Public Health I
Public health is the intersection between which two fields?
Microbiology and epidemiology
At what hierarchical level do we conduct epidemiological analyses?
Population
Can a pathogen have more than one living reservoir?
Yes
Are communicable and noncommunicable diseases both infectious? What's the difference between communicable and noncommunicable diseases?
Yes. Communicable can be spread person to person, but noncommunicable cannot
What was Paul Ehrlich's contribution to the field of antimicrobials? What about Alexander Fleming?
Ehrlich made the magic bullet which was a synthetic antibiotic that targeted syphilis. Fleming discovered the natural antibiotic penicillin.
What is epidemiology?
The study of how disease originates and spreads through a populations with the goal of preventing outbreaks and containing them when they occur
What is the term for the particular thing causing a disease?
Etiologic or causative agent
What is a reservoir of a disease?
Places (living organism or nonliving site like water or soil) for a pathogen to live and to persist for long periods of times
What is the difference between acute, chronic, and latent diseases?
Acute = short and rapid
Chronic = longer time
Latent = dormant for extended periods of time
What are the two primary classifications of antibiotics? What do they do?
Bacteriostatic: cause a reversible inhibition of growth
Bactericidal: kills target bacteria
How are prevalence and incidence different?
Prevalence is the number, or proportion, of individuals with a particular illness in a given population at a point in time. Incidence is the number or proportion of new cases in a period of time.
What is etiology?
The study of the causes of disease
What is a zoonotic disease?
Animals acting as reservoirs of human disease and transmitting the infectious agent to humans through direct or indirect contact. In some cases, the disease also affects the animal
What are the 5 periods of disease?
Incubation, Prodromal, Illness, Decline, Convalescence
What's the difference between narrow-spectrum and broad-spectrum antimicrobials? How do they contribute to drug resistance?
Narrow-spectrum antimicrobials target only specific subsets of bacterial pathogens
Broad-spectrum target a wide variety of bacterial pathogens, including gram-positive and gram-negative bacteria (contributes most to resistance)
How are morbidity and mortality different? How are they measured?
Morbidity is being diseased, mortality is death. These can be measured and expressed as rates which are often the percent of a population
What are the national and international health organizations? What do they do?
CDC and WHO
They track diseases that are notifiable and reportable (emerging, reemerging, etc.) and aim to protect the public from disease and injury
What's the difference between a passive and active carrier?
Passive carriers are contaminated with the pathogen and can mechanically transmit it to another host are not infected. Active carriers are infected individuals who can transmit the disease to others.
Name and explain the four types of communicable diseases.
Contagious = easy spread communicable diseases
Iatrogenic disease = contracted as a result of a medical procedure
Nosocomial disease = acquired in a hospital setting
Zoonotic = transmitted from animals to humans
Explain at least 3 mechanisms that bacteria can employ to become antibiotic resistant.
Develop new cell processes to avoid antibioitc's target, change or destroy the antibiotics with enzymes, restrict access by changing entryways or limiting numbers of them, change the antibiotics target so it no longer fits, gets rid of the antibiotics through pumps
Explain the common relationship between prevalence and incidence. Draw an example of how this could look on a graph.
As the incidence is steadily above zero, we see a steady increase in cases over time (prevalence)
What are the four primary patterns of incidence? Explain each briefly.
Sporadic diseases (seen only occasionally with no real pattern), endemic diseases (constantly present at a low level within a particular region), epidemic (larger than expected number of cases in a short time within a region), pandemic (epidemic on worldwide scale)
Explain the different types of disease transmission. (contact, vehicle, mechanical or biological vector)
Contact = direct (vertical (mother to child) or horizontal (sexual or droplet)) or indirect (fomites)
Vehicle = water, food, air
Mechanical = vector like a fly transferring to surface
Biological = vector like arthropod biting
Explain what's happening at each of the stages of disease.
Incubation: entry of pathogen, pathogen multiplies
Prodromal: continues to multiply, starts causing signs and symptoms
Illness: most obvious signs/symptoms
Decline: less severe response
Convalescence: returns to normal
Explain the two main tests to determine the effectiveness of antimicrobials
Kirby-Bauer Disk Diffusion test
Dilution test for minimum inhibitory concentration