James Shepherd-Barron was Special Adviser to the Minister of Health in Sierra Leone in 2014 during the early phase of the West Africa Ebola crisis and DFID’s Humanitarian Health Adviser in the Democratic Republic of the Congo during the Ebola outbreaks of 2018. A former official in the World Health Organisation, he is an independent disaster management consultant.
SUMMARY
Disinfection of all banknotes in Hubei
province by China’s central bank, the People’s Bank of China, as part of its Covid-19
outbreak response strategy demonstrates that physical currency plays a more
important role in the control of outbreaks of communicable diseases than
hitherto recognised by international health actors.
It is possible that contaminated
banknotes present a public health risk for transmission of infectious diseases
by acting as potential vectors, fomites and reservoirs for a wide range of
bacteria and viruses, including Ebola Virus Disease (EVD) and the new Corona virus
(Covid-19).
The extent to which
banknotes may or may not play a direct role in ‘the chain of transmission’ is only
part of the story. No less relevant is the belief
among affected populations that they do. And this belief can have adverse secondary
consequences when it comes to implementation of outbreak control measures.
International and
national health authorities could take more robust measures to address the
potential threat to public health posed by banknotes in ongoing outbreaks and
should work with the cash industry – specifically, members of the International
Currency Association – to ensure that the disinfection and eventual replacement
of banknotes with disease-resistant alternatives becomes an integrated part of any
control strategy for diseases of epidemic potential.
BACKGROUND
In June 2014, just as the West
Africa Ebola epidemic was gathering momentum, Kenema hospital in Sierra Leone
was attacked by an angry mob armed with machetes bent on destroying the Ebola
Treatment Facility and killing its patients and staff, particularly its international
staff[1].
After a two-hour running battle, the attack was only just thwarted by the local
police, thereby saving the lives of many, including the author.
But what had roused
the mob to such excess in the first place? Partly, and as always with Ebola, a
particularly nasty and deadly disease whose chain of transmission is not widely
understood in Central and West Africa, the motivation was fear. The townspeople
did not want suspected Ebola cases imported into their town; a disproportionate
number of local health staff working at the facility had already died, and the
fear was palpable.
Another reason was
that the residents of Kenema had known for some years the hospital housed an
internationally funded haemorrhagic fevers research laboratory[2]
which, over time, had led to local suspicions that biological agents were being
developed there.
Thirdly, and perhaps
the biggest motivation of all, rumours had circulated wildly in the market to
the effect that the local currency had somehow become infected – perhaps
deliberately – with the virus, resulting in a massive disruption to normal
trading activity. Within hours stallholders, taxi drivers and guest-house
owners simply refused to handle any form of money, even when wearing rubber
gloves, and a barter economy took over. Within days, market stalls shut up shop
across Sierra Leone and it was many months before normal economic activity
resumed[3].
Four years later, in
2018, first in Equateur and then in North Kivu Provinces of the Democratic
Republic of The Congo (DRC), much the same thing happened. First it became difficult
to buy goods in local markets with physical currency and then Ebola Treatment Centres
and national and international health staff began to be attacked.
In all three outbreaks,
social mobilisation programmes tailored to local anthropological and
demographic conditions had been quickly instituted as a key component of the outbreak
control strategy. Despite heroic efforts by the governments concerned, the
World Health Organisation, NGOs and others to correct erroneous information,
rumours that cash was playing a role in transmission of EVD would not go away.
Not only did this have the immediate consequence of disrupting local economic
activity, but it fostered a climate of suspicion which in turn led to the
outbreaks being extended in both time and space. The consequence in all three
cases was that people died unnecessarily. Clearly, public-health messaging
wasn’t working.
So, what more could be
done when it comes to the role of physical currency in communicable disease
outbreaks in general, and EVD and Covid-19 outbreaks in particular?
DISCUSSION
Social Mobilisation
In
terms of their potential to act as vectors, fomites or reservoirs of harmful microbiological
pathogens it is theoretically possible for physical currency to play at least
an indirect role in disease transmission (Kumar, 2009)[i].
