Comparison of Helminth Infection among the Native Populations of the Arctic and Subarctic Areas in Western Siberia Throughout History: Parasitological Researches on Contemporary and the Archaeological Resources.

The aim of this parasitological study is examining contemporary (the late 20th century) specimens of the arctic or subarctic areas in Western Siberia and comparing them with the information acquired from archaeological samples from the same area. In the contemporary specimens, we observed the parasite eggs of 3 different species: Opisthochis felineus, Ascaris lumbricoides, and Enterobius vermicularis. Meanwhile, in archaeoparasitological results of Vesakoyakha, Kikki-Akki, and Nyamboyto I burial grounds, the eggs of Diphyllobothrium and Taenia spp. were found while no nematode (soil-transmitted) eggs were observed in the same samples. In this study, we concluded helminth infection pattern among the arctic and subarctic peoples of Western Siberia throughout history as follows: the raw fish-eating tradition did not undergo radical change in the area at least since the 18th century; and A. lumbricoides or E. vermicularis did not infect the inhabitants of this area before 20th century. With respect to the Western Siberia, we caught glimpse of the parasite infection pattern prevalent therein via investigations on contemporary and archaeoparasitological specimens.

Why were Sardinians the shortest Europeans? A journey through genes, infections, nutrition, and sex.

Since ancient times the Mediterranean island of Sardinia has been known for harboring a population with an average body height shorter than almost every other ethnic group in Europe. After over a century of investigations, the cause(s) at the origin of this uniqueness are not yet clear. The shorter stature of Sardinians appears to have been documented since prehistoric times, as revealed by the analysis of skeletal remains discovered in archaeological sites on the island. Recently, a number of genetic, hormonal, environmental, infective and nutritional factors have been put forward to explain this unique anthropometric feature, which persisted for a long time, even when environmental and living conditions improved around 1960. Although some of the putative factors are supported by sound empirical evidence, weaker support is available for others. The recent advent of whole genome analysis techniques shed new light on specific variants at the origin of this short stature. However, the marked geographical variability of stature across time and space within the island, and the well-known presence of pockets of short height in the population of the southern districts, are still puzzling findings that have attracted the interest of anthropologists and geneticists. The purpose of this review is to focus on the state-of-the-art research on stature, as well as the factors that made Sardinians the shortest among Europeans.

Helminths and human ancestral immune ecology: What is the evidence for high helminth loads among foragers?

OBJECTIVES: Recent theories of human immune ecology have invoked high helminth loads as an important selection factor among early humans. However, few studies have assessed this assumption among extant human foragers. METHODS: We review the current evidence for high helminth loads in documented forager populations and present new data from members of a Kawymeno Waorani forager group in Amazonian Ecuador (n = 16) compared with neighboring Kichwa subsistence farmers (n = 63). RESULTS: Stool samples indicated a near absence of helminths among the Kawymeno foraging group (6.25% with Ascaris lumbricoides and 0% with Ancylostoma duodenale or Trichuris trichiura). In contrast neighboring, isolated Kichwa subsistence farmers in a similar ecosystem had abundant helminth infestations (76.1% with Ascaris lumbricoides, 11.1% with Ancylostoma duodenale, and 1.5% with Trichuris trichiura). The presence of helminths among the Waorani and Kichwa was triangulated across multiple data sources, including presence in stool samples, medical exams, and 3 years of participant observation. CONCLUSIONS: These findings, coupled with the modern forager literature, raise questions as to whether helminths were prevalent enough in Paleolithic humans to be a unique evolutionary selective force in human physiology.

Soil-transmitted helminthiases in secondary school students in selected sites in two provinces in the Philippines: policy implications.

The latest World Health Organization (WHO) strategic plan for eliminating soil-transmitted helminthiases (STHs) as a public health problem in children puts the emphasis on school-age children. On the other hand, the Philippine national helminth control program excludes secondary school students in mass deworming for STH. This study determined the prevalence and intensity of STH in a sample of 633 students (14-15 years old) in selected secondary schools in two Philippine provinces. Stool specimens were processed following the Kato-Katz technique and examined for the presence of helminth ova. Overall cumulative prevalence of STH was 31.3%, while prevalence of moderate-heavy-intensity infections was 7.7%, well beyond the WHO target of ≤1% for reducing morbidity in school-age children. Recommendations were made to update the Philippine helminth control program and to re-examine the WHO strategic plan so that helminth prevention and control strategies may also be emphasized for secondary school students especially in high-prevalence areas.

