blastocystis infections

Summary

Summary: Infections with organisms of the genus BLASTOCYSTIS. The species B. hominis is responsible for most infections. Parasitologic surveys have generally found small numbers of this species in human stools, but higher positivity rates and organism numbers in AIDS patients and other immunosuppressed patients (IMMUNOCOMPROMISED HOST). Symptoms include ABDOMINAL PAIN; DIARRHEA; CONSTIPATION; VOMITING; and FATIGUE.

Top Publications

  1. Nascimento S, Moitinho M. Blastocystis hominis and other intestinal parasites in a community of Pitanga City, Paraná State, Brazil. Rev Inst Med Trop Sao Paulo. 2005;47:213-7 pubmed
    ..The high frequency of B. hominis demonstrated by this study indicates the need to include laboratory techniques that enable identification of the parasite on a routine basis...
  2. Stark D, van Hal S, Marriott D, Ellis J, Harkness J. Irritable bowel syndrome: a review on the role of intestinal protozoa and the importance of their detection and diagnosis. Int J Parasitol. 2007;37:11-20 pubmed
    ..It is essential that all patients with IBS undergo routine parasitological investigations in order to rule out the presence of protozoan parasites as the causative agents of the clinical signs...
  3. Yaicharoen R, Sripochang S, Sermsart B, Pidetcha P. Prevalence of Blastocystis hominis infection in asymptomatic individuals from Bangkok, Thailand. Southeast Asian J Trop Med Public Health. 2005;36 Suppl 4:17-20 pubmed
    ..Other parasites, eg Giardia lamblia, Entamoeba histolytica, Entamoeba coli, Endolimax nana, Trichomonas hominis, Strongyloides stercoralis, Opisthorchis viverrini and Taenia species, were also found by fresh stool examination...
  4. Elwakil H, Hewedi I. Pathogenic potential of Blastocystis hominis in laboratory mice. Parasitol Res. 2010;107:685-9 pubmed publisher
    ..In conclusion, this study revealed that large number of B. hominis is essential for oral infection of mice and that vacuolar forms of B. hominis can invade the lamina propria, the submucosa, and even the muscle layers...
  5. Cirioni O, Giacometti A, Drenaggi D, Ancarani F, Scalise G. Prevalence and clinical relevance of Blastocystis hominis in diverse patient cohorts. Eur J Epidemiol. 1999;15:389-93 pubmed
    ..Immunodepression seems to be a factor of primary importance of the pathogenic role of B. hominis. ..
  6. Eroglu F, Genc A, Elgun G, Koltas I. Identification of Blastocystis hominis isolates from asymptomatic and symptomatic patients by PCR. Parasitol Res. 2009;105:1589-92 pubmed publisher
  7. Fayer R, Santin M, Macarisin D. Detection of concurrent infection of dairy cattle with Blastocystis, Cryptosporidium, Giardia, and Enterocytozoon by molecular and microscopic methods. Parasitol Res. 2012;111:1349-55 pubmed publisher
    ..A commercially available immunofluorescence (IFA) microscopic test confirmed six of seven available PCR-positive Blastocystis specimens and identified one IFA-positive cow that was PCR negative...
  8. Yoshikawa H, Abe N, Wu Z. PCR-based identification of zoonotic isolates of Blastocystis from mammals and birds. Microbiology. 2004;150:1147-51 pubmed
  9. Wong K, Ng G, Lin R, Yoshikawa H, Taylor M, Tan K. Predominance of subtype 3 among Blastocystis isolates from a major hospital in Singapore. Parasitol Res. 2008;102:663-70 pubmed
    ..The predominance of subtype 3 in an urbanized city state such as Singapore is in agreement with the idea that subtype 3 is a genotype of human origin...

More Information

Publications82

  1. Kaya S, Cetin E, Aridogan B, Arikan S, Demirci M. Pathogenicity of Blastocystis hominis, a clinical reevaluation. Turkiye Parazitol Derg. 2007;31:184-7 pubmed
    ..0% and 32.6%. Intestinal symptoms may be seen frequently together with the presence of B. hominis and this protozoan may be regarded as an intestinal pathogen, especially when other agents are eliminated...
