Final answer:
The four key points during the development of disease are the incubation period, prodromal period, period of illness, period of decline, and period of convalescence. These stages are associated with the pathogen load and the severity of the symptoms. The period in which the patient begins to present general signs and symptoms is known as the prodromal period.
Step-by-step explanation:
The development of disease goes through several key stages, which include the incubation period, prodromal period, period of illness, period of decline, and period of convalescence. The incubation period occurs after the initial entry of the pathogen into the host and is a time when the pathogen multiplies but has not yet caused symptoms. The prodromal period is when general signs and symptoms begin to manifest.
Following this, the period of illness is when the most severe symptoms occur, and the number of pathogenic organisms in the body is highest. The period of decline follows, characterized by a decrease in symptoms and pathogen load, but it's also a time when patients might be susceptible to secondary infections. The last stage is the period of convalescence, during which the patient recovers and symptoms disappear, though they might still spread the infection.
It's important to note that the length of these periods can vary depending on factors like the strength of the pathogen, the immune response of the host, and the type of disease (acute or chronic).