Transmission of Mycobacterium tuberculosis from medical waste.

CONTEXT: Washington State has a relatively low incidence rate of tuberculosis (TB) infection. However, from May to September 1997, 3 cases of pulmonary TB were reported among medical waste treatment workers at 1 facility in Washington. There is no previous documentation of Mycobacterium tuberculosis transmission as a result of processing medical waste. OBJECTIVE: To identify the source(s) of these 3 TB infections. DESIGN, SETTING, AND PARTICIPANTS: Interviews of the 3 infected patient-workers and their contacts, review of patient-worker medical records and the state TB registry, and collection of all multidrug-resistant TB (MDR-TB) isolates identified after January 1, 1995, from the facility's catchment area; DNA fingerprinting of all isolates; polymerase chain reaction and automated DNA sequencing to determine genetic mutations associated with drug resistance; and occupational safety and environmental evaluations of the facility. MAIN OUTCOME MEASURES: Previous exposures of patient-workers to TB; verification of patient-worker tuberculin skin test histories; identification of other cases of TB in the community and at the facility; drug susceptibility of patient-worker isolates; and potential for worker exposure to live M tuberculosis cultures. RESULTS: All 3 patient-workers were younger than 55 years, were born in the United States, and reported no known exposures to TB. We did not identify other TB cases. The 3 patient-workers' isolates had different DNA fingerprints. One of 10 MDR-TB catchment-area isolates matched an MDR-TB patient-worker isolate by DNA fingerprint pattern. DNA sequencing demonstrated the same rare mutation in these isolates. There was no evidence of personal contact between these 2 individuals. The laboratory that initially processed the matching isolate sent contaminated waste to the treatment facility. The facility accepted contaminated medical waste where it was shredded, blown, compacted, and finally deactivated. Equipment failures, insufficient employee training, and respiratory protective equipment inadequacies were identified at the facility. CONCLUSION: Processing contaminated medical waste resulted in transmission of M tuberculosis to at least 1 medical waste treatment facility worker. JAMA. 2000;284:1683-1688.

Formation of vesicovaginal fistula: the role of suture placement into the bladder during closure of the vaginal cuff after transabdominal hysterectomy.

OBJECTIVE: The objective of this study was to determine whether suture placement through the bladder during closure of the vaginal cuff at the time of transabdominal hysterectomy is associated with formation of postoperative vesicovaginal fistula. STUDY DESIGN: Virgin female New Zealand White rabbits were used to perform this study. The study protocol was approved by the institutional Animal Use and Care Committee. Animals were housed and maintained in the animal facilities at the University of Mississippi Medical Center according to appropriate guidelines. Thirty-two animals were randomized into two groups at a 2:1 ratio. All animals underwent transabdominal hysterectomy. Animals in group 1 (n = 21) had a figure-of-eight suture placed through the anterior vaginal cuff and intentionally into the bladder. Animals in group 2 (n = 11) were treated in an identical manner but care was taken to exclude the bladder when the suture was placed into the anterior vaginal cuff. Animals were put to death, and necropsy was performed 28 days after surgery. The bladder and vagina of each animal were harvested en bloc. Evidence of a fistula between the bladder and vagina was then determined in three distinct ways. Infant formula was infused into the bladder through a urethral catheter, and the vagina was inspected for leakage. Saline solution tinted with methylene blue was used in the same manner. Last, air was injected through the catheter into the bladder with the en bloc vagina and bladder preparation submerged in water. The vagina was observed for air leakage manifest by bubble formation. RESULTS: The two groups were comparable in regard to weight gain, intraoperative complications, and postoperative complications. One animal in each group died. Neither had a surgical complication directly related to the suture placement. During inspection of the vagina and bladder no animal was noted to have a vesicovaginal fistula. CONCLUSIONS: A suture placed through the bladder during closure of the vaginal cuff after transabdominal hysterectomy, as an isolated event, does not appear to be associated with formation of postoperative vesicovaginal fistula.