U1.6

Question 1

__________________ is determined by the type of infectious disease process acquired. Diseases are often classified in terms of how they behave within a host and within a given population.

Answer 1

Transmission to the host

Question 2

Transmission to the host: What type?

• any disease that spreads from one host to another, either directly or indirectly

Answer 2

Communicable infectious disease

Question 3

Transmission to the host: What type?

• a disease that is readily or highly transmissible especially through direct contact

Answer 3

Contagious infectious disease

Question 4

Transmission to the host: What type?

• one which does not arise through transmission from host to host. This includes diseases acquired by contact with water or soil.

Answer 4

Non-communicable infectious disease

Question 5

The causative agents of disease can be transmitted from the source or reservoir of infection to a susceptible host. There are four principal routes or modes of transmission: what are they?

Answer 5

• contact
• airborne
• vehicles
• vectors

Question 6

What mode of transmission: Contact, airborne, vehicles or vectors?

This implies the coming together or touching of the source and the host.

Answer 6

Contact transmission

Question 7

Contact transmission: What are the 3 mechanisms under it?

Answer 7

• Direct contact transmission (Horizontal transmission & Vertical transmission)
• Indirect contact transmission
• Droplet transmission

Question 8

Contact transmission: What mechanism? Direct, Indirect or Droplet?

• the transmission of pathogens by contact of the portal of exit with the portal of entry, no intermediate object is involved

Answer 8

Direct contact transmission

Question 9

Contact transmission: What mechanism? Direct, Indirect or Droplet?

• the transfer of pathogens from an
  infected host, to an intermediary object or substance, to another
  host.

Answer 9

Indirect contact transmission

Question 10

Contact transmission: What mechanism? Direct, Indirect or Droplet?

• implies the transfer of
  disease agents through droplets of saliva or mucus discharged into the air by coughing, sneezing, laughing, or talking. The route is through the air but because these particles are large (i.e., greater than 5 µ), they travel a short distance (less than 1 meter), and quickly settle out of air.

Answer 10

Droplet transmission

Question 11

Direct Contact transmission: what specification? horizontal or vertical?

• also known as person-to-person
  transmission. Disease transmission occurs by touching, kissing,
  and sexual intercourse.

Answer 11

Horizontal transmission

Question 12

Direct Contact transmission: what specification? horizontal or vertical?

• involves transmission of pathogens from the mother to an infant.
• Disease transmission may occur in two ways: Prenatal and Perinatal

Answer 12

Vertical transmission

Question 13

Vertical Direct Contact transmission: what specification? Prenatal or Perinatal?

• implies transmission of the pathogen across the placenta.

Answer 13

Prenatal

Question 14

Vertical Direct Contact transmission: what specification? Prenatal or Perinatal?

• occurs during passage through the first canal or during close contact between mother and infant in the first few days of life.

Answer 14

Perinatal

Question 15

Indirect Contact Transmission:
- an inanimate object that harbors and transmits a pathogen

Answer 15

fomite

Question 16

What mode of transmission: Contact, airborne, vehicles or vectors?

This occurs when a pathogen is suspended in air contained in dust or within droplet nuclei.

Answer 16

Air-borne transmission

Question 17

What mode of transmission: Contact, airborne, vehicles or vectors?

It is the transmission of disease-causing agents by a common inanimate reservoir such as food, water, or blood.

Answer 17

Common vehicle transmission

Question 18

Air-borne transmission:
- are small particles (1 µ to 4 µ in diameter) that represent what is left from the evaporation of larger droplet particles. They remain suspended in air and travel 1 meter or more from the source.

Answer 18

Droplet nuclei

Question 19

What mode of transmission: Contact, airborne, vehicles or vectors?

It indicates the transmission of pathogens through the aid of a vector.

Answer 19

Vector-borne transmission

Question 20

Vector-borne transmission:

It is an invertebrate (e.g., arthropod, or mollusk) that transmit an infectious agent from one host to another

Answer 20

vector

Question 21

Vector-borne transmission: How? What type?

• during which the pathogen does not undergo morphological or physical changes within the vector (i.e., mechanical vector). That is, the vector is not important in the life cycle of the pathogen.

Answer 21

Harborage or mechanical transmission

Question 22

Vector-borne transmission: How? What type?

• the pathogen goes through morphological or physical changes within the vector (i.e., biologic vector). The vector assists in the completion of the pathogen’s life cycle

Answer 22

Biological transmission

Question 23

To initiate infection, a microbe enters the tissues through a characteristic route - _____________?

Answer 23

the portal of entry

Question 24

This is usually a cutaneous or membranous boundary through which the microorganism enter the tissue.

Answer 24

portal of entry

Question 25

Portal of entry: The microorganism may enter through what routes:

Answer 25

- Gastrointestinal tract - Respiratory tract - Skin and mucus membranes - - Genito-urinary tract - Blood - Placenta

Question 26

Portal of Entry: Which route? (Gastrointestinal tract, Respiratory tract, Skin and mucus membranes, Genito-urinary tract, Blood, or Placenta) - is the portal of entry for pathogens contained in food, drinks and other ingested materials. Agents of diseases such as typhoid fever, cholera, dysentery, botulism enter by way of mouth.

Answer 26

Gastrointestinal tract

Question 27

Portal of Entry: Which route? (Gastrointestinal tract, Respiratory tract, Skin and mucus membranes, Genito-urinary tract, Blood, or Placenta) - the greatest number of pathogens enter by way of the nose and mouth. Infectious diseases with this total of entry include common colds, tuberculosis, pneumonia, measles.

Answer 27

Respiratory tract

Question 28

Portal of Entry: Which route? (Gastrointestinal tract, Respiratory tract, Skin and mucus membranes, Genito-urinary tract, Blood, or Placenta) - nicks, abrasions and punctures on this serve as portal of entry of many pathogens including those that cause boils, and impetigo.

Answer 28

Skin and mucus membranes

Question 29

Portal of Entry: Which route? (Gastrointestinal tract, Respiratory tract, Skin and mucus membranes, Genito-urinary tract, Blood, or Placenta) - is the portal of entry of pathogens that are contracted by sexual means (intercourse, intimate direct contact). Diseases such as gonorrhea, AIDS and syphilis, has been collectively known by a more descriptive term, sexually-transmitted infection (STI).

Answer 29

Genito-urinary tract

Question 30

Portal of Entry: Which route? (Gastrointestinal tract, Respiratory tract, Skin and mucus membranes, Genito-urinary tract, Blood, or Placenta) - agents of so-called blood borne diseases such as hepatitis, AIDS, syphilis, and malaria enter the body through blood transfusion, contaminated needles and syringes, and through blood-sucking insects.

Answer 30

Blood

Question 31

Portal of Entry: Which route? (Gastrointestinal tract, Respiratory tract, Skin and mucus membranes, Genito-urinary tract, Blood, or Placenta) - permits diffusion of dissolved nutrients and gases form the mother’s circulation to the growing fetus in her womb. Several diseases from the mother such as syphilis, AIDS, listeriosis, and toxoplasmosis can also be passed to the fetus by way of the placenta.

Answer 31

Placenta

Question 32

Susceptible Host or the Infectious Agent - the effectivity of the host’s defense mechanisms

Answer 32

Susceptible Host

Question 33

Susceptible Host or the Infectious Agent - the microbe’s pathogenicity and virulence

Answer 33

Infectious Agent

Question 34

Microbial colonization and dissemination is determined by two factors: what are they?

Answer 34

Susceptible Host and the Infectious Agent

Question 35

It is usually but not always the same as the portal of entry. It is of importance since it determines how pathogens spread in a population.

Answer 35

portal of exit