Relapse of Intestinal and Hepatic Amebiasis After Treatment

Six months after returning from a trip to Hawaii, a previously healthy 63-year-old man presented with 5 months of right upper-quadrant abdominal pain and non-bloody diarrhea, 3 months of nausea and non-bloody vomiting, and 1 month of fevers, chills, night sweats, and anorexia, culminating in a loss of 20 lbs. Comprehensive laboratory tests were notable for leukocytosis with a white blood cell (WBC) count of 11,300/mm with 88% neutrophils, elevated liver chemistry tests (total bilirubin 0.6 mg/dl, aspartate aminotransferase [AST] 64 U/l, alanine aminotransferase [ALT] 92 U/l, and alkaline phosphatase 674 U/l), and renal failure (blood urea nitrogen 57 mg/dl, creatinine 2.3 mg/dl). Due to his renal insufficiency, non-contrast imaging of the abdomen was obtained, which revealed a 12-cm, thick-walled, multiloculated cystic lesion in the right lobe of the liver (Fig. 1a). Cultures obtained from the patient’s blood, stool, and fluid aspirated from the liver abscess remained sterile. However, serum antibodies to Entamoeba histolytica were positive at a titer of 1:128. The infection was reported to the Department of Health who corroborated the diagnosis with three other cases of Entamoeba histolytica infection that were traced back to a restaurant worker in Hawaii. The patient was treated with oral metronidazole 750 mg three times daily for 10 days, followed by oral paromomycin 1 g three times daily for 10 days. His abdominal pain and diarrhea resolved. A contrast-enhanced abdominal computed tomography (CT) scan, obtained 2 months after finishing his course of antibiotics, documented complete resolution of the liver abscess (Fig. 1b). One year later, the patient again presented with fevers, chills, fatigue, abdominal pain, and diarrhea for 1 month, but this time also reported melena and maroon-colored stools for 1 week. His abdominal pain originated in the epigastrium, radiated to the right upper quadrant, and worsened when lying on his right side. On retrospection, he noted that he had suffered from diarrhea intermittently since his admission the previous year, but each episode had resolved with loperamide. He denied any weight loss and had actually regained 30 lbs. since discharge. He had not traveled anywhere since returning from Hawaii and could not recall any sick contacts. On physical examination, he had a low-grade fever to 100.2 F, but his vitals were otherwise normal. In general, he was well-appearing and without jaundice. He had normal bowel sounds, but his abdomen was distended and mild tenderness could be elicited upon palpation of the epigastrium, right upper-quadrant and right lower-quadrant of the abdomen. He had heme-positive, black-colored stool on rectal examination. Laboratory testing again revealed leukocytosis (WBC 9,500 with 80% neutrophils) and abnormal liver chemistry tests (total bilirubin\0.5 mg/dl, AST 33 U/l, ALT 39 U/l, and alkaline phosphatase 212 U/l). A contrast-enhanced CT of the abdomen showed a 6.0 9 5.2-cm hypo-attenuating mass in segment 4 of the liver with adjacent hyperemia and E. W. Hwang (&) C. A. Cartwright Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University Medical Center, 300 Pasteur Drive, Alway Building, M211, Stanford, CA 94305-5187, USA e-mail: ehwang@stanford.edu