Final answer:
The nurse should isolate the adolescent with rubella from staff who are pregnant to prevent the spread of the congenital infection. Koplik spots are not associated with rubella and aspirin is not the recommended treatment for its mild fever.
Step-by-step explanation:
A nurse admitting an adolescent who has rubella should take several precautions to prevent the spread of the infection. Among the options provided, the correct action for the nurse to take would be to isolate the client from staff who are pregnant. The rubella virus is teratogenic and can cause severe congenital defects if a woman is infected during pregnancy, especially before the 11th week. Therefore, it's crucial to protect pregnant staff members from exposure. Rubella is also an airborne disease, which would normally warrant airborne precautions; however, since this is not one of the answer options and given the specific threat to pregnant women, isolation from pregnant staff is particularly emphasized.
Administering aspirin is not recommended, especially since the disease typically results in a mild fever that can be managed with other fever reducers that do not carry the same risk for complications as aspirin does. Monitoring for the development of Koplik spots would not be relevant in this case because Koplik spots are associated with measles, not rubella. Additionally, rubella is generally a self-limiting disease with symptoms such as a facial rash that spreads to the extremities and disappears after 2-3 days, typically accompanied by a low-grade fever.