the branch of medical science that studies the causes and nature and effects of diseases
(medicine) the invasion of the body by pathogenic microorganisms and their multiplication which can lead to tissue damage and disease
What does pathology look at?
1. Cause of disease
2. Development of disease
3. State of disease
the multiplication of MO's on or within a host that does not result in cellular injury
ex: normal flora in the intestines however if host susceptibility increases or MO's virulence increases, colonized MO's can become infection
any infection of colonization that cause a change in normal state of health of an individual (37 degrees celcius is normal body temp)
MO's that occur or have adapted , organisms that live inside our bodies without ordinarily causing disease.
areas of body that have normal flora
skin, upper respiratory tract, intestines, external eyes and mouth
a benefit of normal flora, Typically normal flora inhabit and colonize the body and prevent other pathogens from colonizing on the body. Microbes competing against one another for space and nutrients.
sterile body parts
kidney, brain, liver, blood, urine, cerebrospinal fluid
are microorganisms that are present on an animal for a short period of time. can be acquired from the air, water, soil, other people, or animals. ex: staphylococcus aureus and gram negative coliforms such as E. coli from handshakes or doorknob
normal flora that can be potential pathogen if health is compromised
MOs that cause disease
series of microbes that cause problems during pregnancy S=Syphilis, T=Toxoplasmosis, O=Other(Hep B, AIDS, Chlamydia), R=Rubella, C=Cytomegalovirus, H=Herpes simplex. Complications of STORCH include spontaneous abortion, congenital abnormalities, brain damage, prematurity, and stillbirths
infection that is confined to a particular part of the body and is indicated by a lesion containing pus
ex: wart, boils, fungal skin infection
when infectious agent breaks loose from a local infection and is carried to other tissues
An infection throughout the body
ex: bacteremia (presence of bacteria in blood)
septicemia (multiplication of bacteria in blood)
toxemia (toxins in blood)
mixed and concurrent infection
cooperate in breaking down tissues such as gangrene
an acute infection that causes the initial illness
caused by opportunistic microbe after primary weakened host
comes on rapidly, with severe but short-lived effects
infection that occurs slowly, over a very long period, and may last months or years
person carries the pathogen, but does not have symptoms (polio or hepatitis A can be carried this way)
portal of entry
Refers to the method by which the pathogen enters the body, depends on size attachment and virulence.
the infection or disease originates outside the body
the infection or disease originates within the body
Portal of Entry in Integumenatry System
throught a break in the integrity of skin and mucous membranes such as infections of surgical wounds.
Portal of entry in respiratory tract
inhaling contaminated droplets such as cold, flu, measles
Portal of Entry in Urogenital tract
through contact with infected vaginal secretions of semen as in STD
Portal of Entry in Gastrointestinal tract
by ingesting contaminated food or water such as typhoid or hepatitis A
portal of entry in circulatory system
portal of entry by transpacental
penetrate the placenta and infect the fetus
Development of Disease
Incubation Period: no symptoms 2.Prodromal Period: mild symptoms 3. Period of Illness: disease is acute and patient may die 4. Period of decline: symptoms lessen 5. Period Convalescence: recovery (still contagious)
Portal of Exit
pathway by which pathogens leave body of a host; ie. urine, blood, respiratory droplets
n. the branch of medicine that studies the causes, spread, and control of disease in populations
W's plus how of Epidemiology
Who, what, where, when, why and how
By law : Diseases that need to be reported to public health authorities
continual sources of microbes, non living things, animals
animals that carry pathogens from person to person
diseases that occur in animals and can be transmitted to humans 150 known (eg, rabies, lymes, anthrax, ringworm, tapeworm)
Inanimate objects that can spread disease. Fomites.
Ie, c. botulinum in soil, bedding, clothing, syringes, food, water, etc.
