Understanding Nosocomial Infections

Posted on Feb 17, 2025 in Medicine & Health

Nosocomial infections are infections acquired in a hospital or healthcare setting. These infectious diseases are contracted by patients or medical staff *after* admission, meaning they were not present or incubating at the time of admission.

Epidemiological Chain

  • Source: Primarily people (patients, staff, visitors), often asymptomatic carriers, and opportunistic organisms.
  • Transmission Mechanisms:
    • Direct: Via the hands of healthcare staff.
    • Indirect: Through contaminated materials.
    • Air: Droplets of saliva from coughs or sneezes.
    • Vehicle: (Rare) Human carrier.
  • Host: Anyone, but especially patients with:
    • Immunodeficiency
    • Assisted ventilation
    • Catheters
    • Tracheostomies
    • Intubation

Universal Precautions

  • Handwashing.
  • Cleaning, disinfection, and sterilization of equipment.
  • Avoiding touching or manipulating wounds without gloves.
  • Using gloves.

Prevention Measures

  • Vaccination.
  • Closed urinary drainage.
  • Monitoring of mechanical ventilation and oxygen equipment.
  • Care of catheters.
  • Use of single-use materials whenever possible.

Types of Nosocomial Infections

Respiratory Infections

Lower respiratory tract infections, particularly pneumonia, have high mortality rates. Symptoms include cough and purulent lower respiratory tract secretions. Confirmation is generally through chest X-ray. Transmission is often via the hands of healthcare staff or contaminated instruments, rarely airborne.

Prevention:

  • Wash hands after dealing with patients who have tracheostomies or are intubated.
  • Use sterile probes for aspiration of secretions.
  • Implement respiratory physiotherapy measures.

Urinary Tract Infections (UTIs)

These are caused by bacteria that can originate from the patient’s gastrointestinal tract and urethra or from exogenous sources. Factors influencing UTIs can be intrinsic or extrinsic.

  • Intrinsic: Age, sex, underlying disease.
  • Extrinsic: Antibiotic treatment, urinary catheter.

Prevention:

  • Use catheters only when necessary.
  • Utilize closed sterile drainage systems.
  • Apply lubricant to the catheter to avoid injuries.
  • Always keep the collector bag below the bladder.
  • Use a sterile needle to take samples.
  • Practice handwashing and use sterile gloves.

Surgical Site Infections (SSIs)

These infections can occur when skin protection is compromised, such as through a surgical incision. They can also originate from contaminated surgical instruments. SSIs are detected by the appearance of purulent secretions or abscesses at the injury site.

The risk of infection also depends on:

  • Type of surgery (clean or dirty).
  • Surgeries lasting over 2 hours have an increased risk.
  • Abdominal surgeries have a higher risk.
  • Patient’s health status (malnutrition, age, etc.).

Prevention:

  • Reduce hospital stay.
  • Full shower with antiseptic soap the day before surgery.
  • Shave the surgical area immediately before surgery.
  • Administer antibiotic prophylaxis to cover the operating field.
  • Cover the surgical field with sterile drapes.
  • Practice surgical handwashing and use sterile gloves.
  • Use sterile gowns, leggings, and caps.
  • Ensure correct sterilization of materials.

Bacteremia

This occurs when microorganisms enter the bloodstream. The main risk factor is the use of intravascular catheters.

Prevention:

  • Provide appropriate training to personnel.
  • Insert catheters only when necessary and for the shortest time possible.
  • Use sterile technique during placement.
  • Observe the insertion point daily.