It is not useful to test if you've gotten over influenza or for
camp, vacation, school, or work to
see if it's safe to go back. You could ask your doctor for a chest x-ray (CXR) if you have a ILI (Influenza-like-illness) with shortness of breath, abnormal vital signs other than fever, or a pulse oximetry of 95 or lower on room air. This is especially so for those with risk factors.