Viral contamination of intradermal skin test syringes.

Intradermal skin tests are often performed using a common syringe with multiple needles. Bacterial contamination of intradermal skin test syringes can occur as a result of apparent siphoning caused by needle changing. The bacterial contamination of the syringe can be prevented by flushing the contaminated needle prior to changing. In this study, two different needle changing techniques were examined using a polio virus contaminant. Viral contamination of the syringe was not prevented by flushing the infected needle prior to removal. All syringes were contaminated with virus regardless of needle changing technique. We, therefore, cannot recommend the continued use of a common syringe for intradermal skin tests between patients regardless of needle changing technique.