Acute Chagas disease

Infectious diseases

Clinicals - History

Fact Explanation
Asymptomatic Acute Chagas disease can be asymptomatic. May be due to the small inoculation dose of theparasites. Asymptomatic
Acute Chagas disease can be asymptomatic. May be due to the small inoculation dose of theparasites.
Fever Due to release of pyrogens (interferons, tumour necrosis factor and interleukin). Usually intermittent, can be prolonged. Most of the patients present with fever. Fever in acute Chagas disease is often self-limiting. Fever
Due to release of pyrogens (interferons, tumour necrosis factor and interleukin). Usually intermittent, can be prolonged. Most of the patients present with fever. Fever in acute Chagas disease is often self-limiting.
Myalgia This is a non-specific complain, but many patients present with this symptom. Myalgia
This is a non-specific complain, but many patients present with this symptom.
Headache Headache is the other non-specific finding seen in Chagas disease. Fever, myalgia and headache are the common presenting complains. Headache
Headache is the other non-specific finding seen in Chagas disease. Fever, myalgia and headache are the common presenting complains.
Skin manifestations 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. Skin manifestations
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.
Periorbital and palpebral edema 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. Periorbital and palpebral edema
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 One of the constitutional symptom. Loss of appetite
One of the constitutional symptom.
Symptoms of gastrointestinal tract involvement Abdominal pain, diarrhea and vomiting are presenting complaints of acute Chagas disease. Symptoms of gastrointestinal tract involvement
Abdominal pain, diarrhea and vomiting are presenting complaints of acute Chagas disease.
Symptoms of myocarditis This is a rare but life threatening complication of the disease. This occurs due to inflammatory reaction and commonly seen in young children. Chest pain is a common symptom. Symptoms of myocarditis
This is a rare but life threatening complication of the disease. This occurs due to inflammatory reaction and commonly seen in young children. Chest pain is a common symptom.
Symptoms of meningoencephalitis Due to severe inflammatory reaction. Patients present with headache, neck pain and photophobia. Meningoencephalitis and myocarditis are the life threatening complications. Symptoms of meningoencephalitis
Due to severe inflammatory reaction. Patients present with headache, neck pain and photophobia. Meningoencephalitis and myocarditis are the life threatening complications.
Symptoms of pneumonitis These include shortness of breath, cough and fatigue. Symptoms of pneumonitis
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%) and consumption of uncooked food (infected bugs’ feces contain the parasites) are risk factors. Person to person transmission is seen in recipients of blood transfusions and organ transplantations. Laboratory workers may accidentally expose to disease and infection is acquired thorugh breeched skin. 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%) and consumption of uncooked food (infected bugs’ feces contain the parasites) are risk factors. Person to person transmission is seen in recipients of blood transfusions and organ transplantations. Laboratory workers may accidentally expose to disease and infection is acquired thorugh breeched skin.
Features suggestive of congenital Chagas These include prematurity, low birth weight, and low Apgar score at birth. Infection during intra uterine life causes miscarriage and placentitis. Features suggestive of congenital Chagas
These include prematurity, low birth weight, and low Apgar score at birth. Infection during intra uterine life causes miscarriage and placentitis.

Clinicals - Examination

Fact Explanation
Mild hepatomegaly and or splenomegaly Common finding in neonates with congenital Chagas disease. Mild hepatomegaly and or splenomegaly
Common finding in neonates with congenital Chagas disease.
Lymphadenopathy Lymph nodes draining the initial skin lesions may be enlarged. Lymphadenopathy
Lymph nodes draining the initial skin lesions may be enlarged.
Romaña's sign 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. Romaña's sign
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.
Chagoma This is an early sign. The site of entry of the bug causes erythematous and indurated skin lesion. Chagoma
This is an early sign. The site of entry of the bug causes erythematous and indurated skin lesion.
Hypotonia Frequently seen in neonates with congenital Chagas disease. Hypotonia
Frequently seen in neonates with congenital Chagas disease.

