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Gastric echinostomiasis diagnosed by endoscopy
O-J Lee, S-J Hong
Brief Reports
BRIEF REPORTS Gastric echinostomiasis diagnosed by endoscopy Ok-Jae Lee, MD, Sung-Jong Hong, DVM, PhD
Echinostoma hortense is an intestinal fluke belonging to the family Echinostomatidae. The adult echinostomes inhabit the small intestine and reside attached to the mucosal surface where they may produce mild pathologic changes. Although the clinical manifestations of echinostomiasis have been poorly studied, severe infection may be accompanied by abdominal pain and diarrhea.1,2 E hortense infection is endemic in Korea, and over 80 human cases have been reported.3-8 However, gastric echinostomiasis has not been reported. This is a description of a case of gastric echinostomiasis diagnosed by upper endoscopy. CASE REPORT A 40-year-old Korean woman complained of epigastric pain and diarrhea of 1-month duration accompanied by acidic belching, dizziness, and weight loss of 2 kg. Epigastric discomfort had been present for about 1 year. She was a housewife and often ate raw freshwater fish. Her temperature was 36.6°C and blood pressure 110/70 mm Hg. The palpebral conjunctiva were slightly pale. Examination of the chest was normal; slight tenderness was elicited in the epigastrium, and the liver and spleen were not enlarged. From the Department of Internal Medicine, Gyeong-sang National University College of Medicine, Chinju and Department of Parasitology, Chung-Ang University College of Medicine, Seoul, Korea. Reprint requests: Ok-Jae Lee, MD, Department of Internal Medicine, Gyeong-sang National University College of Medicine, 90 Chilam-dong, Chinju, Gyeong-Nam, 660-702, Republic of Korea. Copyright © 2002 by the American Society for Gastrointestinal Endoscopy 0016-5107/2002/$35.00 + 0 37/54/121193 doi:10.1067/mge.2002.121193 440 GASTROINTESTINAL ENDOSCOPY
Figure 1. Endoscopic view of lesser curvature of gastric antrum showing narrow, 10 mm long, worm with a red spot at one end attached to mucosal surface. Laboratory data included the following: hematocrit 30.3% (normal: 36%-48%), white blood cell count 4700/mm3 (400010,000/mm3), and eosinophil count 141/mm3 (<500/mm3). Serum electrolytes and urinalysis were normal. Stool examination was positive for eggs of Clonorchis sinensis, Metagonimus yokogawai, and Echinostomes. Upper endoscopy revealed 2 worms in the stomach. One was penetrating into the mucosa on the lesser curvature of the antrum; it wiggled on stimulation and became tightly stretched during retrieval with a forceps. The other was attached to the mucosal surface of the greater curvature of the antrum. The worms were narrow, elongate, about 10 mm in length, and had a red area at one end (Fig. 1). Both were removed from the stomach with a forceps. The duodenal bulb and descending duodenum were normal. The parasites were partially damaged during retrieval, but could be identified as E hortense. Although the anterior portion (head crown, head-collar with spines, and oral sucker) was missing, a circular ventral sucker and uterus containing eggs located at about the anterior third portion of the body, and an ovary, two distinct testes in tandem, and the vitelline glands at the posterior body were readily evident (Fig. 2A). Eggs about 0.14 mm in size were also visible in the uterus (Fig. 2B). Microscopic examination of endoscopic biopsy specimens VOLUME 55, NO. 3, 2002
Brief Reports
O-J Lee, S-J Hong
revealed dense infiltration by chronic inflammatory cells and some neutrophils in the gastric mucosa, and Helicobacter pylori in the gastric pits. The patient was treated with praziquantel, 10 mg/kg, given orally for 1 day, and thereafter her symptoms disappeared. No parasite eggs were found on follow-up fecal examination.
