Abstract
Blastocystis hominis is commonly found in the intestinal tract of humans. Although the pathogenicity of this unicellular parasite is controversial, anti-protozoan agents are usually administered to infected individuals. At present, the first choice of chemotherapeutic agent is Metronidazole as described in the literature. In this study, we evaluated the effects of metronidazole and Trimethoprim/Sulfamethoxazole (TMP/SMX) on persons infected with B.hominis. A total of 104 subjects infected with B. hominis were admitted to the laboratory from 2002 to 2003. All individuals were non-immunocompromised and subjects were monitored for 1 year after treatment. All stool samples were microscopically examined after staining with iodine and by culturing in an egg slant medium. Of the 104 infected individuals (52±16 years of age, M:F=60:44) with B. hominis infection, 28 were discharging large numbers of parasites before treatment. Of 28 severely infected individuals, 12 were treated with metronidazole/250–750 mg at a regimen of 3x/day/10 days and 4 of the 12 were eradicated. Nine individuals were treated with TMP/SMX/1tab at a regimen of 3x/day/10 days and 2 of the 9 were eradicated. For severe B. hominis infections, it appears that metronidazole and TMP/SMX are effective in some individuals, but not all.
Similar content being viewed by others
References
Alexeieff A (1911) Sur la nature des formations dites kystes de Trichomonas intestinalis. C R Soc Biol 71:296–298
Zierdt CH, Rude WS, Bull BS (1967) Protozoan characteristics of Blastocystis hominis. Am J Clin Pathol 48:495–501
Editorial (1991) Blastocystis hominis: commensal or pathogen? Lancet 337:521–522
Wolfe MS (1982) The treatment of intestinal protozoan infections. Med Clin North Am 66:707–720
Zierdt CH, Swan JC, Hosseini J (1983) In vitro response of Blastocystis hominis to antiprotozoal drugs. J Protozool 30:332–334
Dunn LA and Boreham PF (1991) The in-vitro activity of drugs against Blastocystis hominis. J Antimicrob Chemother 27:507–516
Thathaisong U, Worapong J, Mungthin M, Tan-Ariya P, Viputtigul K, Sudatis A, Noonai A, Leelayoova S (2003) Blastocystis Isolates from a Pig and a Horse Are Closely Related to Blastocystis hominis. J Clin Microbiol 41:967–975
Taamasri P, Leelayoova S, Rangsin R, Naaglor T, Ketupanya A, Mungthin M (2002) Prevalence of Blastocystis hominis carriage in Thaiarmy personnel based in Chonburi. Thai Mil Med 167:643–646
Udkow MP, Markell EK (1993) Blastocystis hominis: prevalence in asymptomatic versus symptomatic hosts. J Infect Dis 168:242–244
Sohail MR, Fischer PR (2004) Blastocystis hominis and travelers. Travel Med Infect Dis Article (in press)
Stenzel DJ, Boreham PFL (1996) Blastocystis hominis revisited. Clin Microbiol Rev 9:563–584
Cirioni O, Giacometti A, Drenaggi D, Ancarani F, Scalise G (1999) Prevalence and clinical relevance of Blastocystis hominis in diverse patient cohorts. Eur J Epidemiol 15:989–993
Church DL, Sutheland L, Gill MJ, Visser ND, Kelly JK, Bryant H, Hwang W, Sharkey K (1992) Absence of an association between enteric parasites in the manifestations and pathogenesis of HIV enteropathy in gay men. Scand J Infect Dis 24:567–575
Carrascosa M, Martinez J, Perez-Castrillon JL (1996) Hemorrhagic proctosigmoiditis and Blastocystis hominis infection. Ann Intern Med 124: 278–279
O‘Gorman MA, Orenstein SR, Proujansky R, Wadowsky RM, Putnam PE, Kocoshis SA (1993) Prevalence and characteristics of Blastocystis hominis infection in children. Clin Pediatr (Phila) 32:91–96
Hazen KC (1993) Controversial fungal and protozoab gastrointestinal infections. Curr Opin Infect Dis 6:77–82
Lee MJ (1991) Pathogenicity of Blastocystis hominis (Letter). J Clin Microbiol 29:2089
Markell EK, Udkow MP (1990) Association of Blastocystis hominis with human disease? (Letter) J Clin Microbiol 28:1085
Nigro L, Larocca L, Massarelli L, Patamia I, Minniti S, Palermo F, Cacopardo B (2003) A placebo-controlled treatment trial of Blastocystis hominis infection with metronidazole. J Travel Med 10:128–130
Haresh K, Suresh K, Khairul Anus A, Saminathan S (1999) Isolate resistance of Blastocystis hominis to metronidazole. Trop Med Int Health 4:274–277
Zaman V, Zaki M (1996) Resistance of Blastocystis hominis cysts to metronidazole. Trop Med Int Health 1:677–678
Garavelli PL, Scaglione L, Bicocchi R, Libanore M (1991) Pathogenicity of Blastocystis hominis (Letter). Infection 19:185
Garavelli PL, Libanore M (1990) Blastocystis immunodeficiency disease (Letter). Rev Infect Dis 12:158
Telalbasic S, Pikula ZP, Kapidzic M (1991) Blastocystis Hominis may be a potential cause of intestinal disease. Scand J Infect Dis 23:389–390
Hahn P, Fleischer NFK (1985) Blastocystis hominis-is it of clinical importance? Trop Med Parasitol 36:7–8
Ok UZ, Girginkardesler N, Balcioglu C, Ertan P, Pirildar T, Kilimcioglu AA (1999) Effect of trimethoprim–sulfamethaxazole in Blastocystis hominis infection. Am J Gastroenterol 94:3245–3247
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Moghaddam, D.D., Ghadirian, E. & Azami, M. Blastocystis hominis and the evaluation of efficacy of metronidazole and trimethoprim/sulfamethoxazole. Parasitol Res 96, 273–275 (2005). https://doi.org/10.1007/s00436-005-1363-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00436-005-1363-1