Final answer:
Airborne isolation precautions are necessary for a client with active tuberculosis due to the disease's high contagiousness through airborne droplets and aerosols.
Step-by-step explanation:
A nurse admitting a client with active tuberculosis should implement airborne isolation precautions. Tuberculosis is highly contagious through the inhalation of droplets or aerosols from an infected person. The disease is transmitted when an infected host coughs, sneezes, or spits, propelling tubercle bacilli into the air, which are then inhaled by others, reaching the alveoli in the lungs. To prevent the spread of infection, patients are often isolated in a separate room to avoid contaminating shared spaces, and healthcare providers must follow strict protocols including wearing appropriate personal protective equipment, such as respiratory masks, and practicing diligent hand hygiene.