Moraxella catarrhalis bacteremic pneumonia

An 81-year-old man with lung cancer with bone metastases, interstitial pneumonia, and emphysema, was hospitalized for pain control. He developed fever and chills during hospitalization. Physical examination revealed a fever of 39.1 °C, but there were no findings on history or physical examination to suggest the source of the infection. Gram-negative cocci were detected in the blood culture (Fig. 1) and in a Gram stained sputum smear (Figs. 3 and 4). Neisseria meningitis and Neisseria gonorrhoeae were ruled out based on history and an absence of suggestive symptoms. The cause of his fever was diagnosed as Moraxella catarrhalis bacteremic pneumonia based on the blood culture and the sputum smear results, and he was treated with intravenous ceftriaxone. This case illustrates the importance of Gram staining of sputum and blood culture. Moraxella catarrhalis should be considered in the differential diagnosis when gram-negative cocci are detected in the blood and the sputum.