Studies on intestinal trematodes in Korea XIII. Two cases of natural human infection by Heterophyopsis continua and the status of metacercarial infection in brackish water fishes

, Seo, Byong Seol; , Lee, Soon Hyung; , Chai, Jong Yil; , Hong, Sung Jong

doi:1984.22.1.51

Korean J Parasito > Volume 22(1):1984 > Article

Original Article


Korean J Parasitol. 1984 Jun;22(1):51-60. English. Published online Mar 20, 1994. http://dx.doi.org/10.3347/kjp.1984.22.1.51
Copyright © 1984 by The Korean Society for Parasitology


Studies on intestinal trematodes in Korea XIII. Two cases of natural human infection by Heterophyopsis continua and the status of metacercarial infection in brackish water fishes
Byong-Seol Seo,Soon-Hyung Lee,Jong-Yil Chai and Sung-Jong Hong
Department of Parasitology and Institute of Endemic Diseases, College of Medicine, Seoul National University, Korea.


Abstract
Two cases of natural human infection by Heterophyopsis continua (Heterophyidae) were identified by collection of adult worms in 1983 in Korea. And in order to know the source of infection a study on fish intermediate hosts was performed along the southwestern coastal areas. The cases were 24 and 50-year old males residing in southern coastal areas. They had the clinical complaints of non-specific gastrointestinal symptoms such as epigastric pain and one of them also complained the discharge of tapeworm segments. Praziquantel in single dose of 10~15 mg/kg was given followed by purgation with mangnesium salt and 2 and 46 specimens of H. continua were collected from the diarrheal stools. They said to have eaten raw flesh of several kinds of brackish water fishes. The results of fish examination for metacercarial infection were as follows: Seventeen (63.0%) out of 27 perches (Lateolabrax japonicus) and 10 (29.4%) out of 34 gobies (Acanthogobius flavimanus) harboured the metacercariae but none of 42 mullets (Mugil cephalus) were found to harbour them. The average metacercarial density in perches was 55.4 and 18.7 per fish respectively. And the majority of the metacercariae were collected from the muscle of body portions in these fishes. After the metacercariae were experimentally fed to two rats and one young dog, two adult worms were recovered from the dog while none from the rats. These worms were also indentified as H. continua. From the results it was concluded that the brackish water fishes which the human cases said to have eaten were the source of infection.

Figures


	Fig. 1 Areas where the human cases were found (arrows) and the brackish water fishes purchased (black dots). (A: Namhae Island, B: Kohung, C: Beolgyo, D: Kangjin, E: Wando, F: Haeman, and G: Mokpo)


	Fig. 2 Topography of a perch to figure out the metacercarial distribution.


	Figs. 3-4 Fig. 3.H. contimua an adult worm from Case 1 directly after fixation. Note the elongated body from, relationship of ventral and genital suckers, and obliquely tandem testes. (Scale: 0.2mm) Fig. 4.H. contimua from Case 2 after acetocarmine staining. (Scale: 0.2mm)

Fig. 5-9
Fig. 5. Metacercaria of H. contimua, encysted, from L. japonicus. Note ventral and genitalsuckers near equatorial portion of bodyand dark "Y" shape excretory bladder. (Scale: 0.1mm)

Fig. 6.Ibid, excysted, from L. japonicus. Note three suckers and ovary and testes primordia adjacent to "Y" shape excretory bladder. (Scale: 0.1mm)

Fig. 7. Adult of H. continua from the experimental dog directly after fixation. Note general body feature, suckers and obliquely tandem testes. (Scale: 0.2mm)

Fig. 8. Magnification of genital sucker of the worm in Fig. 7. A total of 97 rodlets (spines) are counted along its outer margin. (Scale: 0.05mm)

Fig. 9. Magnification of distal uterus showing many mature eggs. (Scale: 0.05mm)

Tables


	Table 1 Infection rate of brackish water fishes with the metacercariae of H. continua according to kinds of fish and localities


	Table 2 Metacercarialdensity of H. continua in brackish water fishes


	Table 3 Status of metacercarial distribution in L. japonicus


	Table 4 Worm recovery results from the experimental animals


	Table 5 Comparison of the measurements of Heterophyopsis spp. and the present specimens from man and dog

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