But in practice there is no evidence that anyone has ever died after handling a
contaminated banknote. As the stories above make clear, however, the
epidemiological evidence is one thing; human belief and behaviour is quite
another.
Through the first year[4]
of the Kivu response in DRC, many local people living in affected areas expressed
the belief that Ebola did not exist; had supernatural origins (e.g. witchcraft);
was created by politicians in order to influence elections; or was introduced by
foreign non-governmental organisations in order to make money (Baggio, 2019)[ii].
In a survey of knowledge,
attitudes and practices about transmission routes for EVD conducted in Senegal
in 2017, nearly half (47%) of respondents thought that banknotes were one of
the main modes of transmission (Lakhe, 2018)[iii].
It is no surprise to see that rumours of banknotes that have been deliberately
infected with deadly diseases can lead to politically motivated outbreaks of
violence perpetrated by ill-informed or superstitious people on national health
workers and foreign aid staff. The impact can be particularly severe in the
case of EVD. But even with less virulent diseases such as Covid-19, “fear can be
as deadly as the illness itself.”[iv]
The question of
whether or not banknotes can act as vectors or fomites of disease is
contentious and, over the years, has given rise to the perpetuation of many
myths. These myths have arisen in large part because of the low priority given
to any statement to the contrary. In part, this is down to the contradictory
nature of the little evidence available[5]
and poor analysis has been exacerbated by simplistic and ill-informed reporting
in the media. A local newspaper in Nigeria, for example, published an article during
their Ebola outbreak of 2014 that artfully blended fear, myth and poor health
messaging entitled ‘Fears that Ebola Virus Disease (EVD) could be transmitted
by exchange of paper currencies may not be completely wrong …!” (Vanguard News)[v]
Persistence
As with much so-called ‘evidence’
it is possible to find contrasting views in academic literature. In a 2014
travel advisory, the European Commission’s Health Committee quoted WHO guidance
at the time to the effect that “You cannot contract Ebola by handling money.”[6] Yet a 2016 study to assess the potential
contribution of fomites to EVD infection in humans demonstrated that EVD
remains infectious for 6.2 days under air-conditioned hospital conditions and
for 2.5 days under environmental conditions on blood-spotted banknotes
indicating that “EVD-contaminated items such as syringes and banknotes may pose
a serious risk to humans” (Westhoff Smith, 2016)[vi].
The peer-reviewed article does not, however, mention how unlikely it is that a
banknote can become contaminated with the blood or secretions of a bed-bound Ebola
patient shedding the virus.
The extent to which hand-to-note
and note-to-hand transmission occurs is determined not just by the environment
but by the type and persistence of the pathogen involved. The main factors
affecting survivability of pathogens on the surface of paper money is the
presence of organic matter, solar radiation, temperature and humidity (Taylor,
2007)[vii].
Shigella, various Mycobacteria
and Clostridium difficile can survive for months on a banknote’s surface, while
Corona viruses, Severe Acute Respiratory Syndrome (SARS) viruses, Rhinoviruses,
and Cholera vibrio persist only for a few days (Kramer, 2006)[viii].
One study that looked at the ability of influenza viruses to infect a cell
culture after varying amounts of time on a banknote showed survival times from
48 hours to 17 days, depending on the environment and how they were deposited
on the banknote (Thomas, 2008)[ix].
There is no information in the papers reviewed for this article on the
persistence of EVD on physical currency.
Paper currency is not
made of paper, but a mix of cotton and linen. It is multi-layered and absorbent
and therefore allows for bacteria and viruses to reside within the substrate as
well as on the surface of both sides (El-Dars, 2005)[x].
This makes it a potential reservoir, not just a fomite (Kumar, 2009).
The longer paper
currency remains in circulation, the more opportunity there is for it to become
contaminated. Lower-denomination notes, being the most often handled in
developing countires, are the most contaminated[xi].
It must be assumed that the more engrained the organic matter – dirt, sweat,
and dead skin – the greater the likelihood of a given pathogen persisting
(though there is currently no official evidence for this). Low denomination
banknotes in West Africa have usually been in circulation for so long that they
have become dirty to the point they are scarcely recognisable.
