Fusobacterium species cardiac device infective endocarditis diagnosed via molecular methods

Background
Endocarditis of an implanted cardiac device is difficult to diagnose but has a high morbidity and mortality if left untreated. We present a case of culture negative endocarditis due to Fusobacterium species detected using molecular methods.

Case report
An 81-year-old female presents with chest pain and breathlessness two months after aortic valve replacement and permanent pacemaker implantation. Fevers, hypoxia, and a single splinter haemorrhage were noted. Transoesophageal echocardiography demonstrated a single vegetation. Blood cultures were negative, but 16S ribosomal RNA matching Fusobacterium species was detected in serum. Antimicrobials were rationalised and the patient made a complete recovery.

Conclusion
Infective endocarditis is a life-threatening condition which patients with cardiac devices in-situ are particularly susceptible to. There should be a low threshold for transoesophageal echocardiography when cardiac device endocarditis is suspected. Molecular methods such as polymerase chain reaction and serology are valuable when assessing culture negative endocarditis.