Trimethoprim–Sulfamethoxazole Compared with Ciprofloxacin for Treatment and Prophylaxis of <i>Isospora belli</i> and <i>Cyclospora cayetanensis</i> Infection in HIV-Infected Patients

In developing countries, Isospora belli and Cyclospora cayetanensis frequently cause chronic diarrhea in HIV-infected patients.To compare 1 week of trimethoprim-sulfamethoxazole treatment and 1 week of ciprofloxacin treatment in HIV-infected patients with chronic diarrhea caused by I. belli and C. cayetanensis.Randomized, controlled trial.HIV clinic in Port-au-Prince, Haiti.42 HIV-infected patients with chronic diarrhea due to I. belli (n = 22) or C cayetanensis (n = 20).Patients were randomly assigned to receive oral trimethoprim-sulfamethoxazole (160 mg or 800 mg) or ciprofloxacin (500 mg) twice daily for 7 days. Patients who responded clinically and microbiologically received prophylaxis for 10 weeks (1 tablet orally, three times per week).Treatment success was measured by cessation of diarrhea and negative stool examination at day 7. Prophylaxis success was measured by recurrent disease rate.Diarrhea ceased in all 19 patients treated with trimethoprim-sulfamethoxazole. Eighteen of 19 patients had negative results on stool examination at day 7 (95%). Among the 23 patients who received ciprofloxacin, diarrhea ceased in 20 (87% [CI; 66% to 97%]) and 16 had negative results on stool examination at day 7 (70%). By survival analysis, diarrhea from isosporiasis and cyclosporiasis ceased more rapidly with trimethoprim-sulfamethoxazole than with ciprofloxacin. All patients receiving secondary prophylaxis with trimethoprim-sulfamethoxazole remained disease-free, and 15 of 16 patients receiving secondary prophylaxis with ciprofloxacin remained disease-free.A 1-week course of trimethoprim-sulfamethoxazole is effective in HIV-infected patients with cyclosporiasis or isosporiasis. Although ciprofloxacin is not as effective, it is acceptable for patients who cannot tolerate trimethoprim-sulfamethoxazole.