It is an illness caused by infectious agent or it’s toxic products, and transmitted from one person to another by direct contact with an infected person or by indirect contact with material containing the causative agent.
Communicable Diseases are divided into:
- preventable disease :by primary immunization.
- non preventable disease: occur more frequently in preschool years.
– the morbidity and mortality rate of communicable disease have been declined because of early recognition of the disease and prompt treatment.
Sources of infection:-
- Environmental factors such as dust and contaminated water or food.
Communicable Diseases may be:
- Endemic:is one that occurs in a proportionately limited number of people in given area and at a relatively constant rate.
- Epidemic:an incidence of illness which is statistically higher than expected in given population.
- Pandemic:when many cases occur over large geographic area.
Incubation period: is the period between exposure to the disease and the appearance of initial symptoms.
Communicability period: is the time during which an infected person can transmit the disease directly or indirectly to another person.
Acarrier: aperson or animal harboring an infectious agent without manifesting symptoms although he may infect others.
Acontact: aperson or animal exposed to an infection through contact with an infected person or animal.
Classification of communicable diseases
- Upper respiratory e.g. measles, pneumonia, diphtheria.
- Gastrointestinal e.g. dysentery, typhoid fever.
- Dermal and membranous e.g. impetigo, venereal disease.
- Parenteral e.g. serum hepatitis, malaria.