Group B Streptococcus Bacteremia and Endocarditis in a Middle-Aged Male

Group B Streptococcus (GBS) is a rare but increasingly recognized cause of invasive disease in nonpregnant adults, particularly in the United States. Invasive GBS can take on many forms and may involve virtually any organ system. This case report describes the presentation, diagnosis, and management of a middle-aged male with GBS bacteremia and endocarditis. A 59-year-old Caucasian male with a history of a heart murmur presented to the emergency department (ED) with two weeks of intermittent fevers, chills, rigors, and back pain. He had also become increasingly agitated and confused over this time. His heart murmur was discovered years prior during a work physical examination but was not investigated further. On arrival, he was afebrile but hypotensive and tachycardic. Physical examination revealed petechiae at the bilateral inferior palpebral conjunctivae as well as a grade 2 holosystolic murmur heard best at the apex. Abnormal laboratory findings included leukocytosis, transaminitis, elevated ferritin, and elevated D-dimer. Blood cultures were positive for Streptococcus agalactiae, and echocardiography demonstrated large mitral valve vegetations. The patient received intravenous (IV) antibiotics and eventually underwent a successful mitral valve replacement with a 31-mm pericardial tissue valve. No source of infection was identified in this patient despite an extensive workup. The incidence of invasive GBS among nonpregnant adults has increased significantly in recent decades. The majority of affected patients are elderly and with significant underlying medical conditions. GBS bacteremia and endocarditis carry a very high mortality rate despite appropriate antimicrobial therapy. Combined medical-surgical therapy confers better outcomes in cases of endocarditis. Our patient's history of a heart murmur could have represented previously undiagnosed mitral valve pathology, placing him at higher risk of endocarditis. Apart from that, however, he lacked most of the typical risk factors associated with invasive GBS infections. Otherwise healthy patients with invasive GBS should undergo a comprehensive workup for potential underlying chronic illnesses. In the proper clinical context, conjunctival petechiae should elicit concern for infective endocarditis as they are present at a rate similar to that of Janeway lesions, splinter hemorrhages, and Roth spots.