The epidemiology of HAI Scotland

Dr Jacqui ReillyConsultant EpidemiologistHead of HAI and IC Group

Overview

1. Current epidemiology of HAI in Scotland

2. Contribution of the national HAI Prevalence survey of HAI in Scotland in understanding the burden and setting the future direction

3. HAI surveillance in ICU

1. Epidemiology of HAI in Scotland

Figure 1: Run chart of quarterly number of S. aureus bacteraemia in Scotland, 1st April 2005 to 31st March 2008 with HEAT target trajectory to 31st March 2010.

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Quarterly number of S. aureus bacteraemias HEAT target

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HEAT target (30% Reduction)

2005-2006 Rate

Data

SAB HEAT trajectory

Inpatient SSI rate for hip arthroplasty and caesarean sections. 2002 to 2007

SSI

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Hip arthroplasty

Caesarean section

CDAD• HPS mandatory surveillance outputs indicate

around 6000 cases per annum • No trends can be assessed as yet

– there appears to be more in the winter-probably because more antibiotics are prescribed in winter - and

– there is variation in numbers of cases between the NHS boards- although this is less obvious when standardised for the population aged 65 years and over by Health Board

• There have been continuing clusters of cases and reported outbreaks in NHS boards

2. Contribution of the National Prevalence survey of HAI in Scotland for future developments

– baseline information on the total prevalence of HAI in Scottish hospitals

– its burden in terms of health service utilisation and costs

– a consistent methodology which will allow the evaluation of measures taken to reduce the burden of HAI

National prevalence survey of HAI

• Based on best methodologies from international epidemiological studies

• Unique because:– Dedicated team of data collectors

• Independent of hospitals being surveyed• Highly trained in diagnosing HAI• Validated diagnoses throughout study

– Investigated the time of year survey undertaken as a factor affecting HAI prevalence

– Looked at all specialties and all infection types– Sample of non-acute care (first national level

survey in UK)– Collected information on economic burden of HAI

Design of the Survey

What was the overall prevalence of HAI?

• Acute hospitals 9.5% (8.8, 10.2)

• Non-acute hospitals 7.3% (6.0, 8.6)

What type of HAI were found in acute hospitals?

HAI Type Infections N % Bone and Joint Infection 6 0.5 Blood Stream Infection 55 4.4 Central Nervous System Infection 2 0.2 Cardiovascular System Infections 11 0.9 Eye, Ear, Nose, Throat or Mouth Infection 155 12.5 Gastrointestinal Infection 191 15.4 Lower Respiratory Tract Infection other than Pneumonia

139 11.2

Pneumonia 109 8.8 Reproductive System Infections 17 1.4 Systemic Infection 2 0.2 Surgical Site Infection 197 15.9 Skin and Soft Tissue Infection 137 11.0 Urinary Tract Infection 222 17.9 Total 1243 100.0

HAIs prevalence by type in the ICU

Infection Percentage No. patientsBlood Stream 8.6 3

Central Nervous System 2.9 1

Ear Nose Throat 2.9 1

Gastrointestinal 2.9 1

Lower respiratory 25.7 9

Pneumonia 14.3 5

Surgical site 14.3 5

Urinary tract 2.9 1

Multiple 25.7 9

Total 100 35

129 patients surveyed in ICU

Prevalence = 35/129= 27.1%

How did HAI prevalence vary in different acute specialties?

Inpatients with HAI

HAI Prevalence

within specialty

95% CI Specialty

N % Lower Upper Care of the Elderly 199 11.9 10.0 13.7

Dentistry 2 12.5 4.1 20.9 Gynaecology 10 4.8 1.2 8.4 Haematology 8 6.7 2.0 11.3

Medicine 491 9.6 8.5 10.7 Obstetrics 4 0.9 0.0 1.9 Oncology 12 8.8 2.0 15.7

Orthopaedics 105 9.2 7.3 11.1 Other 0 0.0 - -

Psychiatry 9 3.5 0.3 6.7 Surgery 247 11.2 9.5 12.9 Urology 16 6.3 3.0 9.5

Total 1103 9.5 8.8 10.2

Prevalence of HAI by ward type

Which organisms were most prevalent?• CDC definition organism requirement

• Acute hospitals– 540 microbiology reports for 1243 HAI– Most common types: Staph. Aureus, C.diff

Antibiotics

• In acute hospitals 32.1% of inpatients were prescribed one or more antimicrobials

• In ICU patients 69.8% were prescribed an antimicrobial and 70% of those on more than one

What were the most prevalent invasive devices in acute hospitals?

Invasive Device Inpatients Invasive Devices

N % N %

No Device 1868 57.3 - -

Urinary Catheter 660 20.2 660 36.2

Peripheral

Vascular Catheter

(PVC)

987 30.3 1034 56.8

Central Vascular

Catheter (CVC) 104 3.2 112 6.1

Invasive Mechanical

Device 16 0.5 16 0.9

Total 3262 100.0 1822 100.0

Prevalence of device use in the ICU

Device Prevalence (%)

No. of patients

Peripheral Vascular Catheter

96.4 54

Central Venous Catheter 75.0 42

Mechanical Ventilation 69.6 39

Urinary Catheter 82.1 46

Using prevalence results for infection control planning

• The prevalence of HAI in a population of male patients aged 81+ years in a care of the elderly specialty during November to January is:

• Hence α = -2.771+0.156+0.847+0.131+0= -1.637

• Prevalence of HAI = exp (-1.637)/[1+exp (-1.637)]= 0.195/1.195=0.163

 • Thus the prevalence in this group is estimated to be 16.3%

What is the impact of HAI in terms of length of stay on NHS activity?

