Which of the following statements is true concerning tuberculosis (TB)

Which of the following statements is true concerning tuberculosis (TB) infections in the United States?

a. Subclinical cases of TB can occur in patients who fight off the infection and thus are not a danger to themselves or others.
b. TB can be cured by a 6-month period of treatment with INH.
c. TB can only be caused by the Mycobacterium bovis bacillus.
d. Under certain conditions, susceptible hosts may be infected by the TB bacillus.

ESSAYBID ANSWER

ANS: D
The principle of multicausation emphasizes that an infectious agent alone is not sufficient to cause disease; the agent must be transmitted within a conducive environment to a susceptible host. Mycobacterium tuberculosis kills cells. M. tuberculosis has low infectivity, low pathogenicity, but high virulence if untreated.