  2. Li L, Zhou X, Du Z, Wang X, Wang L, Jiang J, et al. Molecular epidemiology of human Blastocystis in a village in Yunnan province, China. Parasitol Int. 2007;56:281-6 pubmed
  3. Leelayoova S, Rangsin R, Taamasri P, Naaglor T, Thathaisong U, Mungthin M. Evidence of waterborne transmission of Blastocystis hominis. Am J Trop Med Hyg. 2004;70:658-62 pubmed
    ..Thus, waterborne transmission of B. hominis infection was indicated at this army base. However, other modes of transmission cannot be ruled out...
  4. Stensvold C, Arendrup M, Jespersgaard C, Mølbak K, Nielsen H. Detecting Blastocystis using parasitologic and DNA-based methods: a comparative study. Diagn Microbiol Infect Dis. 2007;59:303-7 pubmed
  5. Nagel R, Cuttell L, Stensvold C, Mills P, Bielefeldt Ohmann H, Traub R. Blastocystis subtypes in symptomatic and asymptomatic family members and pets and response to therapy. Intern Med J. 2012;42:1187-95 pubmed publisher
    ..The high prevalence of Blastocystis infection within households suggested transmission between humans and their pets. Subtyping analysis of SSU rDNA alone in Blastocystis does not appear to predict pathogenicity. ..
  6. Tai W, Hu P, Wu J, Lin X. Six ulcerative colitis patients with refractory symptoms co-infective with Blastocystis hominis in China. Parasitol Res. 2011;108:1207-10 pubmed publisher
    ..They almost completely recovered 3 weeks later. Patients diagnosed with ulcerative colitis should always consider this parasite infection when the symptoms are refractory and cannot be released...
  7. Cheng H, Haung Z, Lan W, Kuo T, Shin J. Epidemiology of Blastocystis hominis and other intestinal parasites in a Vietnamese female immigrant population in southern Taiwan. Kaohsiung J Med Sci. 2006;22:166-70 pubmed
  8. Yoshikawa H, Wu Z, Kimata I, Iseki M, Ali I, Hossain M, et al. Polymerase chain reaction-based genotype classification among human Blastocystis hominis populations isolated from different countries. Parasitol Res. 2004;92:22-9 pubmed
    ..hominis. ..
  9. Clark C. Extensive genetic diversity in Blastocystis hominis. Mol Biochem Parasitol. 1997;87:79-83 pubmed
    ..If only a subset of the B. hominis variants have the potential to cause disease in humans this might explain the disparate findings reported. Future clinical studies must take the heterogeneity of B. hominis into account...
  10. Yakoob J, Jafri W, Jafri N, Khan R, Islam M, Beg M, et al. Irritable bowel syndrome: in search of an etiology: role of Blastocystis hominis. Am J Trop Med Hyg. 2004;70:383-5 pubmed
    ..001). Blastocystis hominis was frequently demonstrated in the stool samples of IBS patients; however, its significance in IBS still needs to be investigated. Stool culture has a higher positive yield for B. hominis than stool microscopy...
  11. Yan Y, Su S, Lai R, Liao H, Ye J, Li X, et al. Genetic variability of Blastocystis hominis isolates in China. Parasitol Res. 2006;99:597-601 pubmed
    ..The results suggest a possible relationship between subtype 1 and a pathogenic potential of this parasite...
  12. Al F, Hokelek M. [Is Blastocystis hominis an opportunist agent?]. Turkiye Parazitol Derg. 2007;31:28-36 pubmed
    ..Isolates resembling B. hominis have been described in a variety of mammals, birds, reptiles, and even insects. The significance of this human infection is uncertain. ..
  13. Zhou X, Zhang X, Qiao J, Cai J, Cheng S, Yuan Y, et al. Encystation--survival of Blastocystis hominis in immunocompetent mice abdomen cavity. Parasitol Res. 2010;106:1315-20 pubmed publisher
    ..Intraperitoneal inoculation to laboratory mice is a good method to maintain and propagate B. hominis. This is also a good model to study the interaction of B. hominis and immune system...
