Download - PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,
![Page 1: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/1.jpg)
PRINCIPLES OF DISEASE
![Page 2: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/2.jpg)
Symbiosis
• Relationship between 2 or more species
• Mutualism- both benefit,
![Page 3: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/3.jpg)
Symbiosis
• Commensalism-one benefits and other unaffected
![Page 4: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/4.jpg)
Parasitism
• One benefits at expense of other
• Pathogen-causes disease
• Metabolically unstable relationship
• Host dies or eliminates pathogen
• Most successful parasites
![Page 5: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/5.jpg)
Parasitism
• Host under continuous pressure from infection
• Battle between host & parasite
• Emergence of new & return of old infectious diseases
![Page 6: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/6.jpg)
Pathogenicity
• Capacity to produce disease– Adherence– Multiply on host– Ability to invade host or cause damage– Avoid being damaged by host’ defenses– Depends upon # of organisms
![Page 7: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/7.jpg)
Virulence
• Intensity of disease produced
![Page 8: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/8.jpg)
Terms
• Contamination
• Infection- multiples and invades tissue
• Disease- disrupts state of health
![Page 9: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/9.jpg)
Normal Flora
• 1 x10 13 body cells with 1 X1014 bacterial cell
• Resident flora always present
![Page 10: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/10.jpg)
Normal Flora
• Resident flora
• Transient flora
![Page 11: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/11.jpg)
Opportunists
• Usually cause no disease
• Conditions allow them to cause disease
![Page 12: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/12.jpg)
Opportunists
• Intro of bug into unusual body sites
• Disturbance of normal flora
![Page 13: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/13.jpg)
Advantage of Normal Flora
• Ensures normal development of immune system
• Prevent over growth of harmful organism-microbial antagonism
![Page 14: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/14.jpg)
Microbial Antagonism
• Normal flora in colon prevents overgrowth of C. difficile
• E. coli produces bacteriocins
![Page 15: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/15.jpg)
Disadvantage of Normal Flora
• Potential for spread into sterile parts of body
• Intestine may perforate
• Skin broken
• Extraction of tooth
• Perianal skin flora enters urinary tract
![Page 16: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/16.jpg)
Etiology
• Cause of disease• Koch’s postulates-organism causes disease
![Page 17: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/17.jpg)
Frequency of Disease
• Endemic– Always present in population
• Epidemic– Occurs in unusually high number of people
• Pandemic-– Epidemics world wide
![Page 18: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/18.jpg)
Types of Infectious Diseases
• Acute -develops rapidly but lasts for short time- influenza
• Chronic disease -develops more slowly and continues or recurs for long periods -TB, hepatitis B
• Latent- agent remains inactive for a time and later becomes active-shingles
![Page 19: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/19.jpg)
Herd Immunity
• Proportion of people in community who are immune
• Important in cyclic diseases• If high, disease can only spread among
susceptible people
• Loss of herd can lead to reemergence of disease
![Page 20: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/20.jpg)
Extent of Disease
• Local infection-limited to small area of body- boils
• Focal - starts as local infection (sinus or teeth) then enter blood or lymph and spreads
• Systemic -organisms or products spread through out body-measles
• Bacteremia- presence of bacteria in blood
![Page 21: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/21.jpg)
Extent of Disease
• Septicemia-bacteria multiplies in blood
• Toxemia-toxins in blood
• Viremia-virus in blood
• Subclinical (inapparent )- no noticeable illness-hepatitis A
• Primary disease- initial acute infection
• Secondary infection -opportunistic infection
![Page 22: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/22.jpg)
Stages of Disease
• Incubation period-time between initial infection and first appearance of S&S
![Page 23: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/23.jpg)
Prodromal Period
• Short period–only in some diseases
![Page 24: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/24.jpg)
