Bacterial Cross-contamination Potential Associated with Contaminated Currency

Area of Science:

• Microbiology
• Environmental Health
• Infectious Disease Transmission

Background:

• Paper currencies are known reservoirs for diverse microbial contaminants.
• Understanding microbial transfer on currency is crucial for assessing public health risks.

Purpose of the Study:

• To quantify the cross-contamination potential of microorganisms between US dollar bills.
• To evaluate bacterial transfer rates under different contact conditions.

Main Methods:

• New US 1-dollar bills were seeded with Bacillus thuringiensis.
• Seeded bills were pressed or rubbed against clean currency.
• Bacterial transfer was quantified using colony-forming unit counts after efficient vortex recovery.

Main Results:

• Transfer rates varied with contact method and duration: 4.8% (24h press), 8.6% (72h press), and 14.3% (rubbing).
• Vortexing for 10 minutes proved the most efficient recovery method (40% ± 8.1% efficiency).

Conclusions:

• Significant bacterial transfer occurs between paper currencies.
• The quantified transfer rates indicate a potential pathway for infectious disease spread via currency.