Levels of
contamination on paper currency varies widely between countries (Varusha, 2017)[xii]
and polymer notes are significantly less contaminated than cotton/linen-based
notes (Vriesekoop, 2010)[xiii].
Public
Health Messaging
In the case of DRC’s two Ebola outbreaks,
World Health Organisation staff in the field at the time[7]
argued that such knowledge was less relevant than it might be in other epidemic
situations owing to the fact that the life-cycle of EVD makes it unlikely that
cash (paper money) would be passing hands during the phase of peak transmission.
This is when the patient was either dead or close to death and, if at home,
surrounded by family members. It should also be noted that cash and voucher
distributions[8]
were not encouraged in the affected areas as it was assumed that this would
stimulate mingling of potentially infected people in marketplaces – a situation
best avoided – and undermine efforts at establishing the vital 21-day period of
self-isolation.
WHO also argued that
addressing the issue of paper currency being a potential vector for disease
transmission in public health messaging could be counter-productive as it would
only serve to dilute the simplest and most effective message of all – that of
the need for regular hand-washing with soap and (chlorinated) water,
particularly before and after handling of food[9].
Food
Security
Ebola outbreaks in Africa have had
an extremely negative impact on what is often an already fragile food security
situation. Reduced farming activities as well as disruption of trade following
travel restrictions and market closures have resulted in food shortages and
high food prices in Ebola-affected countries and beyond (OECD, 2014)[xiv].
New
Technologies in Banknote Production
According to specialised banknote
printers and ink manufacturers it is feasible to include anti-microbial agents
in the banknote substrate, ink, or varnish. There is even an urban myth that
this is indeed what the Swiss authorities intend to do in the event of a
pandemic. However, they also feel such technologies would be unnecessary as
these varnishes can include surfactants which make it difficult for any
contaminant, including oil, water, organic materials and pathogens to remain on
the surface for long[10].
As far as pathogens are concerned, this claim has not been verified by primary
research.
Precedent
There is precedent for the
introduction of new banknotes in humanitarian settings. In Libya, for example,
in 2011, the British government introduced a new paper currency (printed by De
La Rue) following the overthrow of Col. Gaddafi.
There is also precedent for disinfection
of existing banknotes. As part of its Corvid-19 outbreak response strategy in
February 2020, the People’s Bank of China, disinfected all banknotes in Hubei
province which had potentially been in contact with the new virus. The process
involved the use of ultraviolet light, high temperatures and then sealing and
storing the notes for 7-14 days.
Cost
The cost of banknote production
is not as high as it might at first appear as it can be offset by seigniorage[11]
and be integrated into a country’s normal cash handling and withdrawal cycle.
CONCLUSION
As passive fomites, it is likely
that banknotes present no greater risk of disease transmission than other forms
such as doorknobs, credit cards and mobile phones. However, as potential
reservoirs, contaminated banknotes allow pathogens to persist for longer,
thereby presenting a potentially greater public health risk than doorknobs.
This implies that outbreak control efforts must more directly address these
risks – either real or perceived – by more than targeted public-health
messaging and increased prevention and treatment protocols such as provision of
hand-washing facilities and development of vaccines.
New technologies allow
for more robust disease-resistant measures to be included at the time of
banknote production. Application of such technologies will have direct and
indirect effects: the replacement of old banknotes for new will signal that the
authorities are taking their citizen’s concerns seriously while also reducing
the actual risk of disease transmission.
It is likely that secondary
effects in terms of attacks against health facilities and health workers and
reductions in food security and nutritional status due to market disruption
will also be reduced by their introduction. However, more research is needed to
ascertain the survivability and persistence of pathogens such as EVD and
Covid-19 when these new banknote printing technologies are used.
Given these factors, four
actions are recommended:
- Conduct
primary research into the persistence of EVD, Covid-19 and Cholera on polymer
and non-polymer banknotes manufactured with repellant varnishes in a range of
environmental conditions.
- Recognise
that physical currency is perceived by local affected populations as having a
major role in the chain of transmission.
