Development of Outbreak Investigation Database for hospital Infections

1
Development of Outbreak Investigation Database
for hospital Infections

• Osaka University,
• Faculty of Medicine, JAPAN
• Kiyoko Makimoto, Ph.D., MPH

2
What are hospital infections?

• Two types of infections you find in the hospital
• Hospital-acquired infections
• Community-acquired infections
• How can we distinguish them?
• By latency period
• CDC definition for NIs development of infections
  after 48 hours of admission

3
Brief history of hospital infections

• First well documented hospital infections
• In the middle of 1800 Lying-in Hospital in Vienna
  
• Maternal mortality rates exceeded 10, mainly due
  to puerperal fever (child-bed fever) endemic
• Modern epidemiology of hospital infections
• In 1950s, Staphylococcus aureus infection
  outbreaks in hospitals all over the world
• Advances in 1970
• Intensive research in the 1990s

4
What kinds of hospital infections exit?

• Device-related
• Blood stream infections (BSI)
• Urinary tract infections (UTI)
• Ventilator-associated pneumonia (VAP)
• Procedure-related
• Surgical site infections (SSI)
• Environmental contamination
• Water, disinfectant, etc.

5
Devices and procedures as major sources of
hospital infections
Changes in flora due to antibiotic therapy
20-25
Others 20
Respirators
Cross-infections 20-40
Arterial/venous catheters
Surgeries
Patients own flora 40-60
Urinary catheters
6
Why do we need to study hospital infections?

• Not all hospital infections are preventable,
  but they are associated with
• Excess length of hospital stay
• Excess cost
• Excess mortality
• Law suits

7
Distribution of hospital infections by sites,
SENIC study
8
Increases in the mean length of hospital stay due
to hospital infections in the U.S. , SENIC study
9
Excess cost of hospitalization due to hospital
infections in the U.S., 1992
10
Who are at risk for acquiring hospital infections?

• Patients in Intensive Care Units
• ICU (medical, surgical, burn, Neonatal
  ICU?Pediatric ICU)
• Surgery department
• Immunocompromised patients
• Cancer treatment, transplant, HIV infections
• Other factors
• Age, smoking, chronic diseases

11
Distribution of hospital infections by infection
sites and endemic/outbreak status
Endemic
Outbreak
12
Why do we need an outbreak investigation database?

• Literature search is considered essential for
  outbreak investigation
• Difficulty in collecting relevant articles in
  hospitals with limited resources
• Shortage of health care workers trained in
  epidemiology in Japan
• Epidemiology of hospital infections is not taught
  in school

13
Conducting Medline search

• Medline search yielded gt600 articles between 1970
  and 2000
• Only a small number of outbreak investigations
  reported all the information necessary to
  replicate the investigation
• Recent investigations tend to focus on DNA typing
  to identify epidemic strains

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What kinds of outbreaks have been reported?

• The largest number of people affected
• Norwalk-like virus affected 635 employees (27
  attack rate), 79 people affected in a single day
• Am J Epidemiol. 1988 Jun127(6)1261-71.
• The longest duration
• gt 10 years of unrecognized hospital transmission
  of legionnaires' disease among transplant
  patients (25 cases)
• Infect-Control-Hosp-Epidemiol. 1998 Dec
  19(12) 898-904

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Continued

• Unusual source of outbreak
• Klebsiella pneumoniae producing ESBL transmitted
  by gel used for ultrasonography
• 2 adults and 1 neonates were infected 5
  colonized
• J-Clin-Microbiol. 1998 May 36(5) 1357-60
• Outbreak due to non-infectious origin
• Hemolysis (discolored, pink serum visualized in
  spun serum sample) due to defect products (30
  cases in 11 days)
• Kidney-Int. 2000 Apr 57(4) 1668-74

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What kinds of fields do we need?

• Hospital size
• No. of patient affected
• No. of deaths
• Detail investigation process
• Infection control and prevention strategies

• Mode of transmission
• Pathogens
• Type of investigation
• Place (NICU, ICU, surgery, etc.)
• Country
• Author

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Usefulness of the Database I

• A learning tool for epidemiologic and
  microbiologic investigations
• Specific pathogens to look for in certain
  symptoms
• Guide epidemiologic investigations
• Identify study design in similar situations
• Types of information to collect

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Epidemiologic skills required in complex
investigations

• Case definition
• Able to learn how to write a case definition to
  find cases
• Selection of controls in case-control studies
• Selection of controls is the most difficult part

19
Usefulness of the Database II

• Provide infection prevention strategies by
• pathogens
• type of service
• infectious diseases
• mode of transmission, etc.

20
Searching by Pathogens Acinetobacter
baumannii
21
Any impacts of the database on Japanese culture?

• Very few Japanese professionals report outbreak
  investigations
• Reporting outbreaks to professional journals as
  professional and social obligation
• Providing information in sufficient detail to
  help investigations

22
Challenges

• Currently 220 records have been entered
• Changes in hospital practices affecting the
  outbreak investigation
• Funding is necessary to complete and keep
  updating outbreak database

23
Changes in hospital practices

• Factors related to patients
• Shorter hospital stay
• Increased patients acuity
• Increases in intra- and inter-hospital transfer
• Factors related to health care workers
• High turnover of nurses
• Floating shift
• Employment of temporary staff

24
Your comments are greatly appreciate it

• URL for the outbreak investigation database
• http//health-db.net/infection/index.asp