Differences in prevalence of geohelminth infections between indigenous and settler populations in a remote Amazonian region of Peru.

OBJECTIVE: To compare prevalences of intestinal helminths and waterborne protozoa in indigenous and settler populations in a remote area of Peru. These populations live in adjacent but segregated small urban villages. METHODS: Stool samples were collected from representative members of these two populations and analysed for geohelminths and protozoa. RESULTS: The risk of soil-transmitted helminths is significantly higher in the settler than the indigenous population in the same isolated region of Peru (OR 5.18; 95% CI 3.44-7.81; P < 0.001). In contrast, the rates of protozoa presence were similar in both populations (OR 1.28; 95% CI 0.77-2.14; P = 0.336). CONCLUSIONS: Potential explanations for unexpected finding of a lower prevalence of helminths in indigenous relative to the settler population could include housing design in flood - prone areas and the use of local medicinal plants that possibly have antihelmintic properties.

Republished research: Helminths: an unrecognised disease burden prevalent among migrants in the gastroenterology clinic.

OBJECTIVE: To estimate the prevalence of, and implement a diagnostic strategy for, imported helminth infection in the gastroenterology clinic. DESIGN: A retrospective study of eosinophil count and probable tropical exposure (phase I) followed by a prospective study of parasitological investigation (phase II). SETTING: Gastroenterology service of an inner London hospital. PATIENTS: Adult patients newly attending general gastroenterology and inflammatory bowel disease clinics. INTERVENTIONS: In phase I, evidence of undiagnosed helminth infection was sought by analysing patient records for associations between eosinophil count and ethnicity. In phase II, a UK guideline for investigation of eosinophilia in migrants was implemented and diagnostic yield determined. MAIN OUTCOME MEASURES: In phase I, prevalence of eosinophilia was determined; in phase II, helminth prevalence and degree of eosinophilia before and after treatment were reported. Information on symptomatic response to treatment was recorded. Ethnicity was used as a proxy measure for tropical exposure. RESULTS: 426 new patients attended in a 12 month period. Eosinophilia was present in 27 (6.3%). 10/27 (37.0%) patients with eosinophilia were of African or Asian ethnicity whereas only 20% (85/426) of patients overall were from these ethnic groups (χ(2)=5.27, p=0.02). Following implementation of the protocol, 25/36 migrants with eosinophilia attended for parasitological investigations. Helminth infection was diagnosed in 10/25 (40%). Strongyloidiasis (six patients) and schistosomiasis (three patients) were the most common diagnoses. Median eosinophil count was 1.06×10(9)/l in those with helminths and 0.58×10(9)/l in those without (p=0.004). Eosinophil counts normalised in, and symptomatic improvement was reported by, most patients after treatment. CONCLUSIONS: Eosinophilia is associated with African or Asian ethnicity in an inner city gastroenterology service. This association is probably explained by imported helminths, which are prevalent in this setting, may be a cause of gastrointestinal symptoms and is easily diagnosed and treated by standard protocols.

The prevalence of soil transmitted helminth infections in minority indigenous populations of South-East Asia and the Western Pacific Region: A systematic review and meta-analysis.

