ISSN 0915-5813

IASR

Vol. 38 No. 5 (No. 447) May 2017
Infectious Agents Surveillance Reporthttps://www.niid.go.jp/niid/en/iasr-e.html

Clinical manifestation of EHEC cases, according to bacterial
serotype in Japan, 2016 ....................................................................... 89
Food poisoning events attributed to EHEC in Japan, 2016.................. 90
Multi-prefecture food-borne outbreak caused by frozen minced meat
cutlet, October 2016 ............................................................................. 90
Laboratory investigation of a food-borne outbreak caused by frozen
minced meat cutlet contaminated with EHEC O157 VT2, October
2016-Kanagawa Prefecture ................................................................ 91
Food-borne outbreak due to consumption of EHEC
O157-contaminated yukari-seasoned cucumber in Chiba and Tokyo
Prefectures, August 2016 ..................................................................... 92
Epidemiologic investigation of EHEC O157 food poisoning cases in
multiple prefectures attributed to contaminated sugarcane juice
in Okinawa Prefecture, July to August 2016 ...................................... 94
IS-printing analysis of EHEC O157 food poisoning cases in multiple
prefectures attributed to contaminated sugarcane juice-Okinawa
Prefecture ............................................................................................. 95
EHEC O157 outbreak at a barbecue beef restaurant, July 2016Shiga Prefecture................................................................................... 97

National Institute of Infectious Diseases andTuberculosis and Infectious Diseases
Control Division,
Ministry of Health, Labour and Welfare

An outbreak of EHEC O26 infection in a nursery school, August
2016–Nagasaki Prefecture .................................................................. 99
MLVA analysis of EHEC O157, O26 and O111 isolated in Japan,
2016..................................................................................................... 100
PFGE analysis of isolates from geographically dispersed non-O157/
O26/O111 EHEC cases in Japan, 2016 ............................................. 101
Hemolytic uremic syndrome among EHEC-infected patients inJapan, 2016........................................................................................ 102
Bacillary dysentery outbreak in a kindergarten, October 2014
-Kitakyushu City .............................................................................. 103
An adult measles case that developed acute encephalitis during
a business trip to Indonesia, September 2016 .................................. 104
A clinical case of penicilliosis marneffei in a Vietnamese HIV-infectedpatient from whose blood Talaromyces marneffei was detected ...... 105
A norovirus GII.P16-GII.2 variant strain showing atypical
amplification curve in real-time PCR, December 2016 .................... 106
An A(H1N1)pdm2009 isolate with a mutation that affected
detection of drug resistant virus by the allele-specific RT-PCR
method, October 2016-Aichi Prefecture ........................................... 108<THE TOPIC OF THIS MONTH>Enterohemorrhagic Escherichia coli (EHEC) infection, as of April 2017, JapanEnterohemorrhagic Escherichia coli (EHEC) infection is a systemic infection of pathogenic E. coli that produces Verotoxin/
Shiga toxin (VT/Stx) and/or possesses the VT encoding genes. Main signs and symptoms are abdominal pain, watery diarrhea,
and bloody diarrhea. Fever (~38°C) and/or vomiting are occasionally observed. EHEC that produces VT can cause hemolytic
uremic syndrome (HUS) consisting of thrombocytopenia, hemolytic anemia and acute renal failure.
EHEC infection is a category III notifiable infectious disease under the Infectious Diseases Control Law. A physician who hasmade a diagnosis of EHEC infection shall notify the case immediately to a health center (HC). The information is reported from HCs
to the National Epidemiological Surveillance of Infectious Diseases (NESID) system (http://www.nih.go.jp/niid/images/iasr/37/435/
de4351.pdf). When an EHEC infection is notified as food poisoning by a physician or is classified as such by the director of the HC,
the local government investigates the incident and submits the report to the Ministry of Health, Labour and Welfare (MHLW) incompliance with the Food Sanitation Law. Prefectural and municipal public health institutes (PHIs) conduct isolation/identificationof EHEC and serotyping of isolates and typing of VT (VT or the VT gene), and report the laboratory results to NESID (see p. 89 of
this issue). The Department of Bacteriology I of the National Institute of Infectious Diseases (NIID) conducts confirmatory tests
upon request and conducts molecular epidemiology using multiple-locus variable-number tandem-repeat analysis (MLVA) andpulsed-field gel electrophoresis (PFGE) (see pp. 100 & 101 of this issue). NIID’s analysis results are fed back to PHIs and, where
necessary, to the local governments through the National Epidemiological Surveillance of Foodborne Disease (NESFD) system.
Cases notified under NESID system: In 2016, a total of 3,645
EHEC cases were reported. Among them 2,246 were symptomatic andTable 1. Notified cases of EHEC infection
1,399 were asymptomatic (asymptomatic cases are detected during active
Year of diagnosis
No.
(Symptomatic(%)[Jan.1 - Dec.31] Cases*
cases)
surveillance of outbreaks or routine stool specimen screening of food
2007
4,617
(3,083)(67)
handlers) (Table 1). The number of reports peaked in summer as usual
2008
4,329
(2,822)(65)(Fig. 1). Reports from Tokyo, Kanagawa, Osaka, Fukuoka, Chiba and
2009
3,879
(2,602)
(67)
2010
4,135
(2,719)(66)
Saitama Prefectures occupied 41% of all the notified cases (asymptomatic
2011
3,939
(2,659)(68)
cases included). The annual number of reported patients per 100,000
2012
3,770
(2,363)
(63)
2013
4,045
(2,623)(65)
population was highest in Saga (10.2) followed by Aomori (7.4) and
2014
4,156
(2,840)(68)
Nagasaki (6.1) Prefectures (Fig. 2). The notification rates per 100,000
2015
3,568
(2,339)(66)
among 0-4 year old children was highest in Saga and Aomori Prefectures,
2016
3,645
(2,246)(62)

