Jpn. J. lnfect･ Dis･, 54, 148‑150, 2001

Epidemiological Report

Reports of Parasitic Diseases and EntomologlCal Cases in the Department ofMedical Zoology, Jichi Medical School:
Accumulated Cases from Five Years
Hiroyuki Matsuoka*, Shigeto Yoshida, Makoto Hirai and Akira lshii
Department of Medical Zoology, Jichi Medical School,
Yakushlji 3311‑1, Minami‑kawachi, Tochigi 329‑0498, Japan(Received May 2, 2001. AcceptedAugust 15, 2001)
SUMMARY: We summarized the consultation cases of parasitic diseases and entomologlCal cases presentedat the Department ofMedical Zoology, Jichi Medical School･ Among 173 consultations from January 1996 toDecember 2000, 64 cases were parasitologlCally or entomologlCally positive. We prlmarily diagnosed the cases

morphologlCally and intermittently used sero‑diagnosis methods･Ascariasis and diphyllobothriasis due to foods
comprised the major consultation cases. Cases of malaria, second in frequency, were all imported from tropicalcountries. Some rare but important cases, including entomologlCal cases, are discussed･

Jichi Medical School (JMS) was established by the goytreated manure. These activities decreased the number of cases

emments of47 prefectures in Japan in 1972 in order to trainof parasitic nematodes such as ascaris, hook‑worm, trichuria,etc. However, ascariasis is still encountered from time to time,physicians who work inrural areas throughout Japan･ Everyyear, the JMS accepts two or three students from eachas fecal manure is oftenused as a fertilizer in home vegetableprefecture. The students are educated in medicine free ofgardens.

charge fわr 6 years, and then they are obligated to work in

Among 14 cases or ascariasis, no case was diagnosed bytheir own prefecture, particularly in rural areas, for 9 years

fecal examination. In three cases, a worm was discovered

after graduation. Graduates of the JMS are more likely toorally; a worm was found in feces in seven cases; a worm

encounter parasitic diseases than doctors working ln urban

was fわund by chance in one case by gastro‑endoscoplC exami‑areas. Since the initiation of our department and the JMS

nation due to another indication. In three cases, a won washospital in 1974, we have conducted hun血eds ofconsulta‑

found in the common bile duct when endoscopIC retrograde

tions on parasitic diseases and medical entomological cases.

cholanglO‑panCreatOgraphy was perfわrmed due to patient

Here, We describe the cases for which we have provided
consultation during the past 5 years that involve parasitic

complaints of acute upper‑abdominal pain. The wom in thesecases was extracted from the common bile duct by thediseases recently encountered in Japan; We also provide

endoscope; a氏erwards, the patients recovered from the palnmaterial fわr a comparison of parasitic diseases in other coun‑associated with the infection.

AnisakiasIS, paragOnimiasIS, and metagonimiasis are alsotries.

Among 173 consultations over a period of5 years, 60%
were from JMS Hospital and 40% were from other hospitals;

common in Japan because they occur a洗er the ingestion of

raw fish ‑ squid or mackerel ‑ containlng larvae of the Anisakis

doctors in 26 prefectures were consulted. The total number

spp. ; live crabs infected with metacercariae of Paragonimusof diagnosed cases was 64.

miyazakii or P westermanii can also cause this diseases, asConsultations for parasitologlCal cases are listed in Table
1. Ascariasis and diphyllobothriasis were the most common

Metagonimus yokogawai. The incidence of these parasitic

can the ingestion of sweet‑fish containing metaCerCariae ofparasitic diseases among the consultations. These two diseases

diseases has been reduced in number. However, these diseases

are peculiar to Japan in terms of fわods. Japanese people

have not yet been completely eradicated because Japanesefrequently eat fresh vegetables and raw fish.Ascariasis

people continue to Ingest these species of raw fish.

