Chapter 13 - Microbe - Human Interactions: Infection, Disease, and Epidemiology

Which of the following is not a type of bacterial toxin?

• endotoxins

• exotonxins

• antibodies

• hemolysins

Antibodies

What are exogenous agents?

originating form source OUTSIDE the body

What is the correct order of stages for Clinical Infections:

1. Incubation

2. Prodromal

3. Invasion

4. Convascelent period

What happens during the period of invasion?

microbe multiplies and becomes well established

T or F: Among the microbial toxins able to destroy blood cells are hemolysins and leukocidins

True

What is NOT an example of an adhesion property microbes use to gain a foothold at a portal of entry?

Peptidoglycan

Highly communicable (easily spread) disease has a:

contagious agent

The B portion of the A-B exotoxin

binds the host cell with specificity

What best describes microbes that engage in mutual or commensal interactions with humans?

normal resident microbes

Exoenzymes like cellulase, amylase, and penicillinase are active

outside of the cell.

T or F: Edemas a sign of inflammation where there are walled-off collections of inflammatory cells and microbes.

False

The infectious dose is

defined as the MINIMUM number of microbes needed to cause infection

Which of the following describes a small number of microbes present in the blood but not necessarily multiplying?

bacteremia

What are antiphagocytic factors?

factors that prevent phagocytosis by the hosts phagocytic cells

Virulence factors:

increases effectiveness in invasion and cause of disease

What do Koch’s postulates show?

how to prove a microorganism causes a specific disease

Secondary infections occur…

after primary infection

What does “sequelae” mean?

a disease or condition has developed due to a previous condition or injury?

Chronic carriers are considered to be:

An individual who shelters the infectious agent for a long period

Nosocomial infections are

infections acquired during a hospital stay

How do humans initially acquire their microbiome?

from exposure after birth

The morbidity rate is the number of…

illnesses or diseases in a given period of time

When it comes to patterns of infections, sporadic means:

asingle case of infection unrelated to other episodes, occurs irregularly

Microbes that engage in mutual or commensal associations with humans are defined as:

Normal (Natural) Resident microbiota

What is the term defined as: a microbe that has penetrated the host defenses (immune system), invaded sterile tissue, and then multiplied

Infection

A disease is

damage to host, and creates a deviation/ disorder from health

What is a pathogen?

disease-causing microbe

When does initial colonization start

when you are a newborn

What are the seven major factors in the development of an infection?

1. portal of entry

2. adhesion

3. invasion

4. multiplication

5. infection of target

6. disease

7. portal of exit

In the development of an infection, the route a microbe follows to enter the tissues of the body to initiate an infection is termed

the portal of entry

Exogenous agents originate from sources

outside the body

Endogenous agents already exists

on or in the body

What are the main portals of entry on a human?

your skin, gastrointestinal tract, respiratory tract, urogenital tract, and transplacental

What are the main pathogens that infect during pregnancy: (think STARCH)

syphilis, toxoplasmosis, other disease (hepatitis B, AIDS, chlamydia), Rubella, cytomegalovirus, and herpes simplex virus

The MINIMUM number of microbes required for infection to proceed

Infections Dose (ID)

Microbes with smaller IDs have a ________ virulence.

greater

The binding between specific molecules on the host and pathogens is called

adhesion

What are virulence factors?

traits used to invade and establish themselves in the host —> they also determine the degree of tissue damage that occurs (severity of the disease)

What are the four main characteristics for virulence factors?

1. blocking phagocytosis

2. invasion factors

3. exoenzymes

4. toxins

Phagocytes are

cells that engulf and destroy pathogens

Antiphagocytic factors are used to

avoid phagocytosis

Leukpcidins are produced by species of Staphylococcus and Streptococcus and are _____ to WBC.

toxic

The ______ makes it phagocytosis difficult to occur.

slime layer/capsule

Exoenzymes or extracellular enzymes are:

enzymes that are secreted by a cell and function outside the cell ( the barriers/ structures)

ex. Staph or Strep

The capacity to produce toxins at the site of multiplication

toxigenicity

What are the two types of bacterial toxins:

1. endotoxin

2. exotoxin

_______ a toxin that is not secreted by is RELEASED after the cell is damaged.

Endotoxin

_____ is a toxin where the molecule is secreted by a living bacterial cell INTO the infected tissue.

Exotoxin

What are some characteristics of Exotoxins:

• hemolysins

• A-B toxins

• strong specificity

Capsules and slime layers can help pathogens invade the immune system by ________.

prevent phagocytic activity

What are the four main stages/ process of infection and disease for clinical infections?