  14. Stensvold C, Alfellani M, Nørskov Lauritsen S, Prip K, Victory E, Maddox C, et al. Subtype distribution of Blastocystis isolates from synanthropic and zoo animals and identification of a new subtype. Int J Parasitol. 2009;39:473-9 pubmed publisher
    ..The data indicate moderate host specificity, most clearly exemplified by the fact that STs isolated from avian and non-avian hosts rarely overlap...
  15. Patino W, Cavuoti D, Banerjee S, Swartz K, Ashfaq R, Gokaslan T. Cytologic diagnosis of blastocystis hominis in peritoneal fluid: a case report. Acta Cytol. 2008;52:718-20 pubmed
    ..Blastocystis hominis is the most common parasite identified in s worldwide. Although it is commonly identified in stool preparations, unusual to encounter B hominis in abdominal fluid...
  16. Sadaga G, Kassem H. Prevalence of intestinal parasites among primary schoolchildren in Derna District, Libya. J Egypt Soc Parasitol. 2007;37:205-14 pubmed
    ..000), socio-economic status of the family (P = 0.000), family size and number of rooms in houses (P = 0.000). Also, there was a significant differences between infection rate and source of water for human consumption (P = 0.05)...
  17. Stensvold C, Smith H, Nagel R, Olsen K, Traub R. Eradication of Blastocystis carriage with antimicrobials: reality or delusion?. J Clin Gastroenterol. 2010;44:85-90 pubmed publisher
    ..Finally, key methodological and molecular diagnostic tools that will assist in the generation of data required to improve current knowledge are identified and discussed...
  18. Stensvold C, Ahmed U, Andersen L, Nielsen H. Development and evaluation of a genus-specific, probe-based, internal-process-controlled real-time PCR assay for sensitive and specific detection of Blastocystis spp. J Clin Microbiol. 2012;50:1847-51 pubmed publisher
    ..Compared to the TaqMan assay, XIVC had a sensitivity of 79%. This is the first time that a genus-specific, probe-based, internal-process-controlled real-time PCR assay for the detection Blastocystis has been introduced...
  19. Kuo H, Chiang D, Wang C, Chen T, Fung C, Lin C, et al. Clinical significance of Blastocystis hominis: experience from a medical center in northern Taiwan. J Microbiol Immunol Infect. 2008;41:222-6 pubmed
    ..The purpose of this study was to determine the clinical significance of B. hominis in northern Taiwan...
  20. Giacometti A, Cirioni O, Fiorentini A, Fortuna M, Scalise G. Irritable bowel syndrome in patients with Blastocystis hominis infection. Eur J Clin Microbiol Infect Dis. 1999;18:436-9 pubmed
    ..031). In conclusion, there was a set of patients with irritable bowel syndrome in whom the presence of Blastocystis hominis may not be incidental...
  21. Leelayoova S, Taamasri P, Rangsin R, Naaglor T, Thathaisong U, Mungthin M. In-vitro cultivation: a sensitive method for detecting Blastocystis hominis. Ann Trop Med Parasitol. 2002;96:803-7 pubmed
    ..In-vitro cultivation does seem worthwhile in the detection of B. hominis carriage in field studies...
  22. Wang K, Li C, Wang J, Cui Y. Epidemiological survey of Blastocystis hominis in Huainan City, Anhui Province, China. World J Gastroenterol. 2002;8:928-32 pubmed
    ..To provide scientific evidence for prevention and controlling of blastocystosis, the infection of Blastocystis homonis and to study its clinical significance in Huainan City, Anhui Province, China...
  23. Jones M, Whipps C, Ganac R, Hudson N, Boorom K, Boroom K. Association of Blastocystis subtype 3 and 1 with patients from an Oregon community presenting with chronic gastrointestinal illness. Parasitol Res. 2009;104:341-5 pubmed publisher
    ..Most patients with subtype 3 had previously tested negative with conventional parasitological diagnostics, had been symptomatic for over 4 years, and reported antibiotic failure...
