Blastocystis is a common unicellular intestinal protozoa in humans and animals, and the most common clinical manifestations of infections include abdominal pain and diarrhea. Based on the sequence of the small-subunit ribosomal RNA (SSU rRNA) gene, 28 subtypes of B. hominis (ST1 to ST17, ST21 and ST23 to ST32) have been characterized. Previous studies have demonstrated that B. hominis infection is strongly associated with inflammatory bowel disease (IBD), irritable bowel syndrome (IBS) and other intestinal diseases, which threatens the health and quality of life among patients with B. hominis infection and is considered as an important public health problem. This review summarizes the progress of researches on B. hominis infection among IBD and IBS patients during the past 20 years, so as to provide insights into management of blastocystosis in China.
Animals ; Humans ; Irritable Bowel Syndrome/parasitology* ; Blastocystis Infections/complications* ; Quality of Life ; Blastocystis hominis/genetics* ; Feces/parasitology* ; Inflammatory Bowel Diseases/parasitology*

BACKGROUND: Soil-transmitted helminthes (STH) infections are among the most common infections worldwide and affect the most deprived communities. Adequate water, sanitation, and hygiene (WASH) prevents environmental contamination, thereby preventing transmission of STH. Cognizant of this, WASH education was implemented in rural Dembiya to reduce intestinal parasitic infections. This study was, therefore, conducted to assess the impacts of the intervention on households' WASH conditions and prevalence of intestinal parasitic infections. METHOD: An uncontrolled before-and-after intervention study was used. Cross-sectional studies were done before and after the intervention. Two hundred twenty-five and 302 under five children were recruited randomly at the baseline and endline, respectively. Data were collected using a structured questionnaire and observational checklists. Direct stool examination and Kato-Katz methods were used to identify parasites in the stool. We used percent point change and prevalence ratio (PR) to see the effects of the intervention on WASH conditions and prevalence of intestinal parasitic infections respectively. Pearson chi-squared and Fisher's exact tests were used to test for statistically significant percentage point changes of WASH conditions. The effect of the intervention on intestinal parasitic infections was statistically tested on the basis of PR with 95% confidence interval (CI). RESULTS: The baseline prevalence of intestinal parasitic infections was 25.8%, and the endline prevalence was 23.8%. The prevalence of intestinal parasitic infections was not significantly decreased at the endline compared with the baseline [PR = 0.92, 95% CI = (0.62, 1.38)]. Ascaris Lumbricoides was the most prevalent parasitic infection both at the baseline and endline. The proportion of children who had good hygienic condition increased from 1.3% at the baseline to 34.4% at the end line (p <  0.05). The percentage of mothers/care givers who washed hands at different pick times was significantly increased from 24.4% at the baseline to 68.2% at the endline (p <  0.001). The proportion of households who practiced home-based water treatment was significantly increased from 7.6% at the baseline to 47% at the endline (p <  0.001). The proportion of households who used sanitary latrine was increased from 32% at the baseline to 49% at the endline (p <  0.05). CONCLUSION This before-and-after intervention study found that households' WASH performance was significantly improved at the endline compared with the baseline. The endline prevalence of intestinal parasitic infections was slightly lower than the baseline prevalence; however, the reduction was not statistically significant. The local health office needs to strengthen the WASH education program, mobilize the community to construct WASH facilities, and support the community to sustain households' WASH performance.
Adult ; Child, Preschool ; Cross-Sectional Studies ; Drinking Water ; parasitology ; standards ; Ethiopia ; epidemiology ; Family Characteristics ; Feces ; parasitology ; Female ; Health Behavior ; physiology ; Health Education ; Health Knowledge, Attitudes, Practice ; Helminthiasis ; epidemiology ; prevention & control ; Humans ; Hygiene ; education ; Infant ; Intestinal Diseases, Parasitic ; epidemiology ; prevention & control ; Male ; Prevalence ; Rural Population ; Sanitation ; Soil ; parasitology ; Surveys and Questionnaires

