Giardiasis is not uncommon in Taiwan

Abstract

Giardiasis is an important waterand food-borne infectious disease that causes sporadic diarrhea in travelers and daycare center attendees worldwide. We report a 33-year-old diabetic mother with giardiasis presenting as malnutrition and severe weight loss from 85 kg to 40 kg over 6 months, who had close contact with her mentally impaired son at a sanatorium. The duodenal biopsy confirmed the Giardia trophozoites among the villi and crypts (Fig. 1). The architecture of the duodenal mucosa was well preserved. Electron microscopy confirmed the presence of Giardia trophozoites in the duodenal villi. She responded to metronidazole therapy, as her symptoms improved and she regained weight to 50 kg in 24 weeks. As few as 10e25 cysts can cause Giardia infection following the ingestion of cysts from contaminated water or food. Giardia cysts transform into trophozoites in the proximal small bowel, where trophozoites replicate on the mucosal surface and usually do not invade the mucosa. Trophozoites may directly invade or release toxic substances to damage the intestinal epithelium. Trophozoites transform into infectious cysts in the distal small intestine and colon.