Principles of Disease Flashcards
describe and define the BASICS OF DISEASE
- still everyone can be SUSCEPTIBLE TO PATHOGENS
- have a DELICATE BALANCE between our DEFENSES and PATHOGENIC AGENTS
- we get DISEASE if that BALANCE IS DISPALCED
definition of PATHOLOGY
the STUDY OF DISEASE–the science of the CAUSES and EFFECTS of DISEASES
definition of ETIOLOGY
the CAUSE OF THE DISEASE
definition of PATHOGENESIS
the MANNER in which DISEASE DEVELOPS
definition of INFECTION
the INVASION and COLONIZATION of the body
definition of DISEASE
the symptoms that occur due to INFECTION
describe the relation between INFECTION and DISEASE
- we CAN HAVE AN INFECTION, but NO DISEASE
- ex. AIDS patients – can be infected with the virus for YEARS, but show NO SYMPTOMS of the disease
describe and define our NORMAL MICROBIOTA
NORMAL MICROBIOTA:
- a DIVERSE MICROBIAL COMMUNITY that is associated with the SKIN and MUCOUS MEMBRANES (seen in all humans)
- can AID, HARM, or NEITHER BENEFIT the HOST
- organisms can still CAUSE DISEASE within COMPROMISED HOSTS
what are NOT CONSIDERED MEMBERS of NORMAL MICROBIOTA?
viruses and parasites
are BABIES BORN WITH MICROBIOTA?
NO!
- sterile before delivery
- VAGINAL DELIVERY: Lactobacilli is present within vagina and NEWBORNS HAS CONTACT WITH MICROBIOTA–helps extensively to become the PREDOMINANT ORGANISM within the NEWBORNS INTESTINE
- baby will continue to be exposed through their environment
how many cells and bacterial cells does the human body have?
CELLS: 1 x 10^13 cells
BACTERIAL CELLS: 1 x 10^14 cells
what types of MICROBIOTA DO WE HAVE and where are they FOUND?
- NORMAL MICROBIOTA
- TRANSIENT MICROBIOTA:
organisms that are present for a SHORT TIME; from days to months - found and LOCALIZED TO CERTAIN REGIONS–can populate depending on periods in an individual’s life
what factors determine where we find our MICROBIOTA?
- NUTRIENTS
- PHYSICAL & CHEMICAL FACTORS (temp, pH, and oxygen)
- IMMUNE SYSTEM
- MECHANICAL FORCES (cilia in trachea, swallowing)
what are the REPRESENTATIVE NORMAL MICROBIOTA IN THE SKIN?
Staphylococcus epidermidis
Staphylococcus aureus
Corynebacterium spp.
Pseudomonas aeruginosa
what are the REPRESENTATIVE NORMAL MICROBIOTA IN THE EYES?
Staphylococcus epidermidis
Propionibacterium
Corynebacterium
what are the REPRESENTATIVE NORMAL MICROBIOTA IN THE NOSE and THROAT?
Staphylococcus epidermidis
Streptococcus pnuemoniae
Neisseria
what are the REPRESENTATIVE NORMAL MICROBIOTA IN THE MOUTH?
Actinomyces
Lactobacillus
Streptococcus salivarius
Streptococcus mutans
what are the REPRESENTATIVE NORMAL MICROBIOTA IN THE LARGE INTESTINE?
Escherichia coli
Lactobacillus
Enterobacter
Proteus
what are the REPRESENTATIVE NORMAL MICROBIOTA IN THE URINARY and REPRODUCTIVE SYSTEM?
Staphylococcus
Micrococcus
Clostridium
Candida albicans
does our NORMAL MICROBIOTA vary from person to person?
YES!
FACTORS:
- AGE
- NUTRITIONAL STATE
- HEALTH
- STRESS
- PERSONAL HYGIENE
what is the GUT-BRAIN AXIS (GBA)?
relation between gut to brain:
- show causes of how the GUT affects the production of NEUROTRANSMITTERS that affect MENTAL HEALTH CONDITIONS
- show causes of how the BRAIN and various mental health conditions (ex. anxiety) affects and DISRUPTS GUT MOTILITY
definition of MICROBIAL ANTAGONISM
MICROBIAL ANTAGONISM:
- begins to PROTECT HOST from COLONIZATION by PATHOGENIC ORGANISMS
ex. microbiota within vagina maintains a low pH (INHIBITS GROWTH OF OTHER ORG.)
ex. e. coli production of BACTERIOCINS (INHIBITS GROWTH OF OTHER ORG.)
definition of COMMENSAL SYMBIOSIS
- where one organism BENEFITS while the OTHER IS UNAFFECTED
ex. Corynebacteria & S. epidermidis
definition of MUTUALISM
- where BOTH ORGANISMS benefit from the relationship
- ex. E. coli produces VITAMIN K and SOME B VITAMINS – we provide nutrients and shelter for E. coli
definition of OPPORTUNISTIC MICROORGANISMS
organisms that DO NOT CAUSE DISEASE in their NORMAL HABITAT within a HEALTHY PERSON but can cause DISEASE IN A DIFF. LOCATION or IMMUNE COMPROMISED HOST
what are some cases of changes within SYMBIOTIC RELATIONSHIPS that can cause OPPORTUNISTIC MICROORGANISMS?