  24. Suresh K, Smith H. Comparison of methods for detecting Blastocystis hominis. Eur J Clin Microbiol Infect Dis. 2004;23:509-11 pubmed
    ..Cysts were detected in 20.5% of positive samples, but only following Ficoll-Paque concentration of formol-ether concentrates. Cyst excretion was more prevalent in summer than in winter/spring...
  25. Noël C, Dufernez F, Gerbod D, Edgcomb V, Delgado Viscogliosi P, Ho L, et al. Molecular phylogenies of Blastocystis isolates from different hosts: implications for genetic diversity, identification of species, and zoonosis. J Clin Microbiol. 2005;43:348-55 pubmed
    ..Our results also strongly suggest the existence of numerous zoonotic isolates with frequent animal-to-human and human-to-animal transmissions and of a large potential reservoir in animals for infections in humans...
  26. Dogruman Al F, Yoshikawa H, Kustimur S, Balaban N. PCR-based subtyping of Blastocystis isolates from symptomatic and asymptomatic individuals in a major hospital in Ankara, Turkey. Parasitol Res. 2009;106:263-8 pubmed publisher
    ..There were mixed infections with STs 1 and 2 or STs 1 and 3 in nine isolates. There was no statistical significance of the distribution of Blastocystis sp. subtypes between symptomatic and asymptomatic individuals (p > 0.05)...
  27. Rostami Nejad M, Nazemalhosseini Mojarad E, Dabiri H, Nochi Z, Pourhoseingholi M, Sahebekhtiari N, et al. A case-control study of Blastocystis hominis among Iranian population. East Afr J Public Health. 2010;7:101-4 pubmed
    ..A case-control study was conducted to investigate the epidemiology and clinical features of Blastocystis hominis among Iranian patients with and without GI symptoms...
  28. Graczyk T, Shiff C, Tamang L, Munsaka F, Beitin A, Moss W. The association of Blastocystis hominis and Endolimax nana with diarrheal stools in Zambian school-age children. Parasitol Res. 2005;98:38-43 pubmed
    ..This survey supports the recent evidence that B. hominis and E. nana infections are associated with deficient sanitation and low hygiene standards and can contribute to diarrhea in children in developing countries...
  29. Olivo Díaz A, Romero Valdovinos M, Gudiño Ramirez A, Reyes Gordillo J, Jimenez Gonzalez D, Ramirez Miranda M, et al. Findings related to IL-8 and IL-10 gene polymorphisms in a Mexican patient population with irritable bowel syndrome infected with Blastocystis. Parasitol Res. 2012;111:487-91 pubmed publisher
    ..0448 and p=0.0166). Our results suggest that some IL-8 and IL-10 SNPs could change individual susceptibility increasing the relative risk in the development of IBS in Blastocystis carriers...
  30. Yoshikawa H, Abe N, Iwasawa M, Kitano S, Nagano I, Wu Z, et al. Genomic analysis of Blastocystis hominis strains isolated from two long-term health care facilities. J Clin Microbiol. 2000;38:1324-30 pubmed
    ..This study presents the first molecular evidence of possible human-to-human B. hominis infection between and/or among two small communities...
  31. Alfellani M, Jacob A, Perea N, Krecek R, Taner Mulla D, Verweij J, et al. Diversity and distribution of Blastocystis sp. subtypes in non-human primates. Parasitology. 2013;140:966-71 pubmed publisher
    ..While the distribution of ST1, ST2 and ST3 was independent of NHP group or geographical association, ST5 was seen only in apes and OW monkeys and ST8 primarily in arboreal NHPs and only in species native to Asia or South America...
  32. Fathy F. A study on Blastocystis hominis in food-handlers: diagnosis and potential pathogenicity. J Egypt Soc Parasitol. 2011;41:433-53 pubmed
    ..So, culture should be used on routine basis to detect B. hominis which should be considered pathogenic particularly when present alone in large numbers in symptomatic patients...
