THERAPEUTIC EFFICACY OF PAROMOMYCIN IN IMMUNOSUPPRESSED ADULT MICE INFECTED WITH CRYPTOSPORIDIUM-PARVUM

The intent of this study was to evaluate the therapeutic efficacy of p aromomycin in immunosuppressed adult C57BL/6N mice infected with Crypt osporidium parvum. Seven groups of 10 mice/group were used. Groups 1, 2, and 7 served as normal, toxicity, and placebo controls, respectivel y. Groups 2-7 were immunosuppressed with dexamethasone phosphate admin istered ad libitum in drinking water. Groups 3-7 were infected with C. parvum on day 7 postimmunosuppression. Groups 3-6 were treated by adm inistering paromomycin per os for 10 consecutive days, beginning on da y 10 postinfection, at dosage levels of 0.25, 0.5, 1, and 2 g/kg/day, respectively. Paromomycin was judged to be nontoxic at the dosage leve ls used. Groups I and 2 remained uninfected while groups 3-7 began she dding oocysts by day 3 postinfection. Paromomycin was therapeutically effective against C. parvum at 1 and 2 g/kg/day as determined by signi ficant reductions in fecal oocyst shedding (P < 0.01), parasite coloni zation (P < 0.05), and villus atrophy (P < 0.05) in the ilea and termi nal ilea of infected mice. We conclude that paromomycin may be useful in the treatment and palliation of cryptosporidiosis.