TABLE 4.

Studies of treatment and outcome of symptomatic individuals harboring Blastocystis as the sole identified pathogen

Study type	Drug administered, dosagea	Duration between treatment and clinical evaluation	Outcome		Description	Reference
			No. of patients with clinical cure/total no. of patients (%)	No. of patients with total parasite eradication/total number of patients (%)
Placebo controlled, single blind	Metronidazole,1.5 g single dose/day for 10 days	1 mo	Drug, 35/40 (88); placebo, 5/36 (14)	Drug, 32/40 (80); placebo, 1/36 (3)	Excluded Clostridium difficile toxin, pathogenic parasites, bacteria, viruses, and noninfectious causes; follow-up at 6 mo suggested parasitological relapses	165
		6 mo	Drug, 30/40 (75); placebo, 12/36 (33)	Drug, 19/40 (48); placebo, 5/36 (14)
Placebo controlled, double blind, randomized	Nitazoxanide, 500 mg bid for 3 days	7 days	Drug, 36/42 (86); placebo, 16/42 (38)	Drug, 36/42 (86); placebo, 5/42 (12)	Excluded parasitic and bacterial but not viral causes of diarrhea	205
University-based survey						177
Adults	320 mg TMP and 1,600 mg SMX daily in two equal doses for 7 days	7 days	8/15 (53)b	14/15 (93)	Excluded parasitic and bacterial but not viral causes of diarrhea
Children	6 mg/kg TMP and 30 mg/kg SMX daily in two equal doses for 7 days	7 days	31/38 (82)	36/38 (95)
University-based survey	Metronidazolec	14 days	36/41 (88)	39/41 (95)	Excluded parasitic and bacterial but not viral causes of diarrhea	116

^abid, twice a day.

^bSix out of 15 individuals in this group showed decreases in symptoms; collectively, 14 out of 15 individuals were cured or experienced alleviation of symptoms.

^cInformation on the dose for metronidazole was not included in that study.