96 HEALTHCARE
HOW 2015 NOBEL
PRIZE DRUG MIGHT RID
AFRICA OF ANCIENT
SCOURGES
Peter J Hotez, Dean of the National School of Tropical Medicine
and Professor of Pediatrics and Molecular Virology & Microbiology,
Baylor College of Medicine
Although not fatal, elephantiasis can severely
disfigure its victim, resulting in profound social
stigma. By distorting the limbs and other
body parts, elephantiasis renders people too
sick to work so that elephantiasis hinders
economic productivity.
The announcement that
the 2015 Nobel Prize in
Physiology or Medicine
went to three scientists
who developed antiparasitic
disease drugs has important
implications for sub-Saharan
Africa.
Two of the scientists – William C. Campbell
and Satoshi Ōmura – shared the prize for the
discovery of the drug ivermectin. Ivermectin
(trading as mectizan®) is one of the most
widely used medicines in Africa. It is used
in the mass treatment or prevention of two
ancient scourges that have plagued Africa for
centuries – elephantiasis and river blindness.
Understanding the diseases
Elephantiasis, commonly referred to as LF,
is a disease that affects tens of millions of
people in Africa, with Nigeria likely having
the largest number of cases. It is caused
by a parasitic worm, Wuchereria bancrofti,
which affects the lymphatics, genitals and
breasts. The parasite in turn is transmitted
by mosquitoes.
However, there is good news. It was recently
estimated that 139 million people in Africa
received elephantiasis treatments in 2013.
This was made possible by the Mectizan
Donation Programme along with the
World Health Organisation and the Global
Programme to Eliminate Lymphatic Filariasis.
By killing the embryonic microfilaria stages
of W. bancrofti, wide-scale delivery and
treatment with mectizan can interrupt
the transmission of elephantiasis. So far,
Togo may be the first African nation to
eliminateelephantiasis through this approach.
The global goal is to eliminate elephantiasis
by 2020.
Similarly, onchocerciasis is also caused by a
parasitic worm, Onchocerca volvulus, which
is transmitted by black flies that live near fast-
flowing streams and rivers. The microfilarial
stages of parasitic worm cause disfiguring
skin disease, but also invade the cornea to
cause blindness.
Between 17 and 30 million people are
affected by onchocerciasis in sub-Saharan
Africa. Through the Mectizan Donation
Programme and the World Health
Organisation’s African Programme for
Onchocerciasis Control, it is estimated that
100 million people were treated in 2013.
Because of mass treatment
programmes, onchocerciasis has been
eliminated in Mali and Senegal. There is
Tanzanian Seif Ramadhan is washed before being
treated for elephantiasis. Khalfan Said/EPA