History

Fact Explanation
Asymptomatic [1,6] Acute Chagas disease can be asymptomatic. May be due to the small inoculation dose of theparasites. [8]
Fever [1,6] Due to release of pyrogens (interferons, tumour necrosis factor and interleukin). Usually intermittent, can be prolonged. [8] Most of the patients present with fever. [7] Fever in acute Chagas disease is often self-limiting. [8]
Myalgia [1,6] This is a non-specific complain, but many patients present with this symptom. [7]
Headache [1] Headache is the other non-specific finding seen in Chagas disease. Fever, myalgia and headache are the common presenting complains. [7]
Skin manifestations [1,6] The skin rash is seen at the site of the entry point of the parasite. It is an erythematous and indurated lesion called “chagoma”. Painless skin nodules can also be a presenting complain. [6]
Periorbital and palpebral edema [6] This is of a diagnostic value. Edema occurs at the site of entry of the parasite. Bug feces may be wiped to the skin while the person is asleep. This causes periorbital and palpebral edema.
Loss of appetite [1] One of the constitutional symptom.
Symptoms of gastrointestinal tract involvement Abdominal pain, diarrhea and vomiting are presenting complaints of acute Chagas disease. [1,6]
Symptoms of myocarditis [1] This is a rare but life threatening complication of the disease. [8] This occurs due to inflammatory reaction and commonly seen in young children. Chest pain is a common symptom. [6]
Symptoms of meningoencephalitis [1,6] Due to severe inflammatory reaction. Patients present with headache, neck pain and photophobia. Meningoencephalitis and myocarditis are the life threatening complications. [8]
Symptoms of pneumonitis [8] These include shortness of breath, cough and fatigue.
Presence of risk factors Chagas disease is transmitted through a parasite. Triatomine bugs act as the vector for the disease causing parasite Trypanosoma cruzi. People who are bitten by the bug are at risk of acquiring infection. Other than that babies born to infected mothers (approximate risk is 5%) [4] and consumption of uncooked food (infected bugs’ feces contain the parasites) [5] are risk factors. Person to person transmission is seen in recipients of blood transfusions [2,3] and organ transplantations. Laboratory workers may accidentally expose to disease and infection is acquired thorugh breeched skin. [1,6]
Features suggestive of congenital Chagas These include prematurity, low birth weight, and low Apgar score at birth. [9] Infection during intra uterine life causes miscarriage and placentitis. [8]
References
  1. Parasites - American Trypanosomiasis (also known as Chagas disease). Centers for Disease Control and Prevention [online] [viewed 8 May 2014] Available from: http://www.cdc.gov/parasites/chagas/gen_info/detailed.html
  2. YOUNG C, LOSIKOFF P, CHAWLA A, GLASSER L, FORMAN E. Transfusion-acquired Trypanosoma cruzi infection. Transfusion [online]2007: (47) 540–544. [viewed 8 May 2014] Available from: DOI: 10.1111/j.1537-2995.2006.01147.x
  3. PERKINS HA, BUSCH MP. Transfusion-associated infections: 50 years of relentless challenges and remarkable progress. Transfusion [online]2010: 50, 2080–2099. [viewed 8 May 2014] Available from: doi: 10.1111/j.1537-2995.2010.02851.x.
  4. THEILER RN, RASMUSSEN SA, TREADWELL TA, JAMIESON DJ. Emerging and zoonotic infections in women. Infect Dis Clin North Am [online]2008: 22, 755–772. [viewed 8 May 2014] Available from: doi: 10.1016/j.idc.2008.05.007.
  5. BELTRAO HDE B, CERRONI MDE P, FREITAS DR, PINTO AY, VALENTE VDA C, et al. Investigation of two outbreaks of suspected oral transmission of acute Chagas disease in the Amazon region, Para State, Brazil, in 2007. Trop Doct [online]2009: 39, 231–232. [viewed 8 May 2014] Available from: doi: 10.1258/td.2009.090035.
  6. Chagas disease (American trypanosomiasis). [online] [viewed 8 May 2014] Available from: http://www.who.int/neglected_diseases/diseases/chagas/en/
  7. CARYN BERN, SONIA KJOS, MICHAEL J. Y, SUSAN P. MONTGOMERY. Trypanosoma cruzi and Chagas' Disease in the United States. Clin. Microbiol. Rev. [online]October 2011: 24(4) 655-681 [viewed 8 May 2014] Available from: doi: 10.1128/CMR.00005-11
  8. ANIS RASSI, JOSÉ ANTONIO MARIN-NETO. Chagas disease. The Lancet [online]17 April 2010: 375 (9723) 1388 – 1402. [viewed 8 May 2014] Available from: doi:10.1016/S0140-6736(10)60061-X
  9. FREILIJ H, ALTCHEH J. Congenital Chagas' disease: diagnostic and clinical aspects. Clin Infect Dis. [online]1995 Sep;21(3):551-5. [viewed 8 May 2014] Available from: doi: 10.1093/clinids/21.3.551

