Final answer:
The nurse's priority to prevent the spread of a contagious respiratory infection is frequent handwashing, as it is one of the most effective methods for preventing the transmission of infectious diseases.
Step-by-step explanation:
The nurse's priority in preventing the spread of a contagious respiratory infection would be frequent handwashing. While all the measures listed can contribute to controlling the spread of infection, handwashing is universally acknowledged as one of the most effective methods for preventing the transmission of infectious diseases. Handwashing works by removing microbes from the hands, which could otherwise be transferred to oneself or others through touch. This is especially important in a healthcare setting where patients with compromised immune systems may be present. Moreover, following proper handwashing techniques as recommended by the CDC is essential. This entails five steps, including wetting hands with clean water, lathering soap, scrubbing for at least 20 seconds, rinsing thoroughly, and drying with a clean towel or air drying. As described in the case of Marisa, isolation and strict hand hygiene are crucial in a clinical context to prevent further spread.