Infection Process Overview

Infection Process

• Infection: Entry and multiplication of an infectious agent in a host's tissue.
• Cell or Tissue Colonization: Agent causes no injury to host cells or tissues.
• Symptomatic: Pathogens multiply, causing clinical signs and symptoms.
• Communicable: Directly or indirectly transmitted between people.
• Infectious Disease: Organism damages or alters host physiology.
• Pathogens: Disease-causing organisms.
• Nonpathogenic: Organisms that do not cause disease.
• Virulence: Likelihood of an organism causing disease.
• Carrier: Harbors organism, transmits it to susceptible host (often asymptomatic).
• Communicable Disease: Illness caused by infectious agent or its toxic products. Transmitted directly or indirectly.
• Contact: Close association with infected person, animal, or material.
• Contagious Disease: Easily transmitted between people.
• Disinfection: Destruction of pathogens outside the body. Concurrent (immediately after infection) and Terminal (after patient is no longer source).
• Habitat: Place where an organism is usually found.
• Host: Person, animal, plant a parasite depends on for survival.
• Isolation: Limiting movement of people exposed to communicable disease.
• Quarantine: Separation of individual with a communicable disease from others for a period equivalent to the longest incubation period.
• Reservoir: Plant or animal where an infectious agent lives and multiplies.
• Surveillance: Watching, collecting, and recording data from a population or area.
• Incubation Period: Time between exposure and symptom onset. Agent multiplies, reaches symptomatic population.
• Prodromal Period: Mild signs/symptoms appear, rapid pathogen multiplication.
• Clinical Illness Period: Peak pathogen population.
• Convalescence Period: Gradual recovery, return to baseline.
• Exogenous Infection: Microorganism from the environment.
• Endogenous Infection: Microorganism from the host's own normal flora.
• Healthcare-Associated Infections (HAIs): Infections acquired in healthcare facilities.

Infection Prevention and Control

• Standard Precautions: Universal barriers to prevent contact with blood and infectious materials.
• Barrier Precautions: Correct PPE use.
• Workplace Precautions: Prevent needle injuries, safe sharps disposal.
• Airborne Precautions: Special handling and ventilation.
• Droplet Precautions: Large particle droplets travel short distances.
• Contact Precautions: Gloves, mask and gown required.

Hand Hygiene

• 5 Moments for Hand Hygiene: Before patient contact, before procedure, after procedure, after patient contact, after touching patient surroundings.

Disease

• Signs: Objective, measurable (e.g., fever).
• Symptoms: Subjective, experienced by the patient (e.g., pain).

Infection Types

• Subclinical: Asymptomatic infection.
• Latent: Inactive organism, potential future infection.

Epidemiology

• Endemic: Disease consistently present in a specific region or group.
• Epidemic: Disease in a greater-than-expected number in a specific area over a particular time.
• Pandemic: Disease that spreads rapidly to several countries or continents.
• Sporadic: Diseases that occur irregularly without a specific pattern.