T2D. Possible mechanisms are presented by which helminths prevent T1D onset by mitigating pancreatic inflammation and confer protection against T2D by improving insulin sensitivity, alleviating inflammation, augmenting browning of adipose tissue and improving lipid metabolism and insulin signalling.

Taenia sp. in human burial from Kan River, East Siberia

We present an arhaeoparasitological analysis of a unique burial from the Neftprovod II burial ground in East Siberia, which dated from the Bronze Age. Analysis of a sediment sample from the sacral region of the pelvis revealed the presence of Taenia sp. eggs. Because uncooked animal tissue is the primary source of Taenia, this indicated that the individual was likely consuming raw or undercooked meat of roe deer, red deer, or elk infected with Taenia. This finding represents the oldest case of a human infected with Taenia sp. from Eastern Siberia and Russia.

First Paleoparasitological Report on the Animal Feces of Bronze Age Excavated from Shahr-e Sukhteh, Iran

Shahr-e Sukhteh (meaning burnt city in Persian) in Iran is an archeological site dated back to around 3,200-1,800 BC. It is located in Sistan and Baluchistan Province of Iran and known as the junction of Bronze Age trade routes crossing the Iranian plateau. It was appointed as current study area for paleoparasitological investigations. Excavations at this site have revealed various archeological materials since 1967. In the present study, sheep and carnivore coprolites excavated from this site were analyzed by means of rehydration technique using TSP solution for finding helminth eggs. Dicrocoelium dendriticum, Capillaria sp., and Taenia sp. eggs were identified, while some other objects similar to Anoplocephalidae and Toxocara spp. eggs were also retrieved from the samples but their measured parameters did not match those of these species. The present paper illustrates the first paleoparasitological findings of Bronze Age in eastern Iran supporting the economic activities, peopling, and communication as well as the appropriate condition for zoonotic helminthiasis life cycle in Shahr-e Sukhteh archeological site.

Ascaris phylogeny based on multiple whole mtDNA genomes

Ascaris lumbricoides and A. suum are two parasitic nematodes infecting humans and pigs, respectively. There has been considerable debate as to whether Ascaris in the two hosts should be considered a single or two separate species. Previous studies identified at least three major clusters (A, B and C) of human and pig Ascaris based on partial cox1 sequences. In the present study, we selected major haplotypes from these different clusters to characterize their whole mitochondrial genomes for phylogenetic analysis. We also undertook coalescent simulations to investigate the evolutionary history of the different Ascaris haplotypes. The topology of the phylogenetic tree based on complete mitochondrial genomic sequences was found to be similar to partial cox1 sequencing, but the support at internal nodes was higher in the former. Coalescent simulations suggested the presence of at least two divergence events: the first one occurring early in the Neolithic period which resulted in a differentiated population of Ascaris in pigs (cluster C), the second occurring more recently (~900 generations ago), resulting in clusters A and B which might have been spread worldwide by human activities.

The Paleoparasitology in Brazil and Findings in Human Remains from South America: A Review

The review article presents some of the history of how paleoparasitology started in Brazil, making highlight the great responsible Dr. Luiz Fernando Ferreira and Dr. Adauto Araújo, the trajectory of paleoparasitology in Brazil since 1978 and its performance in science to the present day. In sequence, it is made a presentation of parasitological findings on human remains found in archaeological sites in South America, highlighting Brazil, Argentina, Chile, and Peru, where major discoveries have occurred. Many of the parasites found in archaeological material and mentioned in this review went out of Africa with the peopling of Europe and from there they dispersed around the world, where climatic conditions allow the transmission. However, humans have acquired other parasites of animals, since humans invaded new habitats or creating new habits adopting new technologies, thus expanding its range of influence on the environment. Thus, this review article is finalized with information that explain the importance of these findings in the interaction between parasites, human host, and ambient.

Assessing the Archaeoparasitological Potential of Quids As a Source Material for Immunodiagnostic Analyses

In the present study, quids from La Cueva de los Muertos Chiquitos (CMC) were subjected to ELISA tests for 2 protozoan parasites, Toxoplasma gondii (n=45) and Trypanosoma cruzi (n=43). The people who occupied CMC, the Loma San Gabriel, lived throughout much of present-day Durango and Zacatecas in Mexico. The known pathoecology of these people puts them into at-risk categories for the transmission of T. gondii and T. cruzi. Human antibodies created in response to these 2 parasites can be detected in modern saliva using ELISA kits intended for use with human serum. For these reasons, quids were reconstituted and subjected to ELISA testing. All test wells yielded negative results. These results could be a factor of improper methods because there is no precedence for this work in the existing literature. The results could equally be a simple matter of parasite absence among those people who occupied CMC. A final consideration is the taphonomy of human antibodies and whether or not ELISA is a sufficient method for recovering antibodies from archaeological contexts. An additional ELISA test targeting secretory IgA (sIgA) was conducted to further examine the failure to detect parasite-induced antibodies from quids. Herein, the methods used for quid preparation and ELISA procedures are described so that they can be further developed by future researchers. The results are discussed in light of the potential future of quid analysis.