1. incubation period

2. prodromal stage

3. period of invasion

4. convalescent period

What is the period of time from initial contact with the infectious agent to the appearance of the first symptoms?

Incubation period

The stage where there are vague nonspecific feelings of discomfort.

Prodromal stage

The _____ is the peak of infection, with specific signs and symptoms.

period of invasion

This is the last step in the process of infection where a person begins to respond to the infection, and symptoms decline.

convalescent period

What pattern of infection is where microbes enter the body and remain confined to a specific tissue?

localized infection

What pattern of infection is where infections spread to several sites and tissue fluids enter/ travel in the bloodstream.

systemic infection

What pattern of infection is when the infectious agent breaks loose from a local infection and is carried to other tissues.

focal infection

What pattern of infection is when several microbes grow simultaneously at the infection site

mixed infection

What pattern of infection is the initial infection

primary infection

What pattern of infection causes another infection by a different microbe

secondary infection

What pattern of infection comes on rapidly, with severe but short-lived effects/ symptoms?

acute infections

What pattern of infection is when there is progress however it still persists over periods of time

chronic infections

What is the state of infection when a person is MOST symptomatic?

period of invasion

What are the three main signs of inflammation:

1. edema

2. granulomas/ abscesses

3. lymphadenitis

When there is an increase in WBC

leykocytosis

When there is a decrease in WBC

leukopenia

When microorganisms are multiplying in the blood in larger numbers

septicemia

When an individual or host doesnt show any signs of disease, although is infected is called:

asymptomatic

What are the main portals of exit

1. respiratory (coughing or sneezing)

2. skin scales

3. fecal exit

4. urogenital tract

5. removal of blood

What is the term where an infection in which the pathogen is NOT active or causes disease:

latency

When a person with a latent infection sheds the infectious agent is called a ________ carrier.

chronic

The long-term or permanent damage to tissues or organs is called:

sequelae

A _____ is a source of transmission where it is the primary habitat of pathogens in the natural world.

reservoir

A ____ is an individual or object from which an infection is actually obtained

source/transmission

A living reservoir where an individual who shelters a pathogen and spreads it to others

carrier

Contaminated healthcare providers that pick up pathogens and transfers them to other patients are called ________carriers.

passive

If a nurse transfers a pathogen between patients without becoming infected herself, the nurse helps act as the:

passive carrier

Communicable disease is when an infected host can:

transmit the infectious agent to another host (host to host) and is highly contagious

Noncommunicable infectious disease doesn’t arise through host to host, and instead is spread from:

• A compromised person is invaded by their own microflora

• contact with organisms in their natural reservoir.

What is the term for an inanimate object that can transport a pathogen?

fomite

What are nosocomial infections:

a disease that is acquired or developed during a hospital stay (can be from the nurses, surgical procedures, equipment, etc.)

In epidemiology, ______ is the total number of existing cases with respect to the entire population (represented by a percentage of the population)

prevalence

In epidemiology, _______ measures the number of new cases over a certain time period (time based)

incidence

In epidemiology, the _____ is the total number of deaths in a population due to a certain disease

mortality rate

In epidemiology, the ______ is the number of people affected with a certain disease

morbidity rate

An _______ is where disease is a relatively steady frequency over a long period of time in a particular geographic.

endemic

When occasional cases are reported at irregular intervals is termed:

sporadic

An _____ is when the prevalence of a disease is increasing beyond what is expected.

epidemic

A ____ is an epidemic across continents (worldwide)

pandemic

_______________ is an endotoxin that causes fever, fatigue, and general symptoms of discomfort when released from the lysed bacterial cell.

Lipopolysaccharide

If a patient is infected with influenza virus and then shortly thereafter is infected with Streptococcus pneumonia-causing bacterial pneumonia, the pneumonia is best characterized as ____________.

secondary infection

AIDS is an infection that is prevalent across many continents, making this a _______outbreak.

Pandemic

You show up early to class and see a classmate coughing and blowing their nose a couple of rows away. They place the tissue on the desk and get settled into class. In an enthusiastic rush to clean up for lab, their lab partner moves all items off the table, including the tissue, to begin cleaning. If the ab partner becomes ill, how was this infection acquired?

Indirectly by a fomite

If the infectious dose for gonorrhea is 1,000 cells and the infectious dose for tuberculosis is 10 cells, which bacteria is more virulent?

mycobacterium tuberculosis