Hospital acquired infection

2. • Infections acquired during hospital care which are
not present at admission.
• Infections occurring more than 48 hours after
admission are usually considered nosocomial.
• Infections acquired by staff or visitors to the hospital
or other health care setting.

3. Criteria to be classified as Nosocomial
Infections
• Not present at time of admission
• Not related to primary disease at time of
hospitalization

4. Special situations considered as
Nosocomial infections
• Infection acquired in hospital becoming
apparent after discharge

5. Special situations NOT considered as
Nosocomial infections
• Infections associated with complication
• Extension of infection already present

6. Impact of Nosocomial infections
• Mortality - ↑ 7 fold
• Patient cost - ↑ 3 fold
• Length of hospital stay - ↑ 11 days

7. Factors influencing development of
HAI
1. Microbial agent
– Characteristics, including resistance to
antimicrobial agents, and amount (inoculum)
of infective material.
2. Patient Susceptibility
– age, immune status, underlying disease, and
diagnostic and therapeutic interventions.

8. 3. Environmental factors
– Patients with infections or carriers – potential
sources of infection.
– Crowding, frequent transfers of patients, and
concentration of highly susceptible patients in
one area
4. Bacterial Resistance

9. Sources of Infection
1. Exogenous
– Other patients, hospital staff, inanimate objects
2. Endogenous
– Patients own flora which at the time of infection
• May invade patients tissues spontaneously
–Surgical procedure
–Nursing care
–Instrumental manipulation

10. MICROORGANISMS
• BACTERIA(Staph. aureus, Strep. pyogenes,
Strep. Pneumoniae, Cl. Tetani, Enterococci, E.
coli, Klebsiella, Pseudomonas)
• VIRUS(Hep B, C, D, HIV, Herpes, CMV)
• Fungi (Aspergilus, Candida)

11. Broad-spectrum antibiotics
• Any antibiotic that acts against a wide range of
disease-causing bacteria
• Used when a bacterial infection is suspected
but the group of bacteria is unknown
• When infection with multiple groups of
bacteria is suspected
• Powerful, broad-spectrum antibiotics pose
specific risks

12. • The development of antimicrobial resistance
• Kill normal flora
• Example of a commonly used broad-spectrum
antibiotic is ampicillin, Azithromycin,
Carbapenems

13. Narrow-spectrum antibiotic
• An antibiotic that is only able to kill or inhibit
limited species of bacteria.
• Examples of narrow-spectrum antibiotics
include vancomycin, penicillin,

14. Advantages
• Narrow-spectrum antibiotic allow to kill or
inhibit only those bacteria species that are
unwanted
• It leaves most of the beneficial bacteria
unaffected, hence minimizing the collateral
damage on the microbiota
• Low chances of bacterial
resistance development