INTRODUCTION: Soil transmitted helminth (STH) infections cause one of the most prevalent diseases in man. STHs disproportionately impact socio-economically disadvantaged communities including minority indigenous populations. This systematic review aimed to quantify the prevalence of STH infection within minority indigenous populations of the South-East Asia and Western Pacific Regions. METHODS: The systematic review was conducted in accordance with The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines following a published protocol. A random effects meta-analysis was used to estimate the pooled prevalence of STH infection, and meta-regression analysis was used to quantify associations with study characteristics. Where comparative data were available, sub-group analysis was conducted to evaluate the risk of STH infection in minority indigenous people relative to other population groups. The heterogeneity between studies was evaluated visually using Forest plots and was assessed quantitatively by the index of heterogeneity (I2) and Cochran Q-statistics. RESULTS: From 1,366 unique studies that were identified, 81 were included in the final analysis. The pooled prevalence of infection within minority indigenous populations was 61.4% (95% CI 50.8, 71.4) for overall STH infection; 32.3% (95% CI 25.7, 39.3) for Ascaris.lumbricoides; 43.6% (95% CI 32.6, 54.8) for Trichuris.trichiura; 19.9% (95% CI 15.7, 24.5) for hookworm and 6.3% (95% CI 3.2, 10.2) for Strongyloides.stercoralis. A significant increase in T. trichiura prevalence was observed over time. The stratified analysis showed that the prevalence of infection for STH overall and for each STH species were not significantly different in minority indigenous participants compared to other populations groups. CONCLUSION: The prevalence of STH infection is high within minority indigenous populations across countries at very different levels of socio-economic development. The increasing prevalence of T. trichiura calls for the implementation of more effective therapies and control strategies.

Bugs and irritable bowel syndrome: The good, the bad and the ugly.

Recently, there has been strong interest in the therapeutic potential of probiotics for irritable bowel syndrome (IBS). At the same time, there is a rapidly growing body of evidence to support an etiological role for gastrointestinal infection and the associated immune activation in the development of post-infectious IBS. In a more controversial area, small intestinal bacterial overgrowth has been associated with a subset of patients with IBS; the issue of whether it is appropriate to treat a subset of IBS patients with antibiotics and probiotics is currently a matter for debate. Thus, it appears that the gastrointestinal microbial flora may exert beneficial effects for symptoms of IBS under some circumstances, while in other situations gut microbes could give rise to symptoms of IBS. How do we make sense of the apparently diverse roles that 'bugs' may play in IBS? To address this question, we have conducted an in-depth review, attempting where possible to draw lessons from Asian studies.

Life history, immune function, and intestinal helminths: Trade-offs among immunoglobulin E, C-reactive protein, and growth in an Amazonian population.

OBJECTIVES: Infection with helminths is associated with shifts in host immunity, including increased production of immunoglobulin E (IgE) and reduced inflammation. Given limited energy budgets, these shifts may involve changes in energy allocation toward competing demands. Here we test for potential trade-offs between growth, IgE, and the inflammatory marker C-reactive protein (CRP). METHODS: Dried blood spots and anthropometrics were collected from 162 Shuar forager-horticulturalists from a village in southeastern Ecuador. Enzyme-linked immunosorbent assays (ELISAs) were used to measure IgE and CRP. Relationships among IgE, CRP, and anthropometrics were examined in three groups: children aged 2-7 years (n = 63), children aged 8-15 (n = 61), and adults over age 18 (n = 37). RESULTS: Geometric mean IgE was 1,196 IU ml⁻¹ while geometric mean CRP was 1.33 mg l⁻¹. In children, IgE and CRP were negatively correlated (r = -0.21, P = 0.02, df = 122). Controlling for fat stores and age, IgE was associated with lower stature in children (t = -2.04, P = 0.04, df = 109), and adults (t = -3.29, P < 0.01, df = 33). In children there was a significant interaction between age and CRP, such that in younger children CRP was associated with shorter stature, but in older children was associated with greater stature (t = 2.15, P = 0.04, df = 109). CONCLUSIONS: These results suggest that infection with helminths may have hidden costs associated with immunological changes, and that these costs may ultimately affect growth and other life history parameters.

Risk factors associated with soil transmitted helminth (STH) infection in two indigenous communities in Malaysia.

Soil-transmitted helminth (STH) could possibly cause mild to severe health effects such as diarrhea, weakness, intestinal blood loss, and impaired cognitive development and growth. In Malaysia, previous studies depicted a high prevalence rate of STH was due to poor hygiene practice and low efficacies of anthelminthic drugs. This study was conducted to investigate hand hygiene practice and WASH criteria's (Water, sanitation and hygiene) related to STH infection among two indigenous tribes in Peninsular Malaysia. A cross-sectional study was carried out to study the relationship among STH infection compared to water quality, sanitation, and hygiene conditions. A total of 190 individuals from two indigenous villages participated in the study, with ages ranging from 5 to 60 years old. In addition, Pearson's Chisquare (X2) test was utilized to test the relationship among STH with demographic socioeconomic and behavioral factors. The confidence interval (CI) of 95% is used to estimate the precision of the odds ratio (OR). Multivariate logistic regression models were also used to identify the risk factors associated with STH infections. The overall findings indicated a prevalence rate of 72% for STH, and distributed mainly among children aged < 12 years. Furthermore, multivariate analyses using logistic regression revealed chronic health problems, incorrect hand washing, and walking bare footed were associated with STH infection. Overall results indicated high prevalence of STH among the indigenous villagers, which aligns with the published literature and proves to be a problem need to be addressed as neglected disease. Interestingly, there was a significant relationship between the presences of chronic diseases and STH infection, which prompted other questions the awareness needs to be educated and the simple and low-cost intervention on the proper way of hand washing may help to reduce STH infection in these indigenous communities.

