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

Laboratory and Epidemiology Communications

Isolation of Influenza C Virus during the 1 999/2000 ‑ Influenza Season
in Hiroshima Prefecture, Japan
Shinichi Takao*, Yoko MatsuzakiI , Yukie Shimazu, Shinji Fukuda,
Masahiro Noda and Shizuyo Tbkumoto
Division of Microbiology II, Hiroshima Prefectural Institute of Health and EnviylDnment,
Minami‑machi Il6‑29, Minami‑ku, Hiroshima 734‑0007 andJDepartment ofBacleriology, Yamagata UniversiOJ School of Medicine,Iida‑Nishi 2‑2‑2, Yamagata 990‑9585

Communicated by Hiroo lnouye(Accepted August 16, 2000)

Althoughinfluenza C virus is considered to be an etiologicalVimses were isolated by uslng MDCK cells andノor 7‑day‑agent formi1d upper respiratory illness in humans (1), it ca.n

old embryonated hen's eggs (Table). In MDCK cells, thealso?ause lower resplratOry tract infection (2)･ Seroepidem1‑

viruses produced only weak cytopathic effects sand grew very

010glCal studies have revealed that the virus is prevalentslowly. Several passages were necessary to attain a hemag‑

worldwide and that infection occurs at an early stage in life(3,4)･ Howe.ver･ there is little information regarding its
epidemiologlCal and clinical features because the virus has

only occasionally been isolated (2,5,6). According to theInfectious Agents Surveillance Report in Japan, while 5,699
innueTza A(HIN 1 )virus isolates, 12,822 innuenzaA(H3N2)
virus isolates and 5,232 influenza B virus isolates werereported in 1991‑1996 in Japan, only 18 isolates ofinnuenza
C virus were reported during the same period (7). In thispaper, We report eight isolated cases of influenza C virus fromthe 1 999/2000 ‑ influenza season in Hiroshima Prefecture,Japan.

From November 1999 to March 2000, viruses were isolated
from 257 of 667 clinical specimens (throat swabs andnasopharyngeal aspirates), most of which were collectedfrom

pediatriC patients with acute resplratOry illness in Hiroshima
Prefecture. Of these, I 58 were influenza A(H3N2) virus, 79
influen.za A(HINl) virus, 1 influenza Bvirus, 9 †ere

adenovlruSeS Of different serotypes, 5 were coxsackievlruStype 4, 1 was herpes simplex virus type 1, and 8 (0.2%) wereinnuenza C virus.Asshown in Figure and Table, the cases ofinnuenza C virus had no relationship in terms of their locationor the time of collection, i.e., they were sporadic infections.

Table. Characterization of the patientswithisolated innuenza C virus during the I 999/2000 ‑ innuenza season in Hiroshima Prefecture

np:Eebnet, Sex (yea,IAeonth) Speci‑en s｡ecimDeantec.oliecti｡n Clinical Sy‑ptoms influeCuoadecnvaimrues?sf.labs
12 つJ 4M

ly5mthroatMM6yM

14yswabDec. 2, 1999

fever, upper respiratory illness, rash,

C/H i roshima/29 0/99

myelodysplastic syndrome(C/H/2 90/9 9)
C/H/252/2000

9m

throatswab

Dec. 21, 1999

fever (39oC), bronchitis, rhinorrhea

lmthroatswab

Jam. 24, 2000

fever (40oC), bronchitis

C/H/24 8/2 000

throatswab

Feb. 21, 2000

fever (40oC), upper respiratory illness,

C/H/249/2 000

swab

Feゎ. 23, 2000

fever (38.4oC), upper respiratory illness,Omrhino汀hea
5 ▲U 7 00

MlyMMF

C/H/246/2 000

2mthroat3ylm

throatswabFeゎ. 28, 2000

fever(3 8oC), upper respiratory illness

C/H/24 7/2 000

5mthroatswab

Mar. 8, 2000

fever (40.3oC), bronchitis, rhinorrhea

C/H/25 1 /2000

swab

Mar. 28, 2000

fever (39oC), bronchitis

C/H/2 5 0/2 000

3y3y2mthroat

M: male, F: female*Corresponding author: takao@urban.ne.jp173Jpn. J. Infect. Dis., 53, 2000
influenza C virus infection in children. J. Pediatr., I 18,

glutination (HA) titer over 4 units/25 LEI. Hemagglutination
inhibition (HAI) and indirect immunofluorescence tePts by235‑238.

