Content area
Full Text
Background
Moraxella catarrhalis had for long been regarded as a non-pathogenic coloniser of the oropharynx, and was estimated to colonise the oropharynx of around 1-5% of the adult population. 1 2 Over the past two decades it has been recognised as a commensal of the respiratory tract in children and in adults with underlying lung disease, and a common pathogen in respiratory exacerbations; 1-3 however, cases of invasive disease with this pathogen are scant in the literature. 3-7 We report a case of M. catarrhalis bacteraemia and prosthetic valve endocarditis.
Case presentation
A 63-year-old man with a history of ischaemic cardiomyopathy, who had been fitted with a biventricular pacemaker and a bioprosthetic aortic valve due to previous infective endocarditis secondary to Streptococcus gallolyticus bacteraemia, presented at the emergency room, with altered mental status. The patient had been having symptoms of confusion and lethargy, and had been falling frequently, over the past 4 days. Symptoms such as chest discomfort, palpitations, cough, dyspnoea, skin lesion and fever were denied by the patient. The patient was unemployed and had a significant history of alcohol consumption. He denied smoking and illicit drug use. No apparent portal of entry for bacteraemia, such as recent surgical and medical indwelling prosthetic devices (including intravascular catheters, orthopaedic hardware) were identified.
On examination, the patient was tachycardic with a heart rate of 96 bpm, with the remainder of his vital signs within normal limits (temperature 37.4°C, respiratory rate 13/min, blood pressure 116/72 mm Hg). He was poorly nourished and lethargic on examination. On cardiovascular examination, the patient was tachycardic, however, no murmurs, rubs or gallops were appreciated. The remainder of his physical examination was unremarkable.
Investigations
Initial laboratory examination revealed macrocytic anaemia (haemoglobin 9.8 g/dL and mean corpuscular volume 108 fL), normal white cell count (WCC) and differential (5600 cells/[micro]L), elevated...