A healthy 57-year-old university professor presented to the infectious diseases clinic after noticing what resembled motile “grains of rice” in his stool while camping in the mountains of Utah. He searched his stools for additional specimens, which were collected and fixed in 75% ethanol (Fig. 1). The patient was treated with praziquantel (600 mg once), and the structures disappeared from the stools. A detailed clinical history was obtained in search of activities leading to risk of infection. The patient studied ant ecology and traveled extensively, often camping in primitive conditions and eating wild game. Other potential exposure history details included consuming smoked elk jerky in the months prior to the symptom onset and caring for chickens at home. His recent travel included field sites in Costa Rica and urban areas of Brazil. His remote travel included Uganda and Borneo.
FIG 1.
(A) Structures recovered from fresh stools, with sizes ranging from 1.5 to 3 mm in the largest diameter, unfixed. (B) Small chains recovered from stools after treatment, ethanol fixed. (C) Pouches measuring approximately 300 μm in diameter expressed from fixed structures. Magnification, ×1,000. (D) Section of an individual pouch, hematoxylin and eosin stained. Magnification, ×4,000.
For answer and discussion, see page 2562 in this issue (https://doi.org/10.1128/JCM.01724-15).