Chagas’ is one of a triumvirate of diseases — Chagas’, leishmaniasis and African sleeping sickness — caused by parasites of the trypanosomatidae family. Endemic to Central and South America, the parasite (Trypanosoma cruzi) that causes Chagas’ disease is the world’s leading cause of heart disease. It is passed by blood transfusion or with the bite and defecation of the reduviid or "kissing bug," so named for its tendency to attack around the lips. It is estimated that 16 - 18 million people are infected with Chagas’ and about 100 million people are at risk in 21 countries. This includes approximately 25 percent of the population of Latin America.
There are two stages of infection with Chagas’ disease. Acute symptoms only occur in about 1 percent of cases. These appear one to two weeks after infection and include fever, facial swelling around the bite site and enlarged and painful lymph glands and fatigue. In general, symptoms last for 4 – 8 weeks and then disappear. In about one-third of the acute cases, chronic forms develop 10 – 20 years after infection. These are cardiac problems, including an enlarged heart, altered heart rate or rhythm, heart failure or cardiac arrest. Enlargement of the esophagus or colon may also occur, with concomitant nutritional problems. For those who develop chronic symptoms, the average life expectancy decreases by an average of 9 years.
Seattle BioMed headed a consortium of international laboratories to sequence the genome of the Chagas’ disease parasite. This effort led to identification of unusual gene clusters also common to other trypanosomes. The growing database of genomic information for T. cruzi and related parasites helps our researchers grasp the significance of the similarities and differences of the parasites, which in turn pinpoints targets for new drugs and treatments.