Cystoisosporiasis

Cystoisospora belli, formerly Isospora belli

Treatment

Diagnosis of cystoisosporiasis is made in persons with chronic, mostly watery diarrhoea by UV fluorescence or microscopy of stools, duodenal aspirates or intestinal tissue biopsy. If the diarrhea lasts > 4 weeks, the diagnosis of cystoisosporiasis is an AIDS defining illness

Besides antiprotozoal treatment, additional measures are symptomatic treatment, rehydration and electrolyte management

  Drug / Dose Comments
Preferred therapy

TMP-SMX
1600/320 mg bid po

or 800/160 mg bid po

Treat minimally 10 days, increase duration to 3-4 weeks if symptoms worsen or persist.

Treat minimally 10 days, Increase dose to 2 x 2 tablet/day, if symptoms worsen or persist

Alternative therapy, if TMP-SMX is not tolerated 

pyrimethamine
50-75 mg qd po
+ folinic acid
10-15 mg qd po

10 days

Monitor for myelotoxicity, mostly neutropenia, for pyrimethamine

OR ciprofloxacin
500 mg bid po
7 days

Secondary Prophylaxis / Maintenance Therapy

Stop: if CD4 count > 200 cells/μL and HIV-VL undetectable over 6 months and no signs of persistent cystoisosporiasis

  Drug / Dose Comments
Preferred therapy

TMP-SMX
800/160 mg three times weekly po
or 800/160 mg qd po
or 1600/320 mg three times weekly po

 
Alternative therapy, if TMP-SMX is not
tolerated

pyrimethamine
25 mg qd po
+ folinic acid 10-15 mg qd po

Monitor for myelotoxicity, mostly neutropenia, for pyrimethamin