  33. Lee I, Tan T, Tan P, Nanthiney D, Biraj M, Surendra K, et al. Predominance of Blastocystis sp. subtype 4 in rural communities, Nepal. Parasitol Res. 2012;110:1553-62 pubmed publisher
    ..Infection may be transmitted through human-to-human, zoonotic and waterborne transmissions. We provide recommendations to ensure good public health practices...
  34. Yakoob J, Jafri W, Beg M, Abbas Z, Naz S, Islam M, et al. Irritable bowel syndrome: is it associated with genotypes of Blastocystis hominis. Parasitol Res. 2010;106:1033-8 pubmed publisher
    ..30), respectively. Majority of our patients had typeable B. hominis infection. The genotype of B. hominis in IBS-D was type 1 while in control genotype 3 was predominant. ..
  35. Yamamoto Furusho J, Torijano Carrera E. Intestinal protozoa infections among patients with ulcerative colitis: prevalence and impact on clinical disease course. Digestion. 2010;82:18-23 pubmed publisher
    ..Epidemiological and microbiologic studies suggest that enteropathogenic microorganisms play a substantial role in the clinical initiation and relapses of inflammatory bowel disease...
  36. Fouad S, Basyoni M, Fahmy R, Kobaisi M. The pathogenic role of different Blastocystis hominis genotypes isolated from patients with irritable bowel syndrome. Arab J Gastroenterol. 2011;12:194-200 pubmed publisher
    ..hominis was frequent in these patients. This study attempted to distinguish different genotypes of B. hominis isolates obtained from patients with IBS and to evaluate their pathogenic potentials...
  37. Domínguez Márquez M, Guna R, Munoz C, Gómez Muñoz M, Borrás R. High prevalence of subtype 4 among isolates of Blastocystis hominis from symptomatic patients of a health district of Valencia (Spain). Parasitol Res. 2009;105:949-55 pubmed publisher
    ..9%) and ST4 (94.1%). The most common of which is a zoonotic subtype (Blastocystis ratti) which includes, according to recent studies, non-pathogenic and pathogenic variants...
  38. Tan T, Ong S, Suresh K. Genetic variability of Blastocystis sp. isolates obtained from cancer and HIV/AIDS patients. Parasitol Res. 2009;105:1283-6 pubmed publisher
    ..Blastocystis sp. subtype 3 which is reported to be associated with disease was found to be predominant among the study subjects...
  39. Stensvold C, Traub R, von Samson Himmelstjerna G, Jespersgaard C, Nielsen H, Thompson R. Blastocystis: subtyping isolates using pyrosequencing technology. Exp Parasitol. 2007;116:111-9 pubmed
    ..To alleviate some of the problems related to unravelling the molecular epidemiology of Blastocystis infections we developed and evaluated a simple and high-throughput sequence analysis (SQA) pyrosequencing technique ..
  40. Boorom K. Is this recently characterized gastrointestinal pathogen responsible for rising rates of inflammatory bowel disease (IBD) and IBD associated autism in Europe and the United States in the 1990s?. Med Hypotheses. 2007;69:652-9 pubmed
    ..Recent research has shown that Blastocystis infections may be undetectable using existing clinical methods...
  41. Windsor J, Macfarlane L, Hughes Thapa G, Jones S, Whiteside T. Incidence of Blastocystis hominis in faecal samples submitted for routine microbiological analysis. Br J Biomed Sci. 2002;59:154-7 pubmed
    ..Molecular typing of B. hominis has revealed extensive genetic diversity in morphologically identical strains and thus detection by microscopy alone may not be sufficient to confirm the role of this organism in human disease...
  42. Ustun S, Turgay N. [Blastocystis hominis and bowel diseases]. Turkiye Parazitol Derg. 2006;30:72-6 pubmed
    ..The transmission, pathogenicity, culture characteristics, taxonomy, life cycle, biochemistry and molecular biology of B. hominis remain unclear. More studies are necessary for this parasite...
