Principles od disease and epidemiology for exam 3

THE WAR WITH MICROBES...

Monday, February 27, 2012

PRINCIPLES OF DISEASE AND EPIDEMIOLOGY

Monday, February 27, 2012

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

Monday, February 27, 2012

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)

Monday, February 27, 2012

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

Monday, February 27, 2012

STAGES OF DISEASE

Monday, February 27, 2012

TRANSMISSION: MEANS OF SPREAD

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

Monday, February 27, 2012

REPORTING DISEASES & SURVEILLANCE

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

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

Monday, February 27, 2012

REPORTING DISEASES & SURVEILLANCE

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)

Monday, February 27, 2012

REPORTING DISEASES & SURVEILLANCE

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

Monday, February 27, 2012

FEB 28, 2012

Monday, February 27, 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

Monday, February 27, 2012

THE CAST IN THE WAR

Monday, February 27, 2012

THE CAST IN THE WAR

Monday, February 27, 2012

THE CAST IN THE WAR

Monday, February 27, 2012

THE CAST IN THE WAR

Monday, February 27, 2012

STEPS IN PATHOGENESIS

Monday, February 27, 2012

VIRULENCE FACTORS

1. Bacterial Structures (flagella, capsules, pili)

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

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

Monday, February 27, 2012

IMPORTANT ACTIONS OF TOXINS

Monday, February 27, 2012

How do genes get transferred laterally?

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

Transduction:via bacteriophage

Transformation:integrating free DNAor plasmids

Conjugation:direct contact

Monday, February 27, 2012

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

Monday, February 27, 2012

FOR VIRUSES...

Monday, February 27, 2012

Monday, February 27, 2012

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

Monday, February 27, 2012

ENABLING ENVIRONMENT

Monday, February 27, 2012

PREVENTIVE ENVIRONMENT

Monday, February 27, 2012

CLIMATE CHANGE AND WEATHER DISTURBANCES

Monday, February 27, 2012

HEALTH CARE ADVANCES & DEMOGRAPHIC CHANGES

Monday, February 27, 2012