DISCUSSION The echinostomes are naturally occurring parasites in the intestine of a variety of mammalian and avian hosts. Humans are accidental hosts. Human echinostomiasis is acquired through the consumption of such foods as raw or inadequately cooked mollusks or fish.1 E hortense infection is widespread in the Far East including Korea and Japan.3,9 In Korea, over 80 cases of E hortense infection in humans have been reported since the first clinical case was described in 1983.3-8 An epidemiologic study found that 22.4% of residents were infected with E hortense in areas of southeastern Korea.5 In rats experimentally infected with E hortense, the parasites destroyed intestinal villi by means of their oral suckers and collar spines. They produced blunting, fusion, or focal loss of intestinal villi, and also led to proliferation of goblet cells, infiltration of inflammatory cells in stroma, capillary congestion, dilatation of lymphatics, and an increase in fibroblasts. The villous destruction began 1 day after infection and progressed.10 It is suspected that a similar pathogenesis may exist in heavily infected humans. Individuals infected with echinostomes have nonspecific GI symptoms such as abdominal pain (epigastric or lower abdominal), cramps, or discomfort. Symptoms also include anorexia, postprandial burning, flatulence, and diarrhea.11,12 The major symptoms are, as noted in the present case, abdominal pain and diarrhea.13,14 E hortense infection can produce duodenal ulcer with bleeding; penetration of the ulcer base by an adult E hortense has been demonstrated endoscopically.6 Chronic, severe infection may lead to clinical manifestations of malabsorption because of the destruction of intestinal villi. E hortense infection of the stomach in the present case resulted in epigastric discomfort and pain, diarrhea, weight loss, and dizziness. There was no specific pathologic change apparent; the observed infiltration of the gastric mucosa with chronic inflammatory cells and some neutrophils is highly consistent with H pylori gastritis. The disease of gastric echinostomiasis requires further study. Our patient enjoyed eating many kinds of raw freshwater fish, the possible source of infection. The pathogenesis of gastric infection by E hortense is not well understood; perhaps the parasites VOLUME 55, NO. 3, 2002
A
B Figure 2. A, Photomicrograph of parasite removed from stomach. Anterior portions, including head crown, head-collar with spines, and oral sucker, are missing because of damage caused during retrieval with a forceps. A circular ventral sucker and uterus containing eggs located at about the anterior third portion of the body, and an ovary, 2 distinct testes in tandem, and vitelline glands in the posterior body can be identified (Acetocarmine, orig. mag. ×12.5). B, Photomicrograph of eggs in uterus (Unstained, orig. mag. ×200).
creep into the gastric antrum from the duodenum. Neither is the pathogenesis of the infection in the present case clear. It may be possible that after ingestion of infected freshwater fish, the metacercariae were set free in the duodenum, and there reached GASTROINTESTINAL ENDOSCOPY 441
Brief Reports
maturity. The parasites may then have migrated, not to the jejunum, but to the gastric lumen. The identification of E hortense eggs in feces can be diagnostic. However, there is considerable overlap in the shape and size of echinostome eggs, and furthermore, the eggs are similar to those of Fasciola hepatica and Fasciolopsis buski. The identification of the adult fluke is necessary for speciesspecific diagnosis.1 In the present case, the diagnosis was made by identifying the worms removed from the stomach endoscopically as E hortense. Upper endoscopy as well as fecal examination is recommended for patients with GI symptoms who live in areas where echinostomiasis is endemic.
6.
7.
8.
9.
10.
REFERENCES 1. Kumar V. Trematode infections and diseases of man and animals. 1st ed. Dordrecht: Kluwer Academic Pub; 1999. p. 32253. 2. Monroe LS. Gastrointestinal parasites. In: Haubrich WS, Schaffner F, Berk JE, editors. Bockus gastroenterology. 5th ed. Philadelphia: WB Saunders; 1995. p. 3113-96. 3. 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;21:219-23. 4. Ryang YS, Ahn YK, Lee KW, Kim TS, Hhan MH. Two cases of natural human infection by Echinostoma hortense and its second intermediate host in Wonju area [in Korean with English abstract]. Kisaengchunghak Chapchi 1985;23:33-40. 5. Lee SK, Chung NS, Ko IH, Sohn WM. An epidemiologic survey of Echinostoma hortense infection in Chonsong-gun,
442 GASTROINTESTINAL ENDOSCOPY
11.
12.
13.
14.
