Question

The ID50 is

Option 1: the dose that will kill 50 percent of the test population.
Option 2: the dose that will cause an infection in some of the test population.
Option 3: the dose that will kill some of the test population.
Option 4: a measure of pathogenicity.
Option 5: the dose that will cause an infection in 50 percent of the test population.

Answer 1

The ID50 is the concentration of a pathogen that results in infection in 50 percent of inoculated test animals, making Option 5 the correct answer.

Step-by-step explanation:

The ID50 is a measure commonly used in infectious disease research to determine the virulence of a pathogen. Specifically, the ID50 refers to the median infectious dose, which is the concentration of pathogen required to cause active infection in 50 percent of a population of test animals that are inoculated. In contrast, the LD50 refers to the median lethal dose, which is the amount of a substance (pathogen cells, virions, or toxin) needed to kill 50 percent of the test animals. Among different pathogens with varying ID50 values, the one with the lowest ID50 is considered the most virulent because it requires the fewest number of particles to infect half of the test population.

Option 5 is the correct answer to the question: The ID50 is the dose that will cause an infection in 50 percent of the test population.