N

   

Hospital infection Control

n

Nosocomial infections (hospital –acquired infection):

An infection acquired in [a] hospital by a patient who 

was admitted for a reason other than that infection.

OR: 

An infection occurring in a patient in a hospital or 

other health care facility in whom the infection was 

not present or incubating at the time of admission. 

N

As a general timeline, infections occurring more than 48

hours after admission are usually considered nosocomial.

Frequency of infection:

Nosocomial infection occurs worldwide and affects both 

developed and poor countries. 

According to studies conducted by WHO, 8.7% of 

hospitalized  patients had nosocomial infection.

Factors influencing the development of nosocomial infection:

1-The microbial agents and antibiotic-resistance ability:   -Patients are exposed to a variety of microorganisms       during a hospital stay:    A- Endogenous microbes: Part of a patient’s own flora.

    B- Exogenous microbes:           -Patients, and Visitors.            -Medical staff (doctor, nurse, physiotherapist, technician).            -Instruments (Endoscopy, catheter, surgical instruments)            -Fluids, blood, or food.            -Dust, and Insect bite.  

N

Hospital-dwelling microbes:Bacteria:

Staphylococcus aureus (MRSA), coagulase-negative 

Staphylococci, Enterococci (VRE), and Enterobacteriaceae 

species.

Viruses:Hepatitis B and C, Rotaviruses, and Enteroviruses.

Fungi:Candida albicans.

N

Hospital-dwelling bacteria could develop antibiotics 

resistance ability due to conjugation process.

Conjugation: Transfer of bacterial plasmid from one 

bacterium to another by sex pili.

Plasmid: Extracircular supercoiled DNA that carry some 

important gene such as the reporter genes (CAT gene) .

N

2 .Patient susceptibility :Important patient factors influencing acquisition of infection are:

1-Age : infancy and old age .2-Immune status :

chronic diseases like malignant tumor, diabetes, renal failure immunosuppressive therapy and AIDS.

3-Underlying disease : injuries to skin (burn, wound), ischemia.

4-Malnutrition.5-Diagnostic and therapeutic interventions :

biopsies, catheterization, I.V. cannulation, endoscopic examination, 

incubation/ventilation.

n

3 .Environmental Factors:- Different factors play a role in establishment of

Nosocomial infections: 1-Crowded conditions.

2-Frequent transfer of patients from one unit to another.

3-Concentration of susceptible patients :

( newborn infants, burn patient, intensive care.)

4-Microbial flora may contaminate objects, devices that may come in susceptible site of the patient.

Sources of Hospital-acquired Infections:Nimer   

CONTAMINATED HOSPITAL ENVIRONMENT

Instruments, Fluids, Food, Air, Medications

Patient Normal flora

Cutaneous, GIT, Genitourinary,

Respiratory

Invasive medical devices : Iatrogenic

Urinary Catheter, Intravenous catheter, Endotracheal tubes,

Endoscopes

Medical Personnel: Colonized, Infected, Transient, Carriers.

Plasmid transfer

Common Nosocomial Infections:1 .Urinary tract infections (UTI):

This is the most common nosocomial infection it account for 40 % of hospital acquired infections; 80% of infections are associated with the use of an indwelling catheter.

Organisms :

E.coli, multi-resistant Klebsiella, Pseudomonas aeruginosa,

Enterobacter and Candida albicans .Source:

Endogenous flora or exogenous from other patients, health 

care provider, instrument, etc.

N

Diagnosis:

positive urine culture (1 or 2 species) with at least 105

bacteria/ ml, with or without clinical symptoms.Prevention:

1-Remove the indwelling urinary catheter as soon as possible .

2-Use aseptic  technique for inserting or manipulating the catheter.

3-Maintain an unobstructed urinary flow.4-Ensure that the patient is taking sufficient amount of fluids

per day (3-4 L).5-Give proper antibiotic therapy for proper course.

N

2.Nosocomial Pneumonia:

Nosocomial pneumonia is the second most common 

nosocomial infection accounting for 15 % of all nosocomial 

infections .

It is associated with mortality rates that range from

20-50% .

It occurs in several patient groups, the most important are 

patients on ventilator in intensive care units (ICU), where 

the Incidence rate of pneumonia is 3% per day .

N

Organisms:

Staph aureus, Pseudomonas , Enterobacter, Klebsiella

pneumoniae, Candida albicans and Haemophilus

influenzae.

Source: endogenous from upper air way, and exogenous 

from contaminated respiratory equipment, patients, 

visitors, etc.

Diagnosis: isolation of microbe from clinical specimens, 

                    and presence of signs and symptoms of infect. 

n

Prevention:

1-Wear gloves; for contact with respiratory    

    secretions.

2-Wash hands after contact with respiratory secretions, 

    even if gloves have been worn.

3-Maintain open airway.

4-Isolate patient with potentially transferred

    respiratory infections.

N

Other hospital-acquired infections:

1-Surgical site infections: Staphylococcus aureus,    

Staphylococcus epidermidis (Intravenous catheter).

2-Nosocomial Bacteremia.

