ACTINOMYCES BACTEREMIA FROM PULMONARY ACTINOMYCOSIS

Abstract

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Actinomycosis is an infection caused by actinomyces species, an anaerobe colonized within the mouth and gastrointestinal tract. Actinomyces bacteremia is rare clinical finding of which the etiology, identification, and treatment are debated. We present a case report of a 59-year-old male with stage IV breast cancer who required intensive care for actinomyces bacteremia and acute hypoxic respiratory failure secondary to pulmonary actinomycosis. CASE PRESENTATION: A 59-year-old male presented to the hospital with respiratory distress. On initial evaluation, the patient was found to be obtunded and hypoxic, prompting endotracheal intubation. Pertinent history was significant for breast cancer managed with trastuzumab. Three months prior, the patient was diagnosed with trastuzumab induced lung disease of which he was treated with oral prednisone therapy. A CT scan of the chest was significant for bilateral ground glass opacities and a left upper lobe consolidation, the latter being new relative to a CT scan three months prior. Broad spectrum antibiotics and mechanical ventilation were initiated for a diagnosis of acute hypoxic respiratory failure secondary to a superimposed pneumonia. Blood cultures from admission revealed Actinomyces species, and the patient was diagnosed with Pulmonary Actinomycosis. Unfortunately, further identification of the species of Actinomyces isolated in the blood was unable to be obtained. The patient's oxygen requirements improved following antibiotic therapy and the patient was extubated after one week on mechanical ventilation. He was successfully discharged on amoxicillin with plans for a three to six month course. DISCUSSION: Actinomyces bacteremia is a rare finding that has debated clinical significance. Historically, treatment has always been warranted in the event that the patient exhibited signs of Actinomyces infection, with or without evidence of bacteremia. A 2016 retrospective analysis of patients found to have Actinomyces positive blood cultures reported 43 patients who did not receive treatment for Actinomyces bacteremia, all of which had no reported complications after discharge. Though, none of these patients exhibited evidence of an active Actinomycocis infection. Our patient developed an acute respiratory failure in the setting of known trastuzumab induced lung injury that previously did not require supplemental oxygen therapy. Blood isolates of Actinomyces species in conjunction with new pulmonary infiltrates suggested a superimposed pulmonary Actinomyces infection was the source. Because an active source of Actinomycosis infection was present, the decision to treat the patient with antibiotics was not called into question. CONCLUSIONS: Further studies on treatment indications and duration of Actinomyces bacteremia are need. REFERENCE #1: Jeffery-Smith A, Nic-Fhogartaigh C, Millar M. Is the Presence of Actinomyces spp. in Blood Culture Always Significant?. J Clin Microbiol. 2016;54(4):1137-1139. doi:10.1128/JCM.03074-15 REFERENCE #2: G.F. Mabeza, J. Macfarlane. Pulmonary actinomycosis. European Respiratory Journal Mar 2003, 21 (3) 545-551; DOI: 10.1183/09031936.03.00089103 REFERENCE #3: Mani RK, Mishra V, Singh PK, Pradhan D. Pulmonary actinomycosis: a clinical surprise! BMJ Case Rep. 2017;2017:bcr2016218959. Published 2017 Jan 27. doi:10.1136/bcr-2016-218959 DISCLOSURES: No relevant relationships by John Madara, source=Web Response No relevant relationships by Nathaniel Rosal, source=Web Response