Natural infections of Asian Taenia saginata metacestodes in the livers of Korean domestic pigs

우리나라 돼지 폐장내 Asian yuenia suginata 낭미충의 자연감염

The Taenia species in East Asia, hitherto identified as Taenia saginata, has been recognized as differing from the classical descriptions of life cycles and was recently named Taenia saginata taiwanensis (tentatively until 1992) . Major differences between T. saginata and the newly recognized Asian T. saginata are their intermediate hosts and the infected tissues. Asian T. saginata metacestodes are found in the livers of pigs rather than in the muscles of cattle. In this study, we observed the natural infection status of Asian T saginata metacestodes in the livers of 25,358 pigs at an abattoir in Cheongju City, Korea, from 1989 to 1990. Total 256 livers(1.01%) were infected with 1∼96 (mean 2.5 per capita) metacestodes. Most of the metacestodes, however, were either calcified (87.1%) or highly degenerated (12.9%). Living metacestodes were found in only 0.01% (3/25,358) of the examined livers. And these were distributed randomly in each lobe of the livers. The liver of pigs in Korea was con- firmed as an organ hosting the Asian T. saginata metacestode. But its epidemiological significance as a source of human infections should be properly evaluated because of the rarity of the living metacestodes.

충북 청주시 소재 도축장에서 6개월령 균격돈 (Yorkshlre, Landrace, Duroc 및 Hampshire의 교잡종)을 조사하여 Asian Taenin saginata 예미충의 간장내 감염률을 조사하였다. 낭미충은 1.01% (256/25,358 마리)의 돼지에서 발견되었으며 낭미충의 상태는 살아있었거나 (0.01%, 3/25,358), 죽은 후 변성되어 있었거나 (0.12%, 30/25,358), 석회화된 (0.88%, 223/25,358) 상태로 검출되었다. 감염된 제지간 중 석회화된 낭미충만 발견되는 경우가 87.1%(223/256)로 대부분이었다. 간장내에서는 우측엽(14.7%), 우중엽(29.9%), 좌중엽(28.2%), 좌측엽 (27.l%)에 고르게 분포하였고, 표면과 실질에도 각각 45.8% 및 54.2%로서 고르게 분포하였다. 남미충의 크기는 생존상태에서 2.07~2.14$\times$1.98~2.01 mm이었고, 불규칙소구(rudimetary hooklets)는 17.0% (8/47)의 낭미충에서 발견되었다. 이상의 결과는 돼지에 자연 감염된 Asian Taenia sagippata 낭미충이 이제까지 무구조충(Taenia saginata)으 로 오인되었던 Asian Taenia saginata의 인체 감염원이 되었을 것으로 생각되었다.