Human Intestinal Parasites Research Articles

Transcriptomic and proteomic analyses of Giardia intestinalis: Intestinal epithelial cell interactions.

Giardia intestinalis is a unicellular protozoan parasite that infects the small intestines of humans and animals. Giardiasis, the disease caused by the parasite, occurs globally across socioeconomic boundaries but is mainly endemic in developing countries and particularly within young children, where pronounced effects manifests in a failure to thrive condition. The molecular pathogenesis of Giardia has been studied using in vitro models of human and rat intestinal epithelial cells (IECs) and parasites from the two major human genotypes or assemblages (A and B). High-quality, genome sequencing of representative isolates from assemblages A (WB) and B (GS) has enabled exploration of these host-parasite models using 'omics' technologies, allowing deep and quantitative analyses of global gene expression changes in IECs and parasites during their interactions, cross-talk and competition. These include a major up-regulation of immune-related genes in the IECs early after the start of interactions, as well as competition between host cells and parasites for nutrients like sugars, amino acids and lipids, which is also reflected in their secretome interactions. Unique parasite proteins dominate these interactions, with many major up-regulated genes being either hypothetical proteins or members of Giardia-specific gene families like the high-cysteine-rich membrane proteins (HCMPs), variable surface proteins (VSPs), alpha-giardins and cysteine proteases. Furthermore, these proteins also dominate in the secretomes, suggesting that they are important virulence factors in Giardia and crucial molecular effectors at the host-parasite interface.

Genome-Wide Analysis of Known and Potential Tetraspanins in Entamoeba histolytica.

Tetraspanins are membrane proteins involved in intra- and/or intercellular signaling, and membrane protein complex formation. In some organisms, their role is associated with virulence and pathogenesis. Here, we investigate known and potential tetraspanins in the human intestinal protozoan parasite Entamoeba histolytica. We conducted sequence similarity searches against the proteome data of E. histolytica and newly identified nine uncharacterized proteins as potential tetraspanins in E. histolytica. We found three subgroups within known and potential tetraspanins, as well as subgroup-associated features in both their amino acid and nucleotide sequences. We also examined the subcellular localization of a few representative tetraspanins that might be potentially related to pathogenicity. The results in this study could be useful resources for further understanding and downstream analyses of tetraspanins in Entamoeba.

Occurrence and molecular characterization of Giardia duodenalis in child population from Colombia

Giardia duodenalis is one of the most prevalent human intestinal parasite, with children living in developing countries being particularly at risk of infection. The occurrence and molecular diversity of G. duodenalis was investigated in stools specimens from 307 individuals aged one to nineteen years in Colombia. Samples were collected in three educational establishments (n: 163) and two hospital laboratories (n: 144) from urban and rural areas. Feces were concentrated using a biphasic sedimentation method and wet mounts of the sediment were examined by light microscopy. G. duodenalis assemblages and sub-assemblages were determined on positive samples by PCR of the triose phosphate isomerase (tpi), β-giardin (bg) and small-subunit (ssu) rRNA genes. G. duodenalis infection was detected by microscopy in 23 individuals (7.5%). The protozoan was more prevalent among specimens collected in educational establishments (11.6%) than in those obtained from hospital laboratories (2.8%). Infection was most common in individuals from urban areas and children aged 1–5 years. No significant association between diarrhea and infection could be demonstrated. Twenty Giardia-positive samples were successfully allocated to assemblage B (n: 11), sub-assemblage AII (n: 7), and assemblage A (n: 2). Results indicate the potential for transmission of G. duodenalis infection in children attending educational establishments and individuals from urban areas, where transmission seems to be primarily anthroponotic.

Molecular typing of Giardia duodenalis in cattle, sheep and goats in an arid area of central Iran

Giardia duodenalis is one of the most common intestinal parasites in humans as well as livestock and wildlife. It is of both public and veterinary health importance in developing nations. A molecular survey of Giardia duodenalis assemblages in ruminants from Yazd Province, Iran was conducted on 484 animal faecal samples collected per rectum from slaughtered ruminants including 192 cattle, 192 sheep and 100 goats from June to November 2017. Species-specific and assemblage-specific PCRs for assemblages A, B and E at the triose phosphate isomerase (tpi) gene were performed, and samples positive for Giardia were confirmed by sequencing. In total, 25 (5.16%) of examined faecal samples including eight cattle (4.2%), twelve sheep (6.2%) and five goats (5%) were infected with G. duodenalis. Assemblage-specific PCR detected G. duodenalis assemblage E in seven faecal samples (six in sheep and one in a goat). Assemblages A and B were not detected. This study provides the first insight into Giardia infection in slaughtered livestock in Iran. Although the prevalence of infection with Giardia in this hot-arid area of Iran was low, educating people about direct contact with livestock such as farmers and abattoirs workers about this zoonotic infection is important.