Influence of helminth infections on childhood nutritional status in lowland Bolivia.

Infectious disease, such as diarrheal disease, respiratory infections, and parasitic infections, are an important source of nutritional and energetic stress in many populations. Inspired by the research and methodological innovations of A. Roberto Frisancho, this work considers the impact of childhood environment and local disease ecology on child health and nutritional patterns among an indigenous group in lowland Bolivia. Specifically, we examine the association between soil-transmitted helminth infection, especially hookworm species, and anthropometric markers of short- and long-term nutritional status. Fecal samples, anthropometric dimensions, and health interviews were collected for 92 children ranging in age from 2.0 to 10.9 years. Microscopic examination revealed high levels of parasitic infection, with 76% of children positive for hookworm species infections (77% of girls and 74% of boys). Less common infections included Ascaris lumbricoides, Trichurius trichiura, and Strongyloides stercoralis with only 15% of children positive for multiple-species infections. After adjusting for sex and age, no statistically significant associations were observed between helminth infections and the frequency of reported illness or anthropometric measures of nutritional status. These data demonstrate the difficulty of assessing nutritional impacts of endemic infections.

Behavioral and nutritional factors and geohelminth infection among two ethnic groups in the Terai region, Nepal.

Geohelminthiasis is a major health problem in many developing countries. This study was designed to evaluate the role of behaviors and the nutritional status of people with geohelminth infection in two indigenous ethnic groups in lowland Terai, Nepal. One hundred and fourteen individuals (55 Mushar and 59 Tharu) aged 20-60 years participated, and a structured questionnaire was used to investigate socioeconomic status and behaviors. Nutritional status was assessed by anthropometric measurements. Ninety five stool samples of the participants were collected for parasitological analysis. The results showed that the prevalence of geohelminthiasis was 42.1%: 26.3% of the subjects were infected with roundworm, 9.5% with hookworms, and 6.3% with whipworm. Multivariate logistic regression analysis revealed that "not using soap for hand-washing" (adjusted OR = 5.27; 95% CI: 1.41-19.78) and height (adjusted OR = 0.88, 95% CI: 0.79-0.99) were associated with the prevalence of roundworm. "Walking barefoot when outdoor" was associated with the prevalence of hookworm (chi-square test, P = 0.01). Ethnicity was not associated with the prevalence of either of the geohelminths. Because unhygienic behaviors and chronic malnutrition were closely associated with the people's recognition and subsistence pattern, elimination of geohelminth infection in Terai would be possible if deworming campaigns were implemented with in-depth health education and modern agricultural technology.

Helicobacter pylori, helminth infections and growth: a cross-sectional study in a high prevalence population.

AIM: Helicobacter pylori (H. pylori) infection is usually acquired in childhood and may adversely affect growth, although data are inconsistent. This study investigated growth parameters in a paediatric cohort with a high prevalence of H. pylori and helminth infection. METHODS: A cross-sectional study of African refugee children (<16 years) recruited at their initial health assessment following resettlement in Australia. Detailed demographic, infection and anthropometric data were obtained. H. pylori infection was diagnosed by monoclonal faecal antigen enzyme immunoassay testing (MFAT). Growth restriction was defined as children with any anthropometric measures below the fifth centile for age and gender. RESULTS: H. pylori infection was detected in 149/182 (81.9%). Children with H. pylori infection were older (mean 8.5 years, standard deviation (SD) 4.2 years vs. 5.8 years, SD 4.5 years, p < 0.001). No gender differences were observed. After adjustment for age, H. pylori did not adversely affect body mass index or other anthropometric measurements. Helminth infections were common (41.8%) but not associated with reduced growth or with H. pylori infection. CONCLUSION: H. pylori and helminth infections are prevalent in African refugee children but neither is associated with growth restriction. Longitudinal growth velocity studies are necessary to identify any long-term consequences of H. pylori on childhood growth.

