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Sleeping Sickness rampant in Sub-Saharan Africa
By Barry Mason
7 September 2001
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The recent announcement that the Microsoft Gates Foundation
has donated $15 million to fund research into sleeping sickness
has only served to highlight the abysmal response by pharmaceutical
companies and Western governments to a disease that is now affecting
millions in Africa.
The money was awarded to a group of international researchers
led by Dr Richard R Tidwell of the University of North Carolina
(UNC) at Chapel Hill. They are studying the effect of a new drug
known as DB-289. Toxicity tests have been carried out on human
volunteers in Germany and the drug is now to be tested on patients
with sleeping sickness at the Institute for the Combat and Control
of Sleeping Sickness clinic at Viana, near Luanda in Angola.
Sub-Saharan Africa has been hit by three major sleeping sickness
epidemics over the last 100 years. By the 1960s the disease had
almost been eradicated, but the current outbreak, which began
in 1970, is now a threat to 60 million people living in the 36
countries comprising sub-Saharan Africa.
According to the World Health Organisation (WHO) only three
to four million of those people who are at risk are under surveillance
at health centres. The WHO says 45,000 cases were reported in
1999, but estimates the real number of people affected to be ten
times this figure. Many of the figures are based on reports from
areas with only five-percent surveillance of possible infected
people. In some areas of Angola, Southern Sudan and the Democratic
Republic of Congo, the prevalence of the disease is between 20
and 50 percent, making it the first or second highest fatal disease
in these areas and even overtaking AIDS. Overall the disease is
spreading across the continent at three times the rate of AIDS.
Sleeping sickness, or trypanosomiasis, is caused by the trypanosoma
parasite. This is a single celled protozoan. Tsetse flies, about
the size of houseflies, transmit the disease by biting humans.
The disease is confined to sub-Saharan Africa and occurs in
two types. One type, causing chronic infection, is found in Central
and West Africa. Once a person is infected, this form of the disease
can take several months or even years to progress and for the
symptoms to emerge. Once the symptoms have emerged, the disease
is already at an advanced stage.
The other more virulent form of the disease is found in Southern
and Eastern Africa and causes a more acute infection, with symptoms
showing after only a few weeks. Domestic and wild animals act
as reservoirs of the disease and also succumb to it.
In both types of the disease, the parasite multiplies in the
host body, leading to fever, headaches and joint pains. The second
phase of the disease, the neurological phase, occurs when the
parasite crosses the blood barrier into the brain and central
nervous system. This phase causes sensory disturbance, poor co-ordination,
confusion and disturbance of sleep (hence sleeping sickness).
If not treated the disease is fatal. Even if treatment is given,
once the secondary neurological phase has begun it can leave the
patient with irreversible damage.
Two existing drugsSuramine, discovered in 1921, and Pentamidine,
discovered in 1941can be used to treat the first phase of
sleeping sickness, i.e. before it crosses into the central nervous
system.
Currently the main drug used to treat the second advanced phase
of the disease is called Melarspol, which was developed in 1949.
It has undesirable side effects. One such side effect is a reactive
encephalopathya neurological allergic type reaction affecting
the brain. In five percent of cases the side effects prove fatal.
Those who recover from the neurological allergic reaction can
be left damaged.
The drug is the only surviving pharmaceutical product based
on arsenic. It has to be injected directly into veins and is very
painful. One doctor likens it to arsenic suspended in car
anti-freeze solution. An indication of its toxicity is given
by a WHO report, which explained that production of the drug was
being transferred to Brazil because of pressure from environmentalists
and more stringent pollution regulations in the West.
Apart from the side effects, there are now cases of drug resistant
forms of sleeping sickness being reported, making up to 30 percent
of cases in Central Africa. The only alternative drug, Eflornithine,
was registered in 1990 but was withdrawn from production because
it was unprofitable. The WHO was given the licence for the drug
and is currently seeking a manufacturer.
The current spread of the disease can be attributed to the
wars continuing in a number of regions of sub-Saharan Africa,
made worse by the poverty and cuts in what was already minimal
levels of healthcare provision, arising from IMF structural adjustment
programmes. As the WHO fact sheet on sleeping sickness comments,
[It] affects remote and rural areas where health systems
are least effective, or non-existent. It spreads with socio-economic
problems such as political instability, displacement of populations,
war and poverty.
Dr Josenando Theophile is director of the Angolan Institute
for the Combat and Control of Sleeping Sickness, which is undertaking
the trial of the new drug DB-289. He explained that in Angola
in 1974 there were only three cases of the disease, while today
the figure is nearly 100,000.
In a statement made last year Dr Tidwell explained the reason
for the group at UNC applying for the Microsoft Gates Foundation
grant. The pharmaceutical industry, he argued, cannot dedicate
the research funds or technical resources necessary to search
for new, more effective drugs . In the competitive marketplace,
major pharmaceutical companies must concentrate on high-profile
diseases with more potential for profits.
The impact of the drive for profits by the drug companies and
the indifference of Western governments to the spread of disease
in Africa is reflected in statistics given by the charity, Doctors
without Borders. Between 1975 and 1997 the international pharmaceutical
industry put on the market 1,450 new medical products. Of these
only 11 were directly targeted at common diseases found in Africa.
Even the drug DB 289 was not originally developed to combat sleeping
sickness. It was the result of research by Immtech International
Inc (IMMT) into the effects of related compounds on opportunistic
fungal infections that occur in pneumonia and in immune suppressed
patients, such as those with AIDS or who have had organ transplants.
IMMT is to be paid nearly $10m of the grant to the UNC to carry
out clinical trials.
See Also:
AIDS campaigners sue South
African government
[29 August 2001]
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