Epidemiological features and changing patterns of intestinal parasitic diseases in Jiangxi Province

To understand the epidemiological features and changing patterns of intestinal parasitic diseases in Jiangxi Province from 1989 to 2014, so as to provide scientific evidence for formulating the preventive and control strategy for intestinal parasitic diseases. The data regarding the status of intestinal parasitic diseases in Jiangxi Province were captured from the 1989 national survey on the distribution of human parasites in China and the 2014 national survey on major human parasitic diseases in China, and the status of human intestinal parasite infections was compared between the two surveys in Jiangxi Province. The prevalence rate of human intestinal parasite infections was 79.59% and 9.64% in Jiangxi Province in 1989 and 2014, with a decline rate of 87.89% during the 25-year period (χ2 = 30 870.5, P < 0.01). There were 24 and 20 species of human intestinal parasites detected in Jiangxi Province in 1989 and 2014, respectively, with totally 26 species detected during the two surveys. In Jiangxi Province, the 3 most highly prevalent human intestinal parasites included Ascaris lumbricoides (71.06%), hookworm (17.61%) and Enterobius vermicularis (17.59%) in 1989, and E. vermicularis (13.73%), hookworm (4.66%), whipworm (0.95%) in 2014. A higher rate of human intestinal parasite infections was found in females than in males in both surveys in Jiangxi Province (P < 0.01), and the prevalence of human intestinal parasite infections reduced by 82.50% to 95.31% in different age groups in Jiangsu Province during the 25-year period. The prevalence of human intestinal parasite infections shows a remarkable decline tendency in Jiangxi Province, and soil-transmitted nematodes remain the main species of human intestinal parasites in Jiangxi Province.

Prevalence and multilocus genotyping of potentially zoonotic Giardia duodenalis in pigs in Shanghai, China.

Giardia duodenalis is a common intestinal parasite in humans and other mammals, and it causes major public and veterinary health problems worldwide. China is a major pig-raising country, and studies on Giardia in pigs have important public health significance. The present study was conducted to investigate the prevalence of Giardia and assess its genetic characterization. A total of 93 samples were collected from two farms in Shanghai. The presence of Giardia was determined using PCR and sequence analysis of glutamate dehydrogenase, beta-giardin and triose phosphate isomerase genes. The average prevalence of G. duodenalis infection was 26.88% (25/93) in the pigs, with 28.13% (18/64) in farm 1 vs 24.14% (7/29) in farm 2. All the PCR-positive products were successfully sequenced, and assemblage E was more prevalent. Zoonotic assemblages A and B and canine-specific assemblage C were identified in farm 1, whereas, only assemblage E was detected in farm 2. Interestingly, two pig isolates showed 100% homology with human-derived isolates from Australia and China at the bg and tpi loci respectively. Pigs infected with Giardia infect humans by polluting the environment; whether pigs are a potential environmental source of the human pathogen in China requires more epidemiological data.

Investigation on human intestinal parasitic diseases in ecological regions of Qinba Mountains in Henan Province in 2015

