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

A New Approach in Investigation the Chemotaxis Response of Mammalian Parasitic Nematode: In Vitro Study

Chemotaxis is the biologically intrinsic navigation towards or away from chemical stimuli. It is a crucial behavioral response for animals when interacting with their environment and a tool for locating sustenance, hosts, and other vital environmental signals. Prior research has predominantly concentrated on the chemotactic behaviors of free-living and entomopathogenic nematodes in response to volatile soil constituents. The present work conducts for the first time the chemotaxis assay of Syphacia obvelata (Nematoda: Oxyuridae) parasitizing the vertebrate cecum as an experimental model for detecting this behavior in parasitic nematodes. We tested two mouse biological samples, namely urine, and serum, as odorants to study the in vitro chemotactic behavior of S. obvelata. The experiments were conducted in triplicate groups of twenty-two worms for gradient dilutions between 10-0, 10-1, 10-3, and 10-5 ml, using a semi-solid formula of agar (Brenner 1974; Stiernagle. 2006) as a nutrient surface medium for cultivation. The chemotaxis chamber and photography system were applied according to Hirotsu et al. 2015 with some modification to be convenient with the current experiment. The chemotaxis index is computed along with the cultivated worms' mean number attracted toward or repulsed away from the odorants. The control groups included ten worms with an ablated olfactory sense organ (amphid) that was targeted using a 785 nm picosecond pulsed laser with a power of 10 mW and a confocal Raman microscope. dose-dependent chemotactic response to both urine and serum, with diluted concentrations (10⁻⁵) acting as attractants and undiluted forms acting as repellents. There is also a time-dependent enhancement of chemotaxis, with stronger positive responses at 60 min for both stimuli. Unexpectedly, the high concentration of anal gland secretion consistently repels worms, with stronger repulsion over time. This study advances our knowledge of the sensory mechanisms of Oxyuridae, life cycle navigation, and parameters that promote retro-infection. It also provides the first insight into the chemotactic behavior of these creatures. It also highlights the potential of laser microsurgery as a precise tool for investigating complex sensory systems in minute organisms.

Enterobiasis and its risk factors in urban, rural and indigenous children of subtropical Argentina

A cross-sectional survey to assess the prevalence of Enterobius vermicularis infection and its associated factors among the child population of infant, preschool and school age in the urban, rural and indigenous population of Iguazú city, in subtropical Argentina was presented. Additionally, the status of enterobiasis at country level was reviewed and analysed. Enterobius vermicularis presence was assessed employing an oviscopic serial sampling technique. Statistical analysis of socio-demographic determinants was performed by generalized linear mixed models at individual, household and community levels. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were used to gather national information about E. vermicularis prevalence spanning the decade 2010–2020. A total of 916 children from 470 families participated. Overall prevalence was 29.8%, with 25.3, 30.7 and 34.2% detected for children inhabiting urban, rural and indigenous villages, respectively. The multi-level analysis showed that the presence of E. vermicularis was mostly determined by individual (e.g. age, playing habits, previous pinworm infection) and household-level factors (e.g. family size, overcrowding conditions). Interestingly, WASH variables, such as waste disposal, analysed at community level were also important. Data were analysed to provide eco-epidemiological features of enterobiasis in a heterogeneous subtropical child population in the same territory but with different socio-sanitary realities. The importance of promoting multi-level actions against the determinants identified, to control this public health problem integratively was evidenced. The scoping review of national data updated the state of knowledge of this parasitosis, identifying risk determinants and gaps in knowledge at country level.

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'.

Confusing a Pollen Grain with a Parasite Egg: an Appraisal of "Paleoparasitological Evidence of Pinworm (Enterobius Vermicularis) Infection in a Female Adolescent Residing in Ancient Tehran"

There is often the risk of confusing pollen grains with helminth eggs from archaeological sites. Thousands to millions of pollen grains can be recovered from archaeological burial sediments that represent past ritual, medication and environment. Some pollen grain types can be similar to parasite eggs. Such a confusion is represented by the diagnosis of enterobiasis in ancient Iran. The authors of this study confused a joint-pine (Ephedra spp.) pollen grain with a pinworm egg. This paper describes the specific Ephedra pollen morphology that can be confused with pinworm eggs.

