Money as a Potential Vector of Transmissible Disease

Table 1. Most important pathogens isolated from banknotes or coins.
Pathogens	Banknotes	Coins	Ref.
Escherichia coli	Yes	Yes	[6]
Bacillus sp.	Yes	Yes	[18,22]
Staphylococcus aureus	Yes	Yes	[6,17]
Coagulase-negative staphylococci	Yes	Yes	[10,13,28]
Pseudomonas aeruginosa	Yes	Yes	[6]
Salmonella sp.	Yes	No	[18]
Enterococcus sp.	Yes	Yes	[22]
Klebsiella sp.	Yes	Yes	[6,18]
Proteus mirabilis	Yes	Yes	[6,18]
Acinetobacter sp.	Yes	Yes	[10,13,22]
Yersinia sp.	Yes	No	[26]
Enterobacter sp.	Yes	Yes	[22,25]
Shigella sp.	Yes	No	[25]
Vibrio sp.	Yes	No	[18]
Aspergillus	Yes	Yes	[22,26]
Cryptococcus	No	Yes	[22,26]
Candida spp.	Yes	Yes	[22,26]
Rhizopus spp.	Yes	Yes	[22,26]
Penicillium spp.	Yes	Yes	[22,26]
Ascaris lumbricoides	Yes	No	[29]
Enterobius vermicularis	Yes	No	[29]
Trichuris trichiura	Yes	No	[29]
Taenia spp.	Yes	No	[29]

Table 2. Laboratory simulations demonstrating the survival of pathogens on money.
Type of money	Agent	Concentration	Survival	Transfer	Ref.
Banknotes	Influenza A (H3N2)	8.9 × 10⁵ TCID₅₀/ml	2 h	NT	[48]
	Influenza A (H3N2) and mucus	8.9 × 10⁵ TCID₅₀/ml	8 days	NT	[48]
	Influenza B	3.2 × 10³ TCID₅₀/ml	1 day	NT	[48]
	Influenza B and mucus	3.2 × 10³ TCID₅₀/ml	2 h	NT	[48]
Coins	Staphylococcus aureus (MRSA)	10⁵ CFU/ml	4 h	NT	[2]
	S. aureus (MRSA) and organic soil component	10⁵ CFU/ml	13 days	NT	[2]
	Escherichia coli O157:H7	5 × 10⁴ CFU	7 days	Yes	[49]
	Salmonella enteritidis	5 × 10⁴ CFU	1 day	NT	[49]
	HSV-1		Decrease of 2–3 log in 1 h	NT	[50]

NT: Not tested; TCID: Tissue culture infectious dose

Table 3. Laboratory simulations of the potential transmission of pathogens by fomites.
Infectious agents	Concentration	Material	Survival	Hand-to-hand or fomite-to-hand transfer	Ref.
Bacteria
Staphylococcus aureus	10⁵ CFU/ml	Fabric	NT	Yes	[43,46]
Escherichia coli	2.75 × 10⁷ CFU/ml	Paper	10⁵ in 24 h	Yes	[44]
Pseudomonas aeruginosa	2.75 × 10⁷ CFU/ml	Paper	10³ in 7 days	Yes	[44]
Fungi
Candida albicans	10⁵ CFU/ml	Hands	24 h	Yes	[45]
Virus
Influenza	10³ TCID₅₀/ml	Tissue	15 min	Yes	[51]
	10⁷ TCID₅₀/0.1 ml	Hands	10³ reduction after 2 min	Yes	[52]
	<2.15 × 10 to 2.94 × 10 TCID₅₀/ml	Hands	~5 min	NT	[53]
Rhinovirus					[54]
Hepatitis A virus	10⁵ PFU or 6×10⁴ PFU	Hands	NT	Yes	[55,56]
Rotavirus	4 × 10⁴ PFU	Hands	7% alive after 240 min	Yes	[57]

NT: Not tested; TCID: Tissue culture infectious dose.

Box 1. Commonly used objects by healthcare workers serving as reservoirs of nosocomial pathogens
Cell phone Toilet paper Pen Stethoscope Paper money Coins Uniform Computer keyboard Books Paper files Patient equipment, such as beds and bedding

Persistence of pathogens on surfaces

Currency notes

Cotton-based banknotes provide a fibrous surface, which provides ample opportunity for bacterial attachment, and the longer a paper bill stays in circulation, the more opportunity there is for it to become contaminated.
Various bacteria, yeasts, fungi, cysts and ova of intestinal parasites have been isolated from money worldwide.

Coins

The presence of an appreciable amount of copper in coined metal alloys seems to be the limiting factor for bacterial survival on coins in general.
Various bacteria, yeasts and fungi have been isolated from coins worldwide.

Fomites & money in the spread of nosocomial infections

In hospitals, surfaces such as beds and keyboards, which have direct contact with hands, serve as reservoirs of nosocomial pathogens and vectors for cross-transmission.
Banknotes can serve as a potential source of pathogens, and paper currency recovered from hospitals was highly contaminated by Staphylococcus aureus isolates.

Fomites & money in the spread of food-borne outbreaks

Salmonella species, Escherichia coli and S. aureus are commonly isolated from banknotes from food outlets.
Prepared foods, such as salads, sandwiches and bakery items, are frequently associated with outbreaks of viral food-borne disease.

Experimental evidence of pathogen transfer by banknotes & coins

In laboratory simulations, methicillin-resistant S. aureus can easily survive on coins.
In experimental models, human influenza virus, Norovirus, Rhinovirus, hepatitis A virus and Rotavirus were able to be transmitted through hand-to-hand contact.

Prevention

Hygiene training, including training in the techniques of hand washing and disinfection, is an essential measure for preventing nosocomial and food-borne outbreaks.

Paper Money and Coins as Potential Vectors of Transmissible Disease