Transcript African trypanosomiasis (Sleeping Sickness)

African trypanosomiasis
(Sleeping Sickness)
ANDREA BRADY
BIOL 062
Epidemics have
killed hundreds of
thousands since
1900.
http://www.microbiologybytes.com/introduction/Trypa
no.html
http://www.doctorswithoutborders.org/images/news/sleeping/344
76.jpg
Tens of thousands continue to die each year
 WHO estimated that in 2001, there
were 48,000 deaths caused by sleeping
sickness.
www.dcp2.org/pubs/DCP/23/Section/3154
Tens of thousands continue to die each year
 WHO estimated that in 2001, there
were 48,000 deaths caused by sleeping
sickness.
 Currently, it is estimated the number of
deaths per year has increased to 50,000
or as high as 100,000.
http://www.dcp2.org/pubs/DCP/23/Section/3154
As many as 500,000
are currently infected.
http://www.kfwh.org/information.asp
Most cases
are found in
Sub-Saharan
Africa.
Chart from World Bank, 2006
http://www.dcp2.org/pubs/DCP/23/Table/23.1
How can an infectious disease be
contained to such a specific region of the
world?
How can an infectious disease be
contained to such a specific region of the
world?
Let’s take a closer look at how the disease
is spread…
Disease Transfer
 The disease is caused
by two parasites of the
Trypanosoma Genus
and brucei Species.
http://en.wikipedia.org/wiki/Sleeping_sickness
http://farm3.static.flickr.com/2110/1760532740_20189a8cdc.jpg
Disease Transfer
 The disease is caused
by two parasites of the
Trypanosoma Genus
and brucei Species.
 More commonly
called Trypanosomes
http://www.who.int/mediacentre/factsheets/fs259/en/
http://farm3.static.flickr.com/2110/1760532740_20189a8cdc.jpg
 Trypanosomes
are protozoans.
http://www.who.int/mediacentre/factsheets/fs259/en/
http://jcs.biologists.org/content/vol115/issue12/images/medium/jo
ces11512cvf.gif
 Trypanosomes
are protozoans.


(unicellular eukaryotes)
(single flagellum)
http://www.who.int/mediacentre/factsheets/fs259/en/
http://jcs.biologists.org/content/vol115/issue12/images/medium/jo
ces11512cvf.gif
http://www.modares.ac.ir/elearning/Dalimi/P
roto/images/Lectures/fig77_1.JPG
Disease Transfer
 The trypanosomes are
mainly transferred by
the tsetse fly, which is
found primarily in SubSaharan Africa.
the tsetse fly
The tsetse fly
http://www.microbiologybytes.com/introduction/Trypano.html
http://library.truman.edu/test/carol/Tsetse_fly.gif
Areas
Infested
by the
Tsetse Fly
http://www.fao.org/ag/icons/map.gif
Distribution
Map for
African
Sleeping
Sickness
http://www.medicalecology.org/diseases/af
rican_trypano/clip_image002.jpg
Areas Infested by tsetse fly
Distribution of the disease
Trypanosoma brucei:
Two different parasites
African Sleeping Sickness is
caused by two different
parasites.
http://www.microbiologybytes.com/introduction/Trypano.html
Trypanosoma brucei:
Two different parasites
African Sleeping Sickness is
caused by two different
parasites.
 Trypanosoma brucei gambiense
 Trypanosoma brucei rhodesiense
http://www.microbiologybytes.com/introduction/Trypano.html
Trypanosoma brucei:
Two different parasites
 Trypanosoma brucei
gambiense
 Accounts for 90% of
reported cases of African
Sleeping Sickness.
 Causes the chronic form of
the disease
 Prevalent mostly in West
and Central Africa.
http://www.microbiologybytes.com/introduction/Tr
ypano.html
http://www.dmacc.cc.ia.us/instructors/Image11.gif
Trypanosoma brucei:
Two different parasites
 Trypanosoma brucei
rhodesiense
 Accounts for 10% of
reported cases of African
Sleeping Sickness.
 Causes the acute form of
the disease.
 Prevalent mostly in
Eastern and Southern
Africa.
http://www.microbiologybytes.com/introduction/Tr
ypano.html
http://www.uoguelph.ca/~pwoo/fig6.jpg
Method of Infection
Begins with the bite of the tsetse fly
http://www.who.int/mediacentre/factsheets/fs259/en/
http://www.mimg.ucla.edu/faculty/Hill/fig2.jpg
Method of Infection
 The bite will become
red and swollen.
http://www.who.int/mediacentre/factsheets/fs259/en/
http://io.uwinnipeg.ca/~simmons/16cm05/1116/28-11-TrypanosomaLM.jpg
Method of Infection
 The bite will become
red and swollen.
 From here, the
infection will enter the
bloodstream.
http://www.who.int/mediacentre/factsheets/fs259/en/
http://io.uwinnipeg.ca/~simmons/16cm05/1116/28-11-TrypanosomaLM.jpg
Method of Infection
 The bite will become
red and swollen.
 The infection will
enter the bloodstream.
 Long asymptomatic
phase.
http://www.who.int/mediacentre/factsheets/fs259/en/
http://io.uwinnipeg.ca/~simmons/16cm05/1116/28-11-TrypanosomaLM.jpg
 The disease has three distinct stages.
 The disease has three distinct stages.