- Take
earlier and more robust steps to convince affected populations that the risks of
contracting communicable diseases from the handling of banknotes, while
negligible, are real enough to warrant visible action.
- Take
the earliest possible steps to replace existing currency with new banknotes (either
polymer or manufactured with oil and water-repellent varnishes and/or
anti-microbial agents).
End
Approx 2,800 words
To contact the author, e-mail:
[email protected]
[1] On the day of the
attack, there were over 20 suspected or confirmed EVD cases in the treatment
facility, one Belgian laboratory technician, one epidemiologist from Public
Health England, and one visitor from DFID (the author).
[2] Funded by DFID, ECHO
and USAID via partners including Tulane University and the British NGO, MERLIN
(now part of Save the Children, UK)
[3] Market disruption was exacerbated by later imposition of quarantine
restrictions by the Government
[4] The outbreak probably began months before it was formally
recognised in June 2018
[5] An online search of PubMed only showed 20 references to ‘paper
currency and disease transmission’
[6]https://ec.europa.eu/health/sites/health/files/preparedness_response/docs/ebola_infotravellers2014_en.pdf
[7] Conversation between
the author and WHO Chief of Emergency Operations Section, June 2018
[8] Cash and Voucher Assistance Programmes are nowadays the default
relief modality over in-kind distributions around the world, and had been
ongoing in the Kivu provinces for some time before the Ebola outbreak.
[9] Conversation between
the author and WHO Ebola Coordinator in DRC, June 2018
[10] Conversation between
the author and staff of SICPA in Lausanne, March 2019
[11] Profit made by a government by issuing currency, being the
difference between the face value and the cost of production
REFERENCES
[i] Kumar et al: Detection of Virulence Genes in Staphylococcus aureus
Isolated from Paper Currency; International Journal of Infectious Diseases,
Vol.13 (6) 2009
[ii] Baggio et al: Bringing community perspectives to decision-making in
the Ebola response in the Democratic Republic of Congo; Humanitarian Practice
Network, February 2019
[iii] Lakhe et al: Knowledge, Attitudes and Practices towards Ebola Virus
Disease among Participants in an Ebola Vaccine Trial in Dakar, Senegal; Journal
of Tropical Diseases & Public Health. Vol. 6 (4) August 2018 [https://www.omicsonline.org/open-access/knowledge-attitudes-and-practices-towards-ebola-virus-disease-among-participants-in-an-ebola-vaccine-trial-in-dakar-senegal-2329-891X-1000276-104368.html
accessed 28 April 2019]
[iv] Hatfield: US Navy, 2 March 2020
[v] Vanguard Newspaper, September 2014
[vi] Westhoff Smith et al: Ebola Virus Stability Under Hospital and
Environmental Conditions; The Journal of Infectious Diseases, Vol. 214 (3) 15
October 2016 [https://academic.oup.com/jid/article/214/suppl_3/S142/2388079
accessed 28 April 2019]
[vii] Taylor et al: The Persistence of Flood-borne Pathogens on building
surfaces; International Journal of Hygiene and Environmental Health, Vol.216 (1)
2007
[viii] Kramer, Schwebke and Kampf: How long do nosocomial pathogens
persist on inanimate surfaces? A systematic review; British Medical Council
Journal of Infectious Diseases, Vol.6 (130) 2006
[ix] Thomas et al: Survival of Influenza Virus on Banknotes; Journal of
Applied and Environmental Microbiology, Vol. 74 (10) 2008
[x] El-Dars and Hassan: A preliminary bacterial study of Egyptian paper
money; International Journal of Environmental Health Research, Vol.15 (3) 2005
[xi] ibid
[xii] Varusha and Gowri: Paper Money and Coins as Potential Vectors in
Transmissable Diseases – A Review; Journal of Pharmaceutical Sciences and
Research, Vol.9 (2) 2017
[xiii] Vriesekoop et al: Dirty Money- an
investigation into the hygiene status of some of the world’s currencies as
obtained from food outlets; Journal of Foodborne Pathological Disease, Vol.7
(12) 2010
[xiv] http://www.oecd.org/swac/ebola-10facts.htm
