Communicable Diseases and Control Flashcards
(48 cards)
An illness caused by pathogens (e.g., bacteria, viruses, fungi, parasites) that can be transmitted from person to person or from animals to humans through various modes such as direct contact, airborne particles, or contaminated food/water.
Communicable Disease
A disease resulting from the invasion and multiplication of disease-causing agents (pathogens) in a host’s body tissues, leading to a reaction from the host’s immune system. Also known as transmissible or communicable disease.
Infectious Disease
An infection that is active but does not produce noticeable symptoms; also referred to as inapparent, silent, or occult infection.
Subclinical Infection
An infection that produces noticeable symptoms, making it apparent or symptomatic.
Clinical Infection
An inactive or dormant infection where the pathogen remains in the host without causing symptoms but may reactivate under certain conditions (e.g., stress or immunosuppression).
Latent Infection
A short-term infection with rapid onset and brief duration, typically lasting hours to weeks (e.g., influenza).
Acute Infection
A long-term infection that develops slowly and persists for months, years, or a lifetime (e.g., hepatitis B).
Chronic Infection
A microorganism capable of causing disease in healthy individuals due to its inherent virulence and ability to damage the host.
Primary Pathogen
A microorganism that typically causes disease only in immunocompromised hosts or when host defenses are weakened, often entering through unusual access points (e.g., trauma, surgery).
Opportunistic Pathogen
A model describing how infectious diseases spread, involving six steps: the infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host.
Chain of Infection
The natural habitat where a pathogen lives, grows, and multiplies, such as humans, animals, or the environment (e.g., soil, water).
Reservoir
Humans who harbor and can transmit a pathogen, often without showing symptoms (e.g., carriers of STDs, measles).
Human Reservoir
Animals that serve as natural hosts for pathogens causing zoonotic diseases, which can spread to humans (e.g., rabies, plague).
Animal Reservoir
Non-living habitats like soil, water, or plants where pathogens can live and multiply (e.g., Legionella in water).
Environmental Reservoir
An infected individual who can transmit a pathogen, with or without showing symptoms. Types include asymptomatic, incubatory, convalescent, and chronic carriers.
Carrier
The pathway through which a pathogen leaves its host, such as the respiratory tract, urine, feces, or skin lesions.
Portal of Exit
The method by which a pathogen moves from a reservoir to a susceptible host, including direct (e.g., contact, droplets) and indirect (e.g., airborne, vehicleborne, vectorborne) transmission.
Mode of Transmission
Pathogen transfer through close physical contact (e.g., skin-to-skin, kissing) or droplet spread over short distances (e.g., coughing).
Direct Transmission
Pathogen transfer through intermediaries like contaminated objects (vehicleborne), air (airborne), or vectors (vectorborne).
Indirect Transmission
Spread of pathogens via tiny particles (droplet nuclei) or dust suspended in the air, capable of traveling long distances (e.g., measles, tuberculosis).
Airborne Transmission
Spread through contaminated substances or objects, such as food, water, or surgical tools (e.g., foodborne hepatitis A).
Vehicleborne Transmission
Spread by insects or animals (e.g., mosquitoes, ticks) that carry pathogens mechanically or biologically (e.g., malaria).
Vectorborne Transmission
The pathway through which a pathogen enters a susceptible host, such as the respiratory tract, skin, or mucous membranes.
Portal of Entry
An individual who can become infected, with susceptibility influenced by genetics, immunity, and nonspecific defenses (e.g., skin, gastric acid).
Susceptible Host
