Paper Money and Coins as Potential Vectors of Transmissible Disease

Emmanouil Angelakis; Esam I Azhar; Fehmida Bibi; Muhammad Yasir; Ahmed K Al-Ghamdi; Ahmad M Ashshi; Adel G Elshemi; Didier Raoult


Future Microbiol. 2014;9(2):249-261. 

In This Article

Experimental Evidence of Pathogen Transfer by Banknotes and Coins

Laboratory simulations have shown that pathogens can survive on banknotes and coins. Moreover, indirect evidence of hand-to-hand and fomite-to-hand contact has shown that banknotes and coins are viable modes of transmission. In addition, it seems that wet hands can transfer larger numbers of infectious agents[41,42] and that the transfer of pathogens can easily occur when fingers are moist.[43]


Due to the differences between the textures of paper notes and the metal alloys used for coins, paper notes can accommodate a variety of contaminants, and these contaminants can persist for longer periods (Table 2).[10] The inoculation of S. aureus onto paper currency revealed that all of the isolates were able to survive for 8 days at room temperature.[17] On paper surfaces, E. coli was reduced by almost 105 in 24 h, whereas P. aeruginosa and Enterococcus hirae were more resistant to room conditions, and were reduced by only 103 after 7 days.[44] In addition, E. coli was able to be transmitted from one person's hands to paper and back to another person's hands,[44] and C. albicans was able to survive in hands and on inanimate surfaces, and could be transmitted with hand contact (Table 3).[45] Sufficient bacteria numbers to represent a potential hazard if in contact with food occurred when surfaces contaminated with E. coli, Salmonella spp. or S. aureus came into contact with fingers, a steel bowl or laminate surfaces.[46] In a recent study, nonporous surfaces had a greater transfer efficiency for E. coli, S. aureus and Bacillus thuringiensis than porous surfaces.[47] Moreover, the transfer efficiencies were higher under high relative humidity for both porous and nonporous surfaces.[47] However, the occurrence of pathogens on money does not mean that it is effectively transferred to the hands as the transfer efficiency was least with paper currency under both low and high relative humidity conditions for E. coli, S. aureus and B. thuringiensis.[47]

In coins, 105 CFU/ml of MRSA S. aureus did not survive 4 h after inoculation.[2] By contrast, when coins were treated with pus or blood, bacteria survived for at least 2 weeks when stored in the dark at ambient temperature, during which time the quantitative counts were reduced by approximately 10 and 100 for blood and pus, respectively.[2] When 5 × 104 CFU of E. coli O157:H7 and Salmonella enteritidis were applied to the surfaces of sterile US coins, it was found that these coins could serve as potential vehicles for the transmission of pathogens even a few days after contamination.[49] Moreover, it was found that E. coli can survive for up to 7 days on coins,[49] whereas bacteria isolated from coins were able to survive on Cu surfaces for 48 h or more.[28]

In conclusion, laboratory experiments revealed that bacteria are able to survive on banknotes and coins, and that the potential for their transmission via money is possible.


Although viruses have not been found on money, the potential for their transmission via money is possible. Laboratory simulations have demonstrated that the efficiency of viral transmissions varies according to viral strain, the nature of the host cells and surfaces, and atmospheric conditions.[53]

Human influenza viruses were able to survive and remain infectiousness for days when they were deposited on banknotes.[48] Moreover, the virus concentration and presence of a beneficial microenvironment are critical for the duration of viral infectiousness.[48] The concentration of H1N1 deposited on hands by coughing or sneezing was <2.15 × 10 to 2.94 × 10 tissue culture infectious dose (TCID)50/ml,[53] and a 103 to 104 reduction of H1N1 after 2 min of artificial inoculation onto human hands has been reported (Table 3).[52] Influenza virus deposited at a concentration of 8.9 × 105 TCID50/ml was able to survive for up to 17 days, but the concentration of virus diluted in mucus and deposited on banknotes was rapidly decreased (100-fold after 2 h and 105-fold after 2 weeks).[48] Influenza-contaminated hands can transfer the viruses to other surfaces or subjects,[58,59] and hands could become contaminated with influenza by coming into contact with surfaces inoculated with viral secretions containing between 105 and 107 TCID50/ml.[51] In addition, coins contaminated with HSV-1 exhibited a decrease of 100–1000 in the viral concentration within 1 h of contamination.[50]

Although they have not been tested, many other viruses are stable in the environment and exhibit high infectivity and, thus, could possibly be transferred by money and coins. The transmission of Rhinovirus was very efficient by hand-to-hand contact,[60–62] and 50% of subjects developed an infection after handling a coffee cup contaminated with Rhinovirus.[54] However, other studies contradict the efficiency of rhinovirus spread by direct and indirect hand-to-hand contact with self-inoculation.[63] In addition, the spread of HAV, Rotavirus and Astrovirus from hands to fomites and vice versa has been well documented in several experimental models. Astroviruses exhibited a notable persistence when dried on porous and nonporous materials, particularly at low temperature.[64] A longer survival period was found for Rotavirus on nonporous surfaces at low temperature and humidity.[65] Moreover, Rotaviruses can survive for extended periods when dried in fecal matter,[66] and contact between a contaminated and clean hand 20 and 60 min after rotavirus inoculation resulted in the transfer of 6.6 and 2.8%, respectively, of the original infectious virus.[57] Considerable amounts of HAV remained infectious on the finger pads 4 h after infection,[55] and contaminated finger pads transferred 9% of deposited HAV to lettuce.[56]

In summary, laboratory simulations have revealed that the transmission of virus via banknotes and coins is possible.