PHLEB CHP 10 - Infection Control and the Clinical Laboratory

Pathogenic Microorganisms / Pathogens

Infection causing microbes.

• Virus

• Bacteria

• Fungi

• Parasites

Bloodborne pathogens live and are transmitted in blood.

Healthcare-Associated Infection (HAI)

An infection acquired during or after receiving care at a healthcare facility.

Nosocomial infections is a type of HAI acquired in healthcare settings.

Can result form direct contact or contaminated things.

Common HAIs: UTIs, C. difficile, and MRSA (bacteria).

The Chain of Infection

1. Infectious Agent (pathogen)

2. Reservoir

   1. Environment where pathogen lives (human, animal, food, surfaces, etc).

3. Portal of Exit

   1. Secretion of eyes, nose, mouth, body fluids.

4. Mode of Transmission

   1. Air, skin, direct contact, live carriers.

5. Portal of Entry

   1. Mucus membranes, broken skin, body openings, contact.

6. Susceptible Host

   1. Individual who is prone to disease.

Airborne Transmission

Pathogen spreads through tiny infectious particles that remain suspended in the air for extended periods, released by breathing, talking, coughing, or sneezing.

Ex of pathogens: Covid-19, tuberculosis, measles.

Contact Transmission

When an individual is exposed to an infectious agent.

• Direct contact: Physical interaction

• Indirect contact: Contact with an infected inanimate object (fomite) such as doorknobs, clothes, etc.

Ex of pathogens: C. diff, MRSA, herpes

Droplet Transmission

Infected person releases droplets that are larger and travel short distances by coughing, sneezing, or talking.

Ex of pathogens: Pneumonia, Influenza, Covid-19

Parental Transmission

Transfer of pathogens into body through another route such as needlesticks, cuts, puncture wounds, bites, etc.

Ex of pathogens: Hepatitis B/C virus, HIV

Vector Transmission

Spread through insects or animals that act as disease carriers.

Ex of pathogens: Malaria, Zika virus

Vehicle Transmission

Spread through contaminated sources such as food, water, blood, or medicine.

Ex of pathogens: HIV, Hepatitis B virus, E. coli, salmonella

Types of transmissions:

• Airborne

• Contact

• Droplet

• Parenteral

• Vector

• Vehicle

Infection Control Methods:

• Hand hygiene

• Isolation and reverse isolation

• Vaccination

• Aseptic Technique

  • Practice of creating and maintaining an environment free from contamination. Using PPE, strict disinfection, using N95, etc.

• Use of safety devices

• Early detection

• Healthy lifestyle

Center for Disease Control and Prevention (CDC)

Federal agency responsible for controlling, identifying, and managing various communicable diseases.

Universal Precautions

Require healthcare workers to treat all blood, body fluids, and human tissues as if they are infectious, regardless of patient’s health status. Use PPE and safe handling.

Standard Precautions

First tier of CDC’s two-tiered system, built on universal precautions, mandated by OSHA.

• Perform hand hygiene

• Use PPE

• Follow respiratory hygiene/cough etiquette

• Handle and disinfect patient care equipment, instruments, and devices properly

• Clean and disinfect the environment

• Handle textiles and laundry carefully

Transmission-Based Precautions

Second tier in CDC’s two-tiered system, built on universal precautions, mandated by OSHA.

• Contact Precautions: Don gloves and gown before entering the patient’s room.

• Droplet Precautions: Don a surgical mask before entering the patient’s room.

• Airborne Precautions: Don a N95 or high-level respirator and place the patient in an AIIR (isolation room).

Neonatal Unit Precautions

• Personnel must be in good health, without any symptoms of infection

• Hand hygiene must be performed, and clean gloves must be worn

• Only essential collection items should be brought into the unit

• Gloves must be removed, then hand hygiene, and a new pair of gloves applied before moving on to care for another patient

Laboratory Departments

• Chemistry

• Coagulation

• Hematology

• Immunohematology

• Microbiology

• Surgical pathology

• Urinalysis