Examination

Fact Explanation
Mild hepatomegaly and or splenomegaly [1,3] Common finding in neonates with congenital Chagas disease. [3]
Lymphadenopathy [1,2,3] Lymph nodes draining the initial skin lesions may be enlarged.
Romaña's sign [1,2] This is a reliable sign of acute Chagas disease. The eyelids are swollen on the side of the face near the bite site or where the bug feces were deposited. Accidental rubbing of the bug feces into the eyes is also a cause for the swelling. [1]
Chagoma This is an early sign. The site of entry of the bug causes erythematous and indurated skin lesion. [1,2]
Hypotonia Frequently seen in neonates with congenital Chagas disease. [3]
References
  1. Parasites - American Trypanosomiasis (also known as Chagas disease). Centers for Disease Control and Prevention [online] [viewed 8 May 2014] Available from: http://www.cdc.gov/parasites/chagas/gen_info/detailed.html
  2. Chagas disease (American trypanosomiasis). [online] [viewed 8 May 2014] Available from: http://www.who.int/neglected_diseases/diseases/chagas/en/
  3. ANIS RASSI, JOSÉ ANTONIO MARIN-NETO. Chagas disease. The Lancet [online]17 April 2010: 375 (9723) 1388 – 1402. [viewed 8 May 2014] Available from: doi:10.1016/S0140-6736(10)60061-X

Differential Diagnoses

Fact Explanation
Toxoplasmosis [1] Toxoplasmosis is acquired by consumption of food or raw meat contaminated with oocysts. Like Chagas disease infection during the pregnancy can cause congenital disease. Adults are usually asymptomatic or present with non-specific symptoms. [2]
Malaria A mosquito born disease which present with fever, chills and rigors. Blood picture will show malaria parasites in the red blood cells. [3]
Meningitis Meningoencephalitis is a complication of Chagas disease. Meningitis presents with fever, headache, neck pain and photophobia. [4]
Myocarditis Myocarditis usually presents with chest pain, dyspnea and palpitations. Cardiac MRI will help in making the diagnosis. [5]
Myocardial Infarction Chest pain in myocariditis may mimic a myocardial infarction. ECG and assessment of cardiac biomarkers will help in making the definitive diagnosis.
Arrhythmia Ventricular fibrillation and ventricular tachycardia are common tachyarrhythmias seen in chagas disease. ECG will aid the diagnosis. Other possible causes of arrhythmia should also be considered as differential diagnoses (ischemic heart disease is the commonest cause for ventricular tachycardia). [6]
Leishmaniasis Cutaneous leishmaniasis can present with skin nodules and destruction of mucosal epithelium. Hepatomegaly and splenomegaly can be found in visceral leishmaniasis. [7,8]
Sudden cardiac death Acute Chagas disease can cause myocarditis and sudden death. Other causes of sudden cardiac death should also be considered as possible differential diagnoses (ventricular tachycardia, ventricular fibrillation, cardiomyopathy). [9]
References
  1. Chagas disease (American trypanosomiasis). [online] [viewed 8 May 2014] Available from: http://www.who.int/neglected_diseases/diseases/chagas/en/
  2. MONTOYA JG, LIESENFELD O. Toxoplasmosis. Lancet. [online]2004 Jun 12;363(9425):1965-76. [viewed 8 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/15194258
  3. SNOW RW, GUERRA CA, NOOR AM, MYINT HY, HAY SI. The global distribution of clinical episodes of Plasmodium falciparum malaria. Nature. [online]2005 Mar 10;434(7030):214-7. [viewed 8 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/15759000
  4. OLAF HOFFMAN, JOERG WEBER R. Pathophysiology and Treatment of Bacterial Meningitis. Ther Adv Neurol Disord. [online] Nov 2009; 2(6): 1–7. [viewed 8 May 2014] Available from: doi: 10.1177/1756285609337975
  5. SAGAR S, LIU PP, COOPER LT JR. Myocarditis. Lancet. [online]2012 Feb 25;379(9817):738-47. [viewed 8 May 2014] Available from: doi: 10.1016/S0140-6736(11)60648-X.
  6. ASHLEY EA, NIEBAUER J. Cardiology Explained. London: Remedica; 2004. [online] [viewed 8 May 2014] Available from: http://www.ncbi.nlm.nih.gov/books/NBK2219/
  7. REITHINGER R, DUJARDIN JC, LOUZIR H, PIRMEZ C, ALEXANDER B, BROOKER S. Cutaneous leishmaniasis. Lancet Infect Dis [online] 2007 Sep, 7(9):581-96 [viewed 09 May 2014] Available from: doi:10.1016/S1473-3099(07)70209-8
  8. GUERIN PJ, OLLIARO P, SUNDAR S, BOELAERT M, CROFT SL, DESJEUX P, WASUNNA MK, BRYCESON AD. Visceral leishmaniasis: current status of control, diagnosis, and treatment, and a proposed research and development agenda. Lancet Infect Dis [online] 2002 Aug, 2(8):494-501 [viewed 09 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/12150849
  9. SPECTOR PS. Diagnosis and management of sudden cardiac death Heart [online] 2005 Mar, 91(3):408-413 [viewed 09 May 2014] Available from: doi:10.1136/hrt.2003.024026

