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African trypanosomiasis (Sleeping Sickness). Andrea Brady Biol 062. Epidemics have killed hundreds of thousands since 1900. http://www.microbiologybytes.com/introduction/Trypano.html . http://www.doctorswithoutborders.org/images/news/sleeping/34476.jpg.
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African trypanosomiasis (Sleeping Sickness) Andrea Brady Biol 062
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
Most cases are found in Sub-Saharan Africa. Chart from World Bank, 2006http://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://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.JPGhttp://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 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/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. • 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.