The aim of this report is to investigate
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
Six specimens were obtained from the 6 patients respectively and 22 environmental samples were obtained.
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.
Nontuberculous mycobacteria (NTM) are found in the natural environment throughout the world and include at least 65 different species [
Trigger point injection (TPI) is widely used for treatment by some physicians to reduce myofascial pain and headache that is unresponsive to medical treatments in Korea [
There have been few reports of
On 2 March 2009, a patient (index case) who was referred from a local clinic in Ha-dong-gun province, was diagnosed with an NTM infection in hospital A and was reported to the Korea Centers for Disease Control and Prevention (KCDC). He had multiple nodules and abscesses following EB procedure at a rural clinic in mid-October 2008. The lesions were initially treated with antibiotics, abscess incision and drainage, without improvement.
On 9 March 2009, the team from KCDC, the public health center and the provincial government performed an epidemiological investigation at the clinic in Ha-dong-gun province and interviewed the physician who performed the TPI and/or EB procedures. In the field, our team was notified that similar patients had been treated in another hospital B. These events prompted the initiation of an epidemiological study to investigate the outbreak.
From 1 July 2008 to 28 February 2009, 496 patients had visited the clinic in Ha-dong-gun province. We attempted to contact all 496 patients; 428 by telephone and 68 by mail. Our team made contact with 426 patients and found 53 patients had symptoms of a skin and soft tissue infection. Of these 53 patients, 36 (68.0%) agreed to participate in the present study. They were notified of a suspicious outbreak of
Thirty-six patients agreed to participate in the present study were classified into two categories. A confirmed case was defined as a SSTI diagnosed after 1 July 2008 and due to
Active surveillance of patients by medical record survey and telephone who had visited the clinic since 1 July 2008 was conducted to define the extent of the outbreak. Board-certified physicians interviewed potential case patients using a standardized questionnaire to obtain data on demographic characteristics, pertinent details of the TPI and/or EB, additional procedures afterwards, the date of symptom onset, symptoms and treatment. The study protocol was approved by the Institutional Review Board at KCDC.
On 9 March 2009, 22 environmental specimens were collected from the clinic for mycobacterial culture. Specimens were taken from all devices and materials within the clinic that could have come into contact with the patient's skin before, during and after the TPI and/or EB procedure session, including pillows, beds, blankets, humidifier, air conditioner, front desk, telephone and refrigerator. Water samples were taken from the sink, water bucket, bathroom, and faucets. The samples, including disposable syringes, water for injection, drugs for injection may not accurately represent the environmental conditions at the time of infection.
Clinical specimens were obtained from 6 patients. In 2 patients, pus and exudates samples were collected from the infected wounds of the thigh and waist by sterile swabs respectively. In 2 patients, pus sample were collected from the infected wound of the waist and neck by needle-aspiration respectively. In the remaining 2, in addition, excision skin biopsies were done from the thigh and chest.
Specimens were prepared as described previously [
Randomly amplified polymorphic DNA (RAPD) PCR, using three primers, INS-2, IS986-FP, URP-6, as described by Zhang et al. [
Samples then underwent pulsed-field gel electrophoresis (PFGE) analysis. The large restriction fragments were divided and digested with Asel, as previously described [
Isolates were tested for susceptibility against amikacin, cefoxitin, ciprofloxacin, clarithromycin, doxycycline, imipenem, linezolid, tobramycin and moxifloxacin by means of a broth microdilution method at the National Institute of Health [
Twenty-one patients (58.3%) were disinfected with 75% ethanol swabs before a TPI and 17 patients (47.2%) were disinfected again after the TPI with 75% ethanol swabs. Before an EB, the skin was swabbed with povidone iodine and was not re-swabbed after an EB. After the skin was swabbed with 75% ethanol, a TPI was performed using disposable needles without time to dry. Physician applied the antiseptic using concentric circles from the center toward the outside. He used a glove only his left hand without performing hand hygiene. Epidural needle and spinal set were recycled after sterilization by autoclave. Drugs used for the TPIs were lidocaine, normal saline and dexamethasone. Lidocaine and normal saline were used for the EBs. High-frequency therapy was administered after a TPI, but not after an EB. Hot pack s were not used with any patients
The clinic was opened from 7 May 2005 to 1 March 2009. Most patients visited the clinic with neuromuscular pains. Of the 36 patients interviewed, Thirteen (36%) were male and 23 (64%) were female. The median age was 56 years (range 34 to 81 years). Underlying diseases were diabetes (n=4, 11.1%), hypertension (n=4, 11.1%), cerebral infarction (n=1, 2.8%) and malignant disease (n=1, 2.8%).
