Describe the five stages of an infectious disease with a focus on pathogen numbers and immune system response, as well as signs and symptoms for each stage.

Incubation period; this begins after the initial entry of the pathogens into the host (patients.). it is the period of multiplication of the pathogen, however because the pathogen reproductive rate is still slow, enough toxin has not been released to produce manifestations of signs and symptoms.

The length of this period depends on strength of the diereses, pathogens, type of infection and site of infection. the host is not aware of the pathogens

Prodromal period: this is the stage of activation of immune system, because of pathogens are multiplying at high rate. The host experiences some immune reactions as pain, fever, and inflammations. the sign are symptoms are not specific at this stage. Period of illness, follows closely where the high multiplication of the pathogen and increase in the release to the blood leads to manifestation of specific signs and symptoms to an infection, which are usually severe

The period of decline follows. At this period, the pathogen population begins to drop; with reduction in signs and symptoms. The patients may show the manifestation of secondary infections because of the weakened immune system from primary infection.

The Period of convalescence is the last stage where the signs and symptoms has disappeared, and the host begins to return to normal state. Permanent irrecoverable case may occur in some infection