Currency as a mobile environmental reservoir of bacterial pathogens in Africa: a systematic review and meta-analysis
5 affiliations
- 1Department of Microbiology and Immunology, Faculty of Biomedical Sciences, Kampala International University
- 2Department of Publication and Extension, Kampala International University
- 3Department of Pharmacy, Faculty of Health Sciences, Victoria University
- 4Department of Medical Laboratory Science, School of Allied Health Sciences, Kampala International University
- 5Department of Anatomy, Faculty of Biomedical Sciences, Kampala International University
Abstract
Background: Circulating currency is among the most frequently handled objects in daily life and may facilitate microbial transfer between individuals, food products and environmental surfaces. Although bacterial contamination of currency has been documented across Africa, the overall burden and epidemiological significance of this contamination have not been systematically quantified. This systematic review and meta-analysis synthesized available evidence on bacterial contamination of circulating currency in Africa.
Methods: PubMed, Scopus, Web of Science, African Journals Online (AJOL), Google Scholar were systematically searched. Studies investigating bacterial contamination of circulating currency notes in African countries were eligible. Random-effects meta-analysis was performed to estimate pooled contamination prevalence and organism-specific prevalence while narrative synthesis was used for outcomes unsuitable for quantitative pooling.
Results: Forty-six studies met the inclusion criteria and contributed to the systematic and narrative synthesis. Of these, 12 studies involving 2,003 currency notes provided sufficient comparable data for the meta-analysis of overall bacterial contamination prevalence. The pooled bacterial contamination prevalence was 79.3% (95% CI: 60.9–90.4%). Organism-specific analyses showed that Staphylococcus aureus accounted for 31.2% (95% CI: 24.7–38.4%) and Escherichia coli for 24.0% (95% CI: 17.8–31.5%) of bacterial isolates recovered from contaminated currency. Narrative evidence additionally identified Klebsiella , Salmonella , Pseudomonas , Proteus , and Shigella species among frequently reported contaminants. Several studies also documented multidrug-resistant, extensively drug-resistant, and pan drug-resistant bacterial strains. Lower-denomination and physically worn banknotes exhibited higher contamination burdens than higher-denomination or newer notes.
Conclusion: Bacterial contamination of circulating currency is highly prevalent across African settings and includes clinically important and antimicrobial-resistant bacterial species. These findings suggest that circulating currency may serve as an underrecognized environmental reservoir and a potential interface for microbial exchange between human, food, and environmental systems. From a One Health perspective, strengthening hand hygiene, discouraging simultaneous handling of food and money and improving currency management may help reduce contamination risks and limit microbial dissemination within communities.
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BibTeX
@article{anyanwu2026currency,
title = {{Currency as a mobile environmental reservoir of bacterial pathogens in Africa: a systematic review and meta-analysis}},
author = {Chinyere Nkemjika Anyanwu and Paul-Chima Okechukwu Ugwu and Rajendra Neel and Swase Dominic Terkimbi and Michael Ben Okon and Zeinab Adam Abakar Mohamed and Onyinyechi Bede-Ojimadu and Emeka Godson Anyanwu},
journal = {Frontiers in Public Health},
year = {2026},
month = oct,
doi = {10.3389/fpubh.2026.1921421},
url = {https://www.frontiersin.org/articles/10.3389/fpubh.2026.1921421/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Currency as a mobile environmental reservoir of bacterial pathogens in Africa: a systematic review and meta-analysis
AU - Chinyere Nkemjika Anyanwu
AU - Paul-Chima Okechukwu Ugwu
AU - Rajendra Neel
AU - Swase Dominic Terkimbi
AU - Michael Ben Okon
AU - Zeinab Adam Abakar Mohamed
AU - Onyinyechi Bede-Ojimadu
AU - Emeka Godson Anyanwu
PY - 2026
DA - 2026/10/19
JO - Frontiers in Public Health
DO - 10.3389/fpubh.2026.1921421
UR - https://www.frontiersin.org/articles/10.3389/fpubh.2026.1921421/full
AB - Background: Circulating currency is among the most frequently handled objects in daily life and may facilitate microbial transfer between individuals, food products and environmental surfaces. Although bacterial contamination of currency has been documented across Africa, the overall burden and epidemiological significance of this contamination have not been systematically quantified. This systematic review and meta-analysis synthesized available evidence on bacterial contamination of circulating currency in Africa. Methods: PubMed, Scopus, Web of Science, African Journals Online (AJOL), Google Scholar were systematically searched. Studies investigating bacterial contamination of circulating currency notes in African countries were eligible. Random-effects meta-analysis was performed to estimate pooled contamination prevalence and organism-specific prevalence while narrative synthesis was used for outcomes unsuitable for quantitative pooling. Results: Forty-six studies met the inclusion criteria and contributed to the systematic and narrative synthesis. Of these, 12 studies involving 2,003 currency notes provided sufficient comparable data for the meta-analysis of overall bacterial contamination prevalence. The pooled bacterial contamination prevalence was 79.3% (95% CI: 60.9–90.4%). Organism-specific analyses showed that Staphylococcus aureus accounted for 31.2% (95% CI: 24.7–38.4%) and Escherichia coli for 24.0% (95% CI: 17.8–31.5%) of bacterial isolates recovered from contaminated currency. Narrative evidence additionally identified Klebsiella , Salmonella , Pseudomonas , Proteus , and Shigella species among frequently reported contaminants. Several studies also documented multidrug-resistant, extensively drug-resistant, and pan drug-resistant bacterial strains. Lower-denomination and physically worn banknotes exhibited higher contamination burdens than higher-denomination or newer notes. Conclusion: Bacterial contamination of circulating currency is highly prevalent across African settings and includes clinically important and antimicrobial-resistant bacterial species. These findings suggest that circulating currency may serve as an underrecognized environmental reservoir and a potential interface for microbial exchange between human, food, and environmental systems. From a One Health perspective, strengthening hand hygiene, discouraging simultaneous handling of food and money and improving currency management may help reduce contamination risks and limit microbial dissemination within communities.
SN - 2296-2565
ER -