Chagas disease

Last reviewed: 23 Aug 2023
Last updated: 29 Mar 2022



History and exam

Key diagnostic factors

  • prolonged fever
  • palpitations
  • syncope or presyncope
  • hepatosplenomegaly
  • enlarged lymph nodes
  • tachycardia
  • hypotension
  • cardiomegaly
  • dysphagia
  • regurgitation/aspiration
  • odynophagia
  • substernal discomfort
  • prolonged constipation
  • acute abdominal pain
  • abdominal distention
  • swelling around the site of inoculation
  • jaundice
  • abdominal rebound tenderness
  • clinical evidence of meningeal irritation
  • clinical signs of a cerebral mass lesion
More key diagnostic factors

Other diagnostic factors

  • irritability
  • anorexia or fatigue
  • vomiting or diarrhea
  • headache
  • myalgia
  • reduced exercise tolerance
  • dizziness
  • thromboembolic phenomena (e.g., stroke, pulmonary embolism)
  • dyspnea
  • cough
  • generalized edema
  • pericarditis
  • epigastric pain and/or hematemesis
  • melena or hematochezia
  • rash
  • seizures or tremors
Other diagnostic factors

Risk factors

  • living in endemic area
  • exposure to Triatoma species
  • low socioeconomic status
  • consumption of contaminated food or drink
  • blood transfusion
  • organ transplantation
  • history of immunosuppression
  • climate change
  • deforestation
  • healthcare occupations
  • laboratory work occupations
  • travel to endemic areas
  • mother with Chagas disease
More risk factors

Diagnostic investigations

1st investigations to order

  • CBC
  • LFTs
  • serum electrolytes, BUN, and creatinine
  • microscopy: fresh blood
  • microscopy: concentration methods applied to fresh blood
  • microscopy: thick blood smear
  • enzyme-linked immunosorbent assay based on parasite lysate
  • immunofluorescent antibody test
  • indirect hemagglutination antibody test
  • polymerase chain reaction (PCR)
  • urinalysis
  • serum or urine beta-hCG
  • ECG with a 30-second lead II rhythm strip
  • chest x-ray
  • barium swallow
  • barium enema
More 1st investigations to order

Investigations to consider

  • culture (blood and cerebrospinal fluid)
  • xenodiagnosis
  • cerebrospinal fluid analysis
  • coagulation profile
  • ambulatory 24-hour ECG
  • exercise testing
  • echocardiography
  • esophageal manometry
  • upper gastrointestinal endoscopy
  • cranial CT/MRI
  • cardiac MRI
  • nuclear medicine testing
  • cardiac catheterization and coronary angiography
More investigations to consider

Emerging tests

  • radioimmunoprecipitation assay
  • immunofluorescent antibody test
  • western blot

Treatment algorithm


accidental exposure and infection: nonpregnant without severe renal/hepatic insufficiency

accidental exposure and infection: pregnant or with severe renal/hepatic disease


acute infection

reactivated disease


chronic infection: indeterminate disease or mild to moderate symptoms: children

chronic infection: indeterminate disease or mild to moderate symptoms: adults

chronic infection: advanced disease: children and adults

end-stage organ failure



Alberto Novaes Ramos Jr, MD, MPH, PhD
Alberto Novaes Ramos Jr

Senior Lecturer

Department of Community Health

School of Medicine

Federal University of Ceará




ANR Jr is an author of a number of references cited in this topic. ANR Jr declares that he has no other competing interests.

Jorg Heukelbach, MD, DTMPH, MScIH, PhD
Jorg Heukelbach


Department of Community Health

School of Medicine

Federal University of Ceará




JH declares that he has no competing interests.

Andréa Silvestre de Sousa, MD, MMed, PhD
Andréa Silvestre de Sousa

Adjunct Professor of Cardiology

Department of Internal Medicine

Federal University of Rio de Janeiro


Evandro Chagas National Institute of Infectious Diseases

Oswaldo Cruz Foundation

Rio de Janeiro



ASS declares that she has no competing interests.


Dr Alberto Novaes Ramos Jr, Dr Jorg Heukelbach, and Dr Andrea Silvestre de Sousa would like to gratefully acknowledge Dr Francisco Rogerlândio Martins-Melo, a previous contributor to this topic.


FRMM declares that he has no competing interests.

Peer reviewers

Christopher Huston, MD

Assistant Professor of Medicine

Division of Infectious Diseases

University of Vermont College of Medicine




CH declares that he has no competing interests.

Richard Reithinger, MD, PhD


London School of Hygiene and Tropical Medicine




RR declares that he has no competing interests.

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