andrea brady biol 062 african trypanosomiasis (sleeping sickness)
TRANSCRIPT
ANDREA BRADYBIOL 062
African trypanosomiasis (Sleeping Sickness)
Epidemics have killed hundreds of thousands since 1900.
http://www.microbiologybytes.com/introduction/Trypano.html
http://www.doctorswithoutborders.org/images/news/sleeping/34476.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
Chart from World Bank, 2006
http://www.dcp2.org/pubs/DCP/23/Table/23.1
Most cases are found in Sub-Saharan Africa.
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://www.microbiologybytes.com/introduction/Trypano.html
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://www.microbiologybytes.com/introduction/Trypano.html
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/joces11512cvf.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/joces11512cvf.gif
http://www.modares.ac.ir/elearning/Dalimi/Proto/images/Lectures/fig77_1.JPG
Disease Transfer
The trypanosomes are mainly transferred by the tsetse fly, which is found primarily in Sub-Saharan Africa.
http://www.microbiologybytes.com/introduction/Trypano.html
the tsetse fly The tsetse fly
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/african_trypano/clip_image002.jpg
Areas Infested by tsetse flyAreas Infested by tsetse fly
Distribution of the diseaseDistribution 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 gambienseTrypanosoma brucei rhodesiense
http://www.microbiologybytes.com/introduction/Trypano.html
Trypanosoma brucei:Two different parasites
Trypanosoma brucei gambienseAccounts 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/Trypano.html
http://www.who.int/mediacentre/factsheets/fs259/en/
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/Trypano.html
http://www.who.int/mediacentre/factsheets/fs259/en/
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/Winterbottom%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/e64ac496-41d9-4b8b-8cac-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-pills-01.gif
Diagnosis and Treatment
Four drugs are available for treatment Two available for first-
stage treatment Two available for
second-stage treatment
www.who.int/mediacentre/factsheets/fs259/en
http://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.the-scientist.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.the-scientist.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/gesellschaftliches_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.