Final answer:
The nurse's best response is that infectious mononucleosis is primarily acquired through contact with infected oral secretions, explaining the common transmission routes for Epstein-Barr virus (EBV).
Step-by-step explanation:
The nurse's best response to the parent's question about how a child acquired Epstein-Barr virus (EBV) associated infectious mononucleosis would be: "The infection is acquired primarily through contact with infected oral secretions." This mode of transmission explains why EBV is often spread in settings where close contact occurs, such as summer camps. It is commonly known as the 'kissing disease' due to saliva being a vehicle for the virus, but it can also be spread by sharing drinks, utensils, or exposure to the saliva of an infected person in other ways. Transmission through mosquito bites or contact with infected blood is far less common for infectious mononucleosis compared to saliva.