• Those patients with HAI stay in hospital 70% longer than those without

• Normal LOS varies by specialty: – 3.2 additional days in obstetrics– 13.7 days in care of the elderly

What are the costs associated with HAI in Scotland?

• £183 million per year in Scotland in acute hospitals in Scotland

• Costs by specialty ranged from:– £2 million per year in Obstetrics – £49 million per year in Medicine

How much cost saving might be anticipated as a result of HAI control?

% reduction of HAI Cost Saving £ millions

10 28.3

20 36.6

30 54.9

40 73.2

3. HAI surveillance in ICU

HAI surveillance: elements of a successful system

• Defining what outcomes to measure• Reliably collecting data in a standardised

manner• Analysing data for intra/ inter-hospital

comparisons• Using the data in a timely manner to

improve quality of care

Gaynes & Solomon J Quality Improvement 1996; 22: 457 -467

Trends in ventilator-associated pneumonia (VAP) rates for all 283 intensive care units participating in the German nosocomial infection surveillance system (KISS)

from January 1999 through June 2003.

Infection Control and Hospital Epidemiology 28(3):314–318.

Ventilator-associated PNEU

rate*

No. ICUs

No. of VAP

Ventilator days

Pooled mean

Median

Medical/Surgical ICU

Major Teaching 58 302 84,530 3.6 2.5All Others 99 372 135,546 2.7 1.6

Burn ICU 12 124 10,098 12.3 Not calculated**

Coronary ICU 48 100 35,727 2.8 1.3

Surgical cardiothoracic ICU

48 265 46,710 5.7 4.0

Surgical ICU 61 384 73,205 5.2 4.1

Medical ICU 64 339 109,277 3.1 2.8Trauma ICU 19 329 32,297 10.2 Not calculated**

*Number of VAP X 1000Number of ventilator-days

**For percentile distributions, data from at least 20 locations are required

National Healthcare Safety Network (NHSN) report, data summary for 2006. Am J Infect Control 2007; 35:290-301

Pooled means and median of the distribution of Ventilator Associated Pneumonia rates by ICU

type

Central line-associated BSI

rate*

No. ICUs

No. CLAB

Central Line Days

Pooled

Mean

Median

Medical/Surgical ICU

Major Teaching 63 304 128,502 2.4 1.9All Others 102 431 198,551 2.2 1.0

Burn ICU 14 127 18,612 6.8 Not calculated**

Coronary ICU 53 181 63,941 2.8 2.0

Surgical cardiothoracic ICU

51 150 92,484 1.6 1.2

Surgical ICU 72 378 197,484 2.7 2.0

Medical ICU 73 489 170,719 2.9 2.2Trauma ICU 21 182 39,635 4.6 3.3

* Number of CLAB X 1000 Number of Central Line days**For percentile distributions, data from at least 20 locations are required

National Healthcare Safety Network (NHSN) report, data summary for 2006. Am J Infect Control 2007; 35:290-301

Pooled means and median of the distribution of central line-associated BSI rates by ICU type

During 1990-2004, rates of infections from medical devices decreased

Bloodstream infections from central lines decreased by: 54% in medical ICUs43% in coronary ICUs43% in surgical ICUs27% in paediatric ICUs

Trends of ventilator-associated pneumonia rates were assessed and substantially decreased from 31% to 58% among these same ICU types. 

*These data are derived from CDC′s NNIS and NHSN systems

Role of incidence surveillance in US in Monitoring and Preventing Healthcare-Associated

Infections

Surveillance of :

Ventilator Associated PneumoniaCVC Related Infections

» Blood stream infections» Local CVC Infections» General CVC RI (Clinical sepsis)

Blood Stream Infections (non CVC Related)

At Scottish Level

• Establish a national database of ICUAI surveillance data for Scotland

• To provide a nationally agreed methodology for the collection of ICUAI data in Scotland

• To provide training, protocols and support for data collection in participating units

At the EU Level- To contribute Scottish data to the European ICUAI dataset

Objectives of national surveillance of ICUAI

Timescales

• Data collection for the National surveillance programme will begin in January 2009

• HPS will receive data for reporting in January/February 2010

• The first annual report of Scottish data will be produced in Spring 2010

Summary of the Epidemiology of HAI in Scotland– HAI affects 1 in 10 in acute care at any one time– SSI, GI and UTI are most common in acute care– S. aureus and C. difficile are the most common organisms– VAP, LRTI and bacteraemia are prevalent in ICU– 30% of acute care patients and 70% of ICU patients are

prescribed one or more antimicrobials at any one time– Device, intervention and antimicrobial associated HAI are where

there is the most potential for prevention– Prevalence survey results have informed future SGHD policy for

tackling HAI and underpin the new HAI task force delivery plan• Targeted incidence of HAI surveillance in ICU

– Aligned to Scottish Patient Safety Programme work