Basic Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Oct 27, 2020; 12(10): 775-791
Published online Oct 27, 2020. doi: 10.4254/wjh.v12.i10.775
Hepatitis B virus detected in paper currencies in a densely populated city of India: A plausible source of horizontal transmission?
Palashpriya Das, Ruchi Supekar, Ritika Chatterjee, Subrata Roy, Anisa Ghosh, Subhajit Biswas
Palashpriya Das, Ruchi Supekar, Ritika Chatterjee, Subrata Roy, Anisa Ghosh, Infectious Diseases and Immunology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, Kolkata PIN-700032, West Bengal, India
Subhajit Biswas, Infectious Diseases & Immunology Division, Indian Institute of Chemical Biology (Council of Scientific and Industrial Research), Kolkata 700032, West Bengal, India
Author contributions: Biswas S and Das P conceptualized, designed and executed the present work and wrote the manuscript; Supekar R contributed substantially to the virology experiments and in writing of the manuscript; Chatterjee R, Roy S and Ghosh A took part in collecting the samples for this study and also conducted experiments; Das P and Supekar R contributed equally and are joint first authors; all authors have read and approved the final manuscript.
Supported by Institutional Grant by Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, Kolkata, No. MLP-118
Institutional review board statement: The study was reviewed and approved by the Council of Scientific and Industrial Research-Indian Institute of Chemical Biology Institutional Ethical Committee on Human Subjects and Council of Scientific and Industrial Research-Indian Institute of Chemical Biology Biological Safety Committee. This work involved no use of human subjects or human clinical materials.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Subhajit Biswas, DVSc, PhD, Associate Professor, Senior Researcher, Infectious Diseases & Immunology Division, Indian Institute of Chemical Biology (Council of Scientific and Industrial Research), 4 Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, West Bengal, India. subhajit.biswas@iicb.res.in
Received: April 27, 2020
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
Processing time: 179 Days and 16.2 Hours
Abstract
BACKGROUND

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.

AIM

To investigate whether paper currencies could be a plausible mode of horizontal transmission of HBV infection.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Keywords: Hepatitis B virus; Contamination; Paper currencies; Occult hepatitis B virus; Hepatitis B virus surface antigen enzyme-linked immunosorbent assay; Horizontal transmission

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.