Pinworm Infection at Salmon Ruins and Aztec Ruins: Relation to Pueblo III Regional Violence

The study of coprolites has been a theme of archaeology in the American Southwest. A feature of archaeoparasitology on the Colorado Plateau is the ubiquity of pinworm infection. As a crowd parasite, this ubiquity signals varying concentrations of populations. Our recent analysis of coprolite deposits from 2 sites revealed the highest prevalence of infection ever recorded for the region. For Salmon Ruins, the deposits date from AD 1140 to 1280. For Aztec Ruins, the samples can be dated by artifact association between AD 1182–1253. Both sites can be placed in the Ancestral Pueblo III occupation (AD 1100–1300), which included a period of cultural stress associated with warfare. Although neither of these sites show evidence of warfare, they are typical of large, defensible towns that survived this time of threat by virtue of large populations in stonewalled villages with easily accessible water. We hypothesize that the concentration of large numbers of people promoted pinworm infection and, therefore, explains the phenomenal levels of infection at these sites.

Rodloff A, Mössner J, Lübbert C. The Diagnosis and Treatment of Pinworm Infection

BACKGROUND

Symptomatic infection with pinworm (Enterobius vermicularis), a human pathogen, is clinically relevant in Germany, with an estimated prevalence in childhood of 2-20%. Enterobiasis can cause major mental distress. There is little systematically verified knowledge on the treatment of this condition, and there is no corresponding German guideline. This review is, therefore, intended as a summary of the current state of knowledge.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed for literature appearing from 1 January 1990 to 5 February 2019 and containing the search terms "enterobiasis," "oxyuriasis," "Enterobius vermicula- ris," "pinworm," and "threadworm."

RESULTS

More than one billion people worldwide are thought to be infected with pinworm. Estimates of its prevalence among kindergarten and primary-school pupils in Europe are generally near 20%. Infants (<2 years of age), adolescents (>14 years of age), and adults are only sporadically affected. The main risk factors are age 4-11 years, uncontrolled anus-finger-mouth contact, nail-biting (onychophagia/peri- onychophagia), unsupervised body hygiene, and poor compliance with basic hand hygiene. No large-scale, randomized, controlled trials of treatment are available. The approved antihelminthic agents are mebendazole, pyrantel embonate, and pyrvinium embonate (success rates up to >90%). For recurrent infections, prolonged treatment for up to 16 weeks (a "pulse scheme") is recommended.

CONCLUSION

In nearly all cases, antihelminthic treatment along with attention to hygienic measures can successfully eradicate pinworm infection and prevent recurrence and autoinfection. The involvement of all persons living in the patient's house- hold, including sexual partners, is a prerequisite to the lasting success of treatment.

Recovering parasites from mummies and coprolites: an epidemiological approach

In the field of archaeological parasitology, researchers have long documented the distribution of parasites in archaeological time and space through the analysis of coprolites and human remains. This area of research defined the origin and migration of parasites through presence/absence studies. By the end of the 20th century, the field of pathoecology had emerged as researchers developed an interest in the ancient ecology of parasite transmission. Supporting studies were conducted to establish the relationships between parasites and humans, including cultural, subsistence, and ecological reconstructions. Parasite prevalence data were collected to infer the impact of parasitism on human health. In the last few decades, a paleoepidemiological approach has emerged with a focus on applying statistical techniques for quantification. The application of egg per gram (EPG) quantification methods provide data about parasites' prevalence in ancient populations and also identify the pathological potential that parasitism presented in different time periods and geographic places. Herein, we compare the methods used in several laboratories for reporting parasite prevalence and EPG quantification. We present newer quantification methods to explore patterns of parasite overdispersion among ancient people. These new methods will be able to produce more realistic measures of parasite infections among people of the past. These measures allow researchers to compare epidemiological patterns in both ancient and modern populations.