Trimethoprim-sulfamethoxazole compared with ciprofloxacin for treatment and prophylaxis of Isospora belli and Cyclospora cayetanensis infection in HIV-infected patients. A randomized, controlled trial

Ann Intern Med. 2000 Jun 6;132(11):885-8. doi: 10.7326/0003-4819-132-11-200006060-00006.


Background: In developing countries, Isospora belli and Cyclospora cayetanensis frequently cause chronic diarrhea in HIV-infected patients.

Objective: 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.

Design: Randomized, controlled trial.

Setting: HIV clinic in Port-au-Prince, Haiti.

Patients: 42 HIV-infected patients with chronic diarrhea due to I. belli (n = 22) or C cayetanensis (n = 20).

Interventions: 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).

Measurements: Treatment success was measured by cessation of diarrhea and negative stool examination at day 7. Prophylaxis success was measured by recurrent disease rate.

Results: 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.

Conclusions: 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.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • AIDS-Related Opportunistic Infections / drug therapy*
  • Adolescent
  • Adult
  • Animals
  • Anti-Infective Agents / therapeutic use*
  • Chronic Disease
  • Ciprofloxacin / therapeutic use*
  • Coccidiosis / drug therapy*
  • Diarrhea / drug therapy
  • Diarrhea / microbiology
  • Drug Administration Schedule
  • Eucoccidiida*
  • Humans
  • Isospora*
  • Middle Aged
  • Recurrence
  • Trimethoprim, Sulfamethoxazole Drug Combination / therapeutic use*


  • Anti-Infective Agents
  • Ciprofloxacin
  • Trimethoprim, Sulfamethoxazole Drug Combination