| Home | E-Submission | Sitemap | Contact us |  
Korean J Parasitol > Volume 28(1):1990 > Article

Original Article
Korean J Parasitol. 1990 Mar;28(1):45-52. Korean.
Published online Mar 20, 1994.  http://dx.doi.org/10.3347/kjp.1990.28.1.45
Copyright © 1990 by The Korean Society for Parasitology
Chronological observation of intestinal lesions of rats experimentally infected with Echinostoma hortense
S H Lee,T Y Noh,W M Sohn,*W G Kho,*S T Hong and J Y Chai
Department of Parasitology and Institute of Endemic Diseases, College of Medicine, Seoul National University, Seoul 110-460, Korea.

Intestinal histopathological changes due to infection with Echinostoma hortense (Trematoda) were studied in rats after experimental infection with the metacercariae. The metacercariae were obtained from the tadpoles of Rana nigromaculata, a second intermediate host infected in the laboratory. Total 18 albino rats (Sprague-Dawley) were given 200 matacercariae each and sacrificed on the day 1, 3, 7, 11, 22 or 44 post-infection (PI). Segments of the small intestine at 1, 3, 5, 8 and 30 cm posterior to the pylorus (PTP) were resected and studied histopathologically.

1. The flukes were seen to have intruded into the intervillous space in the upper small intestine at early stages (1-3 days PI), however, they were located mainly in the intestinal lumen at later stages (7-44 days PI). The flukes were sucking and destroying the epithelial layers of villi with their oral and ventral suckers.

2. Histopathological changes of the intestine were recognizable in as early as 1-3 days after infection, and the changes became severer as the infection progressed.

3. The intestinal mucosa was histopathologically characterized by villous atrophy and crypt hyperplasia throughout the infection period. Major villous changes were blunting, fusion, severe destruction and loss of epithelial layers of villi. Villous/crypt (V/C) height ratio was remarkably reduced from 3:1 in controls to 1:1 in severely infected animals. In the stroma of villi, inflammatory cell infiltrations, vascular congestion, edema, and/or fibrosis were recognized. The goblet cells were increased in number after 11 days PI.(ABSTRACT TRUNCATED AT 250 WORDS)


Figs. 1-5
Fig. 1. Duodenal villi and crypts of a control (uninfected) rat (3 cm posterior to the pylorus; PTP). Villi are tall, slender, and the villus/crypt (V/C) ratio is about 3 : 1. × 100.

Fig. 2. Duodenum (3 cm PTP) of a 22-day group rat infected with E. hortense. Note remarkably deformed, flattened villi with decreased V/C ratio and significantly increased number of goblet cells. × 40.

Fig. 3. Duodenum (3 cm PTP) of a 1-day group rat infected with E. hortense. A juvenile E. hortense (arrow) is seen crouching on the top of a villus, of which height is significantly reduced. The stroma shows inflammatory cell infiltrations. × 100.

Fig. 4. Jejunal region (8 cm PTP) of a 3-day group rat infected with E. hortense. Villi are seen to be fused each other and atrophic. V/C ratio is about 2 : 1. A sucker (seemingly ventral sucker) of a young worm (arrow) is sucking the epithelial portion of a villus. × 100.

Fig. 5. Jejunum (8 cm PTP) of a 7-day group rat showing inflamed mucosa and sections of 3 young worms. A worm (arrow) is intruding into the intervillous space with its oral sucker and anterior body. × 40.

Figs. 6-11
Fig. 6. Duodenum (5 cm PTP) of a 7-day group rat infected with E. hortense, showing 5 young worms locating free in the lumen. Note blunt, fused, inflamed villi and hyperplastic crypts. × 40.

Fig. 7. Duodenum (3 cm PTP) of another rat, 7-day group. A young worm is pricking the epithelium of a villus with its collar spines (arrow). Villi are edematous and inflamed. × 100.

Fig. 8. Duodenum (5 cm PTP) of a 11-day group rat. The whole lumen is compactly filled with many young adults of E. hortense. The whole mucosa is severely destroyed. × 40.

Fig. 9. Duodenum fo a 7-day group rat (3 cm PTP), showing a sectioned worm and adjacent villi. Villi show marked cell infiltrations. The oral and ventral suckers (arrow) are pinching some portions of a villus. The head collar of the worm is characteristically seen around its oral sucker. × 100.

Fig. 10. Close-up view of a worm and a duodenal villus (5 cm PTP) from a 22-day group rat infedted with E. hortense. The worm is vigorously sucking the villus with its widely open oral sucker. Several collar spines (arrow) are seen on its head collar. × 200.

Fig. 11. Duodenum (5 cm PTP) of a 44-day group rat. The villi are being sucked by a worm. × 40.