Figure 2. Notification rate of EHEC infection
by prefecture, 2016, JapanAll ages
Symptomatic andasymptomatic cases
per 100,000 population(No. of prefectures)
0.0- (1)1.0- (11)2.0- (25)4.0- (9)8.0- (1)0-4 years of age
Symptomatic andasymptomatic cases
per 100,000 population(No. of prefectures)
0.0- (21)8.0- (7)16.0- (10)32.0- (5)64.0- (4)Figure 1. Weekly number of reported EHEC infection cases, week 1 of 2012 toweek 52 of 2016, Japan500

No. of symptomatic and asymptomatic cases

2017**
204
(126)
(62)
*Including asymptomatic cases**Jan.1-Apr.9(National Epidemiological Surveillance of Infectious Diseases:
as of April 12, 2017)

2012

450

2013
400

2014
350

2015

300

2016

250
200
150
100
50
0
1 3

5

7

9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 Week

Week of diagnosis(National Epidemiological Surveillance of Infectious Diseases: as of April 12, 2017)(National Epidemiological Surveillance of Infectious Diseases: as of April 12, 2017)1′（ 87′）（Continued on page 88′）

IASR Vol. 38 No. 5（May 2017） 2′（ 88′）（THE TOPIC OF THIS MONTH-Continued）

Table 2. Outbreaks of EHEC infection, 2016
No.

Prefecture
/City

1
2
3
4
5
6
7
8
9
10
11
12
13

Saga P.
Shiga P.
Hyogo P.
Okinawa P.
Osaka P.
Osaka P.
Saitama C.
Aomori P.
Saga P.
Nagasaki P.
Nagasaki P.
Ibaraki P.
Fukuoka P.

PeriodJun.5-12
Unknown
Jul.2-13
Foodborne
Jul.16-Sep.23 Person to person
Jul.25-Aug.14 Foodborne*1)
Jul.29-Sep.15 Person to person
Jul.30-Sep.8
Person to person
Aug.5-Sep.22 Person to person
Aug.10-Sep.5 Person to person
Aug.10-Sep.14 Person to person
Aug.12-15
Person to person
Aug.16-22
Person to person
Aug.21-Sep.22 Person to person
Aug.22-Oct.3 Unknown
Aug.28-Oct.14
Foodborne*2)
Aug.27-Sep.4

Chiba P.a)Tokyo
15 Hamamatsu C. Sep.3-12
16 Kanagawa P.b) Oct.12-Nov.7
17 Toyama P.
Dec.8 -Jan.18
14

