Chapter 29 : Unusual Parasitic Infections

Histology of rhinosporidiosis; human nasal polyp. (Top) Immature Rhinosporidium seeberi trophocytes; note the thick walls and the surrounding inflammatory cells (from the Centers for Disease Control and Prevention). (Middle) Sporangium containing endospores (from reference 2 , with permission). (Bottom) Rhinosporidiosis of the conjunctiva (courtesy of Doctorfungus Corporation, J. Moses, 2000). doi:10.1128/9781555819002.ch29.f1

Morphologic differences between cytoplasmic fragments of ciliated bronchial cells (arrow) (top) and the flagellate protozoon Lophomonas blattarum (bottom) in stained sputum smears. (Courtesy of Rafael Martinez-Giron, Fundacion INCLINICA, Spain; cover image from J Med Micro, Nov. 2013, volume 62; reference 4.) doi:10.1128/9781555819002.ch29.f2

Dictyostelium polycephalum. (Upper, left) Spherical double wall cysts from culture (Gram stain); (right) corneal button showing cysts (arrow), hematoxylin and eosin stain. (Lower) Cornea of eye showing ring-shaped central infiltrate and central thinning (very similar to that seen with Acanthamoeba infections) (courtesy of reference 6 , with permission.) doi:10.1128/9781555819002.ch29.f3

(A) Normal human spermatozoa. (B) Myxosporean spore from salmon. Note the similarities between panels A and B. (C and D) Two spores demonstrating the polar filaments. (Reprinted from reference 7 with permission.) doi:10.1128/9781555819002.ch29.f4

(Upper) Trypanosoma evansi in a peripheral blood film. (Lower) Trypanosoma lewisi in a blood smear. (From reference 14 , with permission, images courtesy of Marc Desquesnes.) doi:10.1128/9781555819002.ch29.f5

Ancylostoma ceylanicum. (A) Threadlike worms at the terminal ileum. (B) By magnifying endoscopy, hookworm is seen hooking its head into the intestinal mucosa and engulfing blood. (C) Characteristic hookworm mouthparts. (Courtesy of reference 16 , with permission.) doi:10.1128/9781555819002.ch29.f6

Longitudinal section through the rhabditiform esophagus in the anterior end of a mature female Micronema deletrix (renamed Halicephalobus gingivalis) worm in the brain. The procorpus (pc), metacarpus (mc), isthmus (is), bulb (bu), and intestine (in) are indicated (×1,040). (Armed Forces Institute of Pathology photograph; published in Can J Neurol Sci 2:125, 1975.) doi:10.1128/9781555819002.ch29.f7

Life cycle of Oesophagostomum spp. doi:10.1128/9781555819002.ch29.f8

(Upper) Anterior end of an adult Oesophagostomum bifurcum worm recovered from human feces. Note the cephalic groove, characteristic of the genus (×115). (Reprinted from Merial U.S./animal health company, cited as original source from http://cal.vet.upenn.edu/projects/merial/Strongls/strong_6.htm.) (Lower) Oesophagostomum egg; this egg cannot be differentiated from that of hookworm (courtesy of the CDC Public Health Image Library). doi:10.1128/9781555819002.ch29.f9

Scanning electron micrograph of the cephalic end of a female Oesophagostomum bifurcum worm recovered from human feces. Note the inner and outer leaf crowns with 12 and 24 (sometimes 10 and 20) lips, respectively, and the papillae (×630). (Photograph by the Department of Electron Microscopy, Medical Faculty, Leiden University; reprinted from reference 15 with permission.) doi:10.1128/9781555819002.ch29.f10

Nodular lesion of oesophagostomiasis seen as a paraumbilical mass in an otherwise healthy 5-year-old girl in Nigeria. At laparotomy, the lesion was found to have arisen in the ascending colon and was adherent to the muscles and fascia of the anterior abdominal wall (×11). (Armed Forces Institute of Pathology photograph.) doi:10.1128/9781555819002.ch29.f11

Surgically resected nodule of oesophagostomiasis. Note the worm protruding into the cavity. Specific identification of these worms is difficult, because intact specimens are rarely obtained. (Armed Forces Institute of Pathology photograph.) doi:10.1128/9781555819002.ch29.f12

Eustrongylides nematode larvae in raw fish (from A Pictorial Presentation of Parasites: a cooperative collection prepared and/or edited by H. Zaiman). doi:10.1128/9781555819002.ch29.f13

