Principles of Disease and Epidemiology Flashcards
WHAT IS A PATHOGEN
A DISEASE CAUSING MICROBE
DEFINE PATHOLOGY
THE SCIENTIFIC STUDY OF A DISEASE
Define Pathogenesis
The manner in which the disease develops
Define Etiology
The study of the cause of a disease
Epidemology
The study of transmission, incidence and frequency of disease
Define Infection
The growth of microbes in the body
Define Disease
An abnormal state in which part or all of the body is not properly adjusted or is incapable of performing normal functions.
“Any change from a state of health”
Define Normal microbiota
- microbes that establish more or less permanent residense and do not produce disease under normal condition
What is transient microbiota?
Microbes which may be present for several days, weeks, or months, and then disappear.
What is Microbial Antagonism?
The competition between microbes
Ex. Nomal microbiota and harmful microorganisms
What is Symbiosis
Relationship between two organisms, where at least one organism is dependent on the other.
Define Mutualism
A type of symbiosis where both organisms benefit.
Define Commensalism
A symbiotic relationship, where one organism benefits and the other is unharmed.
Define Parasitism
A type of Symbiotic relationship where one organism derives nutrients at the expense of the other.
What are Koch’s Postulate steps?
- Microorganism Isolated from diseased or dead animal
- Grow microbes in pure culture and identify.
- Inject microbes into healthy organism
- Identify pathogen
- Isolate and Identify pathogenic microbes from diseased animals and grow pure culture.
What are the requirements for Koch’s Postulates.
- The same pathogen must be present in every case of the disease.
- The pathogen must be isolated in pure culture
- The isolated pathogen from the pure culture must cause the same disease in a healthy suceptible laboratory animal.
- The pathogen must be re-isolated from the inoculated laboratory animal.
Define Symptoms
- Subjective
- Changes in body function
- May vary from person to person.
Types of Resevoirs
- Diseased individuals
- Carriers
- Zoonoses
- Soil, Water, Food.
Define Signs
Mesurable indications of disease.
ex. fever, lesions, swelling, blood pressuer. etc
Communicable Disease
can be passed from person to person
directly or indirectly
Contagious disease
can be easily spread from person to person.
Noncommunicable disease
cannot be spread from person to person.
ex. food poisoning and tetanus
Incidence
the number of people that have a disease in general
Prevalance
of people that acquire the disease over defined period of time.
zoones
disease that can be passed to humans by animals
Sporadic
a disease the Ocassionally occurs within a population
Endemic
a disease that is CONSTANTLY present within a population
Epidemic
aquired in a SHORT period of time within a populated area.
ex. head lice at school
Pandemic
An epidemic that occurs worldwide
Acute duration
develops rapidly but last a short time
Chronic duration
develops more slowly and body reaction may be less severe but lasts longer
Subacture severity
between acute and chronic severity
Latent severity
causitive agents remain inactive for a time but then becomes active to produce symptoms
Local infection
defined spot or location
Systematic infection
multiple area infection
Primary infection
1st aquired disease
Secondary infection
2nd infection from comprimised immune system
Inapparent infection
no symptoms or detection.
like a yeast infection at times.
Development of a disease
-
Incubation period
- microbes growing and replicating
-
Prodromal period
- feeling sick
-
Period of illness
- actual sickness
-
Period of decline
- Getting better
-
Period of convalescence
- recovery
Direct contact
person to person
ex. sex, kissing, handshaking
indirect contact
through fomites
Fomite: inanimate object
“money”
Droplet transmission
sneezing,
less than 1 m
vehicle transmission
water, food, air
tools that move microbes from point A to point B
Airborne transmission
over long distance
greater than 1 M
Vector transmision
arthropods
Biological: mosquito bite
Mechanical: Fly
Nosocomial infection
infection from hospital stay
Who and how are nosocomial infection transmitted?
compromised patients
mircrobes, direct contact, indirect contact, airbone