To understand and analyze the epidemic status of human intestinal parasitic diseases in the ecological region of the Qinba Mountains in Henan Province, so as to provide the evidence for the control of the diseases in this region. According to the methods of National Survey Scheme on Major Human Parasitic Diseases, 26 survey spots were selected in 8 counties (cities) in ecological regions of Qinba Mountains in Henan Province in 2015. After collecting the human fecal samples, the eggs of intestinal helminthes were detected with the modified Kato-Katz thick smear method, the species of Ancylostoma of the hookworm egg-positive samples were identified with the tube fecal culture method, the eggs of Enterobius vermicularis were detected by using the adhesive tape method in children aged 3 to 6 years, and the cyst and trophozoite of intestinal protozoa were examined by iodine staining. The infections of intestinal parasites in different populations and the related influencing factors were analyzed. Totally 6 706 residents were recruited in this study, 8 kinds of parasites were found including 3 species of helminthes and 5 species of protozoans. The overall infection rate of intestinal parasites was 3.39%, covering 2.92% for helminthes and 0.49% for protozoans. The infection rate of E. vermicularis in children aged 3 to 6 years was 3.93%. The 3 identified helminthes were Ascaris lumbricoides, E. vermicularis, and Dicrocoelium dendriticum, with the highest infection rate of E. vermicularis (2.68%, χ2 = 306.362, P < 0.05). The 5 identified protozoans were Entamoeba hartmani, E. coli, Endolimax nana, Giardia lamblia, and Blastocystis hominis, and the infection rate of E. nana was the highest (χ2 = 23.842, P < 0.05). Among the 8 counties (cities), the highest infection rate of helminthes, mainly with Enterobius infection, existed in Ruyang County, and the infection rate of protozoans in Xin'an County was the highest, mainly with E. nana infection. There was a significant difference in the infection rates of helminthes and protozoans among the 8 counties (cities) (helminthes: χ2 = 357.525, P < 0.05; protozoans: χ2 = 38.795, P < 0.05). There was no significant difference in the helminth infection rate between males and females ( χ2 = 0.034, P > 0.05), but the protozoan infection rate of the males was higher than that of the females ( χ2 = 12.946, P < 0.05). The helminth infection rate of the 0-9 years old group was the highest ( χ2 = 62.600, P < 0.05), up to 6.60%, mainly with E. vermicularis infection. There was no significant difference in the infection rate of intestinal parasites among nationalities ( χ2 = 0.212, P > 0.05). The helminth infection rate of preschool children was the highest and up to 8.43%, mainly with E. vermicularis infection. The infection of A. lumbricoides was mainly happened among farmers, with the infection rate of 0.31%. There was a significant difference in the helminth infection rate among different occupations (χ2 = 84.333, P < 0.05). The intestinal parasites infection rate of the illiterate population was the highest and up to 7.63%, there was a significant difference among the populations with different educational levels (χ2 = 72.013, P < 0.05). The helminth infection rate of plain areas was higher than that of valley and hill ( χ2 = 11.690, P < 0.05). The helminth infection rate of people with low-income was the highest and up to 10.32% (χ2 = 244.999, P < 0.05). The protozoan infection rate of people with middle-income was the highest, who had the annual per capita net income of 6 000 to 7 999 Yuan ( χ2 = 24.749, P < 0.05). The helminth infection rate of people drinking well water was much higher than that of people drinking tap water (χ2 = 62.255, P < 0.05). The protozoan infection rate of people without insect repellent was higher than that of people with insect repellent (χ2 = 5.235, P < 0.05). The infection rates of human intestinal parasites in the ecological region of the Qinba Mountains in Henan Province have decreased sharply. E. vermicularis infection in children should be the main point of prevention and treatment of parasitic diseases in the future.

Identification of eukaryotic microorganisms with 18S rRNA next-generation sequencing in wastewater treatment plants, with a more targeted NGS approach required for Cryptosporidium detection

While some microbial eukaryotes can improve effluent quality in wastewater treatment plants (WWTPs), eukaryotic waterborne pathogens are a threat to public health. This study aimed to identify Eukarya, particularly faecal pathogens including Cryptosporidium, in different treatment stages (influent, intermediate and effluent) from four WWTPs in Western Australia (WA). Three WWTPs that utilise stabilisation ponds and one WWTP that uses activated sludge (oxidation ditch) treatment technologies were sampled. Eukaryotic 18S rRNA (18S) was targeted in the wastewater samples (n = 26) for next-generation sequencing (NGS), and a mammalian-blocking primer was used to reduce the amplification of mammalian DNA. Overall, bioinformatics analyses revealed 49 eukaryotic phyla in WWTP samples, and three of these phyla contained human intestinal parasites, which were primarily detected in the influent. These human intestinal parasites either had a low percent sequence composition or were not detected in the intermediate and effluent stages and included the amoebozoans Endolimax sp., Entamoeba sp. and Iodamoeba sp., the human pinworm Enterobius vermicularis (Nematoda), and Blastocystis sp. subtypes (Sarcomastigophora). Six Blastocystis subtypes and four Entamoeba species were identified by eukaryotic 18S NGS, however, Cryptosporidium sp. and Giardia sp. were not detected. Real-time polymerase chain reaction (PCR) also failed to detect Giardia, but Cryptosporidium-specific NGS detected Cryptosporidium in all WWTPs, and a total of nine species were identified, including five zoonotic pathogens. Although eukaryotic 18S NGS was able to identify some faecal pathogens, this study has demonstrated that more specific NGS approaches for pathogen detection are more sensitive and should be applied to future wastewater pathogen assessments.