Cyclospora cayetanensis is a foodborne and waterborne pathogen that causes endemic and epidemic human diarrhea worldwide. A few epidemiological studies regarding C. cayetanensis infections in China have been conducted. During 2013, a total of 291 stool specimens were collected from patients with diarrhea at a hospital in urban Shanghai. C. cayetanensis was not detected in any of the stool specimens by traditional microscopy, whereas five stool specimens (1.72%, 5/291) were positive by PCR. These positive cases confirmed by molecular technology were all in the adult group (mean age 27.8 years; 2.94%, 5/170) with watery diarrhea. Marked infection occurred in the rainy season of May and July. Sequence and phylogenetic analyses of the partial 18S rRNA genes of C. cayetanensis isolated showed intra-species diversity of this parasite. This study showed, for the first time, that C. cayetanensis is a pathogen in outpatients with diarrhea in Shanghai, albeit at a low level. However, the transmission dynamics of this parasite in these patients remain uncertain.
Adolescent ; Adult ; China ; epidemiology ; Cyclospora ; genetics ; isolation & purification ; Cyclosporiasis ; epidemiology ; Diarrhea ; etiology ; parasitology ; Feces ; parasitology ; Female ; Humans ; Male ; Middle Aged ; Outpatients ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 18S ; analysis ; Retrospective Studies ; Young Adult

Objective: To understand the prevalence of major human parasitic diseases and related factors in Henan province. Methods: This stratified sampling survey was carried out according to the requirement of national survey protocol of major human parasitic diseases, 2014-2015. The prevalence of soil-transmitted helminths infection, taeniasis and intestinal protozoiasis were surveyed in 104 sites selected from 35 counties (districts) and the prevalence of clonorchiasis was surveyed in 62 sites selected from 37 townships. In each survey spot, 250 persons were surveyed. A total of 26 866 persons and 15 893 persons were surveyed. Modified Kato-Katz thick smear was used to detect the eggs of intestinal helminthes. Tube fecal culture was used to identify the species of hookworm. The Enterobius eggs were detected in children aged 3 to 6 years by using adhesive tape. The cyst and trophozoite of intestinal protozoa were examined with physiological saline direct smear method and iodine stain method. Results: The overall infestation rate of intestinal parasites was2.02% in Henan, and the worm infection rate was higher than protozoa infection rate. Fourteen kinds of intestinal parasites were found, including nematode (5 species), trematode (2 species), and protozoan (7 species). The infection rate of Enterobius vermicularis was highest, and Qinba Mountain ecological area had the highest infestation rate of intestinal parasites in 4 ecological areas of Henan. There was no significant difference in intestinal parasite infection rate between males and females (χ(2)=3.630, P=0.057), and the differences in intestinal parasite infection rate among different age groups had significance (χ(2)=124.783, P=0.000 1). The infection rate reached the peak in age group ≤9 years and the major parasite was Enterobius vermicularis. Furthermore the overall human infection rate of parasite showed a downward trend with the increase of educational level of the people (χ(2)=70.969, P=0.000 1), the differences had significance (χ(2)=120.118, P=0.000 1). For different populations, the infection rate of intestinal parasites was highest among preschool children. The infection of intestinal helminth was mainly mild, only 2 severe cases were detected. The infection rate of Clonorchis sinensis in urban residents was only 0.006%. Logistic regression analysis showed that being preschool children (χ(2)=15.765, P=0.000 1) and drinking well water (χ(2)=45.589, P=0.000 1) were the risk factors for intestinal parasite infection, and annual income per capita of farmers was the protective factor against intestinal parasite infection. The infection rates of protozoa and intestinal parasites decreased sharply compared with the results of previous two surveys, and the rate of intestinal helminth infection also dropped sharply compared with the second survey. The numbers of protozoa, helminth and intestinal parasites detected in this survey were all less than the numbers found in the previous two surveys. Conclusions: Compared the results of three surveys in Henan, the infection rate of protozoa and intestinal parasites showed a downward trend. The prevention and treatment of Enterobius vermicularis infection in children should be the key point of parasitic disease control in the future.
Animals ; Child ; Child, Preschool ; Clonorchiasis/epidemiology* ; Farmers ; Feces/parasitology* ; Female ; Helminthiasis/epidemiology* ; Helminths ; Humans ; Intestinal Diseases, Parasitic/parasitology* ; Male ; Prevalence ; Protective Factors ; Risk Factors ; Rural Population ; Soil Microbiology ; Surveys and Questionnaires ; Taeniasis/epidemiology* ; Trematode Infections/parasitology* ; Urban Population ; Water Wells

