Treatment of giardiasis in common marmosets (Callithrix jacchus) with tinidazole

Abstract

Giardia intestinalis is a common protozoan parasite that can infect many laboratory animal primates, although its role as a contributor to the induction of gastrointestinal disease remains unclear. This study sought to investigate the prevalence of Giardia in a colony of common marmosets by using a Giardia antigen-capture assay and to address the possible eradication of this infection by using tinidazole, an antiprotozoal similar to metronidazole but requiring fewer doses. Among 31 colony marmosets, 13 (42%) were positive for Giardia. Two doses of oral tinidazole eliminated the infection in all animals. Repeat testing of the 13 Giardia-positive monkeys 1 y later showed that 11 remained negative and that treated animals had a significant increase in weight at 1 y. Giardia antigen is common in common marmoset feces, and treatment using oral tinidazole is possible and highly effective.

Figure 1.

Fecal scoring system. Grade 0 represents normal marmoset feces. Grade 1 feces are more moist than normal but still formed. Grade 2 feces are beginning to lose form and are moister than grade 1 material. Grade 3 fecal material is diarrhea that has lost much of its form and is very watery with a soft consistency. Grade 4 indicates a further continuation of this process, with loss of almost all of the fecal form. Grade 5 represents severe, watery diarrhea with complete loss of formed feces.