Principles od disease and epidemiology for exam 3

THE WAR WITH MICROBES...

Monday, February 27, 2012

PRINCIPLES OF DISEASE AND EPIDEMIOLOGY


DEFINING TERMS..Pathogenicity: ability to cause disease

Pathogenesis: steps or mechanism involved in the development of the disease

Infection: colonization by a pathogen (may cause or not cause a disease)

Infectious disease: disease caused by the microorganism


DEFINING TERMS...Localized infections: localized to one site (pimples, boils, abscess)

Systemic infections: has spread throughout the body (e.g. miliary TB)

Acute: rapid onset of disease and rapid recovery (e.g. measles. mumps, flu)

Chronic: slow onset of disease and last a long time (e.g. HIV/AIDS, TB, leprosy)


DEFINING TERMS...Signs: subjective evidences of the disease experienced by the patient (aches, pains, itching, etc)

Symptoms: objective evidence of the disease (verified by laboratory tests (heart rate, lumps via scans, etc)

Latent: symptomatic to asymptomatic to symptomatic (e.g. herpes)

Primary infection: first disease

Secondary infection: complications due to opportunistic pathogens


STAGES OF DISEASE


TRANSMISSION: MEANS OF SPREAD

Contact...Aerosols...Droplets...Oral-Fecal, Vectors, Vehicles


REPORTING DISEASES & SURVEILLANCE

MORBIDITY (The rate of incidence of a notifiable disease) = How many got sick?

MORTALITY (deaths from notifiable diseases) = How many died?



PREVALENCE (The total number of cases of a disease in a given population at a specific time)

INCIDENCE (number of new cases during some time period)



DALYs (disability-adjusted life year)

Estimate the number of years of life lost due to premature death and any years lost in disability

Used by policy makers to determine the level of funding for prevention programs, treatment efforts, and research


FEB 28, 2012


CALENDAR UPDATEFEB 28-MAR 6

Last lectures for Exam 3

MAR 9-13

Journal Reporting

MAR 16

Exam 3

MAR 23

Bio 120 PFG


THE CAST IN THE WAR


STEPS IN PATHOGENESIS


VIRULENCE FACTORS

1. Bacterial Structures (flagella, capsules, pili)

2. Enzymes (coagulase, kinases, hyaluronidase, lecithinase, necrotizing enzymes)

3. Toxins (exotoxins, endotoxins like neurotoxins and enterotoxins)


IMPORTANT ACTIONS OF TOXINS


How do genes get transferred laterally?

(from Redfield, Nat. Rev. Genet. 2001)

Transduction:via bacteriophage

Transformation:integrating free DNAor plasmids

Conjugation:direct contact


How do genes get transferred laterally?

(from Redfield, Nat. Rev. Genet. 2001)

Transduction:via bacteriophage

Transformation:integrating free DNAor plasmids

Conjugation:direct contact

Staph aureus = plasmid (B-lactamase, tets, eryth, amynoglycosides); chromosome (nafcillin, meth, oxacillin); tolerance


FOR VIRUSES...


ENVIRONMENT FACTORS: Enabling or Preventing InfectionProbability of Encounters Between Host and Agent

Climate Change and Weather Disturbances

Health Care Advances

Industrialization and Land Use

Non-Adherence to PH and good hygiene practices


ENABLING ENVIRONMENT


PREVENTIVE ENVIRONMENT


CLIMATE CHANGE AND WEATHER DISTURBANCES


HEALTH CARE ADVANCES & DEMOGRAPHIC CHANGES


Principles od disease and epidemiology for exam 3

Health & Medicine

Transcript of Principles od disease and epidemiology for exam 3