Case Report: Molecular Identification of Larval Taenia martis Infection in the Pouch of Douglas

Abstract

Taenia martis is a tapeworm dwelling in the intestine of mustelids and a rare zoonotic cysticercosis pathogen in its larval stage. The metacestode is morphologically very similar to more prevalent cysticercosis parasites, such as the larvae of Taenia solium and Taenia crassiceps, and may be indistinguishable from other metacestodes on histological sections. However, the epidemiology of human T. martis infections is different, and for prognosis, prevention, and detection of natural parasite reservoirs, the species should be identified. We here report the molecular identification of a T. martis larva located in the pouch of Douglas in a female German patient who underwent surgery for endometriosis. This case represents the fifth human infection described worldwide; all previous cases were also in European women, involving the eye, brain, and the peritoneum.

Figure 1.

Cytology of the peritoneal fluid from the pouch of Douglas showing multiple eosinophils. Papanicolaou stain, original magnification ×40. This figure appears in color at www.ajtmh.org.

Figure 2.

Histological section through the cystic tapeworm larva recovered from the patient’s peritoneum. The parasite’s spongy tissue is surrounded by a ruffled tegument. In the center, a sucker is visible and three hooklets. Hematoxylin and eosin stain, original magnification ×6.3. This figure appears in color at www.ajtmh.org.

Figure 3.

Histological detail of the metacestode’s tegument. Underneath the tegument, a thin layer of muscle fibers is found. Hematoxylin and eosin stain, original magnification ×25. This figure appears in color at www.ajtmh.org.