What should visitors be taught to do when caring for a patient with positive AFB smears under airborne precautions?

When caring for a patient with positive acid-fast bacilli (AFB) smears, it is crucial to implement airborne precautions to prevent the transmission of infectious agents, such as Mycobacterium tuberculosis. The correct choice emphasizes the importance of wearing a particulate respirator mask, such as an N95 respirator, which is specifically designed to filter out airborne particles, including those as small as the bacteria related to tuberculosis.

This mask provides a tighter fit and a higher filtration efficiency compared to surgical masks, which primarily protect others from respiratory droplets but do not adequately protect the wearer from inhaling airborne pathogens. By using a particulate respirator, visitors significantly reduce their risk of inhaling infectious aerosols that could be present in the patient's environment.

While gloves and face shields, along with disposable gowns, have their specific roles in infection control, they do not address the airborne routes of transmission that particulate respirators are specifically designed for. Hence, wearing a particulate respirator is the most appropriate choice for ensuring the safety of visitors in the context of airborne precautions for a patient with positive AFB smears.