Blastocystis Hominis infection and Its Relation with Other Intestinal Parasites among Outpatients, Sohag, Egypt

Document Type : Original Article


1 Department of Parasitology, Faculty of Medicine, Assiut University

2 Department of Parasitology, Faculty of Medicine, Al-Azhar University, Assiut Branch

3 Department of Parasitology, Faculty of Medicine, Sohag University

4 department, of Public Health and Community Medicine-Sohag University.


Intestinal parasites have a worldwide distribution, mainly in regions with precarious socio-economic and hygiene conditions.  Blastocystis spp. is an anaerobic enteric protozoan inhabits human intestinal tract. Blastocystis hominis elicits a big controversy about its pathogenicity and its relation to bowel disease conditions. Our aim for this work is to determine the frequency of Blastocystis hominis infection among outpatients attending Ministry of Health hospitals and units in Sohag City and if there is a relation between Blastocystis hominis and other intestinal parasitic infections. The present research involved 150 cases from outpatient clinics of randomly selected hospitals and units in Sohag City from June 2016 to January 2017. Fresh stool samples were gathered and examined. Thirty-three samples (22%) were positive for parasitic infection, of whome, only 25 cases (75.8%) were positive for B. hominis whether single or mixed with other parasites. Single B. hominis infection represented 36% of positive cases. Out of 25 cases infected with B. hominis, 4 cases had mixed infection with G. lamblia (16%) (P-value = 0.027) and 10 cases had combined infection with E. coli (40%) (P-value < 0.001). In conclusion, 33 cases had parasitic infections of whom, 25 cases were positive for B. hominis. G. lamblia and E. coli were more common with B. hominis than other parasitic infection. This might be attributed to symmetry in genetic characters or the need for the same environmental conditions. To confirm this relation and its reasons we need further investigations.


  1. Abdel-Hafeez EH, Ahmad AK, Ali BA, et al. (2012). "Opportunistic parasites among immunosuppressed children in Minia District, Egypt." The Korean journal of parasitology 50(1): 57-62.
  2. Abe N, Wu Z and Yoshikawa H (2003). "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." Parasitology research 89(5): 393-396.
  3. Alsirieti SR, Elahwel  A M and Elamari  A A (2006). "Intestinal protozoa in Libyan patients in Sirt." JMJ-Jamahiriya Medical Journal 6: 59-61.
  4. Amato Neto V, Rodríguez Alarcón RS, Gakiya E, et al. (2003). "Blastocistose: controvérsias e indefinições." Rev Soc Bras Med Trop: 515-517.
  5. Bayoumy A, Mohammed K, Shahat S, et al. (2010). "Role of parasites among chronic diarrheic patients." Journal of the Egyptian Society of Parasitology 40(3): 679-698.
  6. Boorom KF, Smith H, Nimri L, et al. (2008). "Oh my aching gut: irritable bowel syndrome, Blastocystis, and asymptomatic infection." Parasites & Vectors 1(1): 40.
  7. Brink A-K, Mahe C, Watera C, et al. (2002). "Diarrhoea, CD4 counts and enteric infections in a community-based cohort of HIV-infected adults in Uganda." Journal of Infection 45(2): 99-106.
  8. Carbajal J, Villar J, Lanuza M, et al. (1997). "Clinical significance of Blastocystis hominis infection: epidemiologic study." Medicina clinica 108(16): 608-612.
  9. El Shazly A, Awad S, Sultan D, et al. (2006). "Intestinal parasites in Dakahlia governorate, with different techniques in diagnosing protozoa." Journal of the Egyptian Society of Parasitology 36(3): 1023-1034.
  10. Fathy F (2011). "A study on Blastocystis hominis in food-handlers: diagnosis and potential pathogenicity." Journal of the Egyptian Society of Parasitology 41(2): 433-453.
  11. Garcia L (2001). "Protozoa from other body sites." Diagnostic medical parasitology, 4th ed. ASM Press, Washington, DC: 723-730.
  12. Garcia LS (2009). Practical guide to diagnostic parasitology, 2nd ed. Washington, D.C., American Society for Microbiology Press.
  13. Keystone J (1995). "Blastocystis hominis and traveler's diarrhea." Clinical Infectious Diseases 21(1): 102-103.
  14. Licea VC, Crespo AP, Alvarez CM, et al. (2003). "Blastocystis hominis among food vendors in Xochimilco markets." REVISTA LATINOAMERICANA DE MICROBIOLOGIA-MEXICO- 45(1/2): 12-15.
  15. Nissapatorn V, Lim Y, Jamaiah I, et al. (2007). "Parasitic infection: A recurring phenomenon in Malaysia." Southeast Asian Journal of Tropical Medicine and Public Health 38: 181-190.
  16. Ramírez JD, Flórez C, Olivera M, et al. (2017). "Blastocystis subtyping and its association with intestinal parasites in children from different geographical regions of Colombia." PloS one 12(2): e0172586.
  17. Sadek Y, El-Fakahany A, Lashin A, et al. (1997). "Intestinal parasites among food-handlers in Qualyobia Governorate, with reference to the pathogenic parasite Blastocystis hominis." Journal of the Egyptian Society of Parasitology 27(2): 471-478.
  18. Schuster H and Chiodini PL (2001). "Parasitic infections of the intestine." Current Opinion in Infectious Diseases 14(5): 587-591.
  19. Shehata AI and Hassanein F (2015). "Intestinal parasitic infections among mentally handicapped individuals in Alexandria, Egypt." Annals of parasitology 61(4): 275–281.
  20. Stenzel D and Boreham P (1996). "Blastocystis hominis revisited." Clinical Microbiology Reviews 9(4): 563-584.
  21. Stenzel D and Boreham R (2001). "Blastocystis." Principles and Practise of Clinical Parasitology: 355-368.
  22. Sukthana Y (2001). "Is Blastocystis hominis a human pathogenic protozoan." J Trop Med Parasitol 24(1): 16-22.
  23. Takizawa MdGMH, Falavigna DLM and Gomes ML (2009). "Enteroparasitosis and their ethnographic relationship to food handlers in a tourist and economic center in Paraná, Southern Brazil." Revista do Instituto de Medicina Tropical de São Paulo 51(1): 31-35.
  24. Tan KS, Singh M and Yap EH (2002). "Recent advances in Blastocystis hominis research: hot spots in terra incognita." International journal for parasitology 32(7): 789-804.
  25. Yoshikawa H, Wu Z, Howe J, et al. (2007). "Ultrastructural and phylogenetic studies on Blastocystis isolates from cockroaches." Journal of eukaryotic microbiology 54(1): 33-37.
  26. Zierdt CH (1991). "Blastocystis hominis--past and future." Clinical Microbiology Reviews 4(1): 61-79.