hospital acquired.

1. DEPARTMENT OF MICROBIOLOGY AND
IMMUNOLOGY
HOSPITALACQUIRED INFECTIONS
Presenter: Angel Charles
Facilitator: Dr.M.Majigo

2. OUTLINE
 Introduction
 Epidemiology of Hospital Acquired Infections (HAI)
 Sources and agents of Hospital Acquired Infections
 Difference between HAI and Community acquired
infections
 Common types of Hospital Acquired Infections
 Prevention and control of Hospital Acquired Infections
 Challenges in prevention of HAI

3. HOSPITALACQUIRED INFECTIONS (HAI)
Hospital Acquired Infections refers to infections that occur
during hospitalization but are not present nor incubating upon
hospital admission
 These infections are usually acquired after hospitalization and
manifest 48 hours after admission to the hospital.
 Include infections acquired in the hospital but appearing after
discharge, and occupational infections among HCW
 Nosocomial infections (NCI),health care- associated infections
(HAI)

4. EPIDEMIOLOGY
 More than 1.4 million people worldwide are estimated to suffer
from HAI
 HAIs have increased by 36% in the last 20 years, WHO estimates
that 7% of all patients admitted into healthcare facilities will
acquire at least 1 HAI.
 1 in every 10 affected patients dies of HAI
(WHO 2022)

5. Cont.
REASONS FOR RE-EMERGENCE
 Antibiotic resistance : HCAI becoming more difficult to treat
 Increased numbers of vulnerable patients
 progress in medical management
 increasing day-care & ambulatory care
 Failure of staff to comply with infection control procedures

6. SOURCE OF INFECTIONS
 Endogenous - Patient's own flora
 Exogenous
• Cross infection from medical personnel
• Cross infection from patient to patient
• Hospital environment- inanimate objects
– air -dust
– disinfectants -washbowls
– bedpans - endoscopes
– IV fluids & catheters -water, etc
– ventilators & respiratory equipment

7. Cont.
CHAIN OF TRANSMISSION
EXOGENIOUS SOURCE
• Direct contact b/w patients,
visitors, healthcare staff
• Indirect contact-through
dust, environment,
equipment etc.
• Indwelling equipment most
imp source-urinary or I/V
catheters, ventilators, N/G
tube, etc.

9. AETIOLOGY OF HCAI
Micro-organism Examples
Bacteria
– Enterobacteriaceae
– Pseudomonas aeruginosa
– Acinetobacter baumanni
– Staphylococcus spp
– Mycobacteria turberculosis etc.
Viruses
– Blood borne infections : HBV, HCV, HIV
– Others: CMV, rubella, varicella, SARS etc.
Fungal – Candida
– Aspergillus etc.

10. Comparison between HCls and Community
Acquired Infections
Feature Community acquired
Infection
HAIs
Population
affected
Non-hospitalized patients,
otherwise healthy patients
Usually hospitalized patients,
often have compromised
immunity
Causative
agents
Community acquired pathogens
usually sensitive to most
antibiotics
Often have some antibiotic
resistance
Pathogenes
is
Can develop spontaneously Often associated with invasive
devices and medical
procedures
Mortality Usually low Higher morbidity and mortality

11. TYPES OF HAIs
• These infections include
– Surgical site infections (SSI),
– Catheter Associated Urinary Tract Infections (CA-UTIs),
– Central line-associated bloodstream infections (CLABSI),
– Ventilator-associated pneumonia (VAP),
– Hospital-acquired pneumonia (HAP), and
– Clostridium difficile infections (CDI).

