A Pilot study screening bank currency in community circulation for potential carriage of SARS-CoV-2: how safe handling the currency is?

Abstract

Purpose: Currency seems to represent an important vehicle for transmission of pathogenic microorganisms, thus a potential in affecting the public health. Digital transactions are more common in developed countries; however, handling cash currency is still very common in many countries including Bahrain. A recent study from Australia reported that SARS-CoV-2 may survive for 28 days on smooth surfaces (including banknotes), however the study was purely experimental and done in controlled laboratory environment. There were worldwide speculations suggesting the possible transmission of SARS-CoV-2 infection through currency notes. A recent study from Bangladesh reported presence of SARS-CoV-2 in approximately 7% of currency samples collected from the community. No such study has been performed on Bahraini currency, so the present study was proposed to screen the cash currency in circulation in Bahrain for the possible presence of SARS-CoV-2. Method: We collected notes and coins of Bahraini currency and a few of Saudi riyals from different public sources of currency exchange. Two time points were selected for collection when percentage of tested positive cases was on its peak. All the samples were tested for the presence of SARS-CoV-2 antigen with rapid antigen detection kit and qRT-PCR method. For initial validation, 5 samples each of potential SARS-CoV-2 RNAs extracted from known positive cases and 5 samples of extracted RNA from known negative persons were tested by rapid antigen detection kit and qRT-PCR. The results of qRT-PCR were interpreted as per the interpretation chart provided by the supplier. Results: During the study period, a total of 250 currency samples were collected including different denominations of currency notes and coins. Majority of the currency samples were collected from grocery stores followed by food outlets. Following validation, the currency samples were tested, and all turned negative for SARS-CoV-2 by rapid antigen detection test as well as by RT-PCR. Conclusion: This study predicts on Bahraini currency posing no threat of SARS-CoV-2 transmission via currency exchange.