Nosocomial Infections: How do they Affect You?

Nosocomial infections are also known as hospital-acquired infection or more generically, healthcare-associated infection. Such infections can be acquired in hospitals, nursing homes, mental homes, rehabilitation facilities, outpatient clinics, diagnostic laboratories or other clinical settings.

Many infectious agents are present in health care settings. Patients may be infected while receiving health care, health care workers may be infected during the course of their duties and other people may be infected when working or interacting with patients in a health care establishment.

In general nosocomial infections are more serious and dangerous than community-acquired infections because the bacteria in hospitals are more virulent and resistant to typical antibiotics.

Nosocomial Infections are defined as infections in which the etiologic agent (causative organism) was acquired in a hospital.
They usually first appear 48 hours or more after hospital admission or within 30 days after discharge. They are a result of treatment in a hospital or a healthcare service unit, but not secondary to the patient's original condition.

Each nosocomial infection adds about 5-10 days to the affected patient's hospital stay.

Nosocomila Infections affect the hospital stay of patients in various ways;
Of the individuals with hospital-acquired bloodstream or lung infections, 40-60% die each year.
Patients with indwelling catheters have a threefold increased chance of dying from urosepsis.
Since antibiotics have come into common usage, bacteria that are resistant to them have also become common, especially in hospitals, so there are now lots of nosocomial infections.

5.7% of hospitalized patient developed a nosocomial infection as a complication of hospitalization and there are about 3.6 – 4.0 million cases per year.

The organisms commonly involved in Urinary Tract Nosocomial Infections include gram negative rods, E. coli, Pseudomonas spp. and others gram positive organisms and Candida spp.

They usually affect patients with advanced age, female gender, severe underlying disease, and placement of urinary catheters as this might introduce the culprit organisms into the urinary tract.

This affect wound sites of surgeries that have been performed. The organisms commonly involved include gram–positive organisms (like Staphylococcus aureus, Enterococci), gram-negative rods and Candida spp.

This affect the respiratory tract but mostly the lungs. It mostly affects patients of advanced age, patients with chronic lung disease and large volume aspirations. Patients who have done chest surgery, patients hospitalized in ICU and intubated are also susceptible.

Common organisms implicated include gram negative rods, S. aureus and Moraxella catarrahlis.

This affects the blood stream and infects it causing bacteraemia (presence of bacteria in the blood). This kind o infection is highly morbid because it can spread through the blood to affect other body organs. Bacteria can enter the bloodstream as a severe complication of infections (like pneumonia or meningitis), during surgery involving mucous membranes such as the gastrointestinal tract, or even due to catheters and other foreign bodies entering the arteries or veins including during intravenous drug abuse.

It mostly affects patients of extreme ages (age < 1 year or > 60 years), malnourished patients, patients undergoing immunosuppressive therapy and patients with loss of skin integrity due to burns and bed sores.

Common organisms implicated include Coagulase negative staphylococci, Enterococci spp. and Staphylococus aureus.

Risk factors associated with Nosocomial Infections include:

1. Age - hospital-acquired infections are commonest at extremes of age (children and the elderly).
2. Sex - Females more affected than males.
3. Duration of stay in the hospital - the longer the hospital stay, the more the chances of getting infected.
4. Susceptibility of patients to infection - this is usually due to underlying illness like cancer and Diabetes Mellitus.
5. Premature birth
6. Hospital procedures like catheterization, inhalation of anaesthetics, intravenous therapy, surgical operation, immunosuppresives.

Hospital-acquired infections can come from different sources. They can be endogenous (from the patient) or exogenous (from external sources outside the patient).

1. Endogenous Source
   Patients' normal flora changes quickly after hospitalization from organisms like Viridans streptococci,saprophytic Neisseria spp and diphtheroids to potentially resistant microorganisms found in the hospital environment.
   
   
2. Exogenous Sources
   This can be from people or inanimate objects.
   • People - the source of infection is usually from other people which can be:
     • Members of the hospital staff.
     • Other patients who may be infected or just carriers of the culprit organisms.
       
       
   • Inanimate objects - this includes:
     • Surgical instruments
     • Parenteral fluids
     • Anaesthetic apparatus & ventilators
     • Bed pans
     • Urinals
     • Blankets
     • Others such as floors, lockers, baths, and toilets, food and water, dust, etc.

1. Direct contact e.g. contaminated food or IVF 2. Indirect contact e.g. from patient to patient on the hands of a health worker 3. Droplet contact e.g. inhalation of droplets (>5um that cannot travel >3feet-pertusis) 4. Airborne contact e.g. inhalation of droplet (<5um that can travel large distances on air currents- T.B) 5. Vector borne contact e.g mosquitoes-malaria

1. Policy decision

   • Clinical e.g. policy for patient isolation, the use of antibiotics, etc
   • Non-clinical e.g. catering, Laundry, domestic practice, waste disposal, etc
     
     

2. Hand washing

   • With soap and water when visibly soiled
   • Before and after patient contact
   • After contact with any source
   • Immediately after removing gloves
     
     

3. Personal Protective Equipment E.g.; gowns, gloves, mask, foot wears, head covers, etc.
   
   

4. Engineering and waste practice control E.g. use of puncture resistant and leak proof sharps disposal containers, prohibition of 2-handed recapping of needles, waste segregation at source of generation, etc.
   
   

5. Surveillance of infection within the hospital is very important. Information from the wards, theatres and laboratory should be collated daily by an infection control team.
   
   

6. Education
   
   

7. Vaccination
   
   

8. Employer exposure protocol e.g. post exposure prophylaxis (PPE)
   
   

9. Proper sterilization and disinfection procedure

Nosocomial or hospital acquired infections are still a major cause of morbidity and mortality. They have direct or indirect increase in the cost of hospital care and they lead to emergence of new health hazards for the community.

Standard precautions, health education, asepsis and targeted hospital’s policy decisions still remain the main stay in the fight against Nosocomial Infections.