A nurse is discussing communicable diseases with a newly licensed nurse. Which of the following statements should the nurse include?

A. "Initiate contact precautions for a child who has measles.": Measles is transmitted via airborne droplets, not direct contact. Airborne precautions, including placement in a negative-pressure room and use of an N95 respirator, are required instead of contact precautions. B. "Varicella is contagious until all lesions have crusted over.": Varicella (chickenpox) spreads through airborne droplets and direct contact with lesions. Infectivity continues until all vesicular lesions have crusted, making this statement accurate for infection control and isolation planning. C. "Pertussis is most contagious during the paroxysmal stage.": Pertussis (whooping cough) is most contagious during the catarrhal stage, which resembles an upper respiratory infection. The paroxysmal stage occurs later, with severe coughing, but infectivity is reduced. D. "Wear an N95 respirator mask when caring for a child who has scarlet fever.": Scarlet fever is caused by Streptococcus pyogenes and spreads via droplet transmission. Standard surgical masks and droplet precautions are sufficient; N95 respirators are not required.