(Upper) Adult female grasshopper nematode, Mermis nigrescens, climbing vegetation in preparation for depositing eggs. (Lower) Juvenile grasshopper nematode, M. nigrescens, that has descended into the soil after exiting a grasshopper (courtesy of University of Florida, photograph by John Capinera: http://entnemdept.ufl.edu/creatures/beneficial/misc/mermis_nigrescens.htm). doi:10.1128/9781555819002.ch29.f14

(1) Head of Mermis nigrescens removed from the mouth of an infant. Note the mouth opening (arrow), lip papilla (L), and cephalic papillae (C). Bar, 80 μm. (2) Eggs of M. nigrescens inside the uterus of the specimen. Note the thick, double-walled shell surrounding the fully developed embryos. Arrows point to poles containing collapsed byssi. Bar, 55 μm. (Reprinted from reference 37 with permission.) doi:10.1128/9781555819002.ch29.f15

Dioctophyma renale eggs. These eggs measures 60 to 80 μm by 39 to 46 μm and have a thick shell that appears wrinkled; the ends of the egg are usually lighter in color (see egg on the left). doi:10.1128/9781555819002.ch29.f16

Dioctophyma renale in human tissue; cross sections of larvae of D. renale in a subcutaneous nodule (courtesy of the CDC Public Health Image Library). doi:10.1128/9781555819002.ch29.f17

Liesegang rings. (Upper) Liesegang-like rings in slightly dilated breast ducts associated with lactational change (hematoxylin and eosin; original magnification, ×10). (Lower) Higher magnification of Liesegang-like rings and lactational change (hematoxylin and eosin; original magnification, ×40). (Courtesy of reference 42 ; National Institutes of Health.) doi:10.1128/9781555819002.ch29.f18

Liesegang rings in the wall of a hemorrhagic renal cyst (arrows) (hematoxylin and eosin, ×200) (From A Pictorial Presentation of Parasites: a cooperative collection prepared and/or edited by H. Zaiman.) doi:10.1128/9781555819002.ch29.f19

Ternidens deminutus egg. This egg measures 85 by 50 μm and closely resembles the egg of hookworm and Oesophagostomum; however, it is larger. (Left) Drawing; (right) iodine preparation direct mount. doi:10.1128/9781555819002.ch29.f20

Mammomonogamus laryngeus (Syngamus trachea). (Upper) “Y” configuration. (Lower) Worms in the trachea of a turkey; note the typical “Y” configuration of the adult male and female worms. (From A Pictorial Presentation of Parasites: a cooperative collection prepared and/or edited by H. Zaiman.) doi:10.1128/9781555819002.ch29.f21

Mammomonogamus laryngeus eggs. This egg measures 78 to 95 μm by 42 to 54 μm. (Left) drawing; (right) iodine preparation direct mount. doi:10.1128/9781555819002.ch29.f22

Gongylonema pulchrum. (A) Anterior end of the worm (adapted from Ward HB, J Parasitol, 1916). (B) Posterior end of the worm (adapted from reference 4 ). (C) Egg (adapted from reference 54 ). (Far right) Anterior end of the worm. doi:10.1128/9781555819002.ch29.f23

Diplogonoporus tapeworm proglottids. Note the width of the proglottids and their very short length; also note the two genital organs in each proglottid. doi:10.1128/9781555819002.ch29.f24

Diplogonoporus egg. This egg measures 63 to 68 μm by 50 μm; note the resemblance to the Diphyllobothrium latum egg. (Left) Drawing; (right) methylene blue preparation direct mount. doi:10.1128/9781555819002.ch29.f25

Bertiella studeri. (Top) Egg; note the pyriform apparatus (arrow) and hooklets (oval). (Middle) Scolex. (Bottom) Proglottids. (Courtesy of the CDC Public Health Image Library). doi:10.1128/9781555819002.ch29.f26

Inermicapsifer madagascariensis. (Top) Scolex (two views). (Middle, left to right) Egg capsule, strobila, single egg containing a hexacanth larva. (Bottom, left to right) Mature proglottid, young gravid proglottid, gravid proglottid containing egg packets. (Adapted from Kouri P, J Parasitol 26:179–181, 1940; appeared on page 507 of reference 38 ). doi:10.1128/9781555819002.ch29.f27

Raillietina celebensis. (Left) Scolex; (middle) mature proglottid; (right) gravid proglottid containing egg packets. doi:10.1128/9781555819002.ch29.f28

Mesocestoides spp. Tetrathyridium larva contained in meat from animal that serves as the intermediate host and which is ingested by the human. (Courtesy of the CDC Public Health Image Library.) doi:10.1128/9781555819002.ch29.f29

