M1. Infection conrtrol

• Infection is a condition that results when a microorganism is able to invade the body, multiply, and cause injury or disease.
• Microorganism: microscopic organism that can potentially benefit or harm living things
• Pathogens • microorganisms that are capable of causing or producing infection/diseases.
• Communicable Infection: Infections that can be easily spread from person to person.
• Healthcare-associated Infections: Applies to infections associated with healthcare delivery in any healthcare setting, including HOME CARE
• Healthcare-associated Infections • Formerly known as nosocomial infections
• Centers for Disease Control and Prevention: An agency of the U.S. Department of Health and Human Services that is in-charged with the investigation and control of various diseases
• Centers for Disease Control and Prevention: Develops guidelines and recommends safety precautions to protect healthcare workers and others from infection
• Enumerate the 6 components of the Chain of Infection:

  1. Infectious agent
  2. Reservoir
  3. Exit Pathway
  4. Means of Transmission
  5. Entry Pathway
  6. Susceptible Host
• Infectious Agent: Causative agent. The pathogenic microbe responsible for causing an infection.
• Reservoir • Source of infectious agent • A place where the microbe can survive and grow or multiple. • Animal, human equipment, food, soil, water
• Reservoir Host: an individual or animal infected with a pathogen; has the ability to transmit the pathogen
• Fomite: inanimate object that has the ability to transmit infection
• Factors that affect the transmissibility:

  • Viability of the microorganism: ability of the microbe to survive on the object
  • Virulence of the microorganism: degree to which the microbe is capable of causing disease
  • Amount of contamination
  • Amount of time that has passed since the item was contaminated
• Exit Pathway: Pathway where the infectious agent leaves a reservoir host
• Means of Transmission: Method that an infectious agent uses to travel from a reservoir to a susceptible host
• Means of transmission include: Airborne, contact, droplet, vector, vehicle
• Pathway where the infectious agent is able to enter a susceptible host?

  Entry Pathway
• Susceptible host • Someone with a decreased ability to resist infection • Elderly, newborn, acute/chronically ill, immune suppressed, unvaccinated
• most common means of transmitting infection?

  Contact Transmission
• Involves physical transfer of an infectious agent to a susceptible host through close or intimate contact o Touching or kissing?

  Direct Contact Transmission
• Can occur when a susceptible host touches contaminated objects o Fomites?

  Indirect Contact Transmission
• DROPLET SPREAD/TRANSMISSION

  • the transfer of an infectious agent to the mucous membranes of the mouth, nose, or conjunctiva of the eyes of a susceptible individual via infectious droplets (particles 5 um in diameter or larger) generated by coughing, sneezing, or talking or through procedures such as suctioning or throat swab collection
• AIRBORNE TRANSMISSION

  • involves dispersal of infectious agents that can remain infective for long periods of time in particles that are typically less than 5 um in diameter and can be inhaled, such as droplet nuclei (residue of evaporated droplets).
• VECTOR TRANSMISSION

  • is the transfer of an infectious agent carried by an insect, arthropod, or animal
• MECHANICAL TRANSMISSION

  • facilitated by a mechanical vector, an animal that carries a pathogen from one host to another without being infected itself
• BIOLOGIC TRANSMISSION

  • occurs when the pathogen reproduces within a biological vector that transmits the pathogen from one host to another
• VEHICLE TRANSMISSION

  • is the transmission of an infectious agent through contaminated food, water, or drugs
• BLOOD-BORNE PATHOGEN

  • Any infectious microorganism present in blood and other body fluids and tissues
• SUSCEPTIBLE HOST

  • is someone with a decreased ability to resist infection
• Common factors that affect susceptibility

  • Age 
  • Health
  • Immune Status
• HEPATITIS B VIRUS

  • a blood-borne pathogen w/c is the causative agent of serum hepatitis, a systemic disease that primarily affects the liver
• • lower concentrations of Hepa B virus may appear in semen, vaginal fluid and saliva
• • HEPATITIS B VIRUS Modes of transmission: sexual, perinatal and parenteral routes
• HEPATITIS B VIRUS

  • Complications: Flu-symptom; fatigue, loss of appetite, mild fever; jaundice (25%); cirrhosis of the liver; liver cancer
• HEPATITIS B VIRUS

  • Treatment: HBV vaccination (series of 3-equal intramuscular injections)
• HEPATITIS C VIRUS

  • a blood-borne pathogen from the genus Hepacivirus
• HEPATITIS C VIRUS

  • modes of transmission: parenteral, perinatal and sexual
• HEPATITIS C VIRUS clinical manifestations: acute and chronic hepatitis
• HEPATITIS C VIRUS complications: cirrhosis and hepatocellular carcinoma