Suspected routeof infection

Person to person
Foodborne*3)
Unknown

Proportion of symptomatic cases

No. of symptomatic and asymptomatic cases

Figure 3. Age distribution of EHEC infection cases, 2016, Japan
which experienced EHEC outbreaks in nursery schools (Fig. 2). The
100％
500
proportion of symptomatic patients was high in age groups younger than 30
Proportion of symptomatic cases
90
Femaleyears and those 60 years or older, similar to previous years (Fig. 3).
80
400
Male
EHEC was isolated from 61 cases among a total of 96 HUS cases (4.3%
70of symptomatic cases). The O-serogroup was O157 in 51 cases and the toxin
60
300
type was VT2 (VT2 alone or VT1 & VT2) in 47 cases. Among symptomatic
50
cases, HUS was most frequent in 5-9 year olds (8.4%). There were nine fatal
40
200
Femalecases at the time of notification, some of whom were diagnosed by methods
30
Maleother than the bacterial isolation (see p. 102 of this issue).
20
100
10
EHEC isolated by PHIs: In 2016, PHIs reported EHEC from 1,669
00isolations. The figure was considerably less than the number of EHEC cases
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85
reported (n=3,645). The discrepancy was due to the current situation where
4 9 14 19 24 29 34 39 44 49 54 59 64 69 74 79 84
Age group (Years)
many isolates from clinical settings and commercial laboratories are not sent
(National Epidemiological Surveillance of Infectious Diseases:
to PHIs. The most frequently detected O-serogroup was O157 (53%), followed
as of April 12, 2017)by O26 (32%), and O103 (3.6%) (see table in p. 89 of this issue). In 2016, 55%
of O157 isolates were VT1&VT2-positive, while 98% of O26 and 97% of O103 were VT1-positive. Main clinical signs and symptomsof 877 cases, from whom O157 was isolated, were diarrhea (54%), abdominal pain (52%), bloody diarrhea (42%) and fever (22%).
Outbreaks: Among EHEC outbreaks reported by PHIs to NESID in 2016, 17 were outbreaks with ≥10 EHEC-positive cases.
Among them, ten were due to person-to-person transmission in nursery schools (Table 2). Under the Food Sanitation Law, 14
EHEC food poisoning outbreaks with a total of 252 patients (including EHEC isolation negatives) were reported (13 outbreaks with
105 patients in 2013; 25 outbreaks with 766 patients in 2014, and 17 outbreaks with 156 patients in 2015: see p. 90 of this issue).
The main events in 2016 were: (i) O157 outbreak at a barbecue beef restaurant in Shiga Prefecture in July (39 patients) (see p. 97of this issue); (ii) O157 outbreak from July to August among visitors to Okinawa Prefecture (28 patients) attributed to contaminatedsugarcane juice (see pp. 94 & 95 of this issue); (iii) O157 food poisoning in August in nursing homes for the elderly in Chiba andTokyo Prefectures attributed to yukari-seasoned cucumber (84 patients including 10 deaths) (see p. 92 of this issue); and (iv) O157
food poisoning in October caused by frozen minced meat cutlet produced in Shizuoka Prefecture (67 patients) (see pp. 90 & 91 of
this issue).
Department of Bacteriology I, NIID, identified EHEC strains with identical MLVA or PFGE patterns among isolates fromgeographically widely dispersed patients. Though their epidemiological relationship was not established among these sporadic
cases, widespread diffuse EHEC transmission was suggested (see pp. 100 & 101 of this issue).
Prevention and measures to be implemented: In response to food poisoning events caused by raw beef, MHLW revised
the standards of the beef marketed for raw consumption (MHLW notice No. 321, October 2011). Further, upon the detection of
EHEC O157 in the inner part of marketed cattle liver, MHLW banned marketing of cattle liver for raw consumption (notice No. 404
in July 2012). In 2012, in response to the O157 food poisoning outbreaks attributed to contaminated pickles, MHLW revised thehygiene code for processing pickles (Food Safety Inspection notice 1012, No. 1, October 2012). Many food poisoning events attributed
to restaurants occurred in 2016 (Table 2, also see p. 90 of this issue). For preventing EHEC, it is crucial to observe the principles
of proper food hygiene and continue risk communication activities to refrain from eating raw or undercooked meat.
As EHEC establishes infection at a dose as low as ~100 bacteria, it can easily spread from an infected person to anotherdirectly through contact or indirectly through foods or food products. In 2016, EHEC outbreaks continued to occur in large numbers
in nursery schools (Table 2, also see p. 99 of this issue). For preventing such outbreaks, appropriate hygienic practices, such as
routine hand washing and hygiene management at children’s swimming pools, should be implemented (“Infection Control
Guidelines for Nurseries” revised November 2012). When a case of EHEC is detected in households or care facilities, HCs should
ensure that appropriate measures are strictly implemented to prevent further transmission.
(Data based on reports from public health institutes received before April 4, 2017 and references in IASR)
No. ofNo. ofNo. ofFamilial
positives
Reference in IASR
Setting of outbreak Serotype VT type symptomaticconsumers
infection*/examined
cases
䞉䞉䞉
Yes
Nursery school
O26:H11 VT1
2
10 / 96
p.97 of this issue
N.D.
Restaurant
O157:H7 VT1&VT2
39
78
28 / 54䞉䞉䞉Nursery school
O26:H11 VT1
16
35 / 198
Yes
pp.94&95 of this issue
Restaurant
O157:H7 VT2
2855
31 / 42
N.D.
䞉䞉䞉
Nursery school
O26:H11 VT1
13
17 / 140
Yes
䞉䞉䞉
/
Nursery schoolO145:H- VT2
19
31 241Yes䞉䞉䞉
Nursery school
O26:H11 VT1
5
11 / 91Yes
䞉䞉䞉
Nursery school
O157:H7 VT2
65
78 / 291
Yes(11)䞉䞉䞉Nursery school
O157:H7 VT2
1251 / 627
Yes
Nursery school
O26:H11 VT17䞉䞉䞉
15 / 121
Yes
p.99 of this issue
Nursery school
O26:H11 VT125
䞉䞉䞉
13 / 127
Yes
䞉䞉䞉
Nursery school
O157:H7 VT2
13
12 / 177
Yes/
Nursery school
O26:H11 VT118
䞉䞉䞉
56 262
Yes
Nursing homes for
52125
54 / 228No
p.92 of this issue
O157:H7 VT1&VT2
the elderly
32
94
44 / 170
N.D.
䞉䞉䞉
Nursery school
O26:H11 VT1
122 / 64
Yes(8)
pp.90&91 of this issue
Homes, Restaurant
O157:H7 VT267
160
66 / 103Yes䞉䞉䞉
Dormitory
O26:H11 VT1
833 / 168
No

