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Chagas’ Disease American trypanosomiasis. By: Holly Cimprich. The Basics of Chagas’ Disease. Inflammatory infectious condition 2 Caused by protozoan parasite Trypanosoma cruzi Vectors: triatomine “bloodsucking” insects Triatoma Sometimes in Rhodinius & Panstrongylus.
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Chagas’ Disease American trypanosomiasis By: Holly Cimprich
The Basics of Chagas’ Disease • Inflammatory infectious condition2 • Caused by protozoan parasite Trypanosoma cruzi • Vectors: triatomine “bloodsucking” insects • Triatoma • Sometimes in Rhodinius & Panstrongylus
History of the Disease • Carlos Chagas identified the cause in 1909 in northern Brazil • Thought it was spread through the triatomine bite • Dr. Emile Brumpt asserted parasite transmission through vector fecal matter • Research by Salvador Mazza in 1926 in Argentina • Cecilio Romana and Romana’s Sign1
Prevalence • Endemic to Mexico, South America and Central America, infecting 8-11 million people there3 • Kills about 20,000 annually • 100 million at risk of infection4
Vector: Triatoma • a.k.a reduviid or kissing bugs • 0.75-1.25 inches • Live primarily in mud, thatch or adobe huts • Obtain the parasite when they bite an infected animal • Leave feces behind when they bite5
Symptoms • 2 main phases • Acute: 4-8 weeks after infection • IF symptoms present, they are usually mild • Swelling at infection site (chagoma), fever, fatigue, rash, body ache, headaches, loss of appetite, nausea, diarrhea, vomiting, swollen glands, enlargement of liver or spleen • Chronic: 10-20 years after infection • Irregular heartbeat, cardiomyopathy (enlarged heart), congestive heart failure, sudden cardiac arrest, enlarged esophagus which leads to difficulty in swallowing, enlarged colon causing abdominal pain or constipation3
Romaña’s Sign • Most Common Sign: Romaña’s Sign • Swelling of the eye near location of triatomine bite due to feces being rubbed into the eye3
Pathogenesis • Parasite liberates kinins from cell bound forms • Kinins bind to B2 receptors and exert vasoactive activity--> edema • Or kinins metabolized by kinase I and generate [des-Arg] kinins which activate the B1 receptor • Intracellular [Ca2+] increases and activates responses mediated by B2 and B1 receptors--> increases parasite uptake by host cells • May also cause plasma leakage and additional vascular responses9
Diagnostic Tests • Acute: blood smear for microscopic examination • Chronic: serologic tests for antibodies • enzyme-linked immunosorbent assay (ELISA) • immunofluorescent antibody test (IFA)3 • Can determine progression through diagnostic tests: • EKG • Endoscopy • Abdominal x-ray
Treatment • Acute: antiprotozoals • Benznidazole- oral tablet for 60 days3 • Serious side effects: seizures, numbness, tingling pain, weakness in hands and feet, skin discoloration • 64.7% efficacy10 • Appears to inhibit protein and RNA synthesis in T. cruzi but mechanism has not been studied11 • Nifurtimox- oral tablet for 90 days3 • Serious side effects: skin rash • Disrupts structure of proteins and nucleic acids through alkylation12
Treatment & Prevention • Chronic Stage: no available treatment • Management of symptoms • Heart related complications: medication, pacemaker, methods of regulation heart rhythm, surgery, or even heart transplant • Digestive related complications: diet modifications, various medications to treat symptoms, corticosteroids, or surgery5 • Prevention • Insecticides • Bed netting • Improved housing and hygiene • 2007 U.S. FDA instituted screening of blood supply3
Sources • http://www.chagasfound.org/chagas-disease-info.php?ID=4&t=History • http://www.cdc.gov/ncidod/EID/vol9no12/03-0008.htm • http://www.cdc.gov/chagas/ • http://www.experiencefestival.com/a/Chagas_disease_-_Epidemiology_and_geographical_distribution/id/4789599 • http://www.mayoclinic.com/health/chagas-disease/DS00956/DSECTION=tests%2Dand%2Ddiagnosis • http://www.uta.edu/chagas/html/biolTcru.html • http://www.ncbi.nlm.nih.gov/pmc/articles/PMC153290/?tool=pmcentrez • http://iai.asm.org/cgi/content/abstract/67/8/4033 • http://www.bioscience.org/2003/v8/e/1103/figures.htm • http://www.ajtmh.org/cgi/content/full/71/5/594 • http://www.drugs.com/mmx/benznidazole.html • http://www.cancer.gov/drugdictionary/?CdrID=558911