Infection Stage

Infection stage on human that will cause diseases are through several. All infection diseases depend on essentially the same mechanism: invasion by foreign organism and the reaction of the invaded body to them. Therefore, infectious diseases have a common pattern, marked by the five phases summarized here.

 

  

1. Incubation period: the organism invade and multiply in the host. Length of the phase is varies with the kind of disease and with the individual immune system.
2. Prodrome Period: brief interval characterized by general symptoms such as headache, fever, runny nose, irritability, and general discomfort. Disease is highly communicable now.
3. Clinical disease: illness is at its height characteristic symptoms appear, so specific diagnose is possible now.
4. Decline Stage: Symptoms subside. Patient may feel well enough to become active before recovery, which increases the danger of relapse.
5. Convalescence: The recovery period. Disease may still be communicable. Patient who recovers but still gives off disease causing organisms becomes a carrier of that disease.