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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Prediction
Low er Prediction Limit
Upper Prediction Limit
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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1.0%
1.5%
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2002 2003 2004 2005 2006 2007
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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