Aerococcus urinae Endocarditis: An Emerging Infectious Disease

_Aerococcus urinae _is an alpha-hemolytic, catalase-negative, Gram-positive coccus most frequently seen as a cause of urinary tract infections. It can, however, cause more severe diseases such as bacteremia, spondylodiscitis, peritonitis, and endocarditis. The first case of endocarditis was not reported until 1991. Since that time, cases of endocarditis have been reported increasingly in the literature. We report a 59-year-old man with _A. urinae _endocarditis of the aortic valve and review the literature since 1 Jan 2020. _A. urinae _is being reported more frequently and appears to be an emerging infectious disease problem. In our review of the 29 cases since 1 Jan 2020, we found that the aortic and mitral valves are most frequently involved, there is a 24% mortality rate, and those undergoing cardiac surgery have a significantly greater likelihood of survival than those who do not. Physicians should be aware of the potential of _A. urinae _isolated from blood cultures to cause life-threatening endocarditis.