Of the 36 patients, 29 (80.6%) underwent combined TPI and EB procedures at the clinic. Five (13.9%) underwent TPI only, while two (5.6%) underwent an unknown procedure.
Thirty-six patients who underwent TPIs and/or EBs between 1 July 2008 and 28 February 2009 subsequently had skin lesions or abscesses at the injection sites. The outbreak ceased at the end of February 2009 due to the closure of the clinic (
Ten patients (27.8%) had systemic symptoms, such as a fever or chills, and two patients (5.6%) had lymphadenopathy around their skin lesions. Out of 36 patients with papular skin lesions, 23 complained of a burning sensation around the skin lesion and 35 had erythematous papular skin lesions. Thirty-six patients (100%) had skin lesions corresponding to the injection site. The lesion sites were located as follows: thigh (n=20, 55.6%), waist (n=12, 33.3%), knee (n=12, 33.3%), shoulder (n=9, 25.0%), buttocks (n=7, 19.4%), hand (n=5, 13.9%), back (n=2, 5.6%), wrist (n=2, 5.6%) and neck (n=1, 2.8%). In addition, the mean number of lesions was 2.9 (range 0 to 30). The mean incubation time was 5.5 days (range 1 to 15 days). Clinical characteristics are summarized in
The environmental samples were obtained on 9 March 2009. The samples may not have accurately represented the environmental conditions at the time of the outbreak because the clinic was closed due to private problems before the investigation. M. abscessus was not isolated from the 22 environmental samples taken from the clinic. However, most cultures were contaminated by various nosocomial pathogens, including several NTM species such as
Six specimens were obtained from the 6 patients respectively in four different hospitals (A, B, C and D). Mycobacteria were isolated from the wounds of two patients in two hospitals respectively (B and C). For these isolates, nucleotide sequences of the portions of the 16S rRNA,
One was a patient's specimen which was collected from the wound swab in hospital B on 9 March 2009. The other specimen was collected from the wound needle aspiration in another hospital C.
Both of the isolates showed identical antimicrobial susceptibility profiles. They were sensitive to amikacin and clarithromycin, but resistant to doxycycline and ciprofloxacin.
Thirty-three (91.7%) of 36 patients were admitted to the different hospitals. Among them, 13 patients (39.4%) had undergone incision and drainage and two patients (6.1%) underwent aspiration of the lesions. The other 18 patients (54.5%) were given only antibiotic therapy. Ten of 18 patients were treated administration of oral clarithromycin (500 mg, twice daily) for 4-6 months and the other patients also received either amikacin or a combination of clarithromycin and ciprofloxacin. All admitted patients recovered fully during the investigation and no deaths occurred.
Outbreaks of mycobacteria have been reported following injections of histamines, lidocaine, saline solution, vaccines, disinfectant solution and adrenal cortex extracts [
Thirty-six patients who underwent TPIs and/or EBs at a same rural clinic between 1 July 2008 and 28 February 2009 subsequently had skin lesions or abscesses at the injection sites The symptoms seen in our cases is similar to that reported in previous outbreaks of
There were several limitations in identifying the exact contamination source. Because the clinic was closed due to private problems before the completion of the investigation, the environmental sources for the rapidly growing mycobacteria and their mechanism of distribution could not be elucidated.
However, there are several possible sources of the outbreak. First, inadequate sterilization of the injection sites could be the source of the infection. Because 75% ethanol and povidone iodine have a wide-spectrum germicidal effect, they are commonly used as a disinfectant for procedures. When improperly used, however, the mixture is not as effective as a disinfectant. A considerable amount of time is necessary for the prevention of mycobacterial infections after 75% ethanol or povidone iodine is applied [
Another limitation was the difficulty in conducting the epidemiological study. Most of the 36 patients with symptoms had recovered before the study, so we obtained only six specimens in four hospitals (A, B, C and D). Thirty-three (91.7%) of 36 patients were treated in different hospitals, which limited our ability to obtain treatment methodology and results. We did not investigate whether the outbreak had started prior to 1 July 2008, because the physician did not report any patients with adverse effects before then. We could not compare patients with controls due to lack of consent and participation in this present study.
In conclusion, we report an outbreak of
We especially thank Dr. Young A Kang, Dr. Ha Gyoung Lee, Dr Kyoung Chan Lee, Ph. D. Taek Sun Song for their cooperation and support for this study.
No author has a commercial or other association that might pose a conflict of interest.
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Epidemic curve of
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.
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,
PCR, polymerase chain reaction.
Clinical characteristics of patients with
Values are presented as number (%).
TPI, trigger point injection; EB, epidural block.
*Systemic symptoms include febrile sense, chill, and fatigue.