  43. Anuar T, Ghani M, Azreen S, Salleh F, Moktar N. Blastocystis infection in Malaysia: evidence of waterborne and human-to-human transmissions among the Proto-Malay, Negrito and Senoi tribes of Orang Asli. Parasit Vectors. 2013;6:40 pubmed publisher
    ..Blastocystis has been described as the most common intestinal parasite in humans and has an increased impact on public health. However, the transmission of this parasite has not been conclusively determined...
  44. Abdulsalam A, Ithoi I, Al Mekhlafi H, Ahmed A, Surin J, Mak J. Drinking water is a significant predictor of Blastocystis infection among rural Malaysian primary schoolchildren. Parasitology. 2012;139:1014-20 pubmed publisher
    ..Interventions with provision of clean water supply and health education especially to mothers are required...
  45. Parkar U, Traub R, Kumar S, Mungthin M, Vitali S, Leelayoova S, et al. Direct characterization of Blastocystis from faeces by PCR and evidence of zoonotic potential. Parasitology. 2007;134:359-67 pubmed
    ..This study is the first to provide molecular-based evidence supporting the zoonotic potential of Blastocystis in dogs, possums and primates in a natural setting...
  46. Tan K. New insights on classification, identification, and clinical relevance of Blastocystis spp. Clin Microbiol Rev. 2008;21:639-65 pubmed publisher
    ..This review focuses on such recent advances and also provides updates on laboratory and clinical aspects of Blastocystis spp...
  47. Abe N, Wu Z, Yoshikawa H. Molecular characterization of Blastocystis isolates from birds by PCR with diagnostic primers and restriction fragment length polymorphism analysis of the small subunit ribosomal RNA gene. Parasitol Res. 2003;89:393-6 pubmed
    ..It is unclear whether the isolates examined in the present study are zoonotic or not. Therefore, it is important to determine the phylogenetic relationships between unknown genotypes from birds and the multiple genotypes of B. hominis...
  48. Stensvold C, Nielsen H, Mølbak K, Smith H. Pursuing the clinical significance of Blastocystis--diagnostic limitations. Trends Parasitol. 2009;25:23-9 pubmed publisher
  49. Yoshikawa H, Wu Z, Nagano I, Takahashi Y. Molecular comparative studies among Blastocystis isolates obtained from humans and animals. J Parasitol. 2003;89:585-94 pubmed
    ..Our results show that primer PCR can be used as a powerful tool for the typing of Blastocystis populations...
  50. Scicluna S, Tawari B, Clark C. DNA barcoding of blastocystis. Protist. 2006;157:77-85 pubmed
    ..We believe that this approach will prove useful in future epidemiological studies...
  51. Stensvold C, Alfellani M, Clark C. Levels of genetic diversity vary dramatically between Blastocystis subtypes. Infect Genet Evol. 2012;12:263-73 pubmed publisher
    ..The implications of this observation are unclear, however, and the population structure and distribution of ST4 should be subject to further scrutiny in view of the fact ST4 is being increasingly linked with intestinal disease...
  52. Leelayoova S, Siripattanapipong S, Thathaisong U, Naaglor T, Taamasri P, Piyaraj P, et al. Drinking water: a possible source of Blastocystis spp. subtype 1 infection in schoolchildren of a rural community in central Thailand. Am J Trop Med Hyg. 2008;79:401-6 pubmed
    ..Our information supports the evidence of water-borne transmission in this population...
  53. Taamasri P, Leelayoova S, Rangsin R, Naaglor T, Ketupanya A, Mungthin M. Prevalence of Blastocystis hominis carriage in Thai army personnel based in Chonburi, Thailand. Mil Med. 2002;167:643-6 pubmed
    ..hominis carriage was found in the Ordnance Ammunition Battalion. In this battalion, privates who had education lower than the secondary school level had significantly greater risk of B. hominis carriage...
  54. Dogruman Al F, Adisen E, Kustimur S, Gurer M. [The role of protozoan parasites in etiology of urticaria]. Turkiye Parazitol Derg. 2009;33:136-9 pubmed
    ..As a conclusion, protozoans should be considered in the etiology of chronic urticaria and stool examination should be done in these patients routinely...