Mesocestoides spp. (Top) Scolex; two of the suckers are visible with no rostellar hooklets. (Middle) Mature proglottid. CS, cirrus sac; OV, bilobed ovary; TE, numerous testes; VA, vagina. (Bottom) Gravid proglottid. ED, excretory ducts; UT, uterus. (All stained with carmine; courtesy of the CDC Public Health Image Library.) doi:10.1128/9781555819002.ch29.f30

Taenia crassiceps. Retinal photograph showing budding cysticercus in situ. (From A Pictorial Presentation of Parasites: a cooperative collection prepared and/or edited by H. Zaiman; photograph courtesy of Renio Freeman.) doi:10.1128/9781555819002.ch29.f31

Taenia crassiceps cysticercus after surgical removal from the eye. (From A Pictorial Presentation of Parasites: a cooperative collection prepared and/or edited by H. Zaiman; photograph courtesy of Renio Freeman.) doi:10.1128/9781555819002.ch29.f32

Taenia crassiceps. (Left) View of the base of the left index finger of the patient during surgery. Numerous fish spawn- or roe-like cysts were found, measuring approximately 3 mm in diameter. At the right upper quadrant a surgical cut in the back of the hand is visible, where further cysticerci were removed. (Right) T2-weighted magnetic resonance imaging tomography of the left forearm. Bright white areas correspond to parasitic infiltration (arrows). (Courtesy of reference 77 .) doi:10.1128/9781555819002.ch29.f33

Alaria americana. Living mesocercaria removed from a human liver at autopsy. (From A Pictorial Presentation of Parasites: a cooperative collection prepared and/or edited by H. Zaiman; photograph courtesy of R. S. Freeman.) doi:10.1128/9781555819002.ch29.f34

Alaria americana. (Top left) Mesocercaria in the patient's pons; (Top right) Mesocercaria in lung; (Lower) Magnified image from lung. (From A Pictorial Presentation of Parasites: A cooperative collection prepared and/or edited by H. Zaiman. Photograph courtesy of R. S. Freeman.) doi:10.1128/9781555819002.ch29.f35

Alaria americana. Freely moving Alaria mesocercaria on the retina of the human eye (arrow). (From A Pictorial Presentation of Parasites: a cooperative collection prepared and/or edited by H. Zaiman; photograph courtesy of R. S. Freeman.) doi:10.1128/9781555819002.ch29.f36

Plagiorchis spp. (Left) Adult fluke. (Right) Eggs that resemble those of Opisthorchis viverrini and Clonorchis sinensis. (From reference 81 , with permission.) doi:10.1128/9781555819002.ch29.f37

Neodiplostomum seoulense. (Left) Adult fluke. (Right) Eggs that somewhat resemble those of Fasciola, but can be differentiated on the basis of size. (From the Korean Society for Parasitology Web Atlas of Medical Parasitology, http://atlas.or.kr/index.html.) doi:10.1128/9781555819002.ch29.f38

Brachylaima cribbi. (Upper) Egg; these eggs measure 26 to 32 μm long and 16 to 17.5 μm wide. (Lower) Electron microscopy: (A) Adult Brachylaima cribbi trematode (B) has two suckers and a spiny coat and (C) releases sperm from a genital pore. Scale bar, 0.5 mm. (Lower panels from reference 91 , with permission.) doi:10.1128/9781555819002.ch29.f39

Nanophyetus (Troglotrema) salmincola. (Left) Adult fluke, which is quite small and measures 0.8 to 1.1 mm long by 0.3 to 0.5 mm wide. (Right) Egg, which is broadly oval, operculated, thick-shelled, and yellow and measures 60 to 80 μm long by 34 to 50 μm wide. (Courtesy of the CDC Public Health Image Library.) doi:10.1128/9781555819002.ch29.f40

Stellantchasmus falcatus. (Left) Adult fluke (courtesy of the CDC Public Health Image Library). (Right) Eggs, SEM view; these eggs measure 26 to 27 μm long and 12 to 13 μm wide with a narrow/small operculum (from reference 95 , with permission). doi:10.1128/9781555819002.ch29.f41

Phaneropsolus spinicirrus isolated from a patient. (1) Ventral view of the holotype. (2) Ventral view of the structure of the terminal portion of the reproductive system. c, cirrus; cs, cirrus sac; gp, genital pore; mt, metraterm; os, oral sucker; pg, prostate gland, sv, seminal vesicle. (Reprinted from reference 102 with permission.) doi:10.1128/9781555819002.ch29.f42

