A Case of Recurrent Infective Endocarditis Caused by Streptococcus Agalactiae

A 53-year-old man was admitted to hospital with a high fever and shivering. He had undergone aortic valve replacement 4 years previously due to infective endocarditis caused by Streptococcus agalactiae. 18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) showed increased uptake in the tissue surrounding the prosthetic valve. S. agalactiae was detected in blood cultures after admission. We made a diagnosis of prosthetic valve endocarditis due to an S. agalactiae infection relapse. After 6 weeks of antibacterial treatment, the inflammatory findings successfully improved. However, reexamination with 18F-FDG PET/CT suggested the possibility of persistent prosthetic valve infection. Therefore, we decided to continue the oral antibiotic treatment after discharge.