Invasive Period
• Period of illness-most acute
• Overt signs and symptoms
• Cough, sore throat
![Page 25: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/25.jpg)
Decline/Convalescence
• S&S subside
• Regain strength and recovery
![Page 26: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/26.jpg)
Epidemiology
• Study of mechanism and factors involved in the frequency and spread of disease
• Incidence of diseases
• Prevalence of diseases
![Page 27: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/27.jpg)
People FoodEquipment
Entry
Transmission
Reservoir
Portal ofExit
InfectingAgentsSusceptibl
e Host Bacteria Parasites Viruses
Respiratory SystemGI & GU System
Direct ContactIndirect Contact
AirborneDroplet
Broken Skin Respiratory System
GI & GU System
Elderly & Young
Pts w/ Chronic Illness
Diabetic
Use of Invasive Equip
Chain of Infection
![Page 28: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/28.jpg)
Spread of Disease
• Chain of infection• Agent- pathogen• Reservoir-source/site of organism• Human reservoirs
• Animal reservoirs -zoonoses
![Page 29: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/29.jpg)
Humans
• Sick people
• Carriers– Incubatory or asymptomatic carriers
• HIV but not AIDS• Hepatitis C
– Chronic carriers• Typhoid Mary excreted salmonella for years in feces• S. pyogenes in throat
![Page 30: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/30.jpg)
Animals
• Domestic and wild
• Mammals carry rabies-exposure to saliva
• Consume contaminated animals or products
• Arthropod borne-West Nile
• Zoonoses– Lyme disease: wild deer and mice– Hantavirus pulmonary disease: rodents
![Page 31: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/31.jpg)
Environmental Reservoirs
• Able to survive in nonliving reservoirs
• Soil: C. tetani – Humans produces toxin– Survives in soil by forming endospores
• Contaminated water
![Page 32: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/32.jpg)
Portal of Exit
• Via body fluid or feces– Respiratory tract– GI – GU– Nonintact skin-lesions, wounds
![Page 33: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/33.jpg)
Modes of Transmission
• Airborne– Tiny droplet nuclei vs large droplets– Dust particles– Suspended in air don’t fall– More likely to reach lower resp tract– Resistant to drying
• TB, measles and chicken pox
– Spread rapidly in crowded conditions
![Page 34: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/34.jpg)
Droplet
• Large droplets, short distances
• Mucous droplets -coughing , sneezing
• Pertussis, influenza, SARS
• Talking less transmission
![Page 35: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/35.jpg)
Contact
• Direct- person to person, touching ,sex, colds– Horizontal transmission – Fecal-oral transmission especially if public
health & hygiene lacking
![Page 36: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/36.jpg)
Contact
• Vertical– Parent to offspring-birth canal, breast milk,
placenta
• Indirect-via fomites-tissues, diapers , door knobs- hands– Normal person sheds skin atrr rate of 5 x10 8
per day
• Hep B, C, D, lice, STDs
![Page 37: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/37.jpg)
Vehicle
• Via medium-water, food, blood - Shigella in water or food, S. aureus
• Vector-arthropod– Mechanical-passive – Biological- active
•
![Page 38: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/38.jpg)
Portals of Entry
• Respiratory
• GI - in food and water
• GU-sexually transmitted microbes
• Non intact skin- parenteral
![Page 39: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/39.jpg)
Susceptible Host
• Imunocompromised
• Old age or young
• Not vaccinated
• Large inoculum
![Page 40: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/40.jpg)
Healthcare Infections
• Healthcare acquired– Exogenous
– Endogenous
![Page 41: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/41.jpg)
Consequences
• Serious illness or death
• Prolonged hospital stay
• Need for antimicrobial therapy
• Foci for spreading infection
![Page 42: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/42.jpg)
Controlling Disease Transmission
• Standard precautions-everyone
• Isolation for communicable diseases or bugs
![Page 43: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/43.jpg)
Prevention
• SSIs –prophylactic antibiotics
• Devices- central lines & ventilators
![Page 44: PRINCIPLES OF DISEASE. Symbiosis Relationship between 2 or more species Mutualism- both benefit,](https://reader030.vdocument.in/reader030/viewer/2022032706/56649e025503460f94aec767/html5/thumbnails/44.jpg)
Prevention
• Quarantine
• Immunization- influenza & pneumococcal
• Vector control