Presentation is loading. Please wait.

Presentation is loading. Please wait.

African Trypanosomaisis

Similar presentations


Presentation on theme: "African Trypanosomaisis"— Presentation transcript:

1 African Trypanosomaisis http://phil.cdc.gov/phil/details.asp

2  Nagana: -Zulu “To be depressed”  First described in the 14 th century  Noticed by slave traders who would not buy slaves displaying symptoms  Trypanosomes first detected in humansin 1902. http://www.uoguelph.ca/~pwoo/animaltryp.jpg

3  Worked in Ubombo, South Africa with wife Mary  Discovered both trypanosome and transmission by tsetse fly in 1903  ‘trypanosome fever’ = ‘sleeping sickness’

4  Bites of Tsetse flies, vertical, or mechanical transmission  Earliest epidemic took place between 1896 and 1906; estimated 800,000 died.  Major break outs in 1940’s and 1980’s; smaller epidemics from Senegal to Cameroon from 1920- 1940’s.  Linked to droughts and political turmoil due to increase human-fly contact

5 Glossina/Tsetse flies http://www.medicalecology.org/diseases/d_african_trypano.htm#sect5.3

6 http://www.stanford.edu/class/humbio103/ParaSites2001/trypanosomiasis/trypanpo_files/image044.jpg

7 T. brucei gambiense  West African Sleeping Sickness  Chronic, moderate symptoms with delayed onset  Represent more than 90% of sleeping sickness cases T. brucei rhodensiense  East African Sleeping Sickness  Rapid onset of severe symptoms  Intermittent fever within a few weeks

8  Shifts from procyclic to metacyclic to trypomastigotes after exposure  Reproduction occurs through binary fission  Highly aerobic and completely dependent on host glucose for energy  Variant Surface Glycoprotein (VSG) are used to evade antibodies ◦ shields parasitic surface proteins and transport channels ◦ capable of shifting gene expression http://www.medicalecology.org/diseases/d_african_trypano.htm

9

10  Early/hemolytic stage ◦ Bouts of fever, headaches, joint pain and itching ◦ Caused by hemolysis due to IgM-antigen complex which binds to ethryocytes  Late/CNS stage ◦ T. b. rhodensiense may advance within a few weeks while T. b. gambiense may take decades ◦ Begins as the parasite crosses the blood-brain barrier resulting in confusion, sensory disturbances, poor coordination, and sleep cycle disturbances

11 http://www.medicalecology.org/diseases/d_african_trypano.htm

12  Stage dependent ◦ Stage 1: Pentamidine and suramin (few side effects ◦ Stage 2: Melarsoprol – works against both strains but has severe side effects ◦ Eflornithine – Only works against T. b. gambiense but is much less toxic than melarsoprol.  Difficult to apply and requires strict regiment  -New Drugs on horizon

13  On the Neglected Tropical Disease list  2000 – WHO partners with Aventis Pharma to provide treatment and free medicine to endemic countries  2006 – Success of WHO program causes increased private partners to assist in reducing African Trypanosomiasis as a health concern ◦ Still have limited surveillance and diagnostic abilities

14  Insecticides  Bush clearing ◦ Harmful to environment  Game animal killing  Sterile male techniques ◦ Female only mates once  Pheromone-baiting traps ◦ Effective, cheap, nonpolluting, and trusted http://urafikikenya.com/modules/?page=photos

15  Screening: Use clinical signs and/or serological assays to find at-risk individuals  Diagnose  Determine stage: Examine cerebral-spinal fluid for parasites o T. b. gambiense requires active and exhaustive screening necessary in at-risk areas o “No universal methodology”

16  3 million cattle die per year; over 35 million doses of trypancidal drugs administered  Under list B of the World Organization for Animal Health (OIE) ◦ High socio-economic or health importance in countries that are significant in international trade  Most economically important livestock disease ◦ loss of ~1 billion per year http://www.jircas.affrc.go.jp/english/publication/annual/1996/intro/i mages/hl_06.jpg

17  http://www.britannica.com/EBchecked/topic/401566/n agana  http://www.oie.int/eng/maladies/Technical%20disease %20cards/TRYPANO_TSETSE_FINAL.pdf  http://www.medicalecology.org/diseases/d_african_try pano.htm  http://www.whonamedit.com/doctor.cfm/871.html  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC551439 /  http://www.cdc.gov/ncidod/dpd/parasites/trypanosomi asis/default.htm  http://www.who.int/topics/trypanosomiasis_african/en /  http://www.who.int/trypanosomiasis_african/diagnosis /en/index.html  http://www.springerlink.com/content/d4jn0e3c1uypa6j l/


Download ppt "African Trypanosomaisis"

Similar presentations


Ads by Google