6) Clostridioides (Clostridium) difficile infection
Clostridioides (Clostridium) difficile is a spore-forming gram-positive anaerobic bacillus that colonizes the
intestines of about 10% of healthy adults.[3] CDI is a major healthcare-associated infection that causes diarrhea at
hospitals and long-term care facilities for the elderly. In addition, CDI has been recognized as a cause of diarrhea
even in the community.[4]
Observational studies in Japan indicate that the CDI incidence rate in Japan is 0.8-4.7 cases per 10,000 patient
days, while prevalence is 0.3-5.5 cases per 1,000 admissions.[5] In a multi-institutional prospective study (20
wards at 12 institutions) using toxigenic cultures and nucleic acid amplification tests (NAAT), the CDI incidence
rate was 7.4 cases per 10,000 patient days, rising to 22.2 in ICU wards, suggesting that the incidence rate is higher
than indicated by existing reports, with a particularly high risk in ICU wards.[6] CDI surveillance was launched
in 2019 via Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE).
A 2019 J-SIPHE report on inpatients (all wards at 276 facilities: 253 facilities using immunochromatographic
toxin tests, 3 facilities using NAAT testing, and 20 other facilities) found that the CDI incidence rate was 1.38
(IQR: 0.56-2.43) per 10,000 inpatient-days.
In comparisons with other countries, consideration must be given to the impact of such factors as survey subjects,
specimen collection methods, testing methods, the definition of recurrence, and differences in the average length
of admission.
Additional reference
Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE). Annual Report, 2019.

7) Status of health care associated infection
Source: Japan Nosocomial Infections Surveillance (JANIS)
The number of medical institutions participating in the surgical site infection (SSI) division of JANIS has more
than doubled over the past seven years. In 2018, among 305,960 surgical operations undertaken at 802 institutions,
SSI were reported in 15,566 cases (5.1%). The number of reported SSI declined from 2012 during the observed
period.
In the intensive care unit (ICU) division of JANIS, the incidence of infection by ventilator-associated pneumonia
has been 1.3-1.7 per 1,000 days of ICU stay over the past seven years, with a figure of 1.3 per 1,000 days of ICU
stay recorded in 2018. While the incidence of urinary tract infection is around 0.5-0.8 per 1,000 days of ICU stay,
the figure has shown a slight rise since 2016. Meanwhile, the incidence of catheter related bloodstream infection
is around 0.6-0.8 per 1,000 days of ICU stay, but the figure has declined somewhat since 2017. JANIS monitors
cases of infections that occurred between 48 hours after admission to ICU and discharge from ICU.
i. Surgical site infection
Table 35. The trend of reported SSI cases
Total SSI cases per total
surgical operations (%)*
Participated medical
institutions
Total surgical operations
Total SSI cases

2011

2012

2013

2014

2015

2016

2017

2018

6.0

6.8

6.5

6.0

5.8

5.7

5.4

5.1

333

363

442

552

671

730

772

802

127,731

129,825

161,077

207,244

251,832

274,132

292,031

305,960

7,719

8,771

10,445

12,508

14,701

15,674

15,889

15,566

* Total SSI cases per total surgical operations (%) = (Total SSI cases at medical facilities participated in JANIS) / (Total surgical operations
at medical facilities participated in JANIS) times 100
Prepared from annual reports of the SSI division, JANIS.[7]

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