Frequency, associated factors and clinical symptoms of intestinal parasites among tuberculosis and non-tuberculosis groups in Iran: a comparative cross-sectional study.

Co-infection of human tuberculosis (TB) and intestinal parasites infections (IPIs) is a public health problem, especially in low- and middle-income countries. There is no data on this issue in Iran. Therefore, we investigated the prevalence of IPIs among patients with TB in Iran. Stool samples were collected from 161 patients with TB and 181 healthy people (non-TB group). Standard parasitological methods including direct slide smear, formalin-ether concentration, trichrome, modified Ziehl-Neelsen and chromotrope 2R staining techniques were used for detection of intestinal protozoa and helminths. Nested-PCR and sequence analysis were used to identify the genotypes of Cryptosporidium and human-infecting species of microsporidia. Data analysis was performed using SPSS version 16. The frequency of IPIs in the non-TB group (16.5%) was slightly lower than in patients with TB (21.1%), although statistical significance was not observed (OR, 0.74; 95% CI, 0.43-1.27; P= 0.28). Blastocystis (11.8%) was the most common parasite detected in patients with TB. Infection with multiple parasites in the non-TB group (2.2%) was significantly lower than in patients with TB (7.5%) (OR, 0.28; 95% CI, 0.08-0.88; P=0.02). The ova of Taenia spp., Ascaris lumbricoides and Hyamenolepis nana were identified in three patients with TB (1.9%), while only one person (0.5%) in the non-TB group was infected with Enterobius vermicularis. The results of genotyping revealed two C. parvum subtype families (IIa and IId) and three E. bieneusi genotypes (Ebcar4, IH and jLD-1). Our results showed a higher prevalence of IPIs in patients with TB in comparison with non-TB subjects. Moreover, our findings suggest a proper health education program for good personal hygiene habits, and also preventative measures to avoid the acquisition of IPIs in patients with TB.

The Distribution of Human Intestinal Stool Parasites with Respect to Gender and Age in a District Hospital Setting in Biyem-Assi Yaoundé: A Retrospective Study

The Distribution of Human Intestinal Stool Parasites with Respect to Gender and Age in a District Hospital Setting in Biyem-Assi Yaoundé: A Retrospective Study

Epidemiology of Blastocystis sp. infection in China: a systematic review.

Blastocystis sp., a unicellular intestinal parasite in humans and animals worldwide, is frequently found in immunocompromized patients and people in close contact with animals. Here, we reviewed recent studies on the prevalence, subtypes, and distribution of Blastocystis infection in humans and animals in China. To date, more than 12 provinces have reported Blastocystis infection in humans, with identification of six different subtypes (ST1, ST2, ST3, ST4, ST5, and ST6). The overall infection rate reported was 3.37% (3625/107,695), with the lowest prevalence (0.80%) in Fujian province and the highest prevalence (100%) in Guangdong province. ST3 (62%, 186/300) was the most dominant subtype, identified in all tested provinces in China. A total of eight provinces have reported Blastocystis infection in various animals, with the overall prevalence being 24.66% (1202/4874). Molecular analysis revealed 14 subtypes that infected animals, including 10 known (ST1, ST2, ST3, ST4, ST5, ST6, ST7, ST10, ST13, ST14), and 4 novel (Novel1, Novel2, Novel3, Novel4) subtypes. ST5 was the dominant subtype infecting artiodactyls (44.1%, 460/1044), while ST1 commonly infected carnivores (45.5%, 5/11). These findings provide insights into the epidemiological behavior of Blastocystis sp. in China, and could help in developing effective control strategies against the parasite.

