Risks of allergy vial contamination: comparison of mixing in-office versus under ventilation hood

Area of Science:

• Allergy and Immunology
• Microbiology
• Pharmaceutical Compounding

Background:

• Allergy immunotherapy (AIT) involves administering gradually increasing doses of allergens to patients.
• Sterile preparation of AIT vials is crucial to prevent infection.
• Standard practice for compounding sterile preparations often involves ventilation hoods.

Purpose of the Study:

• To compare the incidence of bacterial contamination in allergy immunotherapy vials prepared using two distinct methods: in-office preparation versus preparation under a ventilation hood.
• To assess the safety and efficacy of different AIT vial preparation techniques.

Main Methods:

• A prospective, single-blinded study was conducted over 11 months.
• 537 allergy immunotherapy vials were prepared: 320 in-office and 217 under a ventilation hood.
• Vials were cultured for aerobic and anaerobic bacteria.

Main Results:

• A low rate of bacterial contamination was observed in both preparation groups.
• Two positive cultures occurred in vials prepared in-office, and one in vials prepared under a ventilation hood.
• Follow-up cultures of contaminated vials were negative, and no patient infections were reported.

Conclusions:

• The risk of bacterial contamination in allergy immunotherapy vials is rare, regardless of whether they are prepared in-office or under a ventilation hood.
• Both preparation methods appear to yield safe immunotherapy vials.
• Further research may explore long-term outcomes and cost-effectiveness of each method.