Including 10 or more EHEC-positives, P.: Prefecture, C.: City, N.D.: No data, 䞉䞉䞉: Not applicable because person to person infection was suspected.
*Secondary taransmission within family. Number in ( ) refer to infections from secondary transmission.
a)Includes 10 fatal cases, b) Includes cases in six prefectures (Kanagawa, Tokyo, Chiba, Hiroshima, Akita, and Hyogo)*1) sugarcane juice, *2) yukari-seasoned cucumber, *3) frozen minced meat cutlet

The statistics in this report are based on 1) the data concerning patients and laboratory findings obtained by the National Epidemiological
Surveillance of Infectious Diseases undertaken in compliance with the Law Concerning the Prevention of Infectious Diseases and Medical Care forPatients of Infections, and 2) other data covering various aspects of infectious diseases. The prefectural and municipal health centers and publichealth institutes (PHIs), the Department of Food Safety, the Ministry of Health, Labour and Welfare, and quarantine stations, have provided theabove data.

Infectious Disease Surveillance Center, National Institute of Infectious Diseases
Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, JAPAN Tel (+81-3)5285-1111

病原微生物検出情報 Vol. 38 No. 5（2017. 5） 3 （ 89 ）＜特集関連資料1＞ 腸管出血性大腸菌検出例の血清型別臨床症状, 2016年
Clinical manifestation of EHEC cases, by bacterial serotype in Japan, 2016
（病原微生物検出情報 : 2017年4月12日現在報告数）
臨床症状* Clinical manifestation*
例数
不詳
無症状
発熱
下痢 嘔気嘔吐5)
血便6)
腹痛7) 意識障害8)
脳症9)
HUS10) 腎機能障害11) Cases
6
724
291
746
119
479
655
1
2
17
14
1,669
検出報告総数 Total
O157:H7:VT1
1
4
2
2
5
O157:H7:VT2
2
114
52
128
26
88
122
1
1
6
7
290
O157:H7:VT1&VT2
1
74
95
235
38
198
239
2
3
359
O157:H-:VT1
3
3
3
6
O157:H-:VT2
10
9
20
3
11
17
2
1
33
O157:H-:VT1&VT2
1
20
17
31
7
19
26
55
O157:HNT:VT1
10
2
6
1
4
5
18
O157:HNT:VT2
1
23
8
16
5
16
16
1
45
O157:HNT:VT1&VT2
30
11
29
2
30
30
1
1
71
5
285
194
472
82
368
460
1
1
12
12
882
O157 小計 Subtotal
O26:H11:VT1
1
218
52
148
20
48
90
405
O26:H11:VT1&VT2
3
1
2
1
2
6
O26:H-:VT1
7
4
10
6
8
20
1
O26:H-:VT1&VT2
1
O26:HNT:VT1
61
4
23
3
9
19
95
O26:HNT:VT2
1
1
1
291
61
183
23
64
119
528
O26 小計 Subtotal
O103:H2:VT1
15
6
14
1
3
10
1
1
34
O103:H2:VT1&VT2
1
1
O103:H11:VT1
1
2
2
2
3
4
O103:H25:VT1
1
1
3
1
1
2
O103:H-:VT2
1
1
1
O103:HUT:VT1
3
1
2
1
2
1
5
O103:HNT:VT1
7
5
1
3
12
26