Automating the clinical stools exam using image processing integrated in an expert system

Abstract Background and objective The diagnosis of intestinal parasitosis disease relies on physiological symptoms and stool examination. Often, few specialists are available, and manual stool exam is slow, prone to error, and can cause eye fatigue. Our aim was to design and implement a medical expert system that would be automated and helpful for diagnosis of human intestinal parasitosis. Methods The system was developed based on a decision algorithm. A knowledge base was constructed through information gleaned from books and physicians with information pertaining to the disease. The user interacts with the system by answering questions. The symptoms information collected led to a microscopic examination of stools, which was run on the system to detect parasites. The paradigm for automated microscopic examination of stools consisted of a combined distance regularized level set evolution, automatically initialized by a circular Hough transform, and a trained neuro-fuzzy classifier. The neuro-fuzzy classifier was trained for analysis of twenty human intestinal parasites. Results We combined the reasoning scheme of diagnosis and the automated clinical exam of stools in the same system. The parasites found in microscopic imagery confirmed the suspicious disease. The final recommendation of diagnosis was then completed, with appropriate proposed therapy. The system was evaluated with sixty cases of infection, and compared to the diagnosis of two expert doctors; we obtained fifty eight correct diagnoses, corresponding to a 96.6% accuracy. Conclusions The proposed system is automated, since the parameters of segmentation, feature extraction and classification are set to be computationally guided by the type of suspicious parasite. The system is potentially an important contribution for medical healthcare assistance.

Parasitic Contamination of Raw Vegetables Consumed in Hamadan, West of Iran During 2017-2018

Background: Healthy diets including fruits and vegetables reduce the risk of chronic diseases. This study was aimed at detecting parasitic contamination caused by consuming raw vegetables sold in Hamadan, west of Iran. Methods: A total of 380 vegetable samples consisting of parsley, coriander, basil, savory, mint, cress, tarragon, leek, radish and spring onion were evaluated microscopically after conducting sedimentation and flotation from April 2017 to March 2018. Results: Parasites were detected in 95 out of 380 of vegetable samples (25%). The organisms identified included Entamoeba coli (8.15%), Ascaris lumbricoides (7.1%), Chilomastix mesnili (5%), and Giardia lamblia (1.5%), Blastocystis hominis (0.78%), Toxocara canis (0.26%) and Hymenolepis nana (0.26%). High level of contamination was obtained for parsley (5.52%) while radish was the least contaminated (0.78%). Vegetable contamination was higher in spring and summer (20.6%) (P<0.0001). Samples collected from vegetable fields irrigated by well water supply showed low parasitic contamination (28.5%) compared to those from farms irrigated by surface or sewage water (91%) (P<0.0001). Conclusions: The results emphasize the potential role of raw vegetables consumption in transmission of pathogenic organisms. Besides, it was highlighted that irrigation of vegetables by surface water could be the source of vegetable contamination with human intestinal parasites.

Distribution and genetic diversity of Blastocystis subtypes in various mammal and bird species in northeastern China

BackgroundBlastocystis is one of the most common intestinal parasites in humans and animals worldwide. At least 17 subtypes have been identified in mammals and birds. In China, although some studies have reported the occurrence of Blastocystis in humans and animals, our understanding of the role of animals in the transmission of human blastocystosis is only superficial due to a paucity of available molecular data. The aim of the present study was to understand infection rates of Blastocystis and the distribution and genetic diversity of subtypes in various mammal and bird species in northeastern China, as well as to assess the zoonotic potential of Blastocystis isolates.MethodsA total of 1265 fresh fecal specimens (1080 from ten mammal species and 185 from eight bird species) were collected in Heilongjiang, Liaoning and Jilin provinces of China. Each specimen was examined for the presence of Blastocystis by PCR amplification and sequence analysis of the partial SSU rRNA gene.ResultsFifty-four specimens (4.3%) were positive for Blastocystis. Birds (7.0%) had a higher infection rate of Blastocystis than mammals (3.8%). Blastocystis was found in seven mammal species, reindeer (6.7%), sika deer (14.6%), racoon dogs (7.5%), Arctic foxes (1.9%), dogs (2.9%), rats (3.7%) and rabbits (3.3%), as well as three bird species, pigeons (2.1%), chickens (13.0%) and red crowned cranes (14.0%). Eight subtypes were identified including ST1 (n = 5), ST3 (n = 3), ST4 (n = 13), ST6 (n = 8), ST7 (n = 6), ST10 (n = 13), ST13 (n = 4) and ST14 (n = 2). 64.8% (35/54) of Blastocystis isolates belonged to potentially zoonotic subtypes.ConclusionsTo our knowledge, this is the first report of Blastocystis in reindeer (ST10 and ST13), rabbits (ST4), racoon dogs (ST3) and Arctic foxes (ST1, ST4 and ST7). The findings of potentially zoonotic subtypes suggest that the animals infected with Blastocystis might pose a threat to human health. These data will improve our understanding of the host range and genetic diversity of Blastocystis, and also help develop efficient control strategies to intervene with and prevent the occurrence of human blastocystosis in the investigated areas.