  55. Suresh K, Venilla G, Tan T, Rohela M. In vivo encystation of Blastocystis hominis. Parasitol Res. 2009;104:1373-80 pubmed publisher
  56. El Shazly A, Abdel Magied A, El Beshbishi S, El Nahas H, Fouad M, Monib M. Blastocystis hominis among symptomatic and asymptomatic individuals in Talkha Center, Dakahlia Governorate, Egypt. J Egypt Soc Parasitol. 2005;35:653-66 pubmed
    ..2 cells/100 x field versus 3.8 respectively). The mean number of B. hominis was significantly high in patients complaining of diarrhoea and abdominal pain...
  57. Roberts T, Stark D, Harkness J, Ellis J. Subtype distribution of Blastocystis isolates identified in a Sydney population and pathogenic potential of Blastocystis. Eur J Clin Microbiol Infect Dis. 2013;32:335-43 pubmed publisher
    ..This is the first large-scale study to examine the occurrence of Blastocystis in Australia. This study reports the high incidence of subtype 3 (44 %) in this population and discusses the emerging idea of subtype-dependent pathogenicity...
  58. Ozyurt M, Kurt O, Mølbak K, Nielsen H, Haznedaroglu T, Stensvold C. Molecular epidemiology of Blastocystis infections in Turkey. Parasitol Int. 2008;57:300-6 pubmed publisher
    ..In order to describe the molecular epidemiology of Blastocystis infections in Turkey, 87 isolates from 69 symptomatic and 18 asymptomatic individuals were sequenced...
  59. Alfellani M, Stensvold C, Vidal Lapiedra A, Onuoha E, Fagbenro Beyioku A, Clark C. Variable geographic distribution of Blastocystis subtypes and its potential implications. Acta Trop. 2013;126:11-8 pubmed publisher
    ..The picture emerging from this and other surveys suggests that there is significant variation in ST prevalence between populations. Some of the possible reasons for and implications of this diversity are discussed...
  60. Tan T, Suresh K, Smith H. Phenotypic and genotypic characterisation of Blastocystis hominis isolates implicates subtype 3 as a subtype with pathogenic potential. Parasitol Res. 2008;104:85-93 pubmed publisher
    ..hominis. Blastocystis subtype 3 was found to be correlated well with the disease...
  61. Souppart L, Sanciu G, Cian A, Wawrzyniak I, Delbac F, Capron M, et al. Molecular epidemiology of human Blastocystis isolates in France. Parasitol Res. 2009;105:413-21 pubmed publisher
    ..These 43 isolates belonged to five subtypes (1, 2, 3, 4, and 7) with predominance of subtype 3 (53.5%). Patient symptomatic status was uncorrelated with Blastocystis subtype...
  62. Stensvold C, Lewis H, Hammerum A, Porsbo L, Nielsen S, Olsen K, et al. Blastocystis: unravelling potential risk factors and clinical significance of a common but neglected parasite. Epidemiol Infect. 2009;137:1655-63 pubmed publisher
    ..Only FU individuals hosted ST7, and ST6/7 infections due to ST7 or ST9 were characterized by multiple intestinal symptoms. The data indicate subtype-dependent differences in the clinical significance of Blastocystis...
  63. Pipatsatitpong D, Rangsin R, Leelayoova S, Naaglor T, Mungthin M. Incidence and risk factors of Blastocystis infection in an orphanage in Bangkok, Thailand. Parasit Vectors. 2012;5:37 pubmed publisher
    ..Unlike other intestinal parasitic infections such as giardiasis and cryptosporidiosis, the epidemiology of blastocystosis in children who live in crowded settings such as day-care centers and orphanages has been rarely explored...
  64. Li L, Zhang X, Lv S, Zhang L, Yoshikawa H, Wu Z, et al. Cross-sectional surveys and subtype classification of human Blastocystis isolates from four epidemiological settings in China. Parasitol Res. 2007;102:83-90 pubmed
    ..Five different Blastocystis subtypes were identified from the 192 isolates. Subtype 3 was the predominant type, followed by subtype 1. In conclusion, the epidemiology of Blastocystis varies across China...
