Transmission of a highly drug-resistant strain (strain W1) of Mycobacterium tuberculosis. Community outbreak and nosocomial transmission via a contaminated bronchoscope.
BACKGROUND
Nosocomial transmission of multidrug-resistant tuberculosis (MDR TB) has been reported primarily in New York State and has generally been presumed to occur via respiratory aerosols.


OBJECTIVE
To assess nosocomial transmission of MDR TB. In 1995, 8 patients with MDR TB were identified in South Carolina; all were resistant to 7 drugs and had matching DNA fingerprints (strain W1). Community linkswere identified for 5 patients (Patients 1-5). However, no links were identified forthe other 3 patients (Patients 6-8) except being hospitalized at the same hospital as 1 community patient.


METHODS
Outbreak investigation.


METHODS
Community and hospital.


METHODS
Eight patients whose MDR TB isolates had DNA fingerprint patterns matching strain W1.


METHODS
Clinical characteristics of patients with strain W1 Mycobacterium tuberculosis isolates.


RESULTS
Patient 5 (community patient) and Patient 8, diagnosed April 1995 and November 1995, respectively, had clinical courses consistent with MDR TB, with smear-positive and culture-positive specimens and cavitary lesions on chest radiograph; both died of MDR TB less than 1 month after diagnosis. Patients 6 and 7 (diagnosed May 1995) each had 1 positive culture for MDR TB; specimens were collected during bronchoscopy. Patient 6 had a skin test conversion after bronchoscopy. Neither Patient 6 nor Patient 7 had a clinical course consistent with MDR TB, neither was treated for MDR TB, and both are alive and well. No evidence of laboratory contamination of specimens, transmission on inpatient wards, or contact among patients was found. All 4 received bronchoscopies in May 1995; Patients 6, 7, and 8 had bronchoscopies 1, 12, and 17 days, respectively, after Patient 5. Observations revealed that bronchoscope cleaning was inadequate, and the bronchoscope was never immersed in disinfectant.


CONCLUSIONS
Inadequate cleaning and disinfection of the bronchoscope after the procedure performed on Patient 5 led to subsequent false-positive cultures in Patients 6 and 7 and transmission of infection to Patient 6 and active MDR TB to Patient 8.
Agerton
T
T
Epidemic Intelligence Service Program, Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, Ga 30333, USA.
Valway
S
S
Gore
B
B
Pozsik
C
C
Plikaytis
B
B
Woodley
C
C
Onorato
I
I
D000368:Aged; D000995:Antitubercular Agents / Q000494:pharmacology; D020680:Bronchoscopes; D001999:Bronchoscopy; D003428:Cross Infection / Q000635:transmission*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial; D004196:Disease Outbreaks; D018432:Drug Resistance, Multiple; D004866:Equipment Contamination; D005260:Female; D006761:Hospitals; D006801:Humans; D017053:Infection Control; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics; D013022:South Carolina; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy / Q000453:epidemiology / Q000635:transmission*
D000995:Antitubercular Agents; D004269:DNA, Bacterial