Investigations - for Diagnosis

Fact Explanation
Full blood count Low hemoglobin is detected in congenital Chagas disease. [3]
Blood picture [2] Acute Chagas disease is diagnosed by demonstrating parasite in the red blood cells. Either thin or thick blood films can be used. Microscopic examination of the Buffy coat can also be used for the diagnosis especially in diagnosis of congenital Chagas disease. Cord blood or pheripheral blood smear is used in neonates. [4]
Xenodiagnoses [2] Laboratory-reared insects are allowed to feed on patients’ blood. After about a month intestinal contents of the insect insects are examined for the presence of parasites. This takes long time to make the diagnosis.
Blood culture [2] Allows detection of disease causing parasites.
Anti-T. cruzi IgG antibodies At the age of 6 to 9 months infants should be tested for the presence of antibodies. [3,6]
Polymerase chain reaction (PCR) Allows early and quick diagnosis of congenital Chagas disease. PCR has greater sensitivity than blood picture. [3,5]
Electrocardiogram [1] Frequently shows tachycardia as an indication to cardiac involvement of the disease. [3] Arrhythmia are seen. ECG will aid in the diagnosis of right bundle branch block, left anterior hemiblock, and third-degree heart block.
Esophageal manometry This helps in diagnosing mega esophagus which is a complication of Chagas disease. [3]
References
  1. Parasites - American Trypanosomiasis (also known as Chagas disease). Centers for Disease Control and Prevention [online] [viewed 8 May 2014] Available from: http://www.cdc.gov/parasites/chagas/gen_info/detailed.html
  2. Chagas disease (American trypanosomiasis). [online] [viewed 8 May 2014] Available from: http://www.who.int/neglected_diseases/diseases/chagas/en/
  3. ANIS RASSI, JOSÉ ANTONIO MARIN-NETO. Chagas disease. The Lancet [online]17 April 2010: 375 (9723) 1388 – 1402. [viewed 8 May 2014] Available from: doi:10.1016/S0140-6736(10)60061-X
  4. FREILIJ H, ALTCHEH J. Congenital Chagas' disease: diagnostic and clinical aspects. Clin Infect Dis. [online]1995 Sep;21(3):551-5. [viewed 8 May 2014] Available from: doi: 10.1093/clinids/21.3.551
  5. MORA MC, SANCHEZ NEGRETTE O, MARCO D, BARRIO A, CIACCIO M, SEGURA MA, BASOMBRÍO MA. Early diagnosis of congenital Trypanosoma cruzi infection using PCR, hemoculture, and capillary concentration, as compared with delayed serology. J Parasitol. [online]2005 Dec;91(6):1468-73. [viewed 8 May 2014] Available from: doi: http://dx.doi.org/10.1645/GE-549R.1
  6. MÉDECINS SANS FRONTIÈRES. International meeting: new diagnostic tests are urgently needed to treat patients with Chagas disease. Rev Soc Bras Med Trop [online]2008; 41: 315-319. [viewed 8 May 2014] Available from: http://dx.doi.org/10.1590/S0037-86822008000300020

