Final

Question 1

Define communicable diseases

Answer 1

A disease of human or animal origin caused by an

infectious agent, capable of multiplying

Question 2

What is the usual infectious agent for communciable diseases?

Answer 2

microorganisms

Question 3

what does epidemiology study regarding communicable diseases?

Answer 3

The factors that relate causal agent with the susceptible host

Question 4

The decrease in communicable diseases is due to: (4)

Answer 4

- Improvement of the general
hygienic Conditions (sewerage)
- Better nutrition and housing.
- Personal hygiene.
- Vaccines and antibiotics

Question 5

Why are communicable diseases a problem? and their potential solutions (5)

Answer 5

 Emerging new infectious diseases.
 Exotic diseases in
developed countries (Zika).
 rare opportunistic
infections like Candidiasis of bronchi, trachea, esophagus, or
lungs in HIV patients
 Diseases previously not considered
communicable, are currently communicable
(papilloma virus – cervix cancer – vaccine girls 12 years old)
 antibiotic resistance
(improve the prophylaxis to avoid a later resistance)

Question 6

Which microroganisms are involved in infections? (4)

Answer 6

• Bacteria
• Virus
• Fungus
• Protozoa

Question 7

What are the phases of communicable diseases? (3)

Answer 7

1. • Incubation period: entrance-first symptoms.
2. • Prodromal period: onset of NON-specific symptoms.
3. • Clinical period: typical signs and symptoms of the disease.

Question 8

The development of a communicable disease requires: (2)

Answer 8

1. -A causal agent

2. -Epidemiological chain:

Question 9

What is an epidemiological chain? (5)

Answer 9

Set of factors, which would be the links in the
chain, through which the transmission in made

• Reservoir
• Source of infection
• Transmission mechanism
• Susceptible host

Question 10

What are the characteristics of a casual agent? (4)

Answer 10

1. Contagiousness: ability to propagate
2. infectivity: ability to multiply in tissue
3. Pathogenicity: ability to cause disease
4. Virulence: degree of invasiveness - ability to damage tissue and spread

Question 11

What is the equation for contagiousness?

Answer 11

attack rate =

(infected/exposed)*100

Question 12

What is the equation for pathogenicity?

Answer 12

rate = (ill/infected)*100

Question 13

Median lethal dose aka…

Answer 13

lethal dose 50 (LD50)

-where 50% of population dies

Question 14

What is the best way to deal with communicable diseases?

Answer 14

Cut the chain! Detect and treat infected people

Question 15

Define reservoir

Answer 15

Where an agent replicates and survives during a relatively long period

Living: human, animals, plants
Places: water, soil

Question 16

what animal is NOT a reservoir?

Answer 16

invertebrates - transmit but do not reserve = vector

Question 17

What is a vector?

Answer 17

transmit but do not reserve -

invertebrates

Question 18

Define source of infection

Answer 18

living being or location where the agent passes to the host

Question 19

The most important source of infection are

Answer 19

humans

Question 20

When the source of infection are human beings, The microorganism must be able to leave the subject by (7)

Answer 20

a route of elimination:
- Through the respiratory tract: Pflügge droplets (cold, flu,
pulmonary tuberculosis, etc.)
- Through the digestive tract (feces) (typhoid fever).
- Through a cutaneous route (superficial mycoses).
- Through conjunctival discharge (conjunctivitis).
- Through the blood (hepatitis B, HIV).
- Through genital secretions (gonorrhea, HIV).

Question 21

When the source of infection are human beings, severe forms of a disease tend to be…

Answer 21

more contagious
than the mild ones. However, abortive, subclinical or unapparent
forms can also be contagious.

Question 22

When the source of infection are human beings, transmission depends on…

Answer 22

the phase of the disease

incubation period is dangerous

Question 23

When the source of infection are human beings, treatment can reduce…

Answer 23

the duration of infectiousness