Microbiology: An Introduction - Principles of Disease and Epidemiology

Flashcards covering key vocabulary related to the principles of disease and epidemiology in microbiology.

Pathology

The study of disease.

Etiology

The cause of a disease.

Pathogenesis

The manner in which a disease develops.

Infection

Invasion or colonization of the body by pathogens.

Infectious Disease

Occurs when an infection results in any change in the state of health.

Normal Microbiota (Normal Flora)

Microorganisms that permanently colonize the host and do not cause disease under normal conditions.

Transient Microbiota

Microorganisms that may be present for days, weeks, or months and then disappear.

Microbial Antagonism (Competitive Exclusion)

Competition between microbes; normal microbiota protect the host.

Symbiosis

A relationship between organisms in which at least one organism is dependent on the other.

Commensalism

One organism benefits, and the other is unaffected.

Mutualism

Both organisms benefit.

Parasitism

One organism benefits at the expense of the other.

Opportunistic Pathogens

Normal microbiota that can cause disease under certain conditions.

Koch's Postulates

A set of criteria used to prove the cause of an infectious disease.

Communicable Disease

A disease that is spread from one host to another.

Contagious Disease

Diseases that are easily and rapidly spread from one host to another.

Noncommunicable Disease

A disease that is not spread from one host to another.

Incidence

Number of people who develop a disease during a particular time period.

Prevalence

Number of people who have a disease at a specified time, regardless of when it first appeared.

Sporadic Disease

Disease that occurs only occasionally.

Endemic Disease

Disease constantly present in a population.

Epidemic Disease

Disease acquired by many people in a given area in a short time.

Pandemic Disease

Worldwide epidemic.

Acute Disease

Symptoms develop rapidly but has a short duration.

Chronic Disease

Symptoms develop slowly, likely to last for a long period.

Latent Disease

Causative agent is inactive for a time but then activates and produces symptoms.

Herd Immunity

Immunity in most of a population.

Infection Fatality Ratio (IFR)

Divide the number of deaths attributed to a disease by the total number of infected individuals within a specific time period.

Case Fatality Ratio (CFR)

Proportion of individuals diagnosed with a disease who die from that disease within a certain period of time.

Local Infection

Pathogens are limited to a small area of the body.

Systemic (Generalized) Infection

An infection spread throughout the body by the blood and lymph.

Focal Infection

Systemic infection that began as a local infection.

Sepsis

Toxic inflammatory condition arising from the spread of microbes, especially bacteria or their toxins, from a focus of infection.

Bacteremia

Bacteria in the blood.

Septicemia

Growth of bacteria in the blood; bacteria are proliferating in the blood.

Toxemia

Toxins in the blood.

Viremia

Viruses in the blood.

Primary Infection

Acute infection that causes the initial illness.

Secondary Infection

Opportunistic infection after a primary (predisposing) infection.

Subclinical Infection

No noticeable signs or symptoms (inapparent infection, asymptomatic infection).

Predisposing Factors

Variables that make the body more susceptible to disease or may alter the course of a disease.

Incubation Period

Interval between initial infection and first signs and symptoms.

Prodromal Period

Short period after incubation; early, mild nonspecific symptoms.

Period of Illness

Disease is most severe.

Period of Decline

Signs and symptoms subside.

Period of Convalescence

Body returns to its prediseased state; recovery.

Reservoir of Infection

Continual sources of infection.

Zoonoses

Diseases primarily in wild and domestic animals that can be transmitted to humans.

Fomite

A nonliving object that spreads infection to a host.

Healthcare-Associated Infections (HAIs)

Infections acquired while receiving treatment in a healthcare facility.

Compromised Host

An individual whose resistance to infection is impaired by disease, therapy, or burns.

Emerging Infectious Diseases

Diseases that are new or changing, increasing in incidence, or showing a potential to increase in the near future.

Epidemiology

The study of where and when diseases occur and how they are transmitted in populations.

Morbidity

Incidence of a specific notifiable disease.

Mortality

Deaths from notifiable diseases.

Notifiable Infectious Diseases

Diseases in which physicians are required to report occurrence.

Morbidity Rate

Number of people affected in relation to the total population in a given time period.

Mortality Rate

Number of deaths from a disease in relation to the total population in a given time period.