HSBTE. DMLT. IInd-Semester. Nosocomial Infection: Introduction, Common types and source of nosocomial infection, Control of nosocomial infections.

Introduction: Nosocomial infection:

The infection that develops in patients during the hospitalization period is called nosocomial infection. It is also known as hospital-acquired infection or healthcare-associated infection (HAI). Iatrogenic infection: Infection in the living body after medical treatment or during medical investigation is called iatrogenic infection. These infections prolong hospital stays, increase healthcare costs, and in severe cases lead to complications or even death.

Factors affecting the occurrence and severity of nosocomial infection

• 1. Hospitalised patients have low immunity due to diseased conditions.

• 2. The hospital environment has a wide variety of pathogens.

• 3. A slight lapse in invasive, diagnostic, and therapeutic procedures leads to nosocomial infection.

• 4. Advance treatment such as organ transplantation, cancer treatment, use of sophisticated medical technologies, etc. enhances the chances of nosocomial infection.

Microbiology of Hospital infections:

A microorganism that can survive in the hospital environment for a longer duration and is resistant to antibiotics and disinfectants causes nosocomial infection. Examples are Staphylococcus aureus, Staphylococcus epidermidis, E coli, Enterobacter, Proteus, etc. Tetanus spores can survive in dust for a long duration. They may contaminate cotton, sutures, plaster of Paris, etc. HIV and Hepatitis A and C viruses are transmitted through blood products.

Common types and sources of nosocomial infections

The following are Common types of nosocomial infections:

• 1. Urinary Tract Infections (UTIs): UTIs are the most common nosocomial infections. It is associated with urinary catheterization. UTI results from improper insertion, maintenance, or prolonged use of urinary catheters. Unhygienic toilet in hospitals also causes UTIs.

• 2. Surgical site Infection (SSIs): SSIs occur at the site of a surgical incision. They are linked to surgical procedures. Factors such as inadequate sterilization of equipment, improper wound care, or bacterial contamination during surgery can contribute to SSIs.

• 3. Gastrointestinal infections: Gastrointestinal infections like Clostridium difficile (C. difficile) infection can occur due to the overgrowth of harmful bacteria in the gastrointestinal tract. It results from antibiotic use or poor infection control practices.

• 4. Bloodstream infections: These infections are also known as bacteremia or septicemia. They occur when bacteria or other pathogens enter the bloodstream. Central venous catheters and other invasive devices are common sources of bloodstream infections in hospitals.

• 5. Skin and soft tissue infection: These infections can include cellulitis, abscesses, and surgical wound infections that affect the skin and underlying tissues. Improper wound care, contaminated medical equipment, or surgical procedures can contribute to these infections

• 6. Pneumonia: Nosocomial pneumonia refers to lung infections acquired during a hospital stay. Ventilator-associated pneumonia (VAP) is a specific type of nosocomial pneumonia that develops in patients on mechanical ventilation. It is due to the introduction of pathogens through the ventilator system.

• 7. Methicillin-resistant Staphylococcus aureus (MRSA) infection: MRSA is a type of bacteria that is resistant to many antibiotics commonly used to treat bacterial infections. MRSA infections are visible as skin infections, surgical site infections, bloodstream infections, or pneumonia, posing significant challenges for treatment.

• 8. Vancomycin-resistant Enterococci (VRE) infections: VRE is another type of bacteria that has developed resistance to multiple antibiotics. VRE infections affect various body systems and are often associated with prolonged hospital stays and exposure to hospitals.

Control of nosocomial infections:

Controlling nosocomial infections is essential to maintaining patient safety and minimizing the spread of infectious diseases within hospitals. Effective control measures involve strategies aimed at preventing infections, identifying and isolating infected individuals, and implementing protocols to minimize transmission. The following are some key measures for the control of nosocomial infections:

1. Hand Hygiene: Proper hand hygiene is the most important measure in preventing the spread of infections in hospitals. Healthcare workers should perform hand hygiene using soap and water or alcohol-based hand sanitizers before and after patient contact, after removing gloves, and before performing invasive procedures.

2. Standard precautions: Treat all patients as potentially infectious. This includes the use of personal protective equipment (PPE) to prevent exposure to infectious agents.

3. Isolation Precautions: Isolates patients with known or suspected infectious diseases to prevent the transmission of pathogens to other patients, healthcare workers, and visitors. Types of isolation precautions include contact precautions, droplet precautions, and airborne precautions, depending on the mode of transmission of the infectious agent.

4. Environment cleaning and disinfection: Regular cleaning and disinfection of patient care areas, medical equipment, and frequently touched surfaces are essential to prevent the transmission of pathogens. Healthcare facilities should use appropriate disinfectants and cleaning protocols to maintain a clean and sanitary environment.

5. Education and training: Regular education and training of healthcare workers on infection control practices such as hand hygiene, PPE use, and isolation precautions are essential to promote a culture of safety within the hospital.

6. Patient and visitor education: patients and visitors' education on infection prevention practices such as hand hygiene and respiratory etiquette reduce the risk of transmission within healthcare facilities.

7. Vaccination program: Vaccination of healthcare workers, patients, and visitors against vaccine-preventable diseases such as influenza and measles prevent outbreaks of these diseases. It also protects individuals within the hospital.

8. Infection Surveillance: Surveillance of healthcare-associated infections monitors infection rates, identifies outbreaks, and implements prevention of the infection spread. Surveillance data identify trends, assess the effectiveness of infection control measures, and guide quality improvement efforts.

9. Collaboration and communication: Effective communication and collaboration among healthcare workers, laboratory personnel, and others are essential for implementing infection control measures. Sharing information on emerging threats and coordinating responses to outbreaks of infections are helpful.

Dr Pramila Singh