Fibricola seoulensis Seo, Rim and Lee, 1964 (Trematoda) and Fibricoliasis in Man

Abstract

It has been agreed upon that since several decades three kinds of trematodes of medical importance, namely Clonorchis sinensis, Paragonimus westermani and Metagonimus yokogawai have long been known to be endemic in various areas throughout the country and especially clonorchiasis and paragonimiasis were at one time highly endemic in certain localities of Korea. However, for the past several years, a control project using praziquantel for these trematodiases was implemented In the endemic areas of South Korea with health educational programmes. Thus the liver and lung fluke diseases have recently been showing remarkable decreasing tendency. On the other hand, human infections of various kinds of intestinal trematodes including heterophyids, echinostomatids, fasciolids and others have recently been increasingly reported. Since it was revealed that a diplostomatid fluke. Fibricola has been implicated as a causative agent of human intestinal trematodiases, fibricoliasis had brought about medical attention in Korea. Historically, an investigation of the helminths parasitic in house and field rats of Korea had been carried out by Seo. Rim et Lee from 1956 to 1964. A total of 624 rodents of six species, namely 357 Rattus nonvegicus. 221 Apodemus agrarius. 8 Rattus r. alexandrius. 13 Mus muscu-lus yamashinai, 4 Microtus fortis pellceus, and 21 Crocidura russula, were examined for trematode. Fibricola seoulensis Seo. Rim et Lee. 1964 (Trematoda; Diplostomatidae) was proposed as a new species from house rats in Seoul (Seo et al. 1964). Thirteen specimens of this species were obtained from the small intestine of two rats (Rattus norvegicus) captured in Seoul. Later, according to the survey on the Intestinal trematode of house rats. It was turned out that this species was distributed widely in Korea (Seo et al. 1981). In 1982, seventy nine specimens of this species were obtained by Seo et al. (1982) from diarrheic stools of a 25-year old Korean male. admitted to Seoul National University Hospital because of fever, epigastric discomfort and diarrhea, after bithionol treatment with magnesium purgatlon. It was assumed the first record of human human infection by adult diplostomatid fluke Hong et al, (1982) reported that the frog, Rana nigromaculata and the snake, Rhabdophis tigrina (Natix tigrina lateralis) were found to be naturally infected by the metacercariae of this species. Elaphe rufodorsata, E, dione, Dinodon rufozonatum and Agkistrodon blomhoffii were also confirmed to serve as the second Intermediate and/or paratenic hosts of this fluke by Cho et al.(1983). A planorbid freshwater snail, Hippeutis (Helicorbis) cantori was found to be naturally Infected by the cercariae of this species and proved to be experimentally acceptable (Seo et al 1988). Studies on histopathology and chemotherapy were carried out in experimental fibricoliasis (Lee et al. 1985c; Lee et al 1985a). The aim of this review is to bring together the parasitological and medical aspects of the literatures dealing wholly or partly with Fibricola seoulensis and to summarize the progress in the study of human infection of F, seoulensis, achieved by our domestic investigators for the past ten years.