A Cluster of Central Line–Associated Bloodstream Infections Due to Rapidly Growing Nontuberculous Mycobacteria in Patients with Hematologic Disorders at a Japanese Tertiary Care Center: An Outbreak Investigation and Review of the Literature

Abstract

BACKGROUNDRapidly growing nontuberculous mycobacteria (RGM) are considered rare pathogens, causing central line–associated bloodstream infection. We identified an outbreak of central line–associated bloodstream infection due to RGM at a hematology-oncology ward during a 5-month period.DESIGNOutbreak investigation and literature review.SETTINGA Japanese tertiary care center.PATIENTSAdults who were hospitalized at the hematology-oncology ward from October 15, 2011, through February 17, 2012.RESULTSA total of 5 patients with a bloodstream infection due to RGM (4 cases ofMycobacterium mucogenicumand 1 case ofMycobacterium canariasenseinfection) were identified; of these, 3 patients had acute myeloid leukemia, 1 had acute lymphocytic leukemia, and 1 had aplastic anemia. Four of the 5 patients received cord blood transplantation prior to developing the bloodstream infection. All central venous catheters in patients with a bloodstream infection were removed. These patients promptly defervesced after catheter removal and their care was successfully managed without antimicrobial therapy. Surveillance cultures from the environment and water detectedM. mucogenicumandM. canariasensein the water supply of the hematology-oncology ward. The isolates from the bloodstream infection and water sources were identical on the basis of 16S-rRNA gene sequencing.CONCLUSIONSThe source of RGM in the outbreak of bloodstream infections likely was the ward tap water supply. Awareness of catheter-related bloodstream infections due to nontuberculous mycobacteria should be emphasized, especially where immunocompromised patients are at risk. Also, using antimicrobials after catheter removal to treat central line–associated bloodstream infection due to RGM may not be necessary.Infect Control Hosp Epidemiol 2015;36(1): 76–80