Communicable Disease
• It is a disease that can be transmitted from one person to another.
• A disease that has causative agent
E.g Tetanus (Causative Agent: Clostridium Tetani)
Dengue (Causative Agent: Flavivirus or Dengue virus)
- Take note: Any diseases that have no causative agent are called non-
communicable disease
E.g Hypertension, Diabetes
A. Contagious Disease
• Patient must place in Isolation (separation of infected individual)
“ POC” - period of communicability
- E.g TB -> 2 wks
- Leprosy -> 1 wk of treatment
- Covid- 19
Mild: 10 days of rst symptoms
Severe: 20 days after the 1st signs and symptoms
• Quarantine:
Limitation of freedom of movement to exposed individuals
Basis ( longest incubation period)
E.g Covid 19 quarantine period 14 days
- Ebola - 2 to 21 days
B. Infection
• Presence of pathogenic microorganism in the body
• The disease causing microorganism is inside the body
• Pathogenic means disease causing organism.
Chain of Infection
, 1. Causatieve agent (Pathogen)
2. Reservoir
3. Portal of Exit
4. Mode of transmission (CaVeVe)
a. Contact Transmission
i. Direct Contact - Physical contact (Touch involve)
ii. Indirect Contact - Contaminated object (Fomites)
iii. Droplet Contact - Respiratory secretions (large particles - within
3ft) Surgical mask
b. Airborne Transmission
- Fine particles and transmission of > 3 ft. (N95 mask)
c. Vehicle Transmission
- Non - living e.g food (salmonella), (botulism - Honey= infant:
descending paralysis, Adult: Canned food) & water e.g. Cholera
(rice-washed stool), Amoeba(Bloody mucus stool), Georgia
(Smell like rotten egg)
d. Vector Transmission
- Living e.g Mosquito ( Zika,
5. Portal of entry
6. Susceptible host - prone to infection such as immunocomprimise
Take note: Mode of transmission (MOT) is considered as the easiest link to break
C. Immunity
• Refers to the body’s ability to prevent the invasion of pathogens.
• Immune: resistant ( increase Antibodies)
• Two terms need to remember:
Antigen
- These are called foreign bodies
- These are bacteria, viruses, parasites, protozoa, and toxins that produce
infection
- These are “enemy” microorganisms
Antibodies
- These are proteins that destroy familiar antigen
- These are also called immunoglobulins
IgG
IgA
IgM
IgE
IgD
Take note: Antibodies are more abundant in the body if an individual is immune
I. Types of Immunity
• Natural
Immunity that is inherent in the body
Species-speci c (certain species don’t a ect an individual’s immunity)
E.g. Parvovirus
• It is a disease that can be transmitted from one person to another.
• A disease that has causative agent
E.g Tetanus (Causative Agent: Clostridium Tetani)
Dengue (Causative Agent: Flavivirus or Dengue virus)
- Take note: Any diseases that have no causative agent are called non-
communicable disease
E.g Hypertension, Diabetes
A. Contagious Disease
• Patient must place in Isolation (separation of infected individual)
“ POC” - period of communicability
- E.g TB -> 2 wks
- Leprosy -> 1 wk of treatment
- Covid- 19
Mild: 10 days of rst symptoms
Severe: 20 days after the 1st signs and symptoms
• Quarantine:
Limitation of freedom of movement to exposed individuals
Basis ( longest incubation period)
E.g Covid 19 quarantine period 14 days
- Ebola - 2 to 21 days
B. Infection
• Presence of pathogenic microorganism in the body
• The disease causing microorganism is inside the body
• Pathogenic means disease causing organism.
Chain of Infection
, 1. Causatieve agent (Pathogen)
2. Reservoir
3. Portal of Exit
4. Mode of transmission (CaVeVe)
a. Contact Transmission
i. Direct Contact - Physical contact (Touch involve)
ii. Indirect Contact - Contaminated object (Fomites)
iii. Droplet Contact - Respiratory secretions (large particles - within
3ft) Surgical mask
b. Airborne Transmission
- Fine particles and transmission of > 3 ft. (N95 mask)
c. Vehicle Transmission
- Non - living e.g food (salmonella), (botulism - Honey= infant:
descending paralysis, Adult: Canned food) & water e.g. Cholera
(rice-washed stool), Amoeba(Bloody mucus stool), Georgia
(Smell like rotten egg)
d. Vector Transmission
- Living e.g Mosquito ( Zika,
5. Portal of entry
6. Susceptible host - prone to infection such as immunocomprimise
Take note: Mode of transmission (MOT) is considered as the easiest link to break
C. Immunity
• Refers to the body’s ability to prevent the invasion of pathogens.
• Immune: resistant ( increase Antibodies)
• Two terms need to remember:
Antigen
- These are called foreign bodies
- These are bacteria, viruses, parasites, protozoa, and toxins that produce
infection
- These are “enemy” microorganisms
Antibodies
- These are proteins that destroy familiar antigen
- These are also called immunoglobulins
IgG
IgA
IgM
IgE
IgD
Take note: Antibodies are more abundant in the body if an individual is immune
I. Types of Immunity
• Natural
Immunity that is inherent in the body
Species-speci c (certain species don’t a ect an individual’s immunity)
E.g. Parvovirus