Kyongbuk Province [in Korean with English abstract]. Kisaengchunghak Chapchi 1988;26:199-206. Huh S, Lee SU, Huh SC. A follow-up examination of intestinal parasitic infections of the army soldiers in Whachon-gun, Korea. Korean J Parasitol 1994;32:61-3. Sohn WY, Huh S, Lee SU, Woo HC, Hong SJ. Intestinal trematode infections in the villagers in Koje-myon, Kochang-gun, Kyongsangnam-do, Korea. Korean J Parasitol 1994;32:149-55. Chai JY, Hong ST, Lee SN, Lee GC, Min YI. A case of echinostomiasis with ulcerative lesions in the duodenum. Korean J Parasitol 1994;32:201-4. Tani S. Studies on Echinostoma hortense Asada (1926). (1) Species identification of human echinostomiasis and its infection source [in Japanese with English abstract]. Japanese J Parasitol 1974;23:404-8. Lee SH, Noh TY, Sohn WM, Kho WG, Hong ST, Chai JY. Chronological observation of intestinal lesions of rats experimentally infected with Echinostoma hortense [in Korean with English abstract]. Kisaengchunghak Chapchi 1990;28:45-52. Lee SK, Chung NS, Ko IH, Chai JY. Two cases of natural human infection by Echinostoma hortense [in Korean with English abstract]. Kisaengchunghak Chapchi 1986;24:77-81. Poland GA, Navin TR, Sarosi GA. Outbreak of parasitic gastroenteritis among travelers returning from Africa. Arch Intern Med 1985;145:2220-1. Arizono N, Uemoto K, Kondo K, Mastuno K, Yoshida Y. Studies on Echinostoma hortense (Asada, 1926) with special reference to its human infection [in Japanese with English abstract]. Japanese J Parasitol 1976;25:36-45. Tani S. Studies on Echinostoma hortense (Asada, 1926). (4) Variation of egg count, peripheral eosinophils and antibodies in human volunteers experitally infected with E hortense [in Japanese with English abstract]. Japanese J Parasitol 1979;28:57-62.
VOLUME 55, NO. 3, 2002
Brief Reports
BRIEF REPORTS Gastric echinostomiasis diagnosed by endoscopy Ok-Jae Lee, MD, Sung-Jong Hong, DVM, PhD
Echinostoma hortense is an intestinal fluke belonging to the family Echinostomatidae. The adult echinostomes inhabit the small intestine and reside attached to the mucosal surface where they may produce mild pathologic changes. Although the clinical manifestations of echinostomiasis have been poorly studied, severe infection may be accompanied by abdominal pain and diarrhea.1,2 E hortense infection is endemic in Korea, and over 80 human cases have been reported.3-8 However, gastric echinostomiasis has not been reported. This is a description of a case of gastric echinostomiasis diagnosed by upper endoscopy. CASE REPORT A 40-year-old Korean woman complained of epigastric pain and diarrhea of 1-month duration accompanied by acidic belching, dizziness, and weight loss of 2 kg. Epigastric discomfort had been present for about 1 year. She was a housewife and often ate raw freshwater fish. Her temperature was 36.6°C and blood pressure 110/70 mm Hg. The palpebral conjunctiva were slightly pale. Examination of the chest was normal; slight tenderness was elicited in the epigastrium, and the liver and spleen were not enlarged. From the Department of Internal Medicine, Gyeong-sang National University College of Medicine, Chinju and Department of Parasitology, Chung-Ang University College of Medicine, Seoul, Korea. Reprint requests: Ok-Jae Lee, MD, Department of Internal Medicine, Gyeong-sang National University College of Medicine, 90 Chilam-dong, Chinju, Gyeong-Nam, 660-702, Republic of Korea. Copyright © 2002 by the American Society for Gastrointestinal Endoscopy 0016-5107/2002/$35.00 + 0 37/54/121193 doi:10.1067/mge.2002.121193 440 GASTROINTESTINAL ENDOSCOPY
