Question

Once host defenses have been overcome and disease is developing, the ___ period occurs before the first signs and symptoms appear; this period may be short (10-14 days with typhoid fever) or long (10 years with AIDS).

a) Incubation
b) Latent
c) Convalescent
d) Prodromal

Answer 1

The period occurring before the first signs and symptoms of disease appear after host defenses have been overcome is known as the incubation period. It varies in length depending on factors such as the pathogen's strength and the host's immune defenses.

Step-by-step explanation:

Once host defenses have been overcome and the disease is developing, the incubation period occurs before the first signs and symptoms appear. The incubation period is the time after the initial entry of the pathogen into the host, during which the pathogen begins multiplying. However, there are not enough pathogen particles present to cause signs and symptoms of disease.

For example, acute diseases like influenza have a short incubation period of approximately 1-2 days, whereas chronic diseases such as AIDS can have an incubation period extending up to 10 years. The length of the incubation period is determined by factors such as the strength of the pathogen, the immune defenses of the host, the site of infection, and the infectious dose received.