Echinostomes are intestinal trematodes that infect a wide range of vertebrate hosts, including humans, in their adult stage and also parasitize numerous invertebrate and cold-blooded vertebrate hosts in their larval stages. The purpose of this study was to compare Echinostoma malayanum parasite growth, including worm recovery, body size of adult worms, eggs per worm, eggs per gram of feces, and pathological changes in the small intestine of experimental animals. In this study, 6-8-week-old male hamsters, rats, mice, and gerbils were infected with echinostome metacercariae and then sacrificed at day 60 post-infection. The small intestine and feces of each infected animal were collected and then processed for analysis. The results showed that worm recovery, eggs per worm, and eggs per gram of feces from all infected hamsters were higher compared with infected rats and mice. However, in infected gerbils, no parasites were observed in the small intestine, and there were no parasite eggs in the feces. The volume of eggs per gram of feces and eggs per worm were related to parasite size. The results of histopathological changes in the small intestine of infected groups showed abnormal villi and goblet cells, as evidenced by short villi and an increase in the number and size of goblet cells compared with the normal control group.
Animals ; Body Size ; *Disease Models, Animal ; Echinostoma/growth & development/isolation & purification/*physiology ; Echinostomiasis/*parasitology/*pathology ; Feces/parasitology ; Intestine, Small/parasitology/pathology ; Parasite Egg Count

Laboratory workers, in resource-poor countries, still consider PCR detection of Giardia lamblia more costly and more time-consuming than the classical parasitological techniques. Based on 2 published primers, an in-house one-round touchdown PCR-RFLP assay was developed. The assay was validated with an internal amplification control included in reactions. Performance of the assay was assessed with DNA samples of various purities, 91 control fecal samples with various parasite load, and 472 samples of unknown results. Two cysts per reaction were enough for PCR detection by the assay with exhibited specificity (Sp) and sensitivity (Se) of 100% and 93%, respectively. Taking a published small subunit rRNA reference PCR test results (6%; 29/472) as a nominated gold standard, G. lamblia was identified in 5.9% (28/472), 5.2%, (25/472), and 3.6% (17/472) by PCR assay, RIDA® Quick Giardia antigen detection test (R-Biopharm, Darmstadt, Germany), and iodine-stained smear microscopy, respectively. The percent agreements (kappa values) of 99.7% (0.745), 98.9% (0.900), and 97.7% (0.981) were exhibited between the assay results and that of the reference PCR, immunoassay, and microscopy, respectively. Restriction digestion of the 28 Giardia-positive samples revealed genotype A pattern in 12 and genotype B profile in 16 samples. The PCR assay with the described format and exhibited performance has a great potential to be adopted in basic clinical laboratories as a detection tool for G. lamblia especially in asymptomatic infections. This potential is increased more in particular situations where identification of the parasite genotype represents a major requirement as in epidemiological studies and infection outbreaks.
DNA, Protozoan/genetics ; Developing Countries ; Feces/parasitology ; Genotype ; Giardia lamblia/genetics ; Giardiasis/*diagnosis ; Humans ; Microscopy ; Parasitology/economics/instrumentation/*methods ; *Polymerase Chain Reaction ; *Polymorphism, Restriction Fragment Length ; Reproducibility of Results ; Sensitivity and Specificity

Cryptosporidium, a protozoan parasite that causes watery diarrhea, is found worldwide and is common in areas with low water hygiene. In February 2014, 866 stool samples were collected from the inhabitants of 2 rural areas in White Nile State, Sudan. These stool samples were assessed by performing modified acid-fast staining, followed by examination under a light microscope. The overall positive rate of Cryptosporidium oocysts was 13.3%. Cryptosporidium oocysts were detected in 8.6% stool samples obtained from inhabitants living in the area having water purification systems and in 14.6% stool samples obtained from inhabitants living in the area not having water purification systems. No significant difference was observed in the prevalence of Cryptosporidium infection between men and women (14.7% and 14.1%, respectively). The positive rate of oocysts by age was the highest among inhabitants in their 60s (40.0%). These findings suggest that the use of water purification systems is important for preventing Cryptosporidium infection among inhabitants of these rural areas in Sudan.
Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Cryptosporidiosis/epidemiology/*parasitology ; Cryptosporidium/genetics/*isolation & purification ; Feces/parasitology ; Female ; Humans ; Infant ; Male ; Middle Aged ; Prevalence ; Rural Population ; Sudan/epidemiology ; Young Adult

