Final answer:
The patient with new-onset infective endocarditis most likely underwent a teeth-cleaning procedure, which can introduce oral bacteria into the bloodstream and result in infection.
Step-by-step explanation:
A patient diagnosed with new-onset infective endocarditis is most likely to report having undergone a teeth-cleaning procedure. Infective endocarditis is often the result of bacteria entering the bloodstream through procedures that cause a breach in the normal barrier defenses, like dental procedures, catheterizations, or body piercings. In this context, teeth cleaning can allow oral bacteria to enter the bloodstream, potentially leading to infective endocarditis, particularly in individuals with preexisting heart conditions or prosthetic valves.
Infective endocarditis is an infection of the heart's endocardium, which can be caused by bacteria entering the bloodstream during dental procedures, among other reasons. Certain bacteria, such as Streptococcus, can gain access to the blood if the gums are nicked during teeth cleaning, leading to the development of bacterial endocarditis.