Final answer:
The 30-year-old man with a respiratory infection is at the greatest risk for developing viral pericarditis because his current condition makes it easier for a virus to potentially lead to an inflammation of the pericardium.
Step-by-step explanation:
The patient at greatest risk for developing viral pericarditis is the 30-year-old man with a respiratory infection. Viral pericarditis is typically caused by a viral infection, and since this man already has a respiratory infection, he is at a higher risk of the virus spreading to the pericardium, the sac surrounding the heart. The other patients have conditions that do not predominantly predispose them to a viral etiology of pericarditis. The woman with tuberculosis is at risk for bacterial pericarditis, the man who has had radiation therapy is at risk due to the direct damage from radiation, and the woman with chest trauma might develop pericarditis as a result of physical injury. However, the respiratory infection present in the 30-year-old man creates the right conditions for a viral pathogen to potentially lead to pericarditis.