  65. Yan Y, Su S, Ye J, Lai X, Lai R, Liao H, et al. Blastocystis sp. subtype 5: a possibly zoonotic genotype. Parasitol Res. 2007;101:1527-32 pubmed
    ..These findings provide additional molecular-based evidence supporting the zoonotic potential of Blastocystis sp. subtype 5. This study also showed that Blastocystis sp. subtype 3 overgrew Blastocystis sp. subtype 5 in vitro...
  66. Abdel Hameed D, Hassanin O. Proteaese activity of Blastocystis hominis subtype3 in symptomatic and asymptomatic patients. Parasitol Res. 2011;109:321-7 pubmed publisher
    ..It was concluded that proteases of B. hominis genetic subtype 3, particularly those at 32 kDa, could be considered a virulence factor that is responsible for protein degradation and have a possible pathogenic role in host immune evasion...
  67. Dogruman Al F, Simsek Z, Boorom K, Ekici E, Sahin M, Tuncer C, et al. Comparison of methods for detection of Blastocystis infection in routinely submitted stool samples, and also in IBS/IBD Patients in Ankara, Turkey. PLoS ONE. 2010;5:e15484 pubmed publisher
    ..This study compared diagnostic methods for identifying Blastocystis in stool samples, and evaluated the frequency of detection of Blastocystis in patients with irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD)...
  68. Yakoob J, Jafri W, Beg M, Abbas Z, Naz S, Islam M, et al. Blastocystis hominis and Dientamoeba fragilis in patients fulfilling irritable bowel syndrome criteria. Parasitol Res. 2010;107:679-84 pubmed publisher
    ..030). B. hominis is common, while D. fragilis was less prevalent in our patients with IBS-D. B. hominis and D. fragilis culture had a better yield compared to stool microscopy and PCR...
  69. Leder K, Hellard M, Sinclair M, Fairley C, Wolfe R. No correlation between clinical symptoms and Blastocystis hominis in immunocompetent individuals. J Gastroenterol Hepatol. 2005;20:1390-4 pubmed
    ..The aim of this study was to examine the association between Blastocystis and gastrointestinal symptoms in immunocompetent individuals...
  70. Hussein E, Hussein A, Eida M, Atwa M. Pathophysiological variability of different genotypes of human Blastocystis hominis Egyptian isolates in experimentally infected rats. Parasitol Res. 2008;102:853-60 pubmed publisher
    ..hominis while subtype 2 was irrelevant. Also, the results suggest the presence of pathogenic and nonpathogenic strains among subtypes 3 and 4...
  71. Dogruman Al F, Dagci H, Yoshikawa H, Kurt O, Demirel M. A possible link between subtype 2 and asymptomatic infections of Blastocystis hominis. Parasitol Res. 2008;103:685-9 pubmed publisher
    ..The present study suggests that subtype 2 is a non-pathogenic genotype of B. hominis...
  72. Yoshikawa H, Yoshida K, Nakajima A, Yamanari K, Iwatani S, Kimata I. Fecal-oral transmission of the cyst form of Blastocystis hominis in rats. Parasitol Res. 2004;94:391-6 pubmed
    ..These results show that the Wistar rat is an ideal host for the propagation of strains RN94-9 and NIH:1295:1 of B. hominis, and demonstrate that the cyst form is the only transmissible form of this parasite...
  73. Dogruman Al F, Kustimur S, Yoshikawa H, Tuncer C, Simsek Z, Tanyuksel M, et al. Blastocystis subtypes in irritable bowel syndrome and inflammatory bowel disease in Ankara, Turkey. Mem Inst Oswaldo Cruz. 2009;104:724-7 pubmed
    ..The subtypes of Blastocystis that are commonly found in rodents and certain wild birds were not found in these patients. We suggest a model in which the severity of enteric protozoan infection may be mediated by host factors...