African trypano.ppt

8/10/2019 African trypano.ppt

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Epidemics havekilled hundreds ofthousands since1900.

http://www.microbiologybytes.com/introduction/Trypano.html http://www.doctorswithoutborders.org/images/news/sleeping/34476.jpg


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Tens of thousands continue to die each year

WHO estimated that in 2001, there

were 48,000 deaths caused by sleepingsickness.

www.dcp2.org/pubs/DCP/23/Section/3154


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Tens of thousands continue to die each year

WHO estimated that in 2001, there

were 48,000 deaths caused by sleepingsickness.

Currently, it is estimated the number ofdeaths per year has increased to 50,000or as high as 100,000.

http://www.dcp2.org/pubs/DCP/23/Section/3154


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As many as 500,000are currently infected.

http://www.kfwh.org/information.asp


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Chart from World Bank, 2006

http://www.dcp2.org/pubs/DCP/23/Table/23.1

Most casesare found inSub-Saharan Africa.
http://www.dcp2.org/pubs/DCP/23/Table/23.1http://www.dcp2.org/pubs/DCP/23/Table/23.1


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How can an infectious disease be

contained to such a specific region of the world?


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How can an infectious disease be

contained to such a specific region of the world?

Lets take a closer look at how the diseaseis spread


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Disease Transfer

The disease is caused

by two parasites of theTrypanosoma Genusand brucei Species.

http://en.wikipedia.org/wiki/Sleeping_sickness http://farm3.static.flickr.com/2110/1760532740_20189a8cdc.jpg


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Trypanosomesare protozoans.

http://www.who.int/mediacentre/factsheets/fs259/en/ http://jcs.biologists.org/content/vol115/issue12/images/medium/joces11512cvf.gif


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Trypanosomesare protozoans.(unicellular eukaryotes)(single flagellum)

http://www.who.int/mediacentre/factsheets/fs259/en/ http://jcs.biologists.org/content/vol115/issue12/images/medium/joces11512cvf.gif


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http://www.modares.ac.ir/elearning/Dalimi/Proto/images/Lectures/fig77_1.JPG


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Disease Transfer

The trypanosomes aremainly transferred bythe tsetse fly, which isfound 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


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AreasInfested by the

Tsetse Fly

http://www.fao.org/ag/icons/map.gif


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DistributionMap for

AfricanSleepingSickness

http://www.medicalecology.org/diseases/af rican_trypano/clip_image002.jpg


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Areas Infested by tsetse fly Distribution of the disease


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Trypanosoma brucei:Two different parasites

African Sleeping Sickness is

caused by two differentparasites.



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African Sleeping Sickness is

caused by two differentparasites.Trypanosoma brucei gambiense

Trypanosoma brucei rhodesiense


T b i


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Trypanosoma bruceigambiense

Accounts for 90% ofreported cases of AfricanSleeping Sickness.Causes the chronic form ofthe disease

Prevalent mostly in Westand Central Africa.

http://www.microbiologybytes.com/introduction/Tr ypano.html http://www.dmacc.cc.ia.us/instructors/Image11.gif

T b i


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Trypanosoma bruceirhodesiense

Accounts for 10% ofreported cases of AfricanSleeping Sickness.Causes the acute form ofthe disease.

Prevalent mostly inEastern and Southern Africa.

http://www.microbiologybytes.com/introduction/Tr ypano.html

http://www.uoguelph.ca/~pwoo/fig6.jpg


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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
http://www.who.int/mediacentre/factsheets/fs259/en/http://www.mimg.ucla.edu/faculty/Hill/fig2.jpghttp://www.mimg.ucla.edu/faculty/Hill/fig2.jpghttp://www.who.int/mediacentre/factsheets/fs259/en/


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Method of Infection

The bite will becomered and swollen.

http://www.who.int/mediacentre/factsheets/fs259/en/ http://io.uwinnipeg.ca/~simmons/16cm05/1116/28-11-TrypanosomaLM.jpg


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Method of Infection


From here, theinfection will enter the bloodstream.



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Method of Infection


The infection willenter the bloodstream.Long asymptomaticphase.



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The disease has three distinct stages.


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The disease has three distinct stages. Asymptomatic Phase

http://www.who.int/mediacentre/factsheets/fs259/en/


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The disease has three distinct stages. Asymptomatic PhaseFirst Stage (haemolymphatic phase)



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The disease has three distinct stages. Asymptomatic PhaseFirst Stage (haemolymphatic phase)Second Stage (neurological phase)



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First Stage

The pathogens

will spreadthroughout the blood and thelymph.

http://www.who.int/mediacentre/factsheets/fs259/en/ http://www.pnas.org/content/100/3/F1.medium.gif


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First Stage

Symptoms FeverHeadacheSweatingJoint PainItchingSwollen 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


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Second Stage

Eventually, the disease will manage to crossthe blood-brain barrier.


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Second Stage

Eventually, the disease will manage to crossthe blood-brain barrier.

This will cause an infection of the CentralNervous System

www.who.int/mediacentre/factsheets/fs259/en


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Second Stage

Symptoms

ConfusionSensory DisturbancesPoor CoordinationDisturbances of Sleep

Cycles

www.who.int/mediacentre/factsheets/fs259/en http://www.msf.org.uk/UploadedImages/e64ac496-41d9-4b8b-8cac-423baecb957f.jpg


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If not treated, thedisease is fatal.

www.who.int/mediacentre/factsheets/fs259/en


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Diagnosis and Treatment

Treatment variesdepending on thestage of the

disease.

www.who.int/mediacentre/factsheets/fs259/en http://www.sawitfirst.co.uk/media/pill_clockbig.gif


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The disease is easier and more effectiveto treat the earlier it is diagnosed.



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The disease is easier and more effectiveto treat the earlier it is diagnosed.Much harder after the pathogens havecrossed the blood-brain barrier.



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Four drugs areavailable fortreatment

http://www.pet-comfort-products.com/images/colorful-pills-01.gif


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Four drugs areavailable fortreatment

Two available for first-stage treatment

Two available forsecond-stage treatment

www.who.int/mediacentre/factsheets/fs259/en www.pet-comfort-products.com/images/colorful-pills-01.gif


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The two drugs available for second-stage treatment are significantly moredangerous.



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So, in summary, treatment during

the first- stage is


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So, in summary,treatment duringthe first-stageis

More effective

http://images.the-scientist.com/content/figures/images/yr2002/may13/iv.jpg


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So, in summary,treatment duringthe first-stageis

More effectiveSafer

http://images.the-scientist.com/content/figures/images/yr2002/may13/iv.jpg


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Therefore,early diagnosisis imperative

http://www.who.int/mediacentre/factsheets/fs259/en/ http://www.bayerscheringpharma.de/html/images/upload/gesellschaftliches_engagement/aerztin_patient_205.jpg


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Like with malaria, if we could reduce the

number of people withthe disease, we couldreduce transmissionsand eventually

eradicate the disease.

http://www.ecdl.com/countries/images/map_africa.gif


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Organizations like WHO have began

efforts to eliminatethe risk of thisdisease




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Organizations like WHO have began

efforts to eliminatethe risk of thisdisease

HAT programme

http://www.who.int/mediacentre/factsheets/fs259/en/ http://www.who.int/mediacentre/factsheets/fs259/en/


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Due to lack of funds and turmoil, thereare an estimated 7 nations currently atepidemic level for the disease.

http://www.kfwh.org/information.asp


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Like many other infectious diseases inthird world countries, much change isneeded in world health policies before we can effectively eradicate AfricanSleeping Sickness.


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Documents

African trypano.ppt