Investigations - Diagnosis

Fact Explanation
Full blood count Low hemoglobin is detected in congenital Chagas disease. Full blood count
Low hemoglobin is detected in congenital Chagas disease.
Blood picture 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. Blood picture
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.
Xenodiagnoses 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. Xenodiagnoses
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 Allows detection of disease causing parasites. Blood culture
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. Anti-T. cruzi IgG antibodies
At the age of 6 to 9 months infants should be tested for the presence of antibodies.
Polymerase chain reaction (PCR) Allows early and quick diagnosis of congenital Chagas disease. PCR has greater sensitivity than blood picture. Polymerase chain reaction (PCR)
Allows early and quick diagnosis of congenital Chagas disease. PCR has greater sensitivity than blood picture.
Electrocardiogram Frequently shows tachycardia as an indication to cardiac involvement of the disease. Arrhythmia are seen. ECG will aid in the diagnosis of right bundle branch block, left anterior hemiblock, and third-degree heart block. Electrocardiogram
Frequently shows tachycardia as an indication to cardiac involvement of the disease. 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. Esophageal manometry
This helps in diagnosing mega esophagus which is a complication of Chagas disease.

Investigations - Management

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. 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.
Holter monitoring Allows diagnosis of transient arrhythmias. Holter monitoring
Allows diagnosis of transient arrhythmias.
Chest X-ray Helpful in detection of cardiac failure in symptomatic patients. Radiological signs include cardiomegaly, Kerley B lines, alveolar edema, upper lobe diversion and pleural effusion. Chest X-ray
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 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 esophagus
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 Colonoscopy and barium enema will help in the detection of megacolon. These tests are not done if the patient is asymptomatic. Investigations to detect mega colon
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.
Full blood count should be repeated weekly for early diagnosis of agranulocytosis.
Full blood count
Treatment with benznidazole is known to cause agrnulocytosis as a complication.
Full blood count should be repeated weekly for early diagnosis of agranulocytosis.
Electrocardiogram Frequently shows tachycardia. Arrhythmias are seen. ECG will aid in the diagnosis of right bundle branch block, left anterior hemiblock, and third-degree heart block. Electrocardiogram
Frequently shows tachycardia. 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 Shows signs of cardiac failure like alveolar edema, Kerley B lines, cardiomegaly, upper lobe diversion, and pleural effusions Chest X-ray
Shows signs of cardiac failure like alveolar edema, Kerley B lines, cardiomegaly, upper lobe diversion, and pleural effusions
Serological tests Screening is done with serological tests. One positive test cannot diagnose the disease and need at least two positive tests to diagnose. Serological tests
Screening is done with serological tests. One positive test cannot diagnose the disease and need at least two positive tests to diagnose.

Management - Supportive

Fact Explanation
Conservative management In most of the patients symptoms resolve within few weeks even without treatment. And most of them (60 %-70%) will not develop chronic disease. Conservative management
In most of the patients symptoms resolve within few weeks even without treatment. And most of them (60 %-70%) will not develop chronic disease.
Health education 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. Health education
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.
Screening of blood donors This is recommended in areas with high prevalence of Chagas disease. Screening of blood donors
This is recommended in areas with high prevalence of Chagas disease.

Management - Specific

Fact Explanation
Antitrypanosomal treatment 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. Successful treatment with those drugs cure the acute infection and prevent the progression to chronic disease. Antitrypanosomal treatment
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. Successful treatment with those drugs cure the acute infection and prevent the progression to chronic disease.
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. Heller's myotomy and fundoplication, or esophageal resection is used in advanced disease. 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. Heller's myotomy and fundoplication, or esophageal resection is used in advanced disease.
Treatment of megacolon Patients with megacolon are adviced to take fiber rich diet and adequate fluid intake as the primary mode of treatment. Duhamel-Haddad operation is used in the treatment. Treatment of megacolon
Patients with megacolon are adviced to take fiber rich diet and adequate fluid intake as the primary mode of treatment. Duhamel-Haddad operation is used in the treatment.
Treatment of cardiovascular complications Pacemaker placement or antiarrhythmic drugs 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. Treatment of cardiovascular complications
Pacemaker placement or antiarrhythmic drugs 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.

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