Asymptomatic Phase

http://www.who.int/mediacentre/factsheets/fs259/en/
 The disease has three distinct stages.

Asymptomatic Phase
First Stage
(haemolymphatic phase)

http://www.who.int/mediacentre/factsheets/fs259/en/

 The disease has three distinct stages.

Asymptomatic Phase
First Stage
(haemolymphatic phase)
Second Stage (neurological phase)

http://www.who.int/mediacentre/factsheets/fs259/en/


First Stage
 The pathogens
will spread
throughout the
blood and the
lymph.
http://www.who.int/mediacentre/factsheets/fs259/en/
http://www.pnas.org/content/100/3/F1.medium.gif
First Stage
 Symptoms

Fever
Headache
Sweating
Joint Pain
Itching
Swollen Lymph Nodes

www.who.int/mediacentre/factsheets/fs259/en





http://upload.wikimedia.org/wikipedia/commons/thumb/8/88/Wi
nterbottom%27s_sign.jpg/200px-Winterbottom%27s_sign.jpg
Second Stage
 Eventually, the disease will manage to cross
the blood-brain barrier.
Second Stage
 Eventually, the disease will manage to cross
the blood-brain barrier.
 This will cause an infection of the Central
Nervous System

www.who.int/mediacentre/factsheets/fs259/en
Second Stage
 Symptoms
Confusion
 Sensory Disturbances
 Poor Coordination
 Disturbances of Sleep
Cycles


www.who.int/mediacentre/factsheets/fs259/en
http://www.msf.org.uk/UploadedImages/e64ac496-41d9-4b8b8cac-423baecb957f.jpg
If not treated, the
disease is fatal.

www.who.int/mediacentre/factsheets/fs259/en
Diagnosis and Treatment
 Treatment varies
depending on the
stage of the
disease.

www.who.int/mediacentre/factsheets/fs259/en

http://www.sawitfirst.co.uk/media/pill_clockbig.gif
Diagnosis and Treatment
 The disease is easier and more effective
to treat the earlier it is diagnosed.
http://www.who.int/mediacentre/factsheets/fs259/en/
Diagnosis and Treatment
 The disease is easier and more effective
to treat the earlier it is diagnosed.
 Much harder after the pathogens have
crossed the blood-brain barrier.
http://www.who.int/mediacentre/factsheets/fs259/en/
Diagnosis and Treatment
 Four drugs are
available for
treatment
http://www.pet-comfort-products.com/images/colorful-pills01.gif
Diagnosis and Treatment
 Four drugs are
available for
treatment
Two available for firststage treatment
 Two available for
second-stage treatment


www.who.int/mediacentre/factsheets/fs259/en
www.pet-comfort-products.com/images/colorful-pills-01.gif
Diagnosis and Treatment
 The two drugs available for second-
stage treatment are significantly more
dangerous.
http://www.who.int/mediacentre/factsheets/fs259/en/
Diagnosis and Treatment
 So, in summary, treatment during
the first-stage is…
Diagnosis and Treatment
 So, in summary,
treatment during
the first-stage
is…
 More
effective
http://images.thescientist.com/content/figures/images/yr2002/may13/iv.jpg
Diagnosis and Treatment
 So, in summary,
treatment during
the first-stage
is…
 More
effective
 Safer
http://images.thescientist.com/content/figures/images/yr2002/may13/iv.jpg
Diagnosis and Treatment
Therefore,
early diagnosis
is imperative
http://www.who.int/mediacentre/factsheets/fs259/en/
http://www.bayerscheringpharma.de/html/images/upload/gesells
chaftliches_engagement/aerztin_patient_205.jpg
 Like with malaria, if
we could reduce the
number of people with
the disease, we could
reduce transmissions
and eventually
eradicate the disease.
http://www.ecdl.com/countries/images/map_africa.gif
 Organizations like
WHO have began
efforts to eliminate
the risk of this
disease

http://www.who.int/mediacentre/factsheets/fs259/en/

http://www.who.int/mediacentre/factsheets/fs259/en/
 Organizations like
WHO have began
efforts to eliminate
the risk of this
disease
 HAT programme

http://www.who.int/mediacentre/factsheets/fs259/en/

http://www.who.int/mediacentre/factsheets/fs259/en/
 Due to lack of funds and turmoil, there
are an estimated 7 nations currently at
“epidemic” level for the disease.
http://www.kfwh.org/information.asp
 Like many other infectious diseases in
third world countries, much change is
needed in world health policies before
we can effectively eradicate African
Sleeping Sickness.
THE END.