Jpn. J. Infect. Dis., 54, 2001

Laboratory and Epidemiology Communications

Prevalence ofNorwalk Vimses in Southem and Northem Partsof Hiroshima Prefecture, Japan in 2000/200 1 Season
Shinji Fukuda*, Shinichi Takao, Yukie Shimazu and Kazuo Miyazaki
Division of Microbiology II, Hiy10Shima Prefectural InstituteofPublic Health and Environment,
Minami‑machi 1‑6‑29, Minami‑ku, Hiroshima 734‑0007
Communicated by Hiroo lnouye(Accepted August 28, 200 1 )Acute gastroenteritis in winter is caused mainly by vimses
such as Norwalk virus, Sapporo virus, astrovirus, rotavims,and adenoviTs type 40/41 in Japan (1,2)･ Norwalk virus aswell as rotavlruS is the most important agent of viral gastro‑enteritis among pediatric patients (3), and a variation is seenfrom year to yearinthe prevalent types ofNorwalk viruses (4,5).

We report here on the prevalent types of Norwalk vimses inthe southem and northem parts of Hiroshima Prefecture in
the 2000/2001 season.

Seventy‑six stool specimens from pediatric patients withgastroenteritis, excluding those with rotavims, were collectedfrom hospital sentinel stations, SE and SRC, located in thesouthem and northem parts of Hiroshima Prefecture between

October 2000 and May 2001 (Fig. 1) and examined for gastro‑enteritis viruses. The detection ofNorwalk virus genome wascarried out by the method ofRTIPCR with two pnmer sets of

NV81/NV82/SM82 and Yuri22F/R (6). Viral RNA wasextracted from 10% stool suspension in PBS(‑) byusing
TrizoI LS reagent (Life Technologies Inc., Grand Island, N.Y.,

USA)I Twenty10ne amPlicons ofNorwalk virus genomes wFre
directly sequenced･ Phylogenic analysts Was perf♭med uslng

the Clustal W program (7) with 1000 bootstraps, developedby the National lnstitute of Genetics, Center f♭r lnfbmation

Fig. 1. Location ortwo station hospltals,

Biology and DNA Data Bank of Japan (http://www.ddbj.
nig･ac･jp/), usipg 285 base nucleotide sequences from RNA
polymerase reglOn (nucleotide no. 4307 to 459 1 as CambenVellstrain)･ The phylogenic tree was drawn with Tree Explorer

related to OTH‑25 strain (L23830). Similarities of the strains

in SE subset with Camberwell strain were 92.9 to 93.6%.
The strains in SRC subset showed 95.4 to 96. 1% similarities
with OTH‑25 strain･ The difference ofnucleotide sequences

downloaded from its web site (http://evolgen･biol･metro‑u･ac･jp/TE/TE‑man･html)･ Sapporo virus and astrovlruS

genomes were detected uslng RT‑PCR methods employlng

JV33/SR80 (8) and A230/ACl '(9) primers, respectively.
Adenovirus type 40/4 1 was detected by ELISA kit (MeridianDiagnostics lnc., Cincinnati, Ohio, USA).

in the strains of SE subset from Camberwell strain wasrecognized in the first nucleotide position of the codons, andthe observed three amino acid differences were from Proline

to Serine, from lsoleucine to Valine, and from Methionine toValine. The strains of SRC subset were different in the third

Norwalk virus and Sapporo virus were detected from 12(30･0%) and 2, respectively, of40 stool specimens collected

position of the codon from OTH‑25 strain, but no difference

in SE station･ In s氏c station, Norwalk vims, Sapporo virus,astrovirus, and adenovirus type 40/4l were detected from 14

was fわund in amino acid sequences. The prevalent types of(38･9%), 1, 2, and 3, respectively, of36 stool specimens.

Norwalk viruses differed regionally even within Hiroshima

Twenty of2 1 Norwalk virus strains sequenced so far belonged

Prefecture in the 2000/200 1 season.

to genogroup ll and one belonged to genogroup I. As shownin Fig. 2, 7 of 9 Norwalk virus strains in SE station wereREFERENCES

classified as SE subset group which was related to Camberwell

strain (GenBank accession no. AF145896). Eight of 12 strainsfrom SRC station was classified as SRC subset which was

1. National Institute of Infectious Diseases and Infectious

Diseases Control Division, Ministry of Health and Welfare(1998): Viral gastroenteritis of children, Japan, 1993‑*Corresponding author: Tel: +8 I‑82‑2551713 1 , Fax: +8 1 ‑8212521

1998. 19, 248'‑249'.

8642, E‑mail: Sfukuda@hicat.ne.jp

2･ Nakata, S･, Honma, S･, Numata, K.‑K., Kogawa, K., Ukae,

153

Jpn. J. Infect. Dis., 54, 2001
KY‑8 9NorwaJk
Southam pton

Genogroup1 1000

SE363/1/01
DesertShield

SE409/3/0 1

SRC401/2/01
SRC399/2/01
Genogroup II

SRC301/12/00
SRC300/1 2/00

SRC subset

SRC410/4/01
SRC366/1/01

SRC302/1 2/00
SRC368/1/01

OTH‑25TorontoSnowMountain

Melksham
SRC406/3/01

Hawaii
Bristol
Lordsdale
Camben〝ell

SRC369/1/01
SE274/1 2/00

SE216/1 1/00
SE277/1 2/00
SRC367/1 2/00

SE subset

SE217/ll/00
SE276/1 2/00

SRC303/12/00
SE309/1/01
SE304/1 2/00
ト.一･･･.一･･･.一一1

0.05

Fig. 2. Phylogenic tree ofNorwalk viruses detected from stool specimens in two stations. Bootstrap values are indicated atinternal nodes. GenBank accession numbers for reference strains are as follows: KY189, L23828; Norwalk, M87661 ;Southampton, LO74 1 8; Desert Shield, UO4469; Yuri, ABOO9876; OTH‑25, L23830; Mexico, U22498; Toronto, UO2030; SnowMountain, L2383 1 ; Melksham, X8 1 879; Hawaii, UO761 1 ; Bristo一, X7671 6; Lordsdale, X86557; Camberwell, AF145896.

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