Leishmaniasis needs more attention

“
After malaria, leishmaniasis
ranks as the second most deadly
protozoan disease in humans.
diagnosis, treatment and overall
management. But despite all efforts,
there’s still no vaccine. Which is why
the WHO considers it a neglected
disease of the world – under-funded
and under-researched by both private
and public organisations.
There is no convincing explanation
as to why this is the case. One reason
may be because it affects people who
live in remote areas where reporting
and diagnostic systems are poor and
health care is a luxury.
The gap in knowledge – and
treatment – of the disease is
particularly bad for Africa. This is
because the disease presents as an
opportunistic infection in patients
infected with HIV, tuberculosis and
malaria. Sudan, for example, holds
one of the highest rates of Leishmania
and HIV co-infection. This co-infection
is known as a ‘deadly gridlock’ as
both microbes strengthen each other.
Leishmania infection accelerates the
development of HIV to AIDS while
HIV infection increases the risk of
developing Leishmania infection
between 100 to 2 320 times.
But all is not lost. Several groups
in different continents, including
Africa, are working at understanding
the complexities of this disease. For
example, we are part of a unit at
the University of Cape Town (UCT)
that’s been shedding more light on
the disease. We are analysing how
host factors contribute to the rate of
natural healing – or recurring infection
– with the aim of targeting these
for development as host-directed
therapies.
Tackling a fatal disease
Leishmaniasis is medically complex
and the fact that it ‘hides’ in cells of the
body makes treatment complicated.
Sodium stibogluconate and liposomal
amphotericin B are widely used to
treat infection. But this involves a long
duration of treatment that needs to be
administered into the vein.
These drugs were introduced in the
1940s. Almost 80 years later, they’re
still being used with only one other
drug, Miltefosine, approved in 2002.
Adding to this, new challenges keep
emerging. For example, the efficacy of
sodium stibogluconate is now being
eroded by resistance. In addition, while
liposomal amphotericin B deoxycholate
has been shown to be highly effective,
it’s expensive, restricting its access to
poor populations.
This is why accessible, cheap, highquality medicine is important. The lack
of a vaccine against leishmaniasis also
complicates matters.
The hope is that our research
will identify host factors that could
be developed for alternative or
complementary treatments – termed
host-directed therapies – since an
effective host response is required to
support anti-leishmanial drugs.
Beyond the therapies, the next
important area of work is integrating
awareness to prevent and manage the
spread of the disease.
Prevention better
than cure
Mass drug administration, like that
used for other tropical diseases such
as schistosomiasis and malaria, is not
recommended for leishmaniasis due
to the invasive route of administration
and associated drug toxicity. Thus,
preventative measures instead must
be strengthened. These include vector
control – the use of pesticides and
insecticides – social mobilisation to
educate people in endemic areas on
behavioural changes, treated nets and
environmental management.
In addition, innovative ideas into
alternate treatment options, such
as host-directed therapies, must be
explored.
In line with this, the WHO has
targeted neglected diseases,
including leishmaniasis, for control and
elimination by 2030. This roadmap
is being implemented to achieve
the health-related 2030 United
Nations Sustainable Development
Goals, together with policymakers,
governments, non-governmental
organisations, philanthropists,
stakeholders, industries and –
essentially – the public.
The starting point is that prevention
is better than cure. Central to this
theme is awareness – in endemic
areas as well as more broadly. But, to
build this awareness, we need a wider
platform to reach a larger audience,
both public and private.
Dr Ramona Hurdayal, lecturer and team
leader of the Leishmaniasis Research
Group, University of Cape Town and
Raphael Taiwo Aruleba, PhD candidate,
University of Cape Town.
This article first appeared in The
Conversation (theconversation.com/
africa), a collaboration between
editors and academics
to provide informed news analysis
and commentary.
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