Investigations - Fitness for Management

Fact Explanation
Electrocardiogram [1] Frequently shows tachycardia. [2] Arrhythmias are seen. ECG will aid in the diagnosis of right bundle branch block, left anterior hemiblock, and third-degree heart block.
Chest X-ray [2] Shows signs of cardiac failure like alveolar edema, Kerley B lines, cardiomegaly, upper lobe diversion, and pleural effusions
References
  1. Parasites - American Trypanosomiasis (also known as Chagas disease). Centers for Disease Control and Prevention [online] [viewed 8 May 2014] Available from: http://www.cdc.gov/parasites/chagas/gen_info/detailed.html
  2. ANIS RASSI, JOSÉ ANTONIO MARIN-NETO. Chagas disease. The Lancet [online]17 April 2010: 375 (9723) 1388 – 1402. [viewed 8 May 2014] Available from: doi:10.1016/S0140-6736(10)60061-X

Investigations - Followup

Fact Explanation
ECG ECG can detect the occurrence of cardiac manifestations of the Chagas disease. Among all the cardiovascular complications conduction-system abnormalities (due to fibrosis of the conducting system) are first to develop. These include atrioventricular block, intraventricular block, and sinus node dysfunction. Patients should be followed up 1 to 2 yearly. [1,2]
Holter monitoring Allows diagnosis of transient arrhythmias. [2]
Chest X-ray [2] Helpful in detection of cardiac failure in symptomatic patients. Radiological signs include cardiomegaly, Kerley B lines, alveolar edema, upper lobe diversion and pleural effusion.
Investigations to detect mega esophagus [2] Radiological investigations include barium swallow test, esophageal manometry, and upper gastrointestinal endoscopy. Asymptomatic patients should not be subjected to these investigations.
Investigations to detect mega colon [2] Colonoscopy and barium enema will help in the detection of megacolon. These tests are not done if the patient is asymptomatic.
Full blood count Treatment with benznidazole is known to cause agrnulocytosis as a complication. [3] Full blood count should be repeated weekly for early diagnosis of agranulocytosis.
References
  1. BERN C. Antitrypanosomal Therapy for Chronic Chagas' Disease. N Eng J Med [online]2011; 364(26):2527-2534. [viewed 8 May 2014] Available from: DOI: 10.1056/NEJMct1014204
  2. ANIS RASSI, JOSÉ ANTONIO MARIN-NETO. Chagas disease. The Lancet [online]17 April 2010: 375 (9723) 1388 – 1402. [viewed 8 May 2014] Available from: doi:10.1016/S0140-6736(10)60061-X
  3. PINAZO M.-J., MUNOZ J., POSADA E., LOPEZ-CHEJADE P., GALLEGO M., AYALA E., DEL CACHO E., SOY D., GASCON J.. Tolerance of Benznidazole in Treatment of Chagas' Disease in Adults. Antimicrobial Agents and Chemotherapy [online] December, 54(11):4896-4899 [viewed 09 May 2014] Available from: doi:10.1128/AAC.00537-10

Investigations - Screening/Staging

Fact Explanation
Serological tests Screening is done with serological tests. One positive test cannot diagnose the disease and need at least two positive tests to diagnose. [1,2]
References
  1. CARYN BERN, SONIA KJOS, MICHAEL J. YABSLEY, SUSAN P. MONTGOMERY. Trypanosoma cruzi and Chagas' Disease in the United States. Clin. Microbiol. Rev. [online]October 2011: 24(4) 655-681. [viewed 8 May 2014] Available from: doi: 10.1128/CMR.00005-11
  2. ANIS RASSI, JOSÉ ANTONIO MARIN-NETO. Chagas disease. The Lancet [online]17 April 2010: 375 (9723) 1388 – 1402. [viewed 8 May 2014] Available from: doi:10.1016/S0140-6736(10)60061-X

