A previously healthy 11-year-old girl presented to an emergency department in Boston with a 2-day history of abdominal pain and vomiting. She did not have a fever, diarrhea, melena, or hematochezia by history. She had immigrated to the United States from central Ethiopia 2 months earlier. Her temperature was 37.7°C. She had diminished bowel sounds and lower abdominal tenderness, with guarding and a positive psoas sign. Hematological testing demonstrated a mildly elevated white blood cell count of 11,000 cells/microliter, with a differential of 90% neutrophils, 2% lymphocytes, 6% monocytes, 0% eosinophils, and 1% basophils. Abdominal imaging showed evidence of a complex fluid collection in the pelvis. She underwent abdominal surgery and was found to have a ruptured appendix, which was removed.
Four days after surgery, the patient had loose stool. Her abdomen was soft and mildly tender around the site of surgical incision, without guarding or rebound tenderness. The result for testing of stool for Clostridium difficile toxins A and B by an immunoassay was negative, as were cultures for Salmonella, Shigella, Yersinia, and Campylobacter and a toxin immunoassay for Shiga toxin-producing Escherichia coli. A 3- to 4-cm-long roundworm was seen in the patient's stool by the clinical staff, but it was not submitted to the laboratory for examination. Stool was submitted for ova and parasite testing, and a parasite egg was detected in formalin-preserved stool concentrated with ethyl acetate and stained with iodine (Fig. 1).
Fig 1.
Formalin-preserved stool concentrate stained with iodine.
(For answer and discussion, see page 1508 in this issue [doi:10.1128/JCM.06387-11])
Contributor Information
Thomas J. Sandora, Division of Infectious Diseases Children's Hospital Boston Department of Pediatrics Harvard Medical School Boston, Massachusetts, USA
Alexander J. McAdam, Department of Laboratory Medicine Children's Hospital Boston Department of Pathology Harvard Medical School Boston, Massachusetts, USA