12. SURGICAL SITE INFECTIONS
• Infection of surgical
incision
• Mostly by Staph aureus,
Enterococcus,
Pseudomonas aeruginosa,
E coli, Anaerobes etc.
• Pathogens transmitted by
healthcare staff hands,
dirty equipment, etc

13. Cont.
• Risk of infection dependent upon:
– Contamination level of wound
– Length of time tissues are exposed
– Host resistance

14. PROPHYLACTIC PREOPERATIVE ANTIBIOTICS
• Indicated for clean-contaminated, contaminated operations
• Dirty wounds already infected (therapy)
• Administer at appropriate time
– 30-60 minutes prior to skin incision

15. HOSPITALACQUIRED UTI
• Mostly catheter related
– Enterococcus sp., Pseudomonas
aeruginosa., E coli,
Staphylococcus sp., Candida
spp .
– Multi-drug resistant
• UTIs account for as many as 40–
45% of HAI
• Almost 80% are related to
urethral catheterization

16. Cont.
RISKS FOR UTI
Long duration of catheterization
Colonization of urine bag
Inadequate disinfection
Female gender
Diabetes
Severely ill patients
Immuno-compromised patient

17. HOSPITALACQUIRED RTI
• Ventilator associated, ET intubation
associated
• Pseudomonas aeruginosa, E
coli, Klebsiella spp., Acinetobacter
baumannii, Haemophilus infleunzae,
etc.
• 13-18% of nosocomial infections

18. Cont.
• Early onset (< 4 days of mechanical ventilation)
– Antibiotic sensitive, community organisms
(S. pneumoniae, H. influenzae, S. aureus)
• Late onset (>4 days )
– Antibiotic resistant, nosocomial organisms (MRSA, Ps.
aeruginosa, Acinetobacter spp, Enterobacter spp)

19. RISK FACTORS
Contaminated ventilators
Intubation or NGT
Decreased LOC
Supine position
COPD
Old age

20. NOSOCOMIAL DIARRHEA
• Nosocomial diarrhea is an acute episode of gastroenteritis in a
hospitalized patient that was not present on admission and
arises after ≥3 days of hospitalization (Polage C eta; 2012)
• Risk factors:
The use of broad spectrum antibiotics, Chemotherapy,
radiotherapy, Unhygienic food handling
• Bacterial causes:C.difficile, K.oxytoca
• Viruse:Norovirus,Rotavirus,Torovirus

21. A CENTRAL LINE-ASSOCIATED BLOODSTREAM INFECTION
(CLABSI)
CLABSI: a laboratory-confirmed bloodstream infection not
related to an infection at another site that develops within 48
hours of central line placement.
 Mostly caused by organisms capable of forming biofilm.
Risk Factors:
• Heavy skin colonization at the insertion site
• Duration of placement
• Contamination of the catheter hub
• Immuno supression

22. Nosocomial Bloodstream Infections,
1995-2002
Rank Pathogen Percent
1 Coagulase-negative Staph 31.3%
2 S. aureus 20.2%
3 Enterococci 9.4%
4 Candida spp 9.0%
5 E. coli 5.6%
6 Klebsiella spp 4.8%
7 Pseudomonas aeruginosa 4.3%
8 Enterobacter spp 3.9%
9 Serratia spp 1.7%
10 Acinetobacter spp 1.3%
N= 20,978
Edmond M. SCOPE Project.

23. LABORATORY DIAGNOSIS
• Laboratory testing complements the history and clinical
examination in elucidating the possible source of infection
• Blood profiles (serum creatinine, blood urea, PT, cell count
etc.)
• Obtain samples for culture before initiation of antibiotics.
• Serological and molecular tests can be used.

24. TREATMENT AND MANAGEMENT
• The selection and timing of initiation of antibiotics are critical.
• Empiric antibiotics should be selected based on risk factors for
MDR pathogens and clinical stability of the patients.

25. PREVENTION
 Improving IPC and prophylaxis administration prior surgical
procudures
 Immunisation
 BCG ,Hepatitis B, Tetanus, Rubella,Varicella, Influenza
• Surveillance system for HAIs

26. Cont.
Objectives of surveillance
 Reducing infection rates
 Identifying outbreaks
 Identifying risk factors
 Persuading medical personnel
 Evaluate control measures
 Satisfying regulators
 Document quality of care
 Compare hospitals’ NCI rates

27. CONCLUSIONS
• Preventing HCAI is a very important
aspect of patient safety
• All health care personnel must practise the
highest standards of infection control as
HCAIs
– Cause significant morbidity and mortality to patients and health care
staff
– Contribute to increasing prevalence of antibiotic resistance
– Are difficult and expensive to manage
– Can result in medical litigation