Phaneropsolus bonnei. (Left) Adult fluke, (Right) Eggs, which are quite small and measure 23 to 33 μm long by 12 to 18 μm wide. (Courtesy of Department of Parasitology, Faculty of Medicine, Chulalongkorn University, http://www.cai.md.chula.ac.th/lesson/test/5403/html/04morp.html.) doi:10.1128/9781555819002.ch29.f43

Haplorchis taichui. (Left) Adult fluke. (Right) Egg, which measures 28 by 14 μm. (Courtesy of the CDC Public Health Image Library.) doi:10.1128/9781555819002.ch29.f44

Gymnophalloides seoi. (Left) Adult fluke, which measures 0.4 to 0.5 mm by 0.2 to 0.3 mm—the smallest of all human trematodes reported in the Republic of Korea (courtesy of the CDC Public Health Image Library). (Right) Egg, which measures from 20 to 25 μm to 11 to 15 μm (from reference 107 , with permission). doi:10.1128/9781555819002.ch29.f45

Metorchis conjunctus. (Left) Adult fluke (courtesy of University of Sydney, Centre for Veterinary Education, http://vetbook.org/wiki/dog/index.php/Metorchis_spp). (Right) Egg with very similar morphology to many of the other small trematodes (courtesy of McGill University/Canada, on Stanford's site, http://www.stanford.edu/group/parasites/ParaSites2006/Metorchiasis/diagnostics_management&therapy.html). doi:10.1128/9781555819002.ch29.f46

Schistosoma mattheei. Image of Schistosoma intercalatum egg (very similar to S. mattheei). doi:10.1128/9781555819002.ch29.f47

Adult Philophthalmus lacrimosus trematode. OS, oral sucker; MC, muscular cirrus; VS, ventral sucker; DVCD, distal vitellaria collecting duct; Ut, uterus; Ov, ovary; AT, anterior testis; PT, posterior testis. (Courtesy of Pinto RM et al, Mem Inst Oswaldo Cruz 100:579–583, 2005.) doi:10.1128/9781555819002.ch29.f48

Life cycle of the tongue worms (pentastomids) Armillifer and Linguatula spp. (1) Humans ingest raw or inadequately cooked snake or lizard; (2) humans ingest eggs on vegetation or in water; (3) humans ingest the flesh of intermediate hosts containing infective larvae. doi:10.1128/9781555819002.ch29.f49

(Left) Nonencysted mature Armillifer armillatus larva attached to the abdominal surface of a human diaphragm (magnification, ×4). (Right) Encysted Armillifer armillatus larva on the surface of the liver of a 55-year-old Zairian. The cyst contains a C-shaped larva (magnification, ×12). (Armed Forces Institute of Pathology photographs.) doi:10.1128/9781555819002.ch29.f50

(Left) Worm-like adults of Pantastomum sp. in the trachea of a snake. (Right) Pentastome larva with marked external annulations. (Courtesy of the Natural History Collection, The University of Edinburgh, http://www.nhc.ed.ac.uk/index.php?page=24.25.333.374.) doi:10.1128/9781555819002.ch29.f51

Life cycle of the acanthocephalans (thorny-headed worms). doi:10.1128/9781555819002.ch29.f52

(Left) Thorny-headed worm. Note the proboscis, which is covered with spines. (Illustration by Sharon Belkin.) (Right) Close-up image of the anterior end of the worm and the proboscis containing hooks (courtesy of the CDC Public Health Image Library). doi:10.1128/9781555819002.ch29.f53

Moniliformis moniliformis, complete adult specimen, approximately 133 mm long (magnification, ×5) (Armed Forces Institute of Pathology photograph.) doi:10.1128/9781555819002.ch29.f54

Macracanthorhynchus hirudinaceus proboscis attached to pig bowel wall. The insertion of the toothed proboscis, along with the inflammation, ulceration, and hemorrhage caused, is seen in this low-power view. (From A Pictorial Presentation of Parasites: a cooperative collection prepared and/or edited by H. Zaiman.) doi:10.1128/9781555819002.ch29.f55

Macracanthorhynchus hirudinaceus eggs. These eggs measure 80 to 100 μm by 50 μm, have a thick, dark brown, textured shell, and contain a developed acanthor larva with hooks. (From A Pictorial Presentation of Parasites: a cooperative collection prepared and/or edited by H. Zaiman.) doi:10.1128/9781555819002.ch29.f56

Moniliformis moniliformis eggs. These eggs measure 90 to 125 μm by 65 μm and contain a fully developed acanthor larva with visible hooks. (From A Pictorial Presentation of Parasites: a cooperative collection prepared and/or edited by H. Zaiman.) doi:10.1128/9781555819002.ch29.f57