Background: The Texas Department of State Health Services was notified of six cases of M. abscessus abscesses at allergy injection sites among patients of a single clinic in July of 2009. M. abscessus is a bacterium that is ubiquitous in nature and can contaminate medications, products, and medical devices. An investigation was conducted to identify additional cases, determine risk factors for infection, and provide recommendations for infection control.
Methods: Infection control practices were observed and environmental sampling was conducted at the allergy clinic. A retrospective cohort study to identify differential risks among all allergy injection patients receiving injections at the clinic since May 1, 2009 was conducted. A case was defined as any patient receiving ≥ 1 injection at clinic A from May 1, 2009 to July 10, 2009 who presented with symptoms consistent with local infection at the site of injection(s) and either had laboratory confirmation of M. abscessus or received empiric treatment for Mycobacterium sp.. M. abscessus environmental and patient isolates were compared using pulsed field gel electrophoresis (PFGE).
Results: Twenty-five cases were identified over 3 months among 126 injection patients (attack rate= 20%). All patients in the clinic had skin antisepsis with a benzalkonium chloride topical preparation diluted with reverse osmosis water. Risk of infection did not differ with respect to clinical or treatment factors examined including allergy sera received between cases and controls. M. abscessus did not grow from 22 vials of compounded allergy injection sera from 10 cases or from undiluted benzalkonium chloride topical solution. Three samples of reverse osmosis water used to dilute the benzalkonium chloride solution grew M. abscessus which matched 21 available clinical isolates from 13 case-patients by PFGE (figure).
Conclusion: Our investigation implicated M. abscessus-contaminated reverse osmosis water used to dilute a benzalkonium chloride topical preparation in this outbreak. Healthcare providers should follow appropriate skin preparation guidelines.
S. N. Hocevar,
M. Williams, None
N. Pascoe, None
H. O'Connell, None
B. Jensen, None
M. Hatch, None
T. MacCannell, None
See more of: Abstracts
Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 21 with the exception of research findings presented at IDSA press conferences.