Definition of infectious Disease is a disease that can be transmitted (move from one person to another person, either directly or through intermediaries).
This infectious disease is characterized by the presence of agents or disease causes that live and can move.
Causes of Infectious Diseases
A disease can be transmitted from one person to another that is determined by three factors: the disease-causing agent), Host, and Route of transmission.
a. Infection Agents
Living beings as the important holders in epidemiology that are causes of disease can be grouped into:
1. Virus group, such as influenza, trachoma, smallpox and so on.
2. Rickets group, for example typhoid
3. Bacteria group, for example dysentery
4. Protozoa group, such as malaria, filaria, Schistosoma, and so on
5. Mushroom group, for example tinea versicolor, ringworm
6. Worm group, for example ascaris (roundworm), pinworms, tapeworms, hookworms
b. Sources of Infection and Spread of Disease
Sources of infection are all objects, including people or animals that may cause disease in people. The sources of disease also include reservoirs like human, animal or inanimate objects.
Various Kinds of transmission (mode of transmission)
Transmission Mode is a mechanism which the disease cause or agent transmitted from one person to another or from the reservoir to the new host. Transmission is through various ways including:
1. Contact, it can occur directly through contaminated objects.
2. Inhalation, it is the transmission through the air or breathing.
3. Infection, transmission through the hands, food or drink.
4. In Skin, it can directly by the organism itself. For example, hookworm, vector bites (malaria), through tetanus wound.
c. Host Factor
The occurrence of a disease (infection) in a person is also determined by factors that exist in the host itself. In other words, disease occurrence in a person depends on the immunity or resistance of the person concerned.
