page_title: Chagas disease
section_title: Epidemiology
hierarchical_section_title: Chagas disease / Epidemiology
context_page_description: Chagas disease, also known as American trypanosomiasis, is a tropical parasitic disease caused by Trypanosoma cruzi. 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 swelling at the site of the bite. After four to eight weeks, individuals enter the chronic phase of disease, which in most cases does not result in further symptoms. Up to 45% of people develop heart disease 10–30 years after the initial infection, which can lead to heart failure. Digestive complications, including an enlarged esophagus or an enlarged colon, may also occur in up to 21% of people, and up to 10% of people may experience nerve damage.
  T. cruzi is commonly spread to humans and other mammals by the bite of a kissing bug. The disease may also be spread through blood transfusion, organ transplantation, eating food contaminated with the parasites, and vertical transmission.
context_section_description: In 2017, an estimated 6.2 million people worldwide had Chagas disease, with approximately 162,000 new infections and 7,900 deaths each year. This resulted in a global annual economic burden estimated at US$7.2 billion, 86% of which is borne by endemic countries. Chagas disease results in the loss of over 800,000 disability-adjusted life years each year.
  Chagas is endemic to 21 countries in continental Latin America: Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, Uruguay, and Venezuela. The endemic area ranges from the southern United States to northern Chile and Argentina, with Bolivia (6.1%), Argentina (3.6%), and Paraguay (2.1%) exhibiting the highest prevalence of the disease. In endemic areas, due largely to vector control efforts and screening of blood donations, annual infections and deaths have fallen by 67% and more than 73% respectively from their peaks in the 1980s to 2010. Transmission by insect vector and blood transfusion has been completely interrupted in Uruguay (1997), Chile (1999), and Brazil (2006), and in Argentina, vectorial transmission has been interrupted in 13 of the 19 endemic provinces. During Venezuela's humanitarian crisis, vectorial transmission has begun occurring in areas where it had previously been interrupted and Chagas disease seroprevalence rates have increased. Transmission rates have also risen in the Gran Chaco region due to insecticide resistance and in the Amazon basin due to oral transmission.
  While the rate of vector-transmitted Chagas disease has declined throughout most of Latin America, the rate of orally transmitted disease has risen, possibly due to increasing urbanization and deforestation bringing people into closer contact with triatomines and altering the distribution of triatomine species. Orally transmitted Chagas disease is of particular concern in Venezuela, where 16 outbreaks have been recorded between 2007 and 2018.
  Chagas exists in two different ecological zones: In the Southern Cone region, the main vector lives in and around human homes. In Central America and Mexico, the main vector species lives both inside dwellings and in uninhabited areas. In both zones, Chagas occurs almost exclusively in rural areas, where T. cruzi also circulates in wild and domestic animals. T. cruzi commonly infects more than 100 species of mammals  across Latin America including opossums, armadillos, marmosets, bats, and various rodents, all of which can be infected by the vectors or orally by eating triatomine bugs and other infected animals.
caption: Disability-adjusted life years due to Chagas disease in 2016. Grey indicates no data. Otherwise, colors get increasingly dark red for each order of magnitude increase in DALY burden: 0, white. Up to 1,000 DALYs, yellow. 1,001 to 10,000 DALYs, orange. 10,001 to 100,000 DALYs, light red. Greater than 100,000 DALYs, dark red.[39]