The student asks a professor to explain how tuberculosis (TB) can remain dormant in some people. What explanation by the professor is best?
A)It does not remain dormant but some host defenses can kill the bacteria.
B)The bacilli can become isolated within tubercles in the lungs.
C)Macrophages attack and phagocytize new areas of infection.
D)Virulence factors in the bacilli weaken over time leading to apoptosis.

Question

Quizplus · Accepted Answer

Neutrophils, lymphocytes, and macrophages seal off colonies of the TB bacilli, forming granulomatous tubercles of scar tissue that isolates them. In this manner, and with developing immunity, TB can remain dormant sometimes for years or for life. Some bacilli are killed by host defenses but not enough to rid to body of the disease. Macrophages do phagocytize some of the bacilli. Virulence factors do not weaken over time.

The Student Asks a Professor to Explain How Tuberculosis (TB)