Domiciliary Cockroaches as Carriers of Human Intestinal Parasites in Lagos Metropolis, Southwest Nigeria: Implications for Public Health

Domiciliary cockroaches are obnoxious pests of significant medical importance. We investigated the prevalence of human intestinal parasites in cockroaches and its attendant public health importance. Overall, 749 cockroaches (Periplaneta americana, 509, Blattella germanica, 240) caught by trapping from 120 households comprising 3 different housing types in Somolu, Lagos metropolis, southwest Nigeria, in 2015 were screened for human intestinal parasites using standard parasitological techniques. The prevalence of human intestinal parasites in cockroaches was 96.4%. There was no statistically significant difference (P> 0.05) in parasite prevalences between P. americana (95.7%) and B. germanica (97.9%). Parasite species identified and their prevalence were as follows: Entamoeba histolytica/dispar (44.1%), E. coli (37.8%), Giardia lamblia (18.7%), Cryptosporidium sp. (13.8%), Ascaris lumbricoides (61.3%), Trichuris trichiura (55.8%), hookworms (11.6%), Strongyloides stercoralis (11.7%), Taenia/Echinococcus spp. (10.5%), Enterobius vermicularis (17.2%) and Hymenolepis nana (11.6%). Parasite prevalence and burdens varied with housing type; the prevalence was significantly higher statistically (P< 0.05) in cockroaches from low-cost bungalow, LCB (100%) and low-cost, 2-storey, LC2-S (100%) houses than in medium-cost flats, MCF (81.3%). Parasite burdens were also significantly higher statistically (P< 0.05) in cockroaches from LCB or LC2-S than in cockroaches from MCF. Parasite prevalences between cockroach gut and body surfaces were not statistically significant (P> 0.05) but mean parasite burdens in gut were significantly higher statistically (P< 0.05) than on body surfaces. Cockroaches types carry transmissive stages of human intestinal parasites and may act as reservoirs and potential mechanical vectors for disease transmission.

Prevalence of Human Intestinal Nematode Parasites in Three Rural Communities of the Niger Delta, Nigeria

Prevalence of Human Intestinal Nematode Parasites in Three Rural Communities of the Niger Delta, Nigeria

Stone age disease in the north – Human intestinal parasites from a Mesolithic burial in Motala, Sweden

Eggs from an intestinal parasite has been found in a burial radiocarbon dated to 5210-4840 cal BC in Motala, east-central Sweden. The two helminth eggs are identified as Trichuris trichiura (human whipworm). Control samples from the cemetery site were all negative and confirmed that there was no evident contamination of younger material. This discovery raises new questions concerning the early geographical spread and timing of parasitic diseases among hunter-gatherer societies in northern Europe, and in the temperate zone of the northern hemisphere. Whipworm infection (Trichuriasis) is perhaps the disease most associated with crowding and poor sanitation, and as it manifests itself in the youngest dated burial, it could be a contributing factor to the final abandonment of the Mesolithic settlement. Also, parasite eggs found in a soil sample from the Neolithic Alvastra pile dwelling could indicate the continued presence of the Trichuris parasite in east-central Sweden. Generally, parasite ecology can aid in reconstructing human behaviors that include aspects of sedentism, mobility, food preferences, hygiene and other social practices.

A neuro-fuzzy system for automated detection and classification of human intestinal parasites