3. Homma, M., Ohyama, S. and Katagiri, S. (1982): Age
distribution of the antibody totype C innuenza virus.
Microbiol. Immuno1., 26, 639‑642.

uslng anti‑C/Yamagata/8/89 resulted in the identificat10n Of
eight influenza C virus isolates. The results were confirmed

by RT‑PCR assay uslng influenza C virus HA gene‑specific

4. Chakraverty, P. (1 978): Antigenic relationship between
influenza C viruses. Arch. Viro1., 58, 341‑348.
5. Ohyama, S., Adachi, K., Sugawara, K., Hongo, S"NishimTra, H･, Kitame, F･ and Nakamura, K･ (1992):

primers (8). Among the eight isolates, seven were analyzed
for antlgenic characteristics with a set of monoclonal anti‑
bodies raised agalnSt hemagglutinin‑esterase glycoproteins(9)･ It †as found that the isolates could be divided into two

AntigenlC and geneticanalysis of eight innuenza C strains

antigenlC groups: One Similar to C/Yamagata/26/8 1 (9) that

included C/H/290/99, C/H/247/2000, C/H/248/2000, and C/

isolated in various areas of Japan during 1985‑9.

Hノ249/2000, and the other that included C/H/246/2000, C/H/Epidemiol. Infect., 108, 353‑365.

250/2000, and C/H/25 1/2000. The data suggested that at least

6. Chakraverty, P. and Matthews, R. S. (1994): Detection

two antlgenically different influenza C viruses circulatedof influenza C virus in the United Kingdom. Eur. J. Clin.

Microbiol. Infect. Dis., 13, 622‑624.

during the 1999/2000 ‑ influenza season in Hiroshima Pre‑

7. Editorial Committee of Infectious Agents Surveillance
Report (1 997): Isolation/detection of virus from humanfecture. A similar phenomenon was reported from Yamagata
City fbr仇e years 1988‑1990 (9). As the vims may circulate
throughout the year (2), we are cu汀ently investigating thesources, by year, Japan, 1991‑1996. Jpn. ∫. Med. S°i.

occurrence of the virus in non‑influenza seasons.

Bio1., 50 (suppl.), Sll1‑112.

8. Zhang, W. and Evans, D. H. (1991): Detection andidentification of humaninfluerLZa Virus by the polymerase

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Laboratory and Epidemiology Communications

Outbreaks of Heat Stable Enterotoxin‑Produclng Escherichia coli 0 1 69
in the Kinki District in Japan: Genotypic Comparison by Pulsed‑Field
Gel Electrophoresis oHsolates丘om Two Ou他reaks in 2000

with Isolates from Four Outbreaks in 1997‑1998
Kokichi Hamada*, Tomohiro Oshibe, Hidetaka Tsuji, Satoshi Yoshidal and Yoshinari Aokil
Division ofMicy10biology, Hyogo Prefectural Institute of Public Health,Arata‑cho 211129, Hyogo‑ku, Kobe 652‑0032 andJDepartment ofPyleVentive Health, Nara Prefectural Institute for Public Health,
Omori‑cho 57‑6, Nara 630‑8131
Communicated by Shinsaku lmashuku(Accepted September 1 1 , 2000)

An outbreak of enterotoxigenic Escherichia coli serotype

Hyogo Prefecture in May (case E). Two hundredand sixty‑six

0169:H41 infection was first reported in Japan in 1991 (1,2)･

persons among three package‑tour groups from neighboring

Prefectures ate a Japanese‑Style box lunch prepared by a hotelnear the site of the exposition. About half of the members

From June 1997 to August 1998, we investigated fわuroutbreaks (cases A‑D) due to the same organism in Hyogoand neighboring Prefectures (3). In 2000, two more outbreaks( 1 2 1 persons) experienced watery dia血ea an〟or abdominaloccurred.

pain. We identified E. coli O169:H41 in fecal specimens from22 patients and from one of 19 cooks at the hotel. The otherOne ou也reak occu汀ed at the lntemational Gardening andLandscaplng Exhibition Japan Flora 2000 at Awaji Island inou他reak occu汀ed in April 2000 in a refbmatory in Nara

Prefecture (case F)･ Seventy‑three of 88 boys aged 1 6‑20 yers
*Corresponding author: Fax: +8 1‑78‑53 1‑7080

became ill with symptoms including diarrhea, abdominal paln,

174