Shadow Puppets and Neglected Diseases: Evaluating a Health Promotion Performance in Rural Indonesia.

'Rama and the Worm' is a shadow puppet production targeting neglected diseases in Central Java. It is an entertainment-based intervention study to promote health by reducing the impact of parasitic diseases such as soil-transmitted helminths (STH). The study uses traditional Javanese shadow puppetry (wayang kulit) as a vehicle in village communities to disseminate health messages and promote behaviour change to prevent diseases caused, primarily, by inadequate sanitation and poor hygiene. The health education messages contained in the play, although using traditional characters and themes, required the creation of a completely new narrative script, using characters and plot lines familiar to the wayang kulit repertoire, but placing them in new situations that relate specifically to health promotion objectives. The intervention was piloted in a village in Central Java, Indonesia using a pre/post design with both qualitative and quantitative analysis. A total of 96 male and female villagers, aged between 7 and 87 years, provided both baseline and follow up data. Participant knowledge and behaviours related to gastrointestinal and helminth-related disease were assessed before and after the intervention through a questionnaire administered by interview. Results revealed statistically significant improvements in both knowledge (48.6% pre-intervention score vs. 62.8% post-intervention score, p < 0.001) and behaviour (77.4% vs. 80.6%, p = 0.004) related to gastrointestinal and helminth disease. Findings of the study indicate the wayang kulit performance is an effective health education tool. The results provide proof of concept with scaling up the next step forward. The wayang kulit production provides a significant additional component for an integrated, comprehensive approach to reduction and elimination of STH infection.

Intestinal protozoa and intestinal helminthic infections in displacement camps in Sierra Leone.

Displacement and refugee camps provide ideal grounds for the transmission of parasites and increase the risk of acute respiratory infections, diarhoea diseases, and intestinal parasitic infection. Cryptosporidium parvum, Giardia lamblia, Entomoeba histolytica, Ascaris lumbricoides, hookworm infection, Schistosoma haematobium, S. mansoni and Strongyloides stercoralis are important cosmopolitan intestinal parasites that are common among children, the immunocompromised and displaced populations. Five hundred and eighty one residents from 5 Internally Displaced Persons (IDPs) Camps voluntarily participated in the study by providing stool and urine samples for analysis. The stool specimens were used for the detection of Cryptosporidium specific and Giardia specific antigens by the DMSO modified Acid-Fast and Trichrome-PLUS stain for C. parvum and G. lamblia and E. histoyltica respectively. Stool specimens for the demonstration of helminth eggs and larvae were prepared by the modified Kato technique. One hundred and seventy eight (31%) of the 581 camp residents that submited samples were children below 10 years of age and were selected because they were screened for various forms of malnutrition. However, the data on C. parvum and G. lamblia were included in the analysis for all parasites. More children were positive for G. lamblia (29%) than for C. parvum (10%) and 5% had double infection with both parasites. The antigen positive rate decreased with age for C. parvum and G. lamblia infections. Adult samples were also examined for the C. parvum, G. lamblia, E. histolytica, A. lumbricoides, hookworms, S. haematobium, S. mansoni and S. stercoralis. The prevalence of hookworm was highest at Parade Ground Camp (50%) and hookworm had the highest pevalence rate of 18% among the 581 IDP residents followed by S. mansoni (16.7%) and A. lumbricoides (15%). The overall prevalence of E. histolytica among the study population was 9.0%. The results of this study indicate that intestinal protozoan and helminth parasites are highly prevalent among camp residents in Sierra Leone with five (5) different helminth parasites demonstrated in the stool specimens of residents in the five IDP camps.

Intestinal helminth infection in an ethnic minority commune in southern Vietnam.

