Case series of mycobacterium abscessus infections associated with a trigger point injection and epidural block at a rural clinic

Abstract

Objectives: The aim of this report is to investigate Mycobacterium abscessus infections at a rural clinic and carry out a surveillance program to determine the extent and source of these infections.

Methods: The authors conducted an active surveillance investigation of 36 patients who had visited the clinic since 1 July 2008. Clinical specimens were collected from the patients and an envirnmental investigation. Pulsed-field gel elctrophoresis (PFGE) was performed for comparing with M. abscessus isolates from the patients.

Results: Six specimens were obtained from the 6 patients respectively and 22 environmental samples were obtained. M. abscessus was isolated from the wounds of two patients, and various nosocomial pathogens, but not M. abscessus, were isolated from the surrounding environment. Two strains of M. abscessus from patients were identical as a result of PFGE.

Conclusion: Infection control education including proper hand hygiene should be emphasized for physicians performing invasive procedures. There also needs to be more attention for invasive procedures management, including trigger point injection and epidural block in rural clinics.

Keywords: Epidural block; Mycobacterium abscessus; Outbreak; Trigger point injection.

Figure 1

Epidemic curve of Mycobacterium abscessus infections following trigger point injection and/or epidural block. The mean incubation time was 5.5 days (range 1 to 15 days). TPI, trigger point injection, EB, epidural block. ^*Index case presented with a skin lesion about two weeks after having a TPI and an EB in mid-October 2008; ^†The local clinic was closed; ^‡First patient was reported; ^§A formal epidemiological study was initiated; ^∥The physician at the clinic in Hadong-gun was interviewed. 22 environmental specimens were collected from the clinic.

Figure 2

Molecular strain typing of isolates by randomly amplified polymorphic DNA PCR (RAPD-PCR) (A) and pulsed-field gel electrophoresis (PFGE) (B). (A) DNA fragments amplified by RAPD-PCR using three primers, INS-2, IS986-FP, URP-6. Lane M, 1Kb marker (Solgent); Lane 1, patient isolate in hospital B; Lanes 2, patient isolate in hospital C; Lanes 3, M. abscessus ATCC19977 (Type strain of Mycobacterium abscessus) control. (B) PFGE patterns of genomic DNA digested with Asel. Lane M, Lambda ladder PFG marker (NEB); Lane 1, patient isolate in hospital B; Lane 2, patient isolate in hospital C. Both of the isolates from the two patients had identical patterns. PCR, polymerase chain reaction.