Disease (H&D 002) Flashcards
What is the definition of disease?
An abnormal condition of an organism as a consequence of an infection, inherent weakness or environmental stress that impairs psychological function
What are two types of diseases?
Non-communicable and communicable diseases
What is the definition of non-communicable diseases?
It cannot be transmitted to other people (eg. cancer, diabetes and obesity)
What is the definition of communicable diseases?
It can be transmitted to other people (eg. COVID-19, influenza and the plague)
What is the definition of infection?
The entry and growth of a pathogen within a host
What is the definition of virulence?
The capacity of an organism to cause a disease
What are some advantages of parasitism
Protected from hostile environments, provide nutritional needs and require minimal amount of energy so can use most of its energy reproducing
What are some disadvantages of parasitism
Obliged to go where the host goes, combat against host immune defense systems Most likely to die if the host dies
What is the definition of pathogenicity
The ability of a pathogen to cause disease
What are some risk factors that increase the probability of someone getting a communicable disease
Not vaccinated, malnourished and drug abuse.
What is a definition of a pathogen
A disease causing organism
What is the definition of a host
A susceptible person
What is the definition of portal of entry
A place where pathogens gain entry to the body through the gastrointestinal tract, respiratory tract, urogenital tract and through the skin and eyes
What is the definition of a reservoir
A place where pathogens can multiply in and spread from (eg. humans, animals, food, soil and water)
What are the four different types of carriers
Convalescence, chronic, asymptomatic and contact carriers
What is the definition of a convalescence carrier
A carrier that has had the disease and is recovering but still has the pathogen
What is the definition of a chronic carrier
A carrier that has had the disease for a long period of time
What is the definition of an asymptomatic carrier
A carrier that has no signs or symptoms of the disease but still has the pathogen
What is the definition of a contact carrier
A carrier that does not have the disease but transfers pathogen from host to host
What are the five transmission methods that pathogens use
Direct contact, indirect contact, common vehicle, airborne and vector transmission
What is the definition of direct contact transmission
Transmission of pathogen by physical contact (eg. kissing, shaking hands, sexual contact)
What is the definition of indirect contact transmission
Contact through non-living objects
What is the definition of common vehicle transmission
Ingestion or exposure to contaminated food, water or blood
What is the definition of airborne transmission
Breathing in aerosols, drops of mucus that contain pathogens
What is the definition of vector transmission
Insects moving from an infected person to a new host
What is the reproductive ratio
Shows the average number of people that may be infected by a single disease source.
What does it mean if Ro < 1
The disease will die out in the population
What does it mean if Ro > 1 `
The disease will be able to spread throughout the population
What are the four stages of the natural history of disease
Stage of susceptibility, presymptomatic disease, clinical disease and convalescence
What is the stage of susceptibility
The predisposed host has the disease but the disease itself however is not fully developed. However the host is highly likely to get the disease in the first place
What is the stage of presymptomatic disease
The process of the disease has started but shows no symptoms
What is the stage of clinical disease
Symptoms of the disease are now present
What is the stage of convalescence
The host has not fully recovered from the disease yet
What are the three components of the ecological model of disease
Host factors , Pathogen and Enviromental conditions
What is the definition of health-related event
An event that has favorable and unfavorable health changes
What is the definition of predisposed
Increased likelihood of getting a disease
What is the definition of a fomite
A non-living object that has the bacteria/virus
What are the transmission methods of the influenza virus
Indirect contact via fomites and airborne transmission
Where is the portal of entry and location of infection
In the respiratory tract, epithetical tissue of the upper respiratory tract
What are some predisposing factors that contribute to influenza
Lack of sleep, weak immune system and stress
What are some virulence factors that contribute to the pathogenicity of the influenza virus
Spikes of the virus to allow attachment to the host cell, strain mutation allowing itself to multiply
What are some health prevention and control methods that would help further spread of the influenza virus
Isolation, washing your hands, immunization, coughing hygiene
What are some symptoms of influenza
Headache, sore throat, fatigue, aches and pains and chills