Figure 1. Endoscopic view of lesser curvature of gastric antrum showing narrow, 10 mm long, worm with a red spot at one end attached to mucosal surface. Laboratory data included the following: hematocrit 30.3% (normal: 36%-48%), white blood cell count 4700/mm3 (400010,000/mm3), and eosinophil count 141/mm3 (<500/mm3). Serum electrolytes and urinalysis were normal. Stool examination was positive for eggs of Clonorchis sinensis, Metagonimus yokogawai, and Echinostomes. Upper endoscopy revealed 2 worms in the stomach. One was penetrating into the mucosa on the lesser curvature of the antrum; it wiggled on stimulation and became tightly stretched during retrieval with a forceps. The other was attached to the mucosal surface of the greater curvature of the antrum. The worms were narrow, elongate, about 10 mm in length, and had a red area at one end (Fig. 1). Both were removed from the stomach with a forceps. The duodenal bulb and descending duodenum were normal. The parasites were partially damaged during retrieval, but could be identified as E hortense. Although the anterior portion (head crown, head-collar with spines, and oral sucker) was missing, a circular ventral sucker and uterus containing eggs located at about the anterior third portion of the body, and an ovary, two distinct testes in tandem, and the vitelline glands at the posterior body were readily evident (Fig. 2A). Eggs about 0.14 mm in size were also visible in the uterus (Fig. 2B). Microscopic examination of endoscopic biopsy specimens VOLUME 55, NO. 3, 2002
Brief Reports
O-J Lee, S-J Hong
revealed dense infiltration by chronic inflammatory cells and some neutrophils in the gastric mucosa, and Helicobacter pylori in the gastric pits. The patient was treated with praziquantel, 10 mg/kg, given orally for 1 day, and thereafter her symptoms disappeared. No parasite eggs were found on follow-up fecal examination.
DISCUSSION The echinostomes are naturally occurring parasites in the intestine of a variety of mammalian and avian hosts. Humans are accidental hosts. Human echinostomiasis is acquired through the consumption of such foods as raw or inadequately cooked mollusks or fish.1 E hortense infection is widespread in the Far East including Korea and Japan.3,9 In Korea, over 80 cases of E hortense infection in humans have been reported since the first clinical case was described in 1983.3-8 An epidemiologic study found that 22.4% of residents were infected with E hortense in areas of southeastern Korea.5 In rats experimentally infected with E hortense, the parasites destroyed intestinal villi by means of their oral suckers and collar spines. They produced blunting, fusion, or focal loss of intestinal villi, and also led to proliferation of goblet cells, infiltration of inflammatory cells in stroma, capillary congestion, dilatation of lymphatics, and an increase in fibroblasts. The villous destruction began 1 day after infection and progressed.10 It is suspected that a similar pathogenesis may exist in heavily infected humans. Individuals infected with echinostomes have nonspecific GI symptoms such as abdominal pain (epigastric or lower abdominal), cramps, or discomfort. Symptoms also include anorexia, postprandial burning, flatulence, and diarrhea.11,12 The major symptoms are, as noted in the present case, abdominal pain and diarrhea.13,14 E hortense infection can produce duodenal ulcer with bleeding; penetration of the ulcer base by an adult E hortense has been demonstrated endoscopically.6 Chronic, severe infection may lead to clinical manifestations of malabsorption because of the destruction of intestinal villi. E hortense infection of the stomach in the present case resulted in epigastric discomfort and pain, diarrhea, weight loss, and dizziness. There was no specific pathologic change apparent; the observed infiltration of the gastric mucosa with chronic inflammatory cells and some neutrophils is highly consistent with H pylori gastritis. The disease of gastric echinostomiasis requires further study. Our patient enjoyed eating many kinds of raw freshwater fish, the possible source of infection. The pathogenesis of gastric infection by E hortense is not well understood; perhaps the parasites VOLUME 55, NO. 3, 2002
A
B Figure 2. A, Photomicrograph of parasite removed from stomach. Anterior portions, including head crown, head-collar with spines, and oral sucker, are missing because of damage caused during retrieval with a forceps. A circular ventral sucker and uterus containing eggs located at about the anterior third portion of the body, and an ovary, 2 distinct testes in tandem, and vitelline glands in the posterior body can be identified (Acetocarmine, orig. mag. ×12.5). B, Photomicrograph of eggs in uterus (Unstained, orig. mag. ×200).