Association between predominantly plant-based diets and iron status in Chinese adults: a cross-sectional analysis

Current evidence of the relationship between diets and Fe status is mostly derived from studies in developed countries with Western diets, which may not be translatable to Chinese with a predominantly plant-based diet. We extracted data that were nationally sampled from the 2009 wave of China Health and Nutrition Survey; dietary information was collected using 24-h recalls combined with a food inventory for 3 consecutive days. Blood samples were collected to quantify Fe status, and log-ferritin, transferrin receptor and Hb were used as Fe status indicators. In total, 2905 (1360 males and 1545 females) adults aged 18–50 years were included for multiple linear regression and stratified analyses. The rates of Fe deficiency and Fe-deficiency anaemia were 1·6 and 0·7 % for males and 28·4 and 10·7 % for females, respectively. As red meat and haem Fe consumption differed about fifteen to twenty times throughout the five groups, divided by quintiles of animal protein intake per 4·2 MJ/d, only Fe status as indicated by log-ferritin (P=0·019) and transferrin receptor (P=0·024) concentrations in males was shown to be higher as intakes of animal foods increased. Log-ferritin was positively associated with intakes of red meat (B=0·3 %, P=0·01) and haem Fe (B=12·3 %, P=0·010) in males and with intake of non-haem Fe in females (B=2·2 %, P=0·024). We conclude that diet has a very limited association with Fe status in Chinese adults consuming a traditional Chinese diet, and a predominantly plant-based diet may not be necessarily responsible for poor Fe status.

Temporal and Spatial Distribution of Enterobius vermicularis (Nematoda: Oxyuridae) in the Prehistoric Americas

Investigations of Enterobius sp. infection in prehistory have produced a body of data that can be used to evaluate the geographic distribution of infection through time in the Americas. Regional variations in prevalence are evident. In North America, 119 pinworm positive samples were found in 1,112 samples from 28 sites with a prevalence of 10.7%. Almost all of the positive samples came from agricultural sites. From Brazil, 0 pinworm positive samples were found in 325 samples from 7 sites. For the Andes region, 22 pinworm positive samples were found in 411 samples from 26 sites for a prevalence of 5.3%. Detailed analyses of these data defined several trends. First, preagricultural sites less frequently show evidence of infection compared to agricultural populations. This is especially clear in the data from North America, but is also evident in the data from South America. Second, there is an apparent relationship between the commonality of pinworms in coprolites and the manner of constructing villages. These analyses show that ancient parasitism has substantial value in documenting the range of human behaviors that influence parasitic infections.

Past Intestinal Parasites

This chapter aims to provide some key points for researchers interested in the study of ancient gastrointestinal parasites. These few pages are dedicated to my colleague and friend, Prof. Adauto Araújo (1951-2015), who participated in the writing of this chapter. His huge efforts in paleoparasitology contributed to the development and promotion of the discipline during more than 30 years.

Human Coprolites as a Source for Paleomicrobiology

The paleomicrobiology of coprolites, which are fossilized fecal materials, has already yielded data about various organisms, including micro-eukaryotes, bacteria, and archaea, thus expanding our comprehension of ancient human dietary habits, gut microbiota, and intestinal and systemic infections. This mini-review briefly describes previous works and summarizes the main techniques used in handling coprolites and the findings obtained about ancient gut microbiota. Past intestinal and systemic infections are outlined.

Skin-transmitted pathogens and the heebie jeebies: evidence for a subclass of disgust stimuli that evoke a qualitatively unique emotional response

Skin-transmitted pathogens have threatened humans since ancient times. We investigated whether skin-transmitted pathogens were a subclass of disgust stimuli that evoked an emotional response that was related to, but distinct from, disgust and fear. We labelled this response "the heebie jeebies". In Study 1, coding of 76 participants' experiences of disgust, fear, and the heebie jeebies showed that the heebie jeebies was elicited by unique stimuli which produced skin-crawling sensations and an urge to protect the skin. In Experiment 2,350 participants' responses to skin-transmitted pathogen, fear-inducing, and disgust-inducing vignettes showed that the vignettes elicited sensations and urges which loaded onto heebie jeebies, fear, and disgust factors, respectively. Experiment 3 largely replicated findings from Experiment 2 using video stimuli (178 participants). Results are consistent with the notion that skin-transmitted pathogens are a subclass of disgust stimuli which motivate behaviours that are functionally consistent with disgust yet qualitatively distinct.