- ex. LOCATION MOVEMENT (E. coli can cause disease within URINARY TRACT–UTI)
- ex. LACK OF COMPETITION antibiotic KQ is removed–Candida takes over mouth
- ex. COOPERATION BETWEEN ORGANISMS (receptors of periodontal disease + streptococci)
describe ETIOLOGY and the various aspects to our knowledge about their CAUSES
- some are WELL KNOWN
(ex. LYME DISEASE + TB) - some are NOT COMPLETELY UNDERSTOOD
(ex. virus + cancer) - some are UNKNOWN
(ex. Alzheimer’s disease)
how do we determine the cause of infectious disease?
- Koch’s postulate
- helps with LINKING OF DISEASE to a SPECIFIC ORGANISM
what are some EXCEPTIONS to ETIOLOGY?
- ORGANISMS cannot be cultured on specific LABORATORY MEDIA (ex. can’t be seen on a petri dish)
- use of different ALTERNATIVE ARTIFICIAL MEDIAS
- ex. LEPROSY (Mycobacterium leprae–grown on MOUSE FOOTPAD, ARMADILLO SKIN)
- NON-SPECIFIC SYMPTOMS of DISEASE
- ex. pneumonia is caused by many types of microorganisms
- SOME PATHOGENS can cause SEVERAL DISEASES
- ex. S. pyogenes - can cause sore throat, fever, skin infections etc.. - ABSENCE OF ANIMAL MODEL for disease
how do we CLASSIFY SYMPTOMS of DISEASE?
- often look at CHANGES IN BODY FUNCTION
- SUBJECTIVE: patient exp./fatigue/ pain
- OBJECTIVE: doctors can observe and measure/ fever, swelling, lesions
describe TRANSMISSION of INFECTIOUS DISEASE
COMMUNICABLE:
- transmitted either DIRECTLY or INDIRECTLY from host to new host
- can be CONTAGIOUS (easily spread–ex. chicken pox + measles)
NON-COMMUNICABLE:
- does NOT SPREAD from one host to another
(ex. spread of C. tetani through needle)
describe OCCURRENCE of INFECTIOUS DISEASE
- terms of INCIDENCE and PREVALENCE
definition of INCIDENCE
the NUMBER OF PEOPLE who develop disease during a PARTICULAR TIME PERIOD
definition of PREVALENCE
- describes how ALL INDIVIDUALS are AFFECTED BY DISEASE at a GIVEN TIME
- describes HOW WIDESPREAD IT IS
what are the types of FREQUENCIES of OCCURENCE of INFECTIOUS DISEASE?
- SPORADIC DISEASE
- ENDEMIC DISEASE
- EPIDEMIC DISEASE
- PANDEMIC
definition of SPORADIC DISEASE
- occurs occasionally
- ex. typhoid fever
definition of ENDEMIC DISEASE
- always and CONSTANTLY PRESENT within the population
- ex. the common cold, rabies in squirrels
definition of EPIDEMIC DISEASE
- where MANY PEOPLE in ONE AREA acquires disease
definition of PANDEMIC
- an EPIDEMIC DISEASE that occurs worldwide
describe the various SEVERITIES and DURATIONS of DISEASE
ACUTE:
- develops RAPIDLY but LASTS a SHORT TIME
CHRONIC:
- develops SLOWLY and LASTS for a LONG TIME
ex. mono
LATENT:
- the causative agents remain HIDDEN and INACTIVE for a TIME before causing disease
ex. shingles
infections can be: (3)
- LOCAL
- SYSTEMIC
- FOCAL; infection starts at local site and spreads to the rest of the body
definition of PRIMARY INFECTION
acute infection causing initial illness
definition of SECONDARY INFECTION
subsequent infection caused by an OPPORTUNISTIC PATHOGEN that takes advantage of a weakened immune system,
definition of SEPSIS and SEPTICEMIA
SEPSIS:
- a TOXIC INFLAMMATORY CONDITION that begins to ARISE from SEPTICEMIA
SEPTICEMIA:
- systemic INFECTION due to PATHOGEN in the bLOOD
types:
- BACTEREMIA
- VIREMIA
- TOXEMIA
why are VACCINES so important?
- can help PROVIDE LONG TERM PROTECTION
- can also PROVIDE HERD IMMUNITY
what is HERD IMMUNITY?
If the majority of the population is immune to the disease, the nonimmune minority will be protected because there is reduced exposure to the disease
what is the SEQUENCE OF EVENTS that occur during infection?
- SOURCE OF PATHOGEN
- TRANSMISSION TO SUSCEPTIBLE HOST
- INVASION
- PATHOGENESIS AND DISEASE DEVELOPMENT
definition of RESERVOIRS OF INFECTION
a continual source of the disease causing organism
what are our TYPES OF RESERVOIRS?
