Echinostome infections in the striped-field mouse, Apodemus agrarius, and the Ussuri white-toothed shrew, Crocidura lasiura, caught near the demilitarized zone, Gyeonggi-do (Province), Republic of Korea

Abstract

A total of 1,498 small mammals (rodents and insectivores), including Apodemus agrarius (n = 1,366), Crocidura lasiura (54), Mus musculus (32), Micronytus fortis (28), Eothenomys regulus (9), Micronys minutes (6), and Cricetulus triton (3), were live-trapped in Gyeonggi-do (Province) (Paju-si, Pocheon-gun, and Yeoncheon-gun) near the demilitarized zone (DMZ) from December 2004 to September 2005. A. agrarius was found to be infected with 3 species of echinostomes (Echinostoma hortense, Echinostoma cinetorchis, and Euparyphium murinum), while C. lasiura was infected with 1 species (Echinochasmus japonicas) of echinostome. Other mammals were free from echinostome infections. Total 16 E. hortense were detected in 7 (0.5%) mice, 9 E. cinetorchis from 5 (0.4%), and 3 E. murinum from 2 (0.1%) out of 1.366 A. agrarius examined. E. japonicus was found only in 1 (1.9%; total 3 specimens) C. lasiura. These results demonstrate that A. agrarius and C. lasiura, inhabiting near the DMZ of Gyeonggi-do serve as the natural definitive hosts for several species of echinostomes, although their infection rates are low. This is the first record of natural infections of A. agrarius with E. cinetorchis and C. lasiura with E. japonicus in the Republic of Korea.

Keywords: Apodemus agrarius; Crocidura lasiura; DMZ; Echinochasmus japonicus; Echinostoma cinetorchis; Echinostoma hortense; Euparyphium murinum; shrew; striped field mouse.

Fig. 1

(A) Echinostoma hortense adult recovered from a striped-field mouse, Apodemus agrarius, caught at Yeoncheon-gun, Gyeonggi-do. The characteristic features of this species include the presence of 27-28 collar spines on its head collar and a submedially located ovary. Scale bar = 1 mm. (B) Echinostoma cinetorchis adult recovered from A. agrarius caught at Paju-si, Gyeonggi-do. The characteristic features of this species include the presence of 37-38 collar spines on its head collar, abnormal location or disappearance of 1 or both testes, and a medially located ovary. Scale bar = 1 mm. (C) Euparyphium murinum adult recovered from A. agrarius caught at Paju-si, Gyeonggi-do. The characteristic features of this species include the presence of 45 collar spines on its head collar and a short uterine tubule. Scale bar = 0.5 mm. (D) Echinochasmus japonicus adult recovered from an insectivore, the Ussuri white-toothed shrew, Crocidura lasiura, caught at Paju-si, Gyeonggi-do. The characteristic features of this species include a short, plump body with the presence of 24 dorsally interrupted collar spines and 2 tandem arranged testes. Scale bar = 0.025 mm.