3-Skin and soft tissue infections: 

    Open sores (ulcers, burns and bedsores).

4-Gastroenteritis :    The most common nosocomial infection in the children,      where rotavirus is a chief pathogen.

N

5-Nosocomial Bloodborne diseases:    A-Hepatitis B virus:        -Transmission rate was 25%, reduced due to            application of vaccination, the practice of not           recapping needle, and Hepatitis B surface antigen           screening test.

  B-Hepatitis C: Rate is 3%.       Anti-viral drugs at first 8 hrs reduce the infection by        60%.  

  C-HIV: Rate is 0.3%   

Infection Control :

-Biological safety precautions.

-Hand hygiene.

-Clean & contaminated area.

-Management of blood & body fluid spillage.

-Immunization of health care workers.

-Post exposure management for health care 

   workers. 

Biological safety precautions:

1-All clinical specimens should be considered as 

   potentially hazardous.

2-Wear Lab coat, gloves, shoes (Protective purpose).

3- Remove gloves when using the telephone or   

     photocopier.

4- Skin cuts on the hands, must be covered with a 

     waterproof dressing prior to start working. 

n

5-Never perform any action which may bring your hands 

    into contact with your face, eyes or mouth, such as 

     eating, smoking or adjusting contact lenses.

6-Remove laboratory coat and 

   gloves and wash hands

before leaving your 

    working area.

Hand hygiene:

When Do We Need to Wash Our Hands?-Before eating-Before starting work-Before and after any patient contact-After contact with potentially contaminated materials like   blood, urine, CSF.

-Before wearing gloves.-After removing gloves.-Before and after performing any medical procedure-Before leaving work.

When Do We Need to Wash Our Hands?N

Types of Hand Hygiene (Decontamination):

1-Routine care (minimal): -Hand washing with non antiseptic soap. -Or quick hygienic hand disinfection by rubbing with alcoholic      solution.2-Antiseptic hand cleaning (moderate) – aseptic care of infected patients: -Hygienic hand washing with antiseptic soap. -Quick hand disinfection by rubbing with alcoholic solution.

3-Surgical scrub (surgical care):Surgical hand and forearm washing with antiseptic soap and sufficient time and duration of contact (3 – 5 minutes).

Clean & contaminated area:

Control of spreading of infection could be achieved by classifying hospital environment into one of four zones:Zone A: no patient contact. Normal  cleaning.

( e.g. administration, library.)

Zone B: Care of patients, who are not infected and not highly susceptible. Wet disinfection with detergent.

Zone C: infected patients (isolation wards) . Clean with a detergent/disinfectant solution ,

with separate cleaning equipment for each room.

N

Zone D: High–susceptible patient (protective isolation) or                protected areas such as:                          Operating room, delivery rooms, intensive care              units, premature baby units, and haemodialysis              unit. 

        -Clean using a detergent/disinfectant solution and          separate cleaning equipment.

Blood and body fluid spillage, and contaminationmanagement :

PURPOSE: To protect healthcare workers, patients and 

visitors from unnecessary exposures to bloodborne 

pathogens and other potentially infectious body fluids.

Three types:

1-Low grade disinfection:

    Quaternary ammonium: Bactericidal effect.

     used for low amount- blood spillage.

N

2-Intermediate grade disinfection:    Phenol and 70-90% alcohol ;Bactericidal and     Virucidal effect.     Used for low amount -blood spillage (less than 50ml).

3-High grade disinfection:    Formaldehyde ,Glutaraldehyde, Sodium hydrochlorite    , and hydrogen peroxide.    : Sporicidal ,Mycobactericidal, Fungicidal, and        bactericidal effect.     Used for: high blood spillage (more than 50ml), and                       fungal decontamination.

NOSOCOMIAL INFECTION SURVEILLANCE:

The development of a surveillance is an essential first step 

to identify local problems , and evaluate the effectiveness 

of the infection control activity.

Objectives:

The purpose of surveillance program is to detect, record,

and report hospital acquired infection aiming to reduce

them and their costs.

N

2 .Strategy of Surveillance :A surveillance system must meet the following criteria:Simplicity: to minimize costs and work load, and promote

unit participation by feedback.Flexibility: to allow changes when appropriate.

Acceptability: Evaluated by ICC according to data analysis .

Consistency: use standardized definitions and methodology

Sensitivity .Specificity.

Infection Control Committee:

1-Management2-Epidemiologist                              3-Physicians

4-Other health care workers(Laboratory, or Nurse).5-Clinical microbiologist                  6-Pharmacy

7-Central supply                               8-Maintenance

Tasks (most important) of the committee -To review and approve a yearly program of activity

for surveillance and prevention.-To review epidemiological surveillance data and identify

areas for intervention.

Role of the physician:1-Direct patient care using practices which minimize

infection.2-Appropriate practice of hygiene:

( hand washing, and isolation.)3-Supporting the infection control team.

4-Protecting their own patients from other infected patients and from hospital staff who may be infected.

5-Obtaining appropriate microbiological specimens when an infection is present or suspected.