9
27
3
10
19
1
1
60
O103 小計 Subtotal
O121:H19:VT2
11
7
18
7
9
15
2
1
31
O121:H19:VT1&VT2
1
2
1
2
2
O121:H-:VT2
1
1
1
1
1
1
O121:HUT:VT2
1
1
O121:HNT:VT2
2
3
3
2
3
1
1
5
13
12
25
7
13
22
3
2
40
O121 小計 Subtotal
O111:H8:VT1
1
1
1
1
O111:H-:VT1
8
3
9
1
6
6
18
O111:H-:VT1&VT2
2
1
9
4
8
11
O111:HUT:VT1
2
2
O111:HNT:VT1
1
1
3
3
4
13
5
22
1
11
18
36
O111 小計 Subtotal
O145:H-:VT1
3
2
1
3
6
O145:H-:VT2
3
2
5
1
4
4
1
9
O145:H-:VT1&VT2
2
2
O145:HNT:VT2
2
2
10
2
7
1
5
7
1
19
O145 小計 Subtotal
O91:H14:VT1
4
4
1
O91:H14:VT1&VT2
1
O91:H-:VT1
3
3
O91:H-:VT1&VT2
2
2
O91:HUT:VT1
1
1
O91:HNT:VT1
4
4
15
15
O91 小計 Subtotal
1
1
1
1
1
O1:H-:VT2
O2:H27:VT2
1
1
O5:H-:VT1
1
1
3
3
3
O6:HNT:VT2
1
1
O8:H9:VT2
1
1
O8:H12:VT1
1
1
O8:H19:VT2
3
1
1
4
O21:H-:VT1&VT2
1
1
O22:HNT:VT2
1
1
O28ac:H25:VT2
1
1
O55:H12:VT1
2
2
O76:H19:VT1
3
3
O80:H18:VT2
1
1
O84:H-:VT1
1
1
O89:H-:VT2
1
1
O98:H-:VT1
1
1
O113:H21:VT2
2
2
O115:H2:VT1
1
1
O115:H10:VT1
2
1
3
1
3
6
O115:HNT:VT1
1
1
O125:HNT:VT2
1
1
O126:H20:VT1
1
1
O128:H2:VT1
2
2
O128:H2:VT2
1
1
O128:H2:VT1&VT2
4
1
1
5
O130:H11:VT2
1
1
O136:H12:VT2
1
1
O137:H41:VT2
1
1
O146:H-:VT2
1
1
O146:HNT:VT2
1
1
O148:H18:VT2
1
1
O156:H25:VT1
2
1
1
3
1
O156:H25:VT1&VT2
1
O165:HUT:VT1&VT2
1
1
1
1
1
O166:H15:VT2
1
1
O171:H2:VT2
1
1
O174:H2:VT1
1
1
O177:H-:VT1
1
1
O178:H19:VT2
1
1
O179:H8:VT2
1
1
O182:H25:VT1
1
1
O183:H18:VT1
1
1
O186:H36:VT1
1
1
O untypable
21
1
2
2
1
25
UT: Untypable, NT: Not typed, *2つ以上の臨床症状が報告された例を含む。
地方衛生研究所からの「病原体個票」の報告による。
*Includes cases for whom two or more symptoms were reported, 1) no data, 2) no symptoms, 3) fever, 4) diarrhea,
5) nausea/vomiting, 6) bloody diarrhea, 7) abdominal pain, 8) disturbance of consciousness, 9) encephalopathy, 10) hemolytic uremic syndrome, 11) renal failure
血清型 Serotype

1)

2)

3)

4)

(Infectious Agents Surveillance Report: Data based on the reports from public health institutes received before April 12, 2017)

％
100.0
0.3
17.4
21.5
0.4
2.0
3.3
1.1
2.7
4.3
52.8
24.3
0.4
1.2
0.1
5.7
0.1
31.6
2.0
0.1
0.2
0.2
0.1
0.3
0.7
3.6
1.9
0.1
0.1
0.1
0.3
2.4
0.1
1.1
0.7
0.1
0.2
2.2
0.4
0.5
0.1
0.1
1.1
0.2
0.1
0.2
0.1
0.1
0.2
0.9
0.1
0.1
0.2
0.1
0.1
0.1
0.2
0.1
0.1
0.1
0.1
0.2
0.1
0.1
0.1
0.1
0.1
0.1
0.4
0.1
0.1
0.1
0.1
0.1
0.3
0.1
0.1
0.1
0.1
0.1
0.1
0.2
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
1.5