Infectious Disease Process Review PDF

UNIT 1 Infectious Disease Process Review of modes and mechanisms of transmission DYNAMICS OF DISEASE TRANSMISSION K LOOTAWAN 2/9/24 Week 1 &2  OBJECTIVES Describe the concepts of in...

UNIT 1 Infectious Disease Process Review of modes and mechanisms of transmission DYNAMICS OF DISEASE TRANSMISSION K LOOTAWAN 2/9/24 Week 1 &2  OBJECTIVES Describe the concepts of infection, infectious & infectivity Define terms related to infection prevention and control Explain the infectious disease process (chain of infection) Explain the dynamics of disease transmission  Natural History EXPOSURE RECOVERY/DISABILITY/ The progress of a disease over DEATH time in an infected / affected individual, in the absence of medical intervention.  NATURAL HISTORY: PHASES Pre- Period before onset of disease Favorable conditions for infection pathogenesis exists Active disease Pathogenesis Continues until disease ends  DEFINITION OF TERMS INFECTION- The entry and establishment of an infectious agent in a host Or : Presence of a microorganism in the host tissue, where it lives, grows, multiplies, and induces an immune response in the host that generates signs and symptoms. (IPC manual 2020) INFECTIVITY- The ability to lodge and multiply successfully in a host HOST- A living organism that affords lodgment to an infectious agent (Valanis 1992) Standard Precautions Standard precautions represent the minimum infection prevention practices that apply to all patient care, regardless if the patient is known to have an infection or not(e.g., assume everyone you come in contact with has an infectious agent in their blood and/or body fluid). Elements of Standard Precautions include the following: hand hygiene, use of personal protective equipment, respiratory hygiene and cough etiquette, safe handling of sharps materials, Appropriate decontamination of medical equipment Safe laundry practices Environmental cleanliness Safe waste management  Universal Precautions A protocol for infection prevention and control that treats all human blood and body fluids as if known to be infected with HIV or other blood borne pathogen  Homework –Define The Following Terms Asepsis Nosocomial infection Medical asepsis Universal precautions Surgical asepsis Standard precautions Aseptic technique Transmission based Isolation Reverse precautions Isolation Barrier nursing Personal Protective Equipment (PPE)  DISEASE TRANSMISSION Any mechanism through which an infectious agent is spread through the environment or to people  INFECTIOUS AGENT An infectious agent is a microorganism with the ability to cause an infectious disease. The greater the organism’s virulence (ability to grow and multiply) , invasiveness (ability to enter tissue) and pathogenicity (ability to cause disease), the greater the possibility that the organism will cause an infection. Infectious agents are bacteria, virus, fungi and parasites.  RESERVOIR A place within which microorganisms can thrive and reproduce. For example, microorganisms thrive in human beings, animals, and inanimate objects such as water.  PORTAL OF EXIT A way for a microorganism to leave the reservoir. For example, the microorganism may leave the reservoir through the nose or mouth when someone sneezes or coughs, or can be carried away from the body by feces from an infected bowel.  MODE OF TRANSMISSION Is the route or method of transfer by which the infectious agent moves or is carried from one place to another to reach the new host. The modes (means) of transmission are: Contact (direct and/or indirect), Droplet, Airborne, Vector and Common Vehicle.  PORTAL OF ENTRY The means by which the infectious agents gain access into the host. This can occur, for example, through ingestion, breathing, damaged skin, invasive procedures such as blood transfusion & surgery.  SUSCEPTIBLE HOST A person who is susceptible to the disease, lacking immunity ( immuno-compromised) or physical resistance, to overcome invasion by the microorganism. MODES OF TRANSMISSION AIRBOURNE DROPLET CONTACT VECTOR COMMON VEHICLE  AIRBORNE TRANSMISSION Microorganisms transmitted by this route are carried by dust or other small particles floating in the air and are