Final answer:
The nurse should instruct the client that he will be safe from infecting others approximately two to three weeks after initiation of the chemotherapy regimen for tuberculosis (TB).
Step-by-step explanation:
The nurse should instruct the client that he will be safe from infecting others approximately two to three weeks after initiation of the chemotherapy regimen for tuberculosis (TB). TB is a contagious disease caused by the bacteria Mycobacterium tuberculosis, which is spread through the air by coughing or sneezing. The medication regimen for TB typically lasts for several months to ensure the complete elimination of the bacteria.