Moraxella osloensis Infection Associated with Croup Syndrome: A Case Report

Abstract

Moraxella osloensis is an aerobic, oxidase-positive, gram-negative coccobacillus. Unlike Moraxella catarrhalis, which is one of the important pathogens of otitis media, sinusitis and pneumonia, M. osloensis is rarely pathogenic in humans. Although rare, M. osloensis infection has the potential to cause serious systemic disease. Here we report a 5-month-old baby boy with Moraxella osloensis infection associated with croup syndrome. M. osloensis was isolated from initial blood culture. To our limited knowledge, there is no similar case of M. osloensis infection associated with croup syndrome published on journals that can be found on medline. The use of corticosteroids has now become the standard therapy in moderate- to-severe croup. However, steroids will transiently suppress the immune function and increase the risk of severe infection. We present this unusual case and suggest the necessity of intensive follow-up in croup patients with steroid therapy.