Question from Jeff of Seattle WA
I have been having a hard time getting rid of a case of Giardia. I have read about a new treatment for this and would like some input on it. The treatment is a peptide antibiotic, Bacitracin, stabilized with zinc.
Dear Jeff:
I believe the article you are referring to can be found in the American Journal of Tropical Medicine & Hygiene (see below). Giardia infection can be difficult to eradicate on occasion; when standard treatment fails to produce a cure, it is often worthwhile to rule out other possible causes of recurrence-aside from antibiotic resistance.
Since Giardia may be passed from person to person, it is often important to be certain that a close contact (such as in day care centers, sexual partners, family members) may not be the source of infection. In addition, those who have certain immune deficiencies (such as low levels of particular antibodies-IgA) may have difficulty in clearing the infection or easily become reinfected.
Quinacrine has been used in those who fail initial treatment with metronidazole (FLAGYL) which occurs in about one out of every five cases. Furazolidone is another choice, but is less effective than the other two; recently a class of anti-parasitic agents known as benzimidazole derivatives have been studied with success (albenzadole).
The treatment described in your question has been reported in the journal cited below; this is fairly new form of therapy, and it may not be available in the US. Interestingly, in that study bacitracin without zinc had an 87% cure rate, compared to the zinc stabilized compound which was effective in 94% of cases.
Doxycyline (a form of tetracycline) and rifampicin have also been reported to be effective; combination treatment may be more effective than single therapy. You should discuss all these alternatives with your physicians and perhaps consider seeing an infectious disease specialist if this has not already been done.
Thank you for your question.
Chemotherapy for giardiasis: randomized clinical trial of bacitracin, bacitracin zinc, and a combination of bacitracin zinc with neomycin. Andrews BJ; Panitescu D; Jipa GH; Vasile-Bugarin AC; Vasiliu RP; Ronnevig JR Centre for International Health, University of Bergen, Haukeland Hospital, Norway. Am J Trop Med Hyg, 52: 4, 1995 Apr, 318-21