2. On the basis of whether the diseases are
present since birth or after birth diseases
are of two types.
Congenital Diseases: These are anatomical or
physiological abnormalities present since birth.
Examples are Down’s syndrome ,Turner’s
Syndrome , Cleft palate etc
Acquired Diseases: These diseases develop after
birth and are of two types.
a) Infectious diseases b) Non- infectious diseases
3. Deficiency diseases
The diseases which are caused due the lack of
essential nutrients or dietary elements such
as vitamins and minerals in the human body.
4. Examples of Some deficiency
Diseases are:
Scurvy: It is caused by the deficiency of
vitamin C.
Rickets: It is caused by the deficiency of
vitamin D.
Anaemia: It is caused by the deficiency of iron.
Goitre: It is caused by the deficiency of iodine.
5.
6. Means of spread of a
communicable Disease:
DirectTransmission: The pathogens are
transmitted from an infected person to a healthy
person directly without an intermediate agent. It
occurs by the following ways.
1. Physical contact.
2. Sexual contact.
3. Animal Bites.
4. Soil Contact.
5.Transplacental transmission
7. IndirectTransmission: It involves the spread
of pathogens through some intermediate
agents and occurs in the following ways.
Through Air. (Air borne)
Through contaminated food and water.(Food
andWater Borne Diseases)
Vectors. Eg House fly , Mosquitos etc
Fomite Borne.( Handles of doors, taps , utensils
etc.
8. Pathogens: Disease causing microorganisms
are known as Pathogens.
Vectors: The organisms which spread
diseases.
9. Symptoms & Signs
Symptom: A symptom is a manifestation of
disease apparent to the patient himself.
Sign: Signs are objective findings that can be
seen or measured.
10. Principles of Treatment
There are two ways to treat an infectious
disease.
(I) To Reduce the effects of the disease: It
can be done by providing symptomatic
treatment that will reduce the symptoms of
the disease.
(II)To Kill the cause of the disease, I,e
Pathogens:This method involves the use of
medicines to kill the pathogens. Eg
Antibiotics
11. Principles of prevention
There are two ways of prevention of
infectious diseases:
A. General Ways
Public Hygiene
Eradication of vectors
Strelisation
Isolation
Education
Proper and Sufficient Food
B. Specific Ways of prevention:
Immunisation/Vaccination
12. Vaccines:
Antibody provoking agents are known as
vaccines. It is a preparation of antigenic
proteins of pathogens or weakened or dead
pathogens which on inoculation into a
healthy generates immune response and
produces antibodies, which on actual
exposure in the same pathogen fights the
pathogens and prevents disease.
