Chagas disease is an infection caused by the American trypanosome Trypanosoma cruzi. This parasitic protozoan is transmitted in the feces of reduviid bugs in South and Central America. Acute infection may present with inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body's defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation at the inoculation site Inoculation site Yellow Fever Virus (chagoma), fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, and lymphadenopathy Lymphadenopathy Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy. Untreated, chronic infection can progress to severe complications, including megacolon Megacolon Megacolon is a severe, abnormal dilatation of the colon, and is classified as acute or chronic. There are many etiologies of megacolon, including neuropathic and dysmotility conditions, severe infections, ischemia, and inflammatory bowel disease. Megacolon, megaesophagus, and cardiomyopathy Cardiomyopathy Cardiomyopathy refers to a group of myocardial diseases associated with structural changes of the heart muscles (myocardium) and impaired systolic and/or diastolic function in the absence of other heart disorders (coronary artery disease, hypertension, valvular disease, and congenital heart disease). Cardiomyopathy: Overview and Types. The diagnosis can be confirmed with identification Identification Defense Mechanisms of organisms on blood smear Blood smear Myeloperoxidase Deficiency, serology Serology The study of serum, especially of antigen-antibody reactions in vitro. Yellow Fever Virus, or PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR). Treatment with benznidazole or nifurtimox is effective only in the acute phase Acute phase Short Bowel Syndrome.
Last updated: 23 Jul, 2021
Photomicrograph of a blood smear Blood smear Myeloperoxidase Deficiency showing 5 parasitic, flagellated Trypanosoma cruzi trypomastigotes Trypomastigotes Trypanosoma brucei/African trypanosomiasis
Image: “Photomicrograph of a blood smear Blood smear Myeloperoxidase Deficiency showing five parasitic, flagellated, Trypanosoma cruzi trypomastigotes Trypomastigotes Trypanosoma brucei/African trypanosomiasis” by CDC. License: Public DomainPhotomicrograph of a blood sample specimen showing 4 flagellated Trypanosoma cruzi parasites, referred to as trypomastigotes Trypomastigotes Trypanosoma brucei/African trypanosomiasis
Image: “Under a magnification of 1200X, this photomicrograph of a blood sample specimen, revealed the presence of four flagellated, Trypanosoma cruzi parasites” by CDC. License: Public DomainAmerican trypanosomiasis is called Chagas disease.
A species of Triatoma, or kissing bug:
The kissing bug serves as a vector to transmit the protozoan pathogen Trypanosoma cruzi, which causes Chagas disease.
Life
cycle
Cycle
The type of signal that ends the inspiratory phase delivered by the ventilator
Invasive Mechanical Ventilation of the American trypanosome Trypanosoma cruzi:
During a blood meal, the reduviid bug will defecate. Scratching the area allows entry of parasites through the bite wound or
conjunctiva
Conjunctiva
The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball.
Eye: Anatomy.
Once inside the body, replication and dissemination occurs. There is particular preference for
myocardium
Myocardium
The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow.
Heart: Anatomy and
myenteric plexus
Myenteric plexus
One of two ganglionated neural networks which together form the enteric nervous system. The myenteric (Auerbach’s) plexus is located between the longitudinal and circular muscle layers of the gut. Its neurons project to the circular muscle, to other myenteric ganglia, to submucosal ganglia, or directly to the epithelium, and play an important role in regulating and patterning gut motility.
Gastrointestinal Neural and Hormonal Signaling.
With chronic infection, tissue damage can lead to
cardiomyopathy
Cardiomyopathy
Cardiomyopathy refers to a group of myocardial diseases associated with structural changes of the heart muscles (myocardium) and impaired systolic and/or diastolic function in the absence of other heart disorders (coronary artery disease, hypertension, valvular disease, and congenital heart disease).
Cardiomyopathy: Overview and Types,
megacolon
Megacolon
Megacolon is a severe, abnormal dilatation of the colon, and is classified as acute or chronic. There are many etiologies of megacolon, including neuropathic and dysmotility conditions, severe infections, ischemia, and inflammatory bowel disease.
Megacolon, and megaesophagus.
The incubation Incubation The amount time between exposure to an infectious agent and becoming symptomatic. Rabies Virus period is approximately 1–2 weeks, and the infection lasts 8–12 weeks.