Often fecal-oral in transmission route.
direct contact transmission
Person-to-person transmission. No intermediate object is involved. i.e. touching, kissing, sexual intercourse
indirect contact transmission
Spread of pathogens from one host to another via inanimate objects called fomites
inanimate objects that serve as reservoirs for microbes e.g. contaminated medical equipment
Method of spreading disease from respiratory secretion through the air. Spread is usually confined to within 3 feet of the infected patient.
a disease that may be transmitted directly or indirectly from one individual to another
easily spread from person to person
organism that is not transmittable from one individual to another
Frequency of Death
Disease that occurs occasionally and at random intervals in a population.
diseases that are constantly present in the population
A sudden and simultaneous outbreak or increase in the number of cases of disease in a community
ex : (STD, measles)
An outbreak of a disease that spreads worldwide.
ex: AIDS, influenza
Case Reporting agencies
CDC (Centers for Disease Control and Prevention)
WHO (World Health Organization)
NYSDOH (New York State Dept. of Health)
Detective work involving careful tabulation of data:
Locations and times
Patient's ages, genders, occupations, health histories, socioeconomic groupings, etc. (backtrack to find cause of disease)
analyzes the cause of the disease and the effect of the disease in a given population vs. an uninfected group
Test hypothesis such as effectiveness of a drug
is a acquired by an individual in a healthcare facility
drug resistant strains
methicillin resistant staphylococcus aureus
Methicillin Resistant Staph Epidermis
vancomycin resistant enterococcus
bacteria in intestines of animals and humans
pneumonia, hospital acquired
nosocomial or opportunistic infections in immunocompromised patients and in those who are on mechanical ventilation, urinary catheters, UTIs
Folliculitis (hot tub use)
Aquatic enviornments; disinfectant resistant (hospitals)
Most post-operative wound infections
exist in the GI tract in large numbers. common nosocomial infection.
Host with lowered resistance to infection and disease for any reason (for example, malnutrition, illness, trauma, or immunosuppression).
suppressed immune system
term used to describe an immune system unable to function normally due to the presence of a disease such as AIDS.
a procedure that requires penetrating intact skin or mucous membranes
chain of transmission
• Routes of transmission are a concern
- Direct transmission from staff to patient
staff---->patient (hand washing)
- Direct transmission from patient to patient
- Indirect transmission through fomites
formites--->remote in patients room
- Indirect transmission through ventilation
ventalation--->staph on dust
handwashing, disinfection, sanitation, patient isolation
Infection Control Committee
Conducts epidemiologic studies for patient and employee protection.
Provides education to patients and employees on safeguarding against infectious diseases.
Clinical Microbiology Laboatory
monitors types and numbers of pathogens, participates in infection control
The best descriptive term for the resident microbes is
a. commensals c. pathogens
b. parasites d. contaminants
Resident microbiota is commonly found in the
a. liver c. salivary glands
b. kidney d. urethra
Normal resident microbes are absent from the
a. pharynx c. intestine
b. lungs d. hair follicles
d. all of these
Virulence factors include
d. all of these
the term for the microbes that are normally present in and on the human body; usually beneficial
the degree to which a pathogen can cause disease
break red blood cells
c. damage red blood cells
The specific action of hemolysins is to
a. damage white blood cells
b. cause fever
c. damage red blood cells
d. cause leukocytosis
period of incubation
The ______ is the time that lapses between encounter with a pathogen and the first symtoms.
A short period early in a disease that manifests with general malaise and achiness is the
The presence of a few bacteria in the blood is termed
d. a secondary infection
A ______ infection is acquired in a hospital.
passive animal transporter, an organism that transmits a parasite, but is not part of the parasites' life cycle, for example- flies, roaches, and rodents
disease carrying organism that spreads infectious disease
infectious disease that does not arrive through transmission of infectious agent from host to host ex. tetanus
abnormally large increase in the number of white blood cells
native or confined to a particular region or people
b. inoculate a test animal to observe the disease
Which of the following is not a condiditon of Koch's postulates?
a. isolate the causative agent of a disease
b. cultivate the microbe in a lab
c. incoculate a test animal to observe the disease
d. test the effects of a pathogen on humans