creep into the gastric antrum from the duodenum. Neither is the pathogenesis of the infection in the present case clear. It may be possible that after ingestion of infected freshwater fish, the metacercariae were set free in the duodenum, and there reached GASTROINTESTINAL ENDOSCOPY 441
Brief Reports
maturity. The parasites may then have migrated, not to the jejunum, but to the gastric lumen. The identification of E hortense eggs in feces can be diagnostic. However, there is considerable overlap in the shape and size of echinostome eggs, and furthermore, the eggs are similar to those of Fasciola hepatica and Fasciolopsis buski. The identification of the adult fluke is necessary for speciesspecific diagnosis.1 In the present case, the diagnosis was made by identifying the worms removed from the stomach endoscopically as E hortense. Upper endoscopy as well as fecal examination is recommended for patients with GI symptoms who live in areas where echinostomiasis is endemic.
6.
7.
8.
9.
10.
REFERENCES 1. Kumar V. Trematode infections and diseases of man and animals. 1st ed. Dordrecht: Kluwer Academic Pub; 1999. p. 32253. 2. Monroe LS. Gastrointestinal parasites. In: Haubrich WS, Schaffner F, Berk JE, editors. Bockus gastroenterology. 5th ed. Philadelphia: WB Saunders; 1995. p. 3113-96. 3. 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;21:219-23. 4. Ryang YS, Ahn YK, Lee KW, Kim TS, Hhan MH. Two cases of natural human infection by Echinostoma hortense and its second intermediate host in Wonju area [in Korean with English abstract]. Kisaengchunghak Chapchi 1985;23:33-40. 5. Lee SK, Chung NS, Ko IH, Sohn WM. An epidemiologic survey of Echinostoma hortense infection in Chonsong-gun,
442 GASTROINTESTINAL ENDOSCOPY
11.
12.
13.
14.
Kyongbuk Province [in Korean with English abstract]. Kisaengchunghak Chapchi 1988;26:199-206. Huh S, Lee SU, Huh SC. A follow-up examination of intestinal parasitic infections of the army soldiers in Whachon-gun, Korea. Korean J Parasitol 1994;32:61-3. Sohn WY, Huh S, Lee SU, Woo HC, Hong SJ. Intestinal trematode infections in the villagers in Koje-myon, Kochang-gun, Kyongsangnam-do, Korea. Korean J Parasitol 1994;32:149-55. Chai JY, Hong ST, Lee SN, Lee GC, Min YI. A case of echinostomiasis with ulcerative lesions in the duodenum. Korean J Parasitol 1994;32:201-4. Tani S. Studies on Echinostoma hortense Asada (1926). (1) Species identification of human echinostomiasis and its infection source [in Japanese with English abstract]. Japanese J Parasitol 1974;23:404-8. Lee SH, Noh TY, Sohn WM, Kho WG, Hong ST, Chai JY. Chronological observation of intestinal lesions of rats experimentally infected with Echinostoma hortense [in Korean with English abstract]. Kisaengchunghak Chapchi 1990;28:45-52. Lee SK, Chung NS, Ko IH, Chai JY. Two cases of natural human infection by Echinostoma hortense [in Korean with English abstract]. Kisaengchunghak Chapchi 1986;24:77-81. Poland GA, Navin TR, Sarosi GA. Outbreak of parasitic gastroenteritis among travelers returning from Africa. Arch Intern Med 1985;145:2220-1. Arizono N, Uemoto K, Kondo K, Mastuno K, Yoshida Y. Studies on Echinostoma hortense (Asada, 1926) with special reference to its human infection [in Japanese with English abstract]. Japanese J Parasitol 1976;25:36-45. Tani S. Studies on Echinostoma hortense (Asada, 1926). (4) Variation of egg count, peripheral eosinophils and antibodies in human volunteers experitally infected with E hortense [in Japanese with English abstract]. Japanese J Parasitol 1979;28:57-62.
VOLUME 55, NO. 3, 2002