Chagas disease is named after the Brazilian physician Carlos Chagas, who discovered the disease in 1909. It is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by insect vectors and is found only in the Americas (mainly, in rural areas of Latin America where poverty is widespread). Chagas disease (T. cruzi infection) is also referred to as American trypanosomiasis.
In the United States, Chagas disease is considered one of the neglected parasitic infections (NPI), a group of five parasitic diseases that have been targeted by CDC for public health action.
It is spread mostly by insects known as Triatominae or kissing bugs. The symptoms change over the course of the infection. In the early stage, symptoms are typically either not present or mild and may include: fever, swollen lymph nodes, headaches, or local swelling at the site of the bite. After 8–12 weeks, individuals enter the chronic phase of disease and in 60–70% it never produces further symptoms. The other 30 to 40% of people develop further symptoms 10 to 30 years after the initial infection. This includes enlargement of the ventricles of the heart in 20 to 30% leading to heart failure. An enlarged esophagus or an enlarged colon may also occur in 10% of people.
T. cruzi is commonly spread to humans and other mammals by the blood-sucking "kissing bugs" of the subfamily Triatominae. These insects are known by a number of local names, including: vinchuca in Argentina, Bolivia, Chile and Paraguay, barbeiro (the barber) in Brazil, pito in Colombia, chinche in Central America, and chipo in Venezuela. The disease may also be spread through blood transfusion, organ transplantation, eating food contaminated with the parasites, and from a mother to her fetus. Diagnosis of early disease is by finding the parasite in the blood using a microscope. Chronic disease is diagnosed by finding antibodies for T. cruzi in the blood.
Prevention mostly involves eliminating kissing bugs and avoiding their bites. Other preventative efforts include screening blood used for transfusions. A vaccine has not been developed as of 2013. Early infections are treatable with the medication benznidazole or nifurtimox. They nearly always result in a cure if given early however become less effective the longer a person has had Chagas disease. When used in chronic disease they may delay or prevent the development of end stage symptoms. Benznidazole and nifurtimox cause temporary side effects in up to 40% of people including skin disorders, brain toxicity, and digestive system irritation.
It is estimated that 7 to 8 million people, mostly in Mexico, Central America and South America have Chagas disease. It results in about 12,500 deaths a year as of 2006. Most people with the disease are poor and most people with the disease do not realize they are infected. Large-scale population movements have increased the areas where cases of Chagas disease are found and these now include many European countries and the United States. These areas have also seen an increase in the years up to 2014. It also affects more than 150 other animals.