infection

• infection - the invasion of body tissue by microorganisms with the potential to cause illness or disease
• most microorganisms are harmless, and some are even beneficial
• infection occurs when the hosts immune system is unable to effectively control the microorganism
• bacterial infections


  most common infection causing microorganisms, one called organisms without a true nucleus and require a host for a suitable environment and multiplication. they can live and be transported through air, water, food, soil, body tissues and fluid, and inanimate objects
• viral infections


  a pathogen with a nucleic acid within a protein shell and requires invasion of a host to reproduce. an invading virus may immediately cause disease or may remain dormant for years
• fungal infections


  may grow as single cells or as multicellular colonies. in healthy individuals, fungi do not cause disease and are contained by the body's natural flora. in immunocompromised individuals they can result in infections that lead to death
• parasitic or protozoal infections

  live on other organisms and are typically found in dead material in water and soil. spread by the fecal-oral route by ingesting food or water that is contaminated with the parasitic spores or cysts
• descriptors of infection


  location

  • localized
  • disseminated
  • systemic

  duration

  • acute
  • chronic

  source

  • primary vs secondary
  • HAI vs CAI
• chain of infection six links

  • pathogen: microorganism responsible for causing the infection
  • reservoir: place where the infectious agent lives and multiplies, source for pathogen growth
  • portal of exit: the way the pathogen leaves the reservoir
  • mode of transmission: the way the pathogen travels from the reservoir to a susceptible host
  • portal of entry: the way the pathogen enters the susceptible host
  • susceptible host: the individual who can become infected
• stages of the infectious process

  • incubation period
  • prodronal stage
  • illness stage
  • convalescent stage
• common diagnostic tests


  laboratory tests

  • complete blood count with WBC differential
  • culture and sensitivity
  • c-reactive protein
  • erythrocyte sedimentation rate
  • serological tests to detect specific antibodies or viruses

  radiographic studies

  • x-ray
  • MRI
  • CT scan
  • PET and indium scans
• primary prevention = actions and strategies aimed at preventing the initial occurrence of a disease, injury, or health condition in a population that has not yet been affected
• vaccinations

  • administered to people across the lifespan
• hygiene

  • personal hygiene
  • food hygiene
  • patient care hygiene
  • hand hygiene
  • infection control practices
• secondary prevention = focuses on early detection and intervention to prevent the progression of disease, injuries, or health conditions in individuals who have already been affected or who are at higher risk
• screening

  • for specific pathogens through laboratory tests to identify the presence of infections
• contact tracing

  • identifying and notifying individuals who have been in close contact with an infected person, allowing for timely testing, monitoring, and isolation or treatment
• tertiary prevention = focuses on actions and strategies aimed at reducing the impact, severity, complications and disability associated with existing diseases, injuries, or health conditions
• antimicrobial therapy

  • administering appropriate antibiotics, antiviral medications, or anti-fungal agents to individuals diagnosed with specific infections
• chronic disease management

  • providing ongoing care and treatment for individuals experiencing chronic infections, such as HIV/AIDS or hep B and c to suppress viral replication, manage symptoms, and delay progression
• hand hygiene by who

  • before patient contact
  • before a clean/aseptic procedure
  • after body fluid exposure risk
  • after touching a patient
  • after touching patient surrounding
• universal precautions key principles

  • hand hygiene
  • glove use
  • personal protective equipment
  • safe injection practices
  • respiratory hygiene/cough etiquette
  • environmental cleaning
• three main types of isolations precautions:

  1. contact
  2. droplet
  3. airborne
• contact viruses

  • MRSA
  • VRE
  • conjunctivitis
  • diphtheria
  • respiratory syncytial virus
  • herpes simplex virus
  • human metapneumovirus
  • pediculosis (lice)
  • scabies
  • poliomyelitis
  • staphylococcus aureus
  • c.difficile
  • norovirus
  • rotavirus
• droplet viruses

  • influenza
  • pertussis
  • Mumps
  • rhinovirus
  • adenovirus
  • rubella
  • epiglottitis
  • parvovirus
  • bacterial meningitis
  • Haemophilus influenza type b
  • diphtheria
• airborne viruses

  • tuberculosis
  • rubeola
  • varicella
  • SARS
  • Small pox