- HUMAN RESERVOIRS
(ex. sick people or carries [latent]) - ANIMAL RESERVOIRS
(ZOONOSIS–disease in animals and transmitted to humans–ex. rabies, anthrax, and plague) - NON-LIVING RESERVOIRS
(ex. soil–ring worm/C. tetani, water–vibrio/amoeba)
what are the types of TRANSMISSION (3)?
DIRECT CONTACT:
- have person to person transmission through PHYSICAL CONTACT between the source and susceptible host
INDIRECT CONTACT:
- transmission from the SOURCE TO HOST by NON-LIVING OBJECTS known as FORMITES
DROPLET CONTACT:
- presence of MUCUS DROPLETS that TRAVEL SHORT DISTANCES ex. like coughing or sneezing
definition of VEHICLE TRANSMISSION (3)
disease that is transported by a MEDIUM
such as WATERBORNE
- ex. poorly treated sewage
FOODBORNE
- under cooked or poorly refrigerated
AIRBORNE
- droplets or dust particles
definition of VECTORS and what TYPE OF VECTORS do we have?
animals that carry pathogens from ONE HOST to ANOTHER
TYPES:
- MECHANICAL (organism that is JUST CARRIED by the VECTOR)
- BIOLOGICAL (organism DIVIDES and GROWS in VECTOR)
describe the (5) PERIODS within DISEASE DEVELOPMENT
- INCUBATION PERIOD
- the INTERVAL between INFECTION and FIRST APPERANCE of SYMPTOMS (variable and contagious at this stage)
- PRODROMAL PERIOD
- short period; showing of EARLY MILD SYMPTOMS
- PERIOD OF ILLNESS
- showing of SEVERE SYMPTOMS
- PERIOD OF DECLINE
- SUBSIDING SIGNS of disease
- RECOVERY OF IMMUNE SYSTEM–susceptible still to secondary infection
- CONVALESCENCE
what are some PREDISPOSING FACTORS that can make one SUSCEPTIBLE TO DISEASE (6)?
- GENDER
- GENETICS
- NUTRITION
- AGE
- LIFESTYLE
- PREEXISTING ILLNESS
describe HEALTHCARE-ASSOCIATED INFECTIONS HAIS
specific infections that one gets while getting TREATMENT at a HEALTH CARE FACILITY–also known as NOSOCOMIAL INFECTIONS
- around 1 in 25 patients have at least ONE HAI
what are the THREE FACTORS INVOLVED IN HIAS?
- MICROORGANISMS within a HOSPITAL ENVIRONMENT
- COMPROMISED HOST
- CHAIN OF TRANSMISSION
why are HAIs so prevalent in hospitals? Why doesn’t regular rotations of medicine work to kill them off?
- patients are NOW COMPROMISED within their IMMUNE SYSTEM
- MICROORGANISMS can become ANTIBIOTIC RESISTANT–so commonly seen in hospitals
definition of COMPROMISED HOST
host whose resistance to infection is DECREASED due to disease or therapy
what are the TWO MAIN CONDITIONS where the HOST IS COMPROMISED?
- BROKEN SKIN or MUCUS
- seen in wounds, burns, ventilators, or other invasive procedures
- SUPPRESSED IMMUNE SYSTEM
- drug/radiation therapy, steroids, diabetes, leukemia etc..
how can we CONTROL the SPREAD OF HAIS?
- have to REDUCE THE NUMBER OF MICROORGANISMS
- use of HANDWASHING!!
definition of EMERGING INFECTIOUS DISEASES and why are they INCREASING?
EMI:
- NEW INFECTIONS or OLD ONES that are CHANGING and SHOWING INCREASED INCIDENCE
FACTORS:
- NEW STRAINS
- GLOBAL WARMING
- NEW AREAS OF SPREAD due to MODERN TRANSPORT
- ECOLOGICAL CHANGES
- ANIMAL CONTROL MEASURES
- failure of PUBLIC HEALTH MEASURES
definition of EPIDEMIOLOGY
the SCIENCE that studies WHEN AND WHERE diseases occur and HOW THEY ARE TRANSMITTED in a POPULATION
what do EPIDEMIOLOGISTS DETERMINE?
the ETIOLOGY (cause of the DISEASE)
- look at certain PATTERNS concerning AGE, GENDER, OCCUPATION, SITE OF CONTACT and PERIOD the disease occurs
what are the THREE BASIC TYPES OF EPIDEMOLOGY?
- DESCRIPTIVE
- collect ALL DATA and RECONSTRUCT the OCCURRENCE OF THE DISEASE
- can also be RETROSPECTIVE–basic backtracking
- ANALYTICAL
- finding the CAUSE OF the PARTICULAR DISEASE
- comparing TWO GROUPS OF PEOPLE who HAVE and DO NOT HAVE THE DISEASE–looking for the CAUSE OF DISEASE
- EXPERIMENTAL
- developing a HYPOTHESIS and using EXPERIMENTS to TEST HYPOTHESIS