Photograph of a patient with acute Chagas disease infection with swelling Swelling Inflammation of the right eye Right Eye Refractive Errors (Romaña’s sign).
Image: “An acute Chagas disease infection with swelling Swelling Inflammation of the right eye Right Eye Refractive Errors (Romaña’s sign)” by CDC. License: Public DomainA minority of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship develop chronic infection, which presents 10–20 years after the initial inoculation period.
Congenital Congenital Chorioretinitis disease occurs in a minority of infants born to infected mothers.
Confirmatory tests:
Supporting evaluation:
Photomicrograph of a Giemsa-stained blood smear Blood smear Myeloperoxidase Deficiency specimen revealing the presence of a Trypanosoma cruzi trypomastigote
Image: “Under a magnification of 1000X, this photomicrograph of a Giemsa stained blood smear Blood smear Myeloperoxidase Deficiency specimen revealed the presence of a parasitic Trypanosoma cruzi protozoan” by CDC. License: Public DomainIndirect fluorescent antibody Indirect fluorescent antibody A form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody. Chikungunya Virus testing of a blood smear Blood smear Myeloperoxidase Deficiency in a patient infected with Trypanosoma cruzi.
Image by Lecturio. License: CC BY-NC-SA 4.0ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) showing a right bundle branch block Right bundle branch block Bundle Branch and Fascicular Blocks with left anterior fascicular block Left anterior fascicular block Bundle Branch and Fascicular Blocks in a patient with Chagas disease.
Image: “ ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) showing a right bundle branch block Right bundle branch block Bundle Branch and Fascicular Blocks with left anterior fascicular block Left anterior fascicular block Bundle Branch and Fascicular Blocks” by de Alencar MC et al AL Amyloidosis. License: CC BY 4.0Chest X-ray Chest X-ray X-ray visualization of the chest and organs of the thoracic cavity. It is not restricted to visualization of the lungs. Pulmonary Function Tests image showing cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) enlargement due to chronic Chagas cardiomyopathy Cardiomyopathy Cardiomyopathy refers to a group of myocardial diseases associated with structural changes of the heart muscles (myocardium) and impaired systolic and/or diastolic function in the absence of other heart disorders (coronary artery disease, hypertension, valvular disease, and congenital heart disease). Cardiomyopathy: Overview and Types
Image: “Heart radiology Chagas disease” by CDC. License: Public DomainBarium esophagram demonstrating megaesophagus in a patient with Chagas disease
Image: “Chagas megaseophagus” by CDC. License: Public DomainAcute infection:
Chronic disease:
Giardia Giardia A genus of flagellate intestinal eukaryotes parasitic in various vertebrates, including humans. Characteristics include the presence of four pairs of flagella arising from a complicated system of axonemes and cysts that are ellipsoidal to ovoidal in shape. Nitroimidazoles | Leishmania Leishmania Leishmania species are obligate intracellular parasites that are transmitted by an infected sandfly. The disease is endemic to Asia, the Middle East, Africa, the Mediterranean, and South and Central America. Clinical presentation varies, dependent on the pathogenicity of the species and the host’s immune response. Leishmania/Leishmaniasis | Trypanosoma | Trichomonas Trichomonas A genus of parasitic flagellate eukaryotes distinguished by the presence of four anterior flagella, an undulating membrane, and a trailing flagellum. Nitroimidazoles | |
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Clinical | Giardiasis Giardiasis An infection of the small intestine caused by the flagellated protozoan giardia. It is spread via contaminated food and water and by direct person-to-person contact. Giardia/Giardiasis | Leishmaniasis Leishmaniasis Leishmania species are obligate intracellular parasites that are transmitted by an infected sandfly. The mildest form is cutaneous leishmaniasis (CL), characterized by painless skin ulcers. The mucocutaneous type involves more tissue destruction, causing deformities. Visceral leishmaniasis (VL), the most severe form, presents with hepatosplenomegaly, anemia, thrombocytopenia, and fever. Leishmania/Leishmaniasis |
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Giemsa stain Giemsa stain Borrelia of Giardia Giardia A genus of flagellate intestinal eukaryotes parasitic in various vertebrates, including humans. Characteristics include the presence of four pairs of flagella arising from a complicated system of