Prevalence of Heterophyes Nocens and Pygydiopsis Summa Infections Among Residents of the Western and Southern Coastal Islands of the Republic of Korea

Abstract

To determine the distribution and prevalence of heterophyid fluke infections on coastal islands of the Republic of Korea, fecal specimens were collected from 4,179 people residing on 45 islands in the West (Yellow) and South Seas and examined using the formalin-ether and Kato-Katz techniques. Eggs of Heterophyes nocens were found in 459 (11.0%) residents of 42 islands, with an average number of eggs per gram (epg) of feces of 79.6. Eggs of Pygidiopsis summa were found in 49 (1.2%) on 12 islands, with an average epg of 253.0. The egg-positive rate for H. nocens was the highest on Chungdo (32.6%), followed by Imchado (27.3%); P. summa was most prevalent on Imchado (15.2%). The majority (78.9% [362 of 549] of those infected with H. nocens and 81.6% [40 of 49] of those infected with P. summa) of those infected were adults more than 40 years old. Adult flukes of these species were recovered from residents of Imchado by treatment with praziquantel and purgation. Our results indicate that H. nocens and P. summa are indigenous to the southern and western coastal islands of the Republic of Korea.

Epidemiological Survey on the Infection of Intestinal Flukes in Residents of Muan-gun, Jeollanam-do, the Republic of Korea

“…They were more slender in body shape, when we compared with those from experimental cats [13]. Human infections with this fluke have been reported in about 18 cases so far [2,6,[8][9][10]. Our study adds 7 cases confirmed by worm recovery and 25 egg-positive cases.…”

“…This fluke was recovered from all 9 cases examined, although the intensity of infection was a little lower in the present study (average worm burden; 109) than in Chai et al [6] (average worm burden; 193). The dominancy of H. nocens infections has also been shown in the residents of Shinan-gun and Gangjin-gun (Jeollanam-do), Buan-gun (Jeollabuk-do), Sacheon-si (Gyeongsangnam-do), and western and southern coastal islands of the Republic of Korea [7][8][9][10].…”

A survey of Enterobius vermicularis infection among children on western and southern coastal islands of the Republic of Korea

“…The patterns and prevalence of human helminth infections on coastal islands seem to be quite different from those of the inland (Chai et al, 2001(Chai et al, , 2004. For instance, intestinal trematodes including heterophyids and a gymnophallid are prevalent among residents of western and southern coastal islands, i.e., Heterophyes nocens (11.0%), Gymnophalloides seoi (3.8%), and Pygidiopsis summa (1.2%) (Chai et al, 2004).…”

“…For instance, intestinal trematodes including heterophyids and a gymnophallid are prevalent among residents of western and southern coastal islands, i.e., Heterophyes nocens (11.0%), Gymnophalloides seoi (3.8%), and Pygidiopsis summa (1.2%) (Chai et al, 2004). Moreover, because of their geographical isolation, less medical attention has been paid to these areas, and with regard to E. vermicularis infection, no surveys have been conducted.…”

Foodborne Intestinal Flukes in Southeast Asia

“…Domestic or feral cats are naturally infected with this fluke [35,162,188]. In the Republic of Korea, prevalences ranging from 10% to 70% were detected among residents in southwestern coastal areas, including islands [2,189]. In Japan, human H. nocens infections were reported from Kochi, Chiba, Yamaguchi, Chugoku, Hiroshima, and Shizuoka Prefectures [190,191].…”