mature eggs ofAscaris lumbricoides. Diphyllobothriasis

We have diagnosed four cases of ocular toxocariasis among
the cases reported by the Department of Ophthalmology atoccurs when raw trout or salmon containlng plerocercoids ofJMS Hospital. The cases had a typlCal mass fbmation in thedevelops when people eat fresh vegetables bearlng theDlbhyllobothn'um nihonkaienseare ingested ( 1 ). These parasitic

fundus of eye, and also had histories of living With dogs ordiseases were very common in Japan until the 1950S (2, 3).

cats. Specific antibody to toxocara was detected by Toxocara

Since血en,血e incidence of both of these parasitic diseases has

CHECK (E‑Y Laboratories Ltd., Hong Kong) and ELISA

decreased because public health education has been made(4, 5). The cause in these cases was not only Toxocara cants

available and also because fecal examination and mass treat‑(canine.round worm) but also T cati (feline round worm)･

ment were both perf♭med in the 1 960S. The commonly used

ExcessIVe COntaCt With pets can be a cause orthis larvalfTertilizers were also changed from fecesand urine to chemicallymlgrant disease･Pinworms (Entey10bius vermicularis) were found by chance*Corresponding author: Tel.I+8 1‑285‑5817339, Fax: +811285‑44‑

in a 72‑yeaト01d woman, whose large intestine was examined

6489, E‑mail: hiroyuki@jichi.acjp

by endoscopy. A female whipworm(TTrichuris trichiura) was

148

Table 1. List orparasitcs rcportcd to the Department ofMcdical Zoology, Jichi Medical School, Japan (January I 996 ‑ December 2000)
Diagnosed place oflnfection

N｡.of Japanese

Scientific NameCases Domestic ImportedbyProtozoan(1 6 cases)

Plasmodium fblciparumsmear Tanzanla, Indonesia

22 ∠U 1 l･ 1 1 1 1 1 1

Plasmodium vL'vax

42

smear india, Indonesia, Sri Lanka

smear Ghana

PlasmodL'um ovale

Entamoeba histolyEica (colon)

smear Tbchigi
smear Tbch igi(liver)smear Tbchigi

Blasto(ystt's ham I‑His

Cryptosporidium pan,umsmear Saitama

Gt'afldia lamblia

smear Rumania

LeL'shmant'a spp.

serum

TYypa170SOma CruZL'

scrum Bolivia

unknown

Ncmatodcs (24 cas°s)

Ascaris lumbrt'cot'des4 4 2 1一‑一1 1wonn Tochigi, Saitama, Ibaraki, Gunma, YalllaguChi, Vietnam

tJ 4 2 I1 ‑ ‑ 一‑

ZToxocara spp.

senlm Saitama, lbaraki

Anisakt's spp.

EnterobL'us verm iculart's

wom Tbchigi
wom Tbchigi

Thlchuris Ericht'ura

womDirofilaria immitis

worm Tochigi

T:helazia callipaeda

wom Yamaguchi¶)chigi

Trcmatodcs (5 cas°s)

Paragom'mus mtyazakL'i

wom Tbchigi

1 2 ‑ ･‑

Metagont'mus yokogawai

egg, worm Kagawa, Tochigi

SchL'slOSOma haemalobium

egg

Kenya

ClonoyICh is sinensis

egg

ChinaCcstodcs (12 cas°s)

DljlhyllobothrL'um nihonkaiense

worm lwate, Tochigi, Saitama, Fukui

0ノ 2 1

Taefula saginata

worm Vietnam, Thai

Spirometra erinaceieuropaei

scrum China or Thai

Tbta1

57

117

also fわund endoscoplCally in the large intestine of a 78‑year

reemerged case ofPlasmodium vivax was reported in 1 992

old male. The reason fわr the endoscoplC examination was toand the number of cases had increased to more than a thou‑screen the patient fわr colon cancer. ln both cases, parasites

sand by 1999 (8).

Amebiasis by Entamoeba histolytica continues to occur

were fわund incidentally.

A larvae of dirofilaria (Dirojilaria immitis) was found in ain Japan. The cause of this disease used be water or foodtumor in the right lung of a 69‑year‑old male farmer. The

contamination by E. histolytica cysts. Currently in Japan,

tumor was removed with an intra‑thorax scope. Diagnosis

Some cases are from forelgn countries, but some are domes‑

was made after the operatiod.

tic･ We have encountered domestic amebiasis in hospitals fb∫

The larva of Thelazia callipaeda (three males and six

the elderly and in homosexual men.

females) Were found in a hospital in Yamaguchi Prefecture.

