Rifaximin cure reported for cryptosporidium in advanced HIV

One small poster went virtually unnoticed and unreported. Cryptosporidium in the pre-HAART era was one of the principle causes of debilitating diarrhoea, malabsorption and wasting.

It is one of the reasons for recommending bottled water or boiled water, and although tap water is treated to routinely remove crypotosporidium, occasional outbreaks of water contamination still causes health alerts. Infection commonly results in 2-3 weeks of diarrhoea until the body clears the parasite naturally, but it causes more serious problems for people with impaired immune systems including the elderly, young children and people with HIV.

Joe Gathe and colleagues from Texas presented results from a small prospective open label study using the antibiotic rifaximin in five patients with symptomatic cryptosporidial diarrhea and CD4 <20 cells/mm³.

Symptomatic cryptosporidiosis was proven by stool analysis in all patients, who had a range of 6 to 15 stools/day for 2-6 months, without successful treatment. All required hospitalisation for weight loss and dehydration and had significant coinfections including CMV, bacterial sepsis/arthritis, campylobacte, giardiasis, disseminated CMV infection, cryptosporidial cholecystitis and mycobacteria tuberculosis.

Multiple anti-cryptosporidial interventions had failed in 3/5 patients. All patients received rifaximin 400mg p.o. BID with diarrhea control within one week and organism eradication in 2-8 weeks. None of the patients received effective HAART over the treatment period. Relapse/recurrence was not seen over 1-7 months despite 4/5 patients continuing with CD4 <50 cells/mm³.

This was a small, uncontrolled study, but the authors concluded that immediate larger studies of rifaximin for cryptosporidial gastrointestinal disease in HIV patients are warranted.

Comment

This is an interesting study, but similar small studies or case reports wth paromomycin, albendazole and even casein could not be confirmed in controlled studies.

Rifaximin (Xifaxin) is a rifamycin marketed by Salix, with an indication for treatment for travellers diarrhoea caused by noninvasive strains of Escherichia coli. Although only approved in the US in May 2004, it has been available in Europe for many years. Several posters at ICAAC referred to ongoing research with rifaximin as a treatment for for clostridium difficile. [2, 3]

As cryptosporidium is often difficult to isolate, and rifaximin produced a rapid reduction in symptoms, this option could be considered already for patients with persistent diarrhoea. Activity against microsporidia should also be considered.