Trypanosomiasis Jane Ngai вЂ“ Simon Zappia Protista пѓ Kinetoplastida пѓ Trypanosoma вЂў African Trypanosomiasis вЂ“ 400,000 affected causing 50,000 to 70,000 deaths/year. вЂў American Trypanosomiasis вЂ“ 11 million people affected causing 50,000 deaths/year. Trypomastigote FORM Epimastigote Promastigote Amastigote вЂў African Trypanosomiasis вЂ“ Sleeping Sickness вЂ“ пѓ Trypanosoma brucei brucei (cattle) вЂ“ пѓ Trypanosoma brucei gambiense вЂ“ пѓ Trypanosoma brucei rhodesiense вЂў American Trypanosomiasis вЂ“ Chagas Disease вЂ“ пѓ Trypanosoma cruzi AFRICAN TRYPANOSOMIASIS Fly belt distribution Transmission вЂў Via vector вЂ“ bite from the tse tse fly вЂў Mother to child infection (perinatal death) вЂў Blood transfusion вЂў Sexual contact Lifecycle Fly injects metacyclic trypomastigotes when it feeds on blood. Trypomastigotes reproduce asexually in the bloodstream Parasite reproduces asexually in the flyвЂ™s gut (epimastigotes), migrates to the flyвЂ™s salivary glands (metacyclic trypomastigote) Fly ingests trypomastigotes when it feeds on blood of infected individual. Pathogenesis (2 stages) вЂў Stage 1: Haemolymphatic stage (ACUTE) вЂ“ Most patients do not notice this stage of infection. вЂ“ Small papule from bite may develop exciting local inflammation. вЂ“ When trypomastigotes enter the haemo-lymphatic system to multiply,clinical symptoms include: вЂ“ Fever, headache and joint pain вЂ“ WinterbottomвЂ™s sign: swelling of lymph nodes at the posterior neck region. вЂў Stage 2: Meningoencephaltic stage (CHRONIC) вЂ“ Sleeping sickness stage because trypanosomes have crossed the blood-brain barrier вЂ“ Personality changes, headaches and withdrawal from the environment. вЂ“ Simple tasks become harder to accomplish as individual experience nocturnal insomnia and daytime lethargy, apathy and ultimately succumb to secondary infections such as pneumonia. Treatment вЂў Stage I вЂ“ Pentamidine: 7-10 injections for T. b. gambiense infection. Side effects include: Painful injections with risk of hypotension and shock, pancreatic, renal or hepatic dysfunction; bone marrow suppression and polyneuropathy вЂ“ Suramin вЂ“ multiple doses on varying days for T.b. rhodesiense infection. Side effect include: renal impairment, peripheral neuropathy and bone marrow suppression. Treatment вЂў Stage II вЂ“ Melarsoprol (arsenical compound) вЂ“ slow IV injection. Side effects include: encephalopathy вЂ“ Eflornithine вЂ“ infusion for 2 weeks every 6 hours. Drug is expensive and more effective against T. b. gambiense. Cyclical waves of infection Prevention вЂў Control in the reservoirs like livestock and wildebeest вЂў Remove scrub (where tse tse flies reproduce) вЂў DDT вЂў Education вЂў Public awareness вЂўOnly specific species of genus Glossina transmit the parasite resulting in a spotty distribution through the fly belt. T. b. gambiense (Chronic) T. b. rhodesiense (Acute) AMERICAN TRYPANOSOMIASIS Transmission вЂў Mediated via vector of genus Triatoma, Rhodnius and Panstrongylus also known as вЂњkissing bugsвЂќ вЂў Ingestion of food contaminated with parasites вЂў Blood transfusion вЂў Fetal transmission (13% stillborn deaths/year in Brazil) Lifecycle Pathogenesis (Acute) вЂў Acute phase вЂ“ Starts 1 week after infection вЂ“ Fever, lymph node enlargement, unilateral swelling of the eyelids (RomanaвЂ™s sign), acute myocarditis, damaged muscle cells and edema. Pathogenesis (Chronic) вЂў Chronic Phases: вЂ“ Starts 2 months after initial infection. вЂ“ Indeterminate form: 60-70% of people with Chagas. Completely free of cardiac, gastrointestinal and neurological symptoms but 25% of patients convert to cardiac or digestive forms each year (reason not clear). Cardiac manifestation вЂў Cardiac form: вЂ“ 30-40% of people with Chagas. Induces arrhythmia, cardiac failure, thromboembolism, atrioventricular fibrillation, ventricular hypertrophy Gastrointestinal manifestation вЂў Digestive form: вЂ“ 10% of people. Megaoesophagus 3%, megacolon and may be associated with cardiac form. Difficulty in swallowing, regurgitation, aspiration may cause pneumonia and death. Chronic constipation, fecal compacting causes perforation of the colon. Treatment вЂў Treatment exists for symptoms but there are no cures for the disease. вЂў All available pharmaceuticals are expensive and are of inefficient efficacy. No medications are given to patients with the chronic phase. Prevention вЂў Elimination of вЂњkissing bugвЂќ environment with building structures that discourage the bugвЂ™s habitation. вЂў Avoid pets in the home environment to limit attraction. вЂў Avoid building homes with palm roofs and cracks. вЂў Use of insecticides. вЂў Mechanical elimination of the vector (ie. squish it). вЂў Education. New developments вЂў Clinical manifestations of the cardiac and gastrointestinal forms are unknown. вЂў Heart problems may be linked to autoimmune responses triggered by parasites being engulfed in the macrophage and not completely destroyed. вЂў Others think heart problems may be linked to the parasites themselves. вЂў Inconclusive data. Questions вЂў Consider the nature of both diseases; their vector, distribution and impact on local populations. Which disease, in your opinion, deserves more attention and funding? Why? How would you invest the money?