A program to control intestinal helminth infections, based on stool surveys, mass treatment of children below 17 years, improvement of sanitation and health education was performed between 1997 and 1999 in Phan Tien, an ethnic minority community in mountainous southern Vietnam. Before intervention, 28.6% of children excreted eggs of at least one parasite, hookworm being the most common (23%), followed by Trichuris trichiura (1.9%), Hymenolepis nana (1.9%), Enterobius vermicularis (0.9%), Ascaris lumbricoides (0.5%), and multiple kinds of helminthes (0.5%). Strongyloides stercoralis was never detected. Poor sanitation and personal hygiene, and walking barefoot were considered the main risk factors for intestinal helminth infections. The success of 400 mg albendazole single dose mass treatment was initially frustrated by the poor quality of the drug formulation used, only containing half of the indicated amount of albendazole. Using another formulation quickly reduced the hookworm infection rate. Praziquantel was used to treat H. nana infections. After three years of intervention, intestinal helminth infections were reduced to 3.3% (p<0.0001). We conclude that interventions combining health education, improvement of sanitation and mass treatment effectively control intestinal helminth infections, but the quality of the drugs used is an important factor.

Prevalence of intestinal parasitic infestation in schoolchildren in the northeastern part of Kathmandu Valley, Nepal.

This paper presents the status of intestinal parasitosis in public schoolchildren (1 to 10 classes) in a rural area of the Kathmandu Valley, Nepal. A total of 533 schoolchildren (269 girls and 264 boys, aged 4 to 19 years) were included in this study. A questionnaire was filled out regarding hygienic and other habits, including factors predisposing to parasitic infections. Fecal samples from the children were examined by formol-ether concentration technique. The overall prevalence of parasitosis was 66.6% (395/533) with no significant difference between boys and girls (p> 0.05). Tibeto-Burman children had a non-significant higher prevalence, compared with Indo-Aryan and Dalit children (p>0.05). Half (53.8%; 191/355) of the children had multiple parasitic infections. Altogether, nine types of parasites were recovered. The recovery rate of helminths was higher (76.9%) than protozoa (23.1%). Trichuris trichiura was the most common helminth detected, followed by hookworm, Ascaris lumbricoides and others. Entamoeba coli was the most common protozoan parasite, followed by E. histolytica, Giardia lamblia and others.

Control of intestinal helminths in schoolchildren in Low-Napo, Ecuador: impact of a two-year chemotherapy program.

A school-based control program of intestinal helminths was undertaken among schoolchildren in the Low-Napo region, north-eastern Ecuador. Forty-eight percent of children were infected with one or more helminths at the first examination. The prevalence at the baseline was Ascaris 33.2% followed by hookworm 24.1% and Trichuris 6.5%. Sex was found to be a significant factor influencing the prevalence of hookworm and Trichuris. Prevalence was compared 9 months and 18 months after treatment. After 9 months, Ascaris and Trichuris prevalence had decreased but not hookworm. All of them increased after 18 months. The findings suggest that only a course of mebendazol had a minor effect on the control of helminth infections.

Intestinal helminthiases in Ecuador: the relationship between prevalence, genetic, and socioeconomic factors.

Prevalence of infection with the intestinal helminths, Ascaris lumbricoides, Trichuris trichiura, Ancylostoma duodenale and Strongyloides stercoralis was examined in 632 residents of communities in Esmeraldas Province of Ecuador. These communities were divided into two groups according to area of habitation which reflected different socioeconomic circumstances. Attempts were made to correlate infection status with race and ABO blood group phenotype. The racial groups included blacks, Chachi amerindians, and mixed-race mestizos. Greater prevalences of infection were seen in the area of lower socioeconomic status. No racial or blood group associations with helminth infection were seen controlling for socioeconomic status.

[Prevalence of intestinal parasites among Thais in Israel].

Stool samples from 93 Thais working in Israel were examined for the presence of parasites. The overall prevalence of infection by 1 or more species was 74%. Opisthorchis viverrini and hookworm were the most prevalent parasites (51.6% and 44.1%, respectively). They were also the parasites most frequently found in mixed infections; about a quarter of the workers were infected with both. Other helminths found in only a few cases were: Fasciolopsis buski (3 cases), Taenia sp. (3), Paragonimus sp. (1), Ascaris lumbricoides (1), Trichuris trichiura (1) and Trichostrongylus sp. (1).