Used Nigerian currency notes as potential sources of infection in Calabar, Nigeria

Abstract

Background: Currency notes when not used and in circulation, remain clean and fresh but when in use and have changed hands, may be soiled and liable to tear and microbial contamination. As unrelated to human health as it seems, money could serve as a vehicle in the transmission of pathogenic microbial organisms as well as disease if handled unhygienically during its transit.
Aim: This study was therefore aimed to investigate the potentials of the Nigerian currency notes as vehicle for the transmission of microbial agents of infection in Calabar.
Methodology: A cross sectional study was carried out between May and September, 2017 to examine 200 randomly selected used Nigerian currency notes for bacteria and fungi of medical importance. Organisms were isolated using standard swabbing, direct microscopy and cultural techniques and identified using various biochemical techniques.
Results: Overall, 154 (77%) samples tested positive for potential bacterial pathogens, with Staphylococcus aureus taking the lead in prevalence (36%), followed by Pseudomonas aeruginosa (13.5%), Escherichia coli (11.5%) Klebsiella aerogenes (9.5%) and Proteus mirabilis (6.5%). Fungal isolates had a total of 147 (73.50%) with Aspergillus niger ranking highest (30.50%) in prevalence, followed by Aspergillus fumigatus (19.50%), Candida albicans (10%), Blastomyces dermatitidis (7.5%), and Penicillium spp (6%). The polymer notes recorded insignificantly higher bacterial and fungal organisms than the paper notes (p>0.05). The 50 naira note was the most (86.76%) while 5, 500, and 1000 naira notes were the least contaminated (50.0%) each.
Conclusion: The study has demonstrated a high rate of bacterial and fungal contamination of the Nigerian currency notes in Calabar. They may play a role in the spread of diseases in Calabar, hence adequate hygiene measures in the handling of money as well as the enforcement of cashless economy policy is suggested.