Table 1
Pathological changes of intestinal villi* and crypts

1. Ahn YK, Ryang YS. [Experimental and epidemiological studies on the life cycle of Echinostoma hortense Asada, 1926 (Trematoda: Echinostomatidae)]. Korean J Parasitol 1986;24(2):121–136.
2. Bindseil E, Christensen NO. Thymus-independent crypt hyperplasia and villous atrophy in the small intestine of mice infected with the trematode Echinostoma revolutum. Parasitology 1984;88(Pt 3):431–438.
3. Castro GA. Immunophysiology of enteric parasitism. Parasitol Today 1989;5(1):11–19.
4. Chai JY. Seoul J Med 1979;20:104–117.
5. Chai JY, Hong SJ, Sohn WM, Lee SH, Seo BS. Studies on intestinal tematodes in Korea: XVI. Infection status of loaches with the metacercariae of Echinostoma hortense. Korean J Parasitol 1985;23(1):18–23.
6. Ferguson A, Jarrett EE. Hypersensitivity reactions in small intestine. I Thymus dependence of experimental 'partial villous atrophy'. Gut 1975;16(2):114–117.
7. Huffman JE, Michos C, Fried B. Clinical and pathological effects of Echinostoma revolutum (Digenea: Echinostomatidae) in the golden hamster, Mesocricetus auratus. Parasitology 1986;93(Pt 3):505–515.
8. Kang SY, Cho SY, Chai JY, Lee JB, Jang DH. A Study On Intestinal Lesions Of Experimentally Reinfected Dogs With Metagonimus Yokogawai. Korean J Parasitol 1983;21(1):58–73.
9. Kim ER, et al. Chung-Ang J Med 1985;10(3):291–306.
10. Kim S, Fried B. Pathological effects of Echinostoma caproni (Trematoda) in the domestic chick. J Helminthol 1989;63(3):227–230.
11. Lee SH, Yoo BH, Hong ST, Chai JY, Seo BS, Chi JG. A histopathological study on the intestine of mice and rats experimentally infected by Fibricola Seoulensis. Korean J Parasitol 1985;23(1):58–72.
12. Lee SK, Chung NS, Ko IH, Ko HI, Chai JY. [Two cases of natural human infection by Echinostoma hortense]. Korean J Parasitol 1986;24(1):77–81.
13. Lee SK, Chung NS, Ko IH, Sohn WM, Hong ST, Chai JY, Lee SH. [An epidemiological suryey of Echinostoma hortense infection in Chongsong-gun, Kyongbuk province]. Korean J Parasitol 1988;26(3):199–206.
14. Manson-Smith DF, Bruce RG, Parrott DM. Villous atrophy and expulsion of intestinal Trichinella spiralis are mediated by T cells. Cell Immunol 1979;47(2):285–292.
15. Mohandas A, Nadakal AM. In vivo development of Echinostoma malayanum Leiper, 1911 with notes on effects of population density, chemical composition and pathogenicity and in vitro excystment of the Metacercaria (Trematoda: Echinostomatidae). Z Parasitenkd 1978;55(2):139–151.
16. Cdaibo AB, et al. Proc Helminthol Soc Washington 1988;55:265–269.
17. Olson LJ, Richardson JA. Intestinal malabsorption of D-glucose in mice infected with Trichinella spiralis. J Parasitol 1968;54(3):445–451.
18. Ryang YS, Ahn YK, Lee KW, Kim TS, Han MH. [Two cases of natural human infection by Echinostoma hortense and its second intermediate host in Wonju area]. Korean J Parasitol 1985;23(1):33–40.
19. Seo BS, Lee SH, Chai JY, Hong SJ. Studies on intestinal trematodes in Korea XX. Four cases of natural human infection by Echinochasmus japonicus. Korean J Parasitol 1985;23(2):214–220.
20. Seo BS, et al. Seoul J Med 1986;27(2):125–134.
21. Seo BS, et al. Seoul J Med 1980;21(1):21–29.
22. Seo BS, Chun KS, Chai JY, Hong SJ, Lee SH. Studies on intestinal trematodes in Korea: XVII. Development of egg lying capacity of Echinostoma hortense in albino rats and human experimental infection. Korean J Parasitol 1985;23(1):24–32.
23. Seo BS, Hong ST, Chai JY, Lee SH. Studies On Intestinal Trematodes In Korea: VIII. A Human Case Of Echinostoma Hortense Infection. Korean J Parasitol 1983;21(2):219–223.
24. Shiner M, Doniach I. Histopathologic studies in steatorrhea. Gastroenterology 1960;38:419–440.
25. Swanson VL, Thomassen RW. Pathology of the Jejunal Mucosa in Tropical Sprue. Am J Pathol 1965;46:511–551.
26. Tani S. Jap J Parasitol 1976;24(4):262–273.
27. Thorndyke MC, Whitfield PJ. Vasoactive intestinal polypeptide-like immunoreactive tegumental cells in the digenean helminth Echinostoma liei: possible role in host-parasite interactions. Gen Comp Endocrinol 1987;68(2):202–207.
28. Yamashita J. Progress of Med Parasit 1964;1:289–313.
Editorial Office
Department of Molecular Parasitology, Samsung Medical Center, School of Medicine, Sungkyunkwan University,
2066 Seobu-ro, Jangan-gu, Suwon 16419, Gyeonggi-do, Korea.
Tel: +82-31-299-6251   FAX: +82-1-299-6269   E-mail: kjp.editor@gmail.com
About |  Browse Articles |  Current Issue |  For Authors and Reviewers
Copyright © 2022 by The Korean Society for Parasitology and Tropical Medicine.     Developed in M2PI