The opportunity fわr the diagnosis of parasitic diseases byThe larva were removed &om the eye of a 77‑year‑old female

fecal examination is very rare. Among 57 cases of parasitic

who was an in‑patient in the hospital. This nematoda usuallydiseases, only four cases were diagnosed by fecal examina‑

infests dogs'eyes and is transmitted together with Amiotation. Cysts of Giardia lamblia were found in a female whospp. (small nies, Japanese name "mematoi"). Human cases

had worked in Rumania as a nurse. Blastocystis hominis wasof T callipaeda are reported mainly ln Western Parts Of

found by a routine fecal examination of a woman who had

Japan, because Amiota spp. are distributed in westem parts

worked in a hospitalas a cook. The eggs ofM. yokogawaiof Japan.

were found in a boy who had no symptoms. Clonorchis sinensis

Nine cases of malaria were all imported from forelgn

eggs were found in a Chinese woman who had immlgratedcountries. These involved Japanese people who had traveled

to Japan.

to tropical areas and forelgn laborers, students, and theirConsultations involving entomologlCal cases are listed

family members from tropical areas. More than ten million
Japanese (about lO% of the Japanes.e population) travel
abroad, and three million fbrelgnerS VISit Japan every year.

in Table 2. All of these cases were domestic. Tick bites andcentipede bites were occumd in people who had worked inforests or fields. A pubic louse, a sexually transmissible insect,

We cammot prevent malaria at the airports because of the latency

was fわund in a 42‑yeaト01d man through prostitution. A caseperiod and the incidence ofrelapse of this disease. Even in aof scabiasis (due to Sarcoptes scabiei) Occurred in an old

clinic in a rural area of Japan, it is possible to encounter aman who was an in‑patient in a hospital for elderly persons.

patient with malaria. Although we eradicated domestic malaria

Fortunately, this infection did not spread to any of the othercases by 1962, some Anophline mosqultOeS, Anopheles

patients in the hospital･ A bethylid wasp (Scleroder77㌢S

sinensis, An･ minimus, An. saperoi, An. omorii, still surviven如'onicus) stung a､ 68‑year‑Old fbmale and caPsed dermatltlS;in the rural areaP of Japan (6,7)･ If the number of malaria

the wasp was sent by the clinic that adminlStered medical

parasite‑carriers Increases, the transmission of malaria might

treatment.

occur in Japan by these vector mosquitoes. In Korea, one

Besides these patient consultations, we have received samples

149

Table 2･ List ofarthropods reported to the Department of Medical Zoology, Jichi Medical School,Japan (January I 996 ‑ Deccmbcr 2000)
Common Name (Scientific Name)

tickNo.or Japancsc

Place orCas°s Domestic lmportcd

Infection

Tbchigi, Shizuoka

22111

2 2 1 ▲‑ ▲‑ccntipcdc

Tochigi, Hyogo

pubic louse (Plhirus pubis)

Hokkai do

Crustcd scabies (Swcoples scabiet')

Tochigibcthylid wasp (Sclerodermus nL'jPOnt'cus)

Gifu
0of bees ( Vespa simillima xanthoptera), mosquitoes (An･04. Dubinsky, P., Akao, N., Reiterova, 良. and Konakova, G･si?ensis), chironomid larva, ny larva (Sarcophaga spp.), ticks,(2000): Comparison of the sensitive screening kit withmlteS (Balaustium spp.), earthworms, rice weevil (Triboliumtwo ELISA sets fわr detection of anti‑Tbxocara antibodies.

spp･), and other such insect samples･ Thes.e insects are not

Southeast Asian ∫. Trop. Med. Public Health, 31, 394‑

listed in Table 2 because they did not cause lnJury･398.
5. Sakai, 良., Kawashima, H., Shibui, H., Kamata, K.,

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