Moraxella catarrhalis Bacteremia in a 3-Year-Old Child without Underlying Disease

Moraxella catarrhalis is a common causative bacterium of otitis media and respiratory tract infection in children. Childhood-onset M. catarrhalis bacteremia is more common in children with underlying conditions, such as immunodeficiency, or those using a nasal device. In children without underlying conditions, the onset is usually at younger than 2 years of age.We encountered a case of M. catarrhalis bacteremia in a previously healthy 3-year-old boy. The patient was hospitalized with a 5-day history of fever. Physical examination on admission showed redness and swelling of the ear drums bilaterally. Blood culture and upper nasopharyngeal swab culture both grew M. catarrhalis, which led to the diagnosis of bacteremia and otitis media caused by this organism. The patient was treated with intravenous cefotaxime for 3 days and sulbactam/ampicillin for the subsequent 3 days, followed by oral clavulanate/amoxicillin for 8 days, with good response. Absence of abnormalities in immunological screening tests and absence of any significant past medical history suggested that the patient was not immunocompromised.