Pramod Theetha Kariyanna^{1, 2}, Bayu Sutarjono³, Naga Pranavi Ellanti⁴, Apoorva Jayarangaiah⁵, Amog Jayarangaiah⁶, Sushruth Das⁶, Harshith Priyan Chandrakumar², Isabel M. McFarlane^2,

Background. The diagnosis of infective endocarditis is difficult, especially when it involves atypical organisms. Therefore, our study identified risk factors of infective endocarditis caused by rare pathogen, Gemella spp. Methods. A systematic review was conducted to investigate characteristics of endocarditis patients infected with Gemella spp. using the search term “Gemella” and “endocarditis.” Case reports were gathered by searching Medline/Pubmed, Google Scholar, CINAHL, Cochrane CENTRAL, and Web of Science databases. 83 articles were selected for review. Results. 5 species of Gemella were identified. Typical patient affected were male between 31 and 45 years of age. On admission, patients had fever, tachycardia, and normal blood pressure. Common clinical manifestation other than fever included fatigue and weakness, chills and sweating, and nausea, vomiting, diarrhea, and weight changes. 1 in 4 reported a history of congenital heart disease, and a recent oral infection. 1 in 2 patients underwent surgical procedure. Laboratory tests revealed anemia, leukocytosis, and elevated erythrocyte sedimentation in all age groups, as well as elevated C-reactive protein in adult and geriatric populations only. Mitral and aortic valves were most commonly infected by Gemella spp.. The most common Gemella spp.-susceptible antibiotics were penicillin, vancomycin, cephalosporin, macrolide, and aminoglycosides. However, antibiotic resistance was observed against penicillin, aminoglycoside, and fluoroquinolone. Antibiotic therapy of at least 6 weeks resulted in superior clinical improvements than durations under 6 weeks. Finally, 1 in 2 patients underwent valve replacement or repair, with common complications affecting the cardiovascular, neurological, and renal systems. Finally, death occurred in 1 in 8 patients, half of which occurred post-surgical procedure, and the majority occurring equal to or greater than 1 week from admission. Conclusion. Our systematic review highlights the importance of considering rare pathogens, particularly in the presence of predisposing risk factors.

infective endocarditis, Gemella spp, heart valve vegetations, clinical features, mortality, risk factors