Lecture 14 - Principles of Disease & Epidemiology Flashcards
etiology
the cause of a disease
pathogenesis
how a disease develops
-genesis
to produce/origin
path/o
disease
virulence factors
factors that make a pathogen more pathogenic
What is the basis for disease?
cellular damage
signs
OBJECTIVE evidence of disease and can be measured
(temp, blood pressure, sweating, etc)
symptoms
SUBJECTIVE evidence of disease - cannot be observed by others, but can be explained by the patient
(throbbing, pain, headache, hot, etc)
Is bacteria ever normally found internally?
No.
Bacteria should only ever be found on external surfaces (remember: your GI tract is considered external).
What percent of your cells are bacteria versus human?
90% bacteria
10% human
Lactobacillus accidophilus produces _______.
Lactic Acid
competetive inhibition AKA microbial antagonism
normal bacteria protect against harmful microorganism simply by taking up space so that there is no room for harmful microorganisms to easily take up residence and cause adverse effects
Where in the body is Lactobacillus acidophilus commonly found?
the vagina
Symbiotic Relationship
the relationship between two species
Name the 3 main types of Symbiotic Relationships
- Mutualism
- Commensalism
- Parasitism
Mutualism
both organisms benefit
Parasitism
one oragnism benefits while the other is harmed
Commensalism
one organism benefits while the other is unaffected
What two vitamins does E. coli produce?
B12 and K vitamins
When is it strongly recommended to take probiotics?
When you are on strong antibiotics
- this helps to replace bacteria killed off by the antibiotic with bacteria that will be beneficial to you
Prebiotics
contains carbohydrates to feed the probiotics
Common treatment for C. diff
Fecal Transplant AKA Fecal Bacteriotherapy
What is the purpose of preempt probiotics?
It is sprayed onto baby chicks so that it will eventually get into their gut and competetively inhibit the growth of harmful bacteria such as salmonella
opportunistic pathogen
bacteria that are normally harmless, but become harmful when they get somewhere in the body where they normally are not found or the person is immunocompromised
Where in the body is Neisseria meningitidis normally found?
the respiratory tract
ectopic
an abnormal place or position
Koch’s Postulates
specific microbes cause specific diseases
i.e. Bacillus anthracis causes anthrax
List a few limitations to Koch’s Postulates
- not all pathogens can be easily cultured
- some illnesses (signs and symptoms) can be caused by several different pathogens
- some pathogens can cause several different diseases depending where it settles in the body
communicable disease
disease that spreads from one person to another
Direct Transmission of Disease
direct transmission of disease from one host to another
(i.e. kissing/sex, droplets less than 1 meter distance, bites from vectors such as mosquitoes or fleas)
Indirect Transmission
transmission of disease from food, water, air droplets that have traveled a long distance, or fomites
fomite
contaminated objects carrying pathogenic bacteria
(i.e. doorknobs, utensils, clothes, etc)
zoonotic disease
disease tranmitted from animals to people
(i.e rabies)
reservoir
source of infection
noncommunicable disease
diseases that cannot be passed from one person to another (i.e. cancer, diabetes, UTI, tetanus)
incidence
the number of NEW cases of disease
prevalence
the TOTAL number of cases of disease (new and old combined)
endemic
the regular occurence of disease within an area
epidemic
the widespread occurence of a disease within an area at a particular time
pandemic
widespread occurence of disease
(generally transcending national boundaries)
Which type of viruses mutate faster? DNA or RNA viruses?
RNA virues
Describe the Stages of Disease
- Incubation Period: the person is infected, but has no signs or symptoms yet
- Prodromal Period: early, non-specific signs and symptoms of disease #malaise
- Period of Illness
- Death (IF the immune system or medical treatments fail)
- Period of Decline - signs and symptoms start to improve as the pathogen is killed off
- Period of Convalescence
Incubation Period
the time in which a person is infected with a pathogen before they begin to exhibit signs and symptoms
Prodromal Period
the period of time in which one has been infected with a pathogen, but it’s still early and signs and symptoms experienced are non-specific (i.e. feeling of malaise)
Period of Convalescence
the period in which a person is nearly fully recovered from their illness
Nosocomial Infections
infections acquired at a hospital or other healthcare setting
Iatrogenic Disease
infections acquired due to the careless actions of a healthcare worker
Two Most Common Sites of Nosocomial Infections
UTIs & Surgical Site Infections
UTI
urinary tract infection
Emerging Infection Diseases
diseases that are new or changing or showing an increase in incidence
Notifiable Infectious Disease
diseases which providers are required by law to reprot to the US Public Health Service when a patient is diagnosed
MMWR
Morbitity & Mortality Weekly Report
morbidity
sickness
mortality
death
the number of NEW cases of disease
incidence
the TOTAL number of cases of disease (new and old combined)
prevalence
the regular occurence of disease within an area
endemic
the widespread occurence of a disease within an area at a particular time
epidemic
CDC
Centers for Disease Control
The CDC is an agency within the _______.
US Public Health Service