Hymenolepiasis

Figure A: Egg of H. diminuta in a wet mount stained with iodine. Four of the hooks are visible at this level of focus. Image courtesy of the Georgia Department of Public Health.

Figure B: Egg of H. diminuta in a wet mount stained with iodine. Four of the hooks are visible at this level of focus.

Figure C: Eggs of H. diminuta in an unstained wet mount of concentrated stool. Image taken at 200x magnification.

Figure D: Higher magnification (400x) of one of the eggs in Figure C.

Figure E: Egg of H. diminuta in an unstained wet mount of concentrated stool. Image taken at 400x magnification.

Figure F: Egg of H. diminuta in an unstained wet mount of concentrated stool. Image taken at 400x magnification.

Figure A: Egg of H. nana in an unstained wet mount. Note the presence of hooks in the oncosphere and polar filaments within the space between the oncosphere and outer shell.

Figure B: Egg of H. nana in an unstained wet mount. Note the presence of hooks in the oncosphere and polar filaments within the space between the oncosphere and outer shell.

Figure C: Egg of H. nana in an unstained wet mount.

Figure D: Egg of H. nana in an unstained formalin ethyl acetate (FEA) wet mount. In this image, four of the hooks in the oncosphere are clearly visible. Image courtesy of the Oregon State Public Health Laboratory.

Figure E: Egg of H. nana in an unstained wet mount. In this image, the polar filaments in the space between the oncosphere and outer shell are clearly visible.

Figure F: Egg of H. nana in an unstained wet mount. In this image, the polar filaments in the space between the oncosphere and outer shell are clearly visible.

Figure A: Egg of H. nana in a trichrome-stained stool specimen. Although trichrome is not the preferred method for observing helminth eggs, they can be detected this way. The eggs are distorted, probably due to the zinc polyvinyl alcohol (PVA) used for preserving specimens for trichrome stain. Images courtesy of the Oregon State Public Health Laboratory.

Figure B: Egg of H. nana in a trichrome-stained stool specimen. Although trichrome is not the preferred method for observing helminth eggs, they can be detected this way. The eggs are distorted, probably due to the zinc polyvinyl alcohol (PVA) used for preserving specimens for trichrome stain. Images courtesy of the Oregon State Public Health Laboratory.

Figure A: Cross-sections of mature proglottids of H. nana stained with hematoxylin and eosin (H&E), taken at 100x. Note the craspedote (overlapping) proglottids.

Figure B: Higher magnification of eggs within the proglottid in Figure A, taken at 400x.

Figure C: Higher magnification of the eggs in Figures A and B, taken at 1000x, oil. Hooks do not stain with H&E but are refractile and may be visible in stained specimens with proper adjustment of the microscope. Polar filaments are visible in the egg in the upper right quadrant of the image.

Figure D: Proglottids of H. diminuta stained with carmine. Notice the craspedote form of the proglottids.

Figure A: Three adult specimens of H. nana. Image courtesy of the Georgia Department of Public Health.

Figure B: Scolex of H. nana in an unstained wet mount of stool. Image courtesy of Dr. David Bruckner.

Figure C: Higher magnification of the scolex in Figure B. In this image, two of the suckers and the rostellar hooks are clearly visible.

Figure A: Tribolium confusum, a common intermediate host for Hymenolepis spp. Tribolium and related genera breed in cereals, grains, and grain-based snack foods and are easily ingested by humans and rodents. Since these food products are usually not heated prior to consumption, cysticeroids within the beetles remain viable and infective. Image courtesy of Parasite and Diseases Image Library, Australia.

Figure B: Tribolium castaneum, another beetle commonly found in grain products that may serve as an intermediate host for Hymenolepis spp. Image courtesy of Parasite and Diseases Image Library, Australia.