Abstract Background and objective Human intestinal parasites are a major public health concern in tropical countries. The most reliable diagnosis of these parasites relies on the visual analysis of stool specimens. However, this method is time consuming, tedious, and prone to diagnosis error. Hence, the aim of this work is the automatic analysis of microscopic images for the classification of intestinal parasites. A combination of a fuzzy system and an artificial neural network leads to an artificial intelligence system appropriate for this task. Methods The approach is based on segmentation and training of a classifier. The input to the system is a microscopic image of a given stool sample with parasites. The parasite is firstly localized by the circular Hough transform and secondly, the distance regularized level set evolution is automatically initialized for segmentation. From the extracted parasite, we determined the histogram oriented region with feature vectors being of high interest. The dimension of feature vectors is reduced using linear discriminant analysis and is considered as input to the classifier. Finally, the neuro-fuzzy classifier is trained according to a speeded up scaled conjugate gradient algorithm. Results The proposed scheme has been applied for recognition and classification of twenty human intestinal parasites. The results demonstrate satisfactory classification for each of the twenty classes of parasites, with a recognition rate of 100%. The measure of root mean square error decreases with the number of epochs; subsequently, that error vanishes while training and evaluating the system, and confirms the high recognition rate achieved by the proposed classifier. Conclusions In this paper, we proposed a neuro-fuzzy system that classifies human intestinal parasites (Protozoa and Helminths) with high accuracy, independent to their stage of development (egg, cyst, or trophozoite). A satisfactory classification for twenty classes of parasites was successfully achieved, with possible extensions in future work.

Epidemiology of Blastocystis spp. in primary school students at a central village of Ordu province

Blastocystis spp. is one of the most common intestinal parasites in humans and its pathogenicity is still controversial. The epidemiology of this parasite varies depending on the socio-cultural, socio-economic and geographic circumstances. In this study, Blastocystis spp. was investigated in stool samples of a Primary School students’ in a Central Village in Ordu province who did not have any intestinal complaints. Before starting work, we were granted permission from National Education Directorate and the School Board. Blastocystis spp. was investigated in Primary School Students’ stool samples by direct microscopy and Trichrome staining. The stool samples which showed any form of Blastocystis spp. were evaluated as “microscopically positive” regardless of the number per microscope field. Eighty and 85 of the 165 students participating in working were male and female, respectively. As a result of the microscopic investigation, 45 (27.3%) students were identified as positive. Eighteen of the positive students (40%) were male and 27 (60%) were female. Direct microscopic inspection, sedimentation and permanent staining are routine methods used in diagnosis of Blastocystis spp. This study also evaluated trichrome staining for each stool samples. In our research, this parasite was identified in 27.3% of asymptomatic Primary School students’ stool samples. This suggests the parasite is relatively common in the region. Blastocystis spp. infects via the fecal-oral route. As a result, we presented recommendations for the enhancing personal hygiene, social education and the provision of water treatment for the students to protect themselves from infection with Blastocystis spp.

A Survey on Prevalence of Intestinal Parasites Infections in Patients Referred to the Public Hospital in Khoy, West Azarbaijan Province, Iran, 2014 - 2016

Background: Intestinal parasites are one of the most important human infections in many tropical and sub-tropical areas. Objectives: The aim of the present study was to determine the prevalence of intestinal parasites and their association with some demographic factors in patients referred to the Ghamar Bani Hashem hospital Khoy, West Azarbaijan province. Methods: This cross-sectional study was conducted from April 2014 to March 2016. Stool samples of 5610 patients referred to the Ghamar Bani Hashemhospitalwere examinedusing the formalin-ether concentrationand direct smearmethods. Determinationof intestinal parasites was based on the morphological characteristics of the parasites. The scotch tape method was used for detection of Enterobius vermicularis ova in 133 suspected individuals. Microscopic results were recorded and analyzed. Results: A total of 5610 people (51.6% male and 48.4% female) were examined. The mean age of the patients was 47.26 ± 1.3. Among these, 32.1% were infected to at least 1 of the intestinal parasites. Prevalence of protozoa and helminths parasites was 30.1% and 1.2%, respectively. The prevalence rate of intestinal parasites was: Blastocystis sp.12.9%, Giardia lamblia 11%, Entamoeba coli 4.1%, Iodamoeba butschlii 2.1%, Endolymax nana 1.5%, Entamoeba histolytica/E.dispar 0.25%, Trichomonas hominis 0.09%, Ascaris lumbricoides 0.09%, Hymenolypis nana 0.03%, and Enterobius vermicularis 4.5%. Although the highest prevalence was in the age group of 20 - 29 years (31.8%), there was no significant relationship between age and parasite infection. However, a significant relationship was observed between the Giardia lamblia infection and age. Conclusions: Human intestinal parasite infections, especially protozoan infection, are still abundantin the Khoy region. Adequate knowledge andperiodic surveillance of theprevalence of parasites andthe variables that affectfrequency are importantfor effective control.