Jpn. J. Infect. Dis., 53, 2000

Laboratory and Epidemiology Communications

Has Echinococcus granulosus Settled in Hokkaido?
K亘ii Fumya*, Masanori Kawanakal, Naoki Sato2, Hiroshi Honma

and Masahide Tamura
Hokkaido Institute of Public Health,
Kita‑19, Nishi‑12, Kita‑ku, Sappwo 060‑0819,'Department ofParasitology, National Institute of Infectious D iseases,
Toyama 1‑23‑1, Shinjuku‑ku Tokyo 162‑8640 and2school of Medicine, Hokkaido UniversiOl,

Kita‑1 4, Nishi‑5, Kita‑ku, Sapporo 060‑8648
Communicated by Kazuo Kato(Accepted September 1 1 , 2000)

Two fbms of human echinococcosis or hydatidosis havebeen reportedinJapan: alveolar hydatidosis (AHD), which

and histopathologlCal observations, was E. mu/tilocularis foris caused by larval Echinococcus multilocularis, and cysticof the infected cattle (the infected cattle were all imported

all of the infected swine and horses, and E. granulosus for all

hydatidosis (CHD), which is caused by larval E. granulosus

from E. granulosus‑enzootic countries). Infected sheep or( 1 ). Thee hundred and eighty‑three AHD cases were reportedgoats were not detected.

from 1937‑1998 in Hokkaido, a large northemmost island ofJapan (2). In contrast, CHD cases were reported from threeother large islands, Honshu, Shikoku and Kyushu (1). The
totalnumber ofCHD cases in Japan from 1881‑1994 was 69

Tbough no human case ofCHD has been reported thus far,
E. granulosus infection was actually found among autoch‑thonous domestic animals in Hokkaido (3). Therefore, oc‑cu汀enCe OrCHD in residents in Hokkaido has been suspected.

Namely, Some cases ofAHD reported from Hokkaido may
have been CHD.

(1).

However, many cases ofE. granulosus infection among

Westem blot (WB) using the hydatid 8 kDa antigen (4) for

imported animals have been reported from Hokkaido meat
inspection centers (3). Table I shows data from the Obihiro
meat inspection center over the fiscal years of 1994‑1999.

serodiagnosis ofCHD has been found sufrlCiently useful (5).
We applied this method to whether any of the echinococcosis

There were 2,994 Echinococcus‑infected swine, 34 infectedpatients in Hokkaido were infected by E. granulosus･ Among

71 AHD patients'sera in Hokkaido, 15 (21.2%) were positive

cattle, and 7 infected horses. Diagnosis, based on macroscopIC(Table 2)･ All of the sera from patients with other p.arasitic'kCorresponding author: Fax: +81 ‑1 1‑736‑9476, E‑mail:furuya@

diseases were negative, excepting one toxocariasIS Case,

iph.pref.hokkaido.jp

though this case was later found also to have been infected176

Jpn. J. Infect. Dis., 53','2000
Table 1. Domestic animals with echinococcosis found in Obihiro meat inspection centerfrom the fiscal years of 1994 to 1999

Heads of confirmed animals in each fiscalyear
Animals 1 994

1 995

Cattle69,452

Swine

66,3 827

1 997

59,372

864L,脚$1 ,249f
Horse

1 996

65,956

16L

ND

1 998

57,07名

15

154,326

55 ,320
1

1 999

58,925､60,070154,076J

249,276

I,087

3,57

60

71

70

178

85

8152

30

4

3000

Upper row: Totalheads of inspected animals.
Lower row: Heads of animals diagnosed as echinococcosis.

ND: Inspection was not performed far echinococcosis･

Table 2. Results of examination of serum specimens from patients withr various parasitic diseases
by the Westem blot method using the hydatid 8 kDa antlgefl
Parasitic diseases No. of tested serum spec]mens No. of positive specimens
Cystic hydatidosis

1 7 1 ‑ ′▲U 2 5 ′人U 5 つJ 2 075100000000

Alveolar hydatidosis

1
2つJ

Toxocariasi s

Amebiasis (amebic dysentery)

Diphyllobothriasis
SchistosomiasIS Japonica
Paragonimiasis
Fascioliasis
Sparganosi sGnathostom i as i sAnisakiasis
I Nine sera 80m Italy and two sera from Argentina.
2Five sera kom Argentina.
3Five sera kom PhilipplneSby E. granulosus. SeroIPOSitivity among CHD cases wasechinococcosis prevalence in humans and animals in

63.6% (7/ll).
Al1 15 cases positive on the 8 kDa antlgen WB test, were,Hokkaido. Jpn. J. Infect. Dis., 52, 117‑120.

3. Ohbayashi, M. (1988): Echinococcosis and its wide‑
spreading distribution. Media Circle, 33, 81‑88 (inhowever, found to be the "complete type" by the E.

multilocu/arts zmtigen‑WB test (2). Because bands consdtuting

J叩aneSe).

Specific EM18 (6) and Em2PIus (7) antigens, the above 154. Maddison, S. E., Slemenda, S. B., Schantz, P. M., Fried,J. A., Wilson, M. and Tsang, V. C. W. (1989): A specificpatients were classirled as AHD though their sera reacted

diagnostic antigen of Echinococcus granulosus with an

positively on the 8 kDa antlgen WB. Namely, the 8 kDa
antigen WB test was not specific enough to differentiate CHD

Hyg., 40, 377‑383.

the …complete type" are considered to include both AHD‑

apparent molecular weight of 8 kDa. Am. J. Trop. Med.

from AHD.

5. Fumya, K., Kawanaka, M., Sato, N., Yagi, K., Sawa血,We conclude here that, although many E. granulosus‑

Y., Honma, H. and Tamura, M. (2000): Eva)uation of theinfected cattle have been imported, the parasite has not yet

Westem blot test uslng hydatid 8 kDa antigen fわr theestablished its life cycle in Hokkaido. This conclusion isserodiagnosis or hydatid disease. Rep. Hokkaido lnst.
Publ. Health, 50, 1‑5 (in Japanese).

supported by the lack of reports ofE. granulosus‑infected dogs

6. Ito,A., Wang, X. G. andLin, Y. H. (1993): Differential

or foxes which are the final hosts ofE. granulosus.

serodiagnosis of alveolar and cystic hydatid disease in

the People's Republic of China. Am. J. Trop. Med. Hyg.,

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177