2000~2010년까지 감염성질병 발생에 의한 것으로 의심되는 폐사가 발생한 23개소 양식장의 병든 뱀장어를 대상으로 총 29건의 병원체 검사를 실시하였다. 총 7종의 병원체 감염이 확인되었고, 병원체의 감염률은 Pseudodactylogyrus sp. (65.5%, 19/29 시료), aquabirnavirus (ABV, 62.5%, 15/24 시료), Edwardsiella sp. (44%, 11/25 시료), anguillid herpesvirus 1 (AngHV1, 16.7%, 2/12 시료), Heterosporis sp. (10.3%, 3/29 시료), Vibrio sp. (8%, 2/25 시료), Trichodina sp. (3.4%, 1/29 시료) 순으로 높게 나타났다. 병원체의 감염은 단독감염 (44.8%, 13/29 시료) 보다 혼합감염(62.1%, 18/29 시료) 이 높게 나타났으며, 혼합감염의 경우 2~5종의 병원체가 복합적으로 감염되어 있었다. 혼합감염률은 Pseudodactylogyrus sp.-Edwardsiella sp. (10.3%, 3/29 시료), Pseudodactylogyrus sp.-ABV (10.3%, 3/29 시료), Edwardsiella sp.-ABV (6.9%, 2/29 시료) 순으로 높게 나타났다. 기생충, 세균 및 바이러스에 의한 감염은 조사된 대부분의 지역에서 나타났으며, 수온 $25{sim}30^{circ}C$ 범위에 사육되고 있는 뱀장어 치어를 비롯한 성어에 이르기까지 무차별적으로 발생하는 것으로 확인되었다.
Disease survey was conducted to investigate the cause of high mortality in 23 farms of eel, Anguilla japonica, during the period from 2000 to 2010. Seven kinds of fish pathogens were confirmed in the tested fish, which included: Pseudodactylogyrus sp. (infection rate: 65.5%, 19/29 samples), aquabirnavirus (ABV, 62.5%, 15/24 samples), Edwardsiella sp. (44%, 11/25 samples), anguillid herpesvirus 1 (AngHV1, 16.7%, 2/12 samples), Heterosporis sp. (10.3%, 3/29 samples), Vibrio sp. (8%, 2/25 samples), Trichodina sp. (3.4%, 1/29 samples). The rate of single infection was 44.8% (13/29 samples), while 62.1% (18/29 samples) showed mixed type of infection with 2 to 5 different pathogens. The most predominant mixed infection were Pseudodactylogyrus sp.-Edwardsiella sp. (10.3%, 3/29 samples), Pseudodactylogyrus sp.-ABV (10.3%, 3/29 samples), Edwardsiella sp.-ABV (6.9%, 2/29 samples). Infection by the above infectious parasites, bacteria and virus was confirmed in tested eels of juvenile to adult sizes that were cultured at $25{sim}30^{circ}C$ in almost the examined farms.
