Published online Oct 27, 2020. doi: 10.4254/wjh.v12.i10.775
Peer-review started: April 27, 2020
First decision: August 9, 2020
Revised: August 18, 2020
Accepted: September 14, 2020
Article in press: September 14, 2020
Published online: October 27, 2020
The recent rise in the incidence of hepatitis B virus (HBV) infections in a densely populated city of eastern India (“mixing vessel” of people of varied socio-economic and immune status) prompted this study. Applying saliva on fingers for enumerating bank notes is a common practice in the Indian subcontinent. Paper notes may be a potential source of “horizontal” transmission of this virus, especially if there are cuts/bruises on the oral mucous membrane or skin.
To investigate whether paper currencies could be a plausible mode of horizontal transmission of HBV infection.
Polymerase chain reactions (PCR) followed by nucleotide sequencing was done for the detection of HBV. Hepatitis B virus surface antigen enzyme-linked immunosorbent assay(HBsAg ELISA) was performed on all HBV deoxyribonucleic acid-positive samples to check the detectability of the virus. Atomic force microscopy (AFM) was carried out for visual confirmation of HBV particles in ultracentrifuged/immunoprecipitated samples from currency paper washings.
HBV-specific PCRs on pellets obtained after ultracentrifugation/ immunoprecipitation of the currency paper washings detected potentially intact/viable HBV (genotype D2) in 7.14% of samples (n = 70). AFM gave the visual confirmation of HBV particles in ultracentrifuged/immunoprecipitated samples from currency paper washings. However, HBV isolates from the currency notes could not be detected by HBsAg ELISA.
It is a common practice in the Indian subcontinent to count paper currencies by applying saliva on fingertips. Paper notes may be a potential source of “horizontal” transmission of this virus, especially if there are cuts/bruises on the oral mucous membrane or skin, but it was practically not possible to demonstrate experimentally such transmission. Detection of potentially intact/viable and “occult” HBV from currency poses potential risk of silent transmission of this virus among the general population.
Core Tip: The recent upsurge in hepatitis B virus (HBV) infections in eastern India prompted the search for this virus in low denomination paper notes in this region. Applying saliva on finger tips for enumerating currency notes is a common practice. Thus, paper currencies may be a potential source of “horizontal” HBV transmission, especially if there are cuts/bruises on the oral mucous membrane or skin. We discovered that intact HBV particles are present in about 7.14% of the currencies. Molecular analysis and immunoassays suggested that the circulating HBV are “occult” in nature, hence capable of “silent transmission” in the general population.