Efficacy of various methods of sterilization of acupuncture needles

The iatrogenic transmission of hepatitis B virus by inadequately sterilized acupuncture needles recently has been reported. Because some licensed chiropractors use acupuncture as a therapeutic modality, we have evaluated sterilization methods for these needles, which would be adaptable for use in a chiropractic office. Dry heat, boiling water, pressurized steam, sodium hypochlorite, and 70% alcohol were compared with a glass bead dry heat sterilizer originally developed for dental instruments. Presterilized acupuncture needles were contaminated with Bacillus stearothermophilus, Escherichia coli or Staphylococcus epidermidis and sterilized for intervals ranging from 5 sec to 30 min. The needles were then cultured to determine the efficacy of the sterilization regimen. Seventy percent alcohol was ineffective as a sterilization method. In terms of both time and convenience, the glass bead apparatus was the most efficient of the remaining methods tested. B. stearothermophilus-contaminated acupuncture needles were sterilized within 10 sec of exposure to preheated glass beads. Less than 10 sec exposure killed E. coli and S. epidermidis. A significant advantage of the glass bead sterilizer over the other methods was the absence of physical damage to the needles.