WEEK 1 Infection control Flashcards
Infection control (17 cards)
Define an Infectious agent
Infectious diseases are caused by diverse living agents that can replicate in their hosts and cause local and systemic responses (in the body). Medical microbiology is the branch of microbiology that deals with the study of pathogens - which are microorganisms that can cause disease.
The agents that cause disease can be classified into four groups: bacteria, viruses, fungi, and parasites
Define Bacteria
- Single-celled prokaryotic organisms.
- Various shapes (cocci, bacilli, spirilla).
- Some are beneficial (normal flora), while others can cause infections (pathogens).
Define Viruses
- Tiny infectious particles consisting of genetic material (DNA or RNA) surrounded by a protein coat.
- Obligate intracellular parasites that depend on host cells for replication.
- Cause a wide range of diseases, from the common cold to HIV/AIDS.
Define Fungi
- Eukaryotic microorganisms, including yeasts and molds.
- Can cause fungal infections, such as candidiasis and ringworm.
Define Parasites
- Organisms that live on or within a host organism and derive nutrients from the host.
- Parasites include protozoa (e.g., Plasmodium causing malaria) and helminths (e.g., intestinal worms).
Define the chain of infection
Is a conceptual framework used in healthcare to understand how infectious diseases are transmitted and how they can be prevented. It consists of several interconnected stages or links that must be present for an infection to occur. Breaking any one of these links can help prevent the spread of infections.
What are the chain of infections stages
- Infectious Agent
- Reservoir
- Portal of Exit
- Mode of Transmission : Direct and Indirect Transmission and Airborne Transmission
- Vector-Borne
- Susceptible Host
Define Infectious Agent
This is the first link in the chain. It refers to the microorganism (e.g., bacteria, viruses, fungi, or parasites) that can cause disease. These agents can vary in terms of their ability to cause illness, modes of transmission, and resistance to treatment.
Define Reservoir
The infectious agent needs a place to live and multiply, known as a reservoir. Reservoirs can be living organisms (such as humans or animals), inanimate objects (like medical equipment or surfaces), or the environment (such as water or soil).
Define Portal of Exit
Once the infectious agent has multiplied in the reservoir, it needs a way to exit and spread to a new host. Common portals of exit include bodily fluids (such as saliva, blood, or respiratory secretions), open wounds, and excretions (urine, faeces).
Define Mode of Transmission
This stage involves the methods by which the infectious agent is transmitted from the reservoir to a susceptible host. Modes of transmission can be classified into three main categories:
Define Direct Transmission
Occurs through physical contact between an infected person or reservoir and a susceptible host (e.g., touching, kissing, or sexual contact).
Define Indirect Transmission
Occurs when a contaminated object or surface (fomite) serves as an intermediary in the transmission of the infectious agent (e.g., touching a contaminated doorknob or medical equipment).
Define Airborne Transmission:
Involves the spread of infectious particles through the air, typically via droplets produced when an infected person coughs, sneezes, or talks
Define Vector-Borne
When a vector (e.g., mosquito, tick) carries the pathogen from one host to another
Define Portal of Entry
Once the infectious agent is transmitted, it must enter the body of a susceptible host through a portal of entry. This can be the same as or different from the portal of exit. Common portals of entry include mucous membranes (e.g., the eyes, nose, or mouth), open wounds, and the respiratory, gastrointestinal, or genitourinary tracts.
Define Susceptible Host
The final link in the chain is a person or organism that is susceptible to the infectious agent. Susceptibility depends on various factors, including the person’s overall health, immune system status, and genetic predisposition.