In order to examine the prevalence of Cryptosporidium infection in wild rodents and insectivores of South Korea and to assess their potential role as a source of human cryptosporidiosis, a total of 199 wild rodents and insectivore specimens were collected from 10 regions of South Korea and screened for Cryptosporidium infection over a period of 2 years (2012-2013). A nested-PCR amplification of Cryptosporidium oocyst wall protein (COWP) gene fragment revealed an overall prevalence of 34.2% (68/199). The sequence analysis of 18S rRNA gene locus of Cryptosporidium was performed from the fecal and cecum samples that tested positive by COWP amplification PCR. As a result, we identified 4 species/genotypes; chipmunk genotype I, cervine genotype I, C. muris, and a new genotype which is closely related to the bear genotype. The new genotype isolated from 12 Apodemus agrarius and 2 Apodemus chejuensis was not previously identified as known species or genotype, and therefore, it is supposed to be a novel genotype. In addition, the host spectrum of Cryptosporidium was extended to A. agrarius and Crosidura lasiura, which had not been reported before. In this study, we found that the Korean wild rodents and insectivores were infected with various Cryptosporidium spp. with large intra-genotypic variationa, indicating that they may function as potential reservoirs transmitting zoonotic Cryptosporidium to livestock and humans.
Animals ; Animals, Wild/*parasitology ; Cryptosporidiosis/*parasitology ; Cryptosporidium/classification/*genetics/*isolation & purification ; Feces/parasitology ; Genotype ; Insectivora/*parasitology ; Molecular Sequence Data ; Murinae ; Phylogeny ; Republic of Korea ; Rodent Diseases/*parasitology

Nematomorpha, horsehair or Gordian worms, include about 300 freshwater species in 22 genera (Gordiida) and 5 marine species in 1 marine genus (Nectonema). They are parasitic in arthropods during their juvenile stage. In the present study, the used gordian worm was found in the feces of a dog (5-month old, male) in July 2014. Following the worm analysis using light and scanning electron microscopes, the morphological classification was re-evaluated with molecular analysis. The worm was determined to be a male worm having a bi-lobed tail and had male gonads in cross sections. It was identified as Gordius sp. (Nematomorpha: Gordiidae) based on the characteristic morphologies of cross sections and areole on the cuticle. DNA analysis on 18S rRNA partial sequence arrangements was also carried out, and the gordiid worm was assumed to be close to the genus Gordius based on a phylogenic tree analysis.
Animals ; Dog Diseases/diagnosis/*parasitology ; Dogs ; Feces/*parasitology ; Helminthiasis, Animal/diagnosis/*parasitology ; Helminths/classification/genetics/*isolation & purification ; Male ; Molecular Sequence Data ; Phylogeny

The increasing prevalence of Toxoplasma gondii infection in the human population in the Republic of Korea (= Korea) is due to various reasons such as an increase in meat consumption. However, the importance of cats in transmitting T. gondii infection through oocysts to humans has seldom been assessed. A total of 300 fecal samples of stray cats captured around Seoul from June to August 2013 were examined for T. gondii B1 gene (indicating the presence of oocysts) using nested-PCR. Fourteen (4.7%) of 300 cats examined were positive for B1 gene. Female cats (7.5%) showed a higher prevalence than male cats (1.4%). Cats younger than 3 months (5.5%) showed a higher prevalence than cats (1.5%) older than 3 months. For laboratory passage of the positive samples, the fecal suspension (0.2 ml) of B1 gene positive cats was orally inoculated into experimental mice. Brain tissues of the mice were obtained after 40 days and examined for the presence of tissue cysts. Two isolates were successfully passaged (designated KNIH-1 and KNIH-2) and were molecularly analyzed using the SAG5D and SAG5E gene sequences. The SAG5D and SAG5E gene sequences showed high homologies with the ME49 strain (less virulent strain). The results indicated the importance of stray cats in transmitting T. gondii to humans in Korea, as revealed by detection of B1 gene in fecal samples. T. gondii isolates from cats were successfully passaged in the laboratory for the first time in Korea.
Animals ; Cat Diseases/diagnosis/epidemiology/*parasitology ; Cats ; Feces/*parasitology ; Female ; Genotype ; Humans ; Male ; Mice ; Protozoan Proteins/genetics ; Seoul/epidemiology ; Toxoplasma/genetics/*isolation & purification ; Toxoplasmosis/epidemiology/parasitology/transmission ; Toxoplasmosis, Animal/diagnosis/epidemiology/*parasitology