Communicable Diseases

COMMUNICABLE DISEASES

Introduction

Infections due to living organisms are called communicable diseases. They spread from person to person, or sometimes from animals to people. They occur at all ages but are most serious in childhood and they are preventable to a great extent. In developed countries, communicable diseases have been prevented. But in India it is going through a period of transition, both epidemiological and demographically. Infectious diseases are still persisting as major health problems in spite of having National programmes for the control of many diseases.

Terminology

·  Infection: The entry and development or multiplication of an infectious agent in the body of human being or animals.

·  Contamination: The presence of infectious agent on a body surface or in clothes, beddings, toys, surgical instruments or dressings or other inanimate articles or substances including water, milk and food.

·  Infestation: For persons or animals the lodgment, development and reproduction of arthropods on the surface of the body or in the clothing (e.g) lice, itch mite.

·  Host: A person or animal including birds and arthropods that affords subsistence or lodgment to an infectious agent under natural condition.

·  Communicable diseases: An illness due to specific infectious agent or its toxic products capable of being directly or indirectly transmitted from man to man, animal to animal or from the environment to man or animal.

·  Epidemic: The unusual occurrence or sudden outbreak of disease in a community or region.

·  Endemic: It refers to the constant presence of a disease or infections agent within a given geographic area or population group.

·  Sporadic: The word sporadic means scattered about. The diseases are so few and separated widely in space.

·  Pandemic: An epidemic usually affecting a large proportion of the population, occurring over a wide geographic area such as a section of a nation, the entire nation, a continent or world (eg.) influenza pandemic

·  Zoonosis: An infection transmissible under natural conditions from vertebrate animals to man. Eg. Rabies, plague

·  Eradication: Termination of all transmission of infection through surveillance.

Carriers

A carrier is defined as “an infected person or animal that harbours a specific infectious agent in the absence of clinical manifestation and serves as a potential source of infection to others.

Definition

Communicable Disease - “An illness due to a specific infectious agent or its toxic products capable of being directly or indirectly transmitted from man to man, animal to animal, or from the environment (through air, dust, soil, water, food, etc.) to man or animal.

Chain of Infection