Management - General Measures

Fact Explanation
Conservative management [1] In most of the patients symptoms resolve within few weeks even without treatment. And most of them (60 %-70%) will not develop chronic disease. [4]
Health education [2] People should be educated about possible ways of disease transmission. Improved living conditions (indoor sleeping, cement floor and walls) and protective measures to prevent bug bites (bed nets cloths which cover the extremities well) are helpful in preventing the disease. [3,5]
Screening of blood donors This is recommended in areas with high prevalence of Chagas disease. [4]
References
  1. Parasites - American Trypanosomiasis (also known as Chagas disease). Centers for Disease Control and Prevention [online] [viewed 8 May 2014] Available from: http://www.cdc.gov/parasites/chagas/gen_info/detailed.html
  2. PETER J. HOTEZ, ERIC DUMONTEIL, LAILA WOC-COLBURN, JOSE A. SERPA, SARAH BEZEK, et al. Chagas Disease: “The New HIV/AIDS of the Americas” PLoS Negl Trop Dis [online] 6(5): e1498. [viewed 8 May 2014] Available from: DOI: 10.1371/journal.pntd.0001498
  3. Chagas disease (American trypanosomiasis). [online] [viewed 8 May 2014] Available from: http://www.who.int/neglected_diseases/diseases/chagas/en/
  4. ANIS RASSI, JOSÉ ANTONIO MARIN-NETO. Chagas disease. The Lancet [online]17 April 2010: 375 (9723) 1388 – 1402. [viewed 8 May 2014] Available from: doi:10.1016/S0140-6736(10)60061-X
  5. MONCAYO A. Chagas disease: current epidemiological trends after the interruption of vectorial and transfusional transmission in the Southern Cone countries. Mem Inst Oswaldo Cruz [online]2003; 98: 577-591. [viewed 8 May 2014] Available from: http://dx.doi.org/10.1590/S0074-02762003000500001

Management - Specific Treatments

Fact Explanation
Antitrypanosomal treatment [1] Best given early in the course of illness. benznidazole (5—10 mg/kg daily) or nifurtimox (15 mg/kg daily) are the first line medications used to treat acute Chagas disease. Treatment should be given for about 2 to 3 months. [2,3,4] Successful treatment with those drugs cure the acute infection and prevent the progression to chronic disease. [5]
Treatment of the mega esophagus This includes sublingual nitrates and nifedipine to relax the lower esophageal sphincter or wide esophagocardiomyectomy and valvuloplasty. Surgery can be done either laparoscopically or as an open surgery. Endoscopic botulin toxin injection and balloon dilatation provides short term symptom control. [5] Heller's myotomy and fundoplication, or esophageal resection is used in advanced disease. [6]
Treatment of megacolon Patients with megacolon are adviced to take fiber rich diet and adequate fluid intake as the primary mode of treatment. [5] Duhamel-Haddad operation is used in the treatment.
Treatment of cardiovascular complications Pacemaker placement or antiarrhythmic drugs [1] for arrhythmia and ablation procedures for tachycardia are treatment options for cardiovascular complications of chronic Chagas disease. Pharmacological management of heart failure is also important. Cardiac resynchronization therapy is one of the second line option to treat heart failure. End stage Chagas heart disease may require heart transplantation. [5]
References
  1. Parasites - American Trypanosomiasis (also known as Chagas disease). Centers for Disease Control and Prevention [online] [viewed 8 May 2014] Available from: http://www.cdc.gov/parasites/chagas/gen_info/detailed.html
  2. PETER J. HOTEZ, ERIC DUMONTEIL, LAILA WOC-COLBURN, JOSE A. SERPA, SARAH BEZEK, et al. Chagas Disease: “The New HIV/AIDS of the Americas” PLoS Negl Trop Dis [online]6(5): e1498. [viewed 8 May 2014] Available from: DOI: 10.1371/journal.pntd.0001498
  3. BERN C. Antitrypanosomal Therapy for Chronic Chagas' Disease. N Eng J Med [online]2011; 364(26):2527-2534. [viewed 8 May 2014] Available from: DOI: 10.1056/NEJMct1014204
  4. Chagas disease (American trypanosomiasis). [online] [viewed 8 May 2014] Available from: http://www.who.int/neglected_diseases/diseases/chagas/en/
  5. ANIS RASSI, JOSÉ ANTONIO MARIN-NETO. Chagas disease. The Lancet [online]17 April 2010: 375 (9723) 1388 – 1402. [viewed 8 May 2014] Available from: doi:10.1016/S0140-6736(10)60061-X
  6. HERBELLA FA, AQUINO JL, STEFANI-NAKANO S, ARTIFON EL, SAKAI P, CREMA E, ANDREOLLO NA, LOPES LR, DE CASTRO POCHINI C, CORSI PR, GAGLIARDI D, DEL GRANDE JC. Treatment of achalasia: lessons learned with Chagas' disease. Dis Esophagus [online] 2008, 21(5):461-7 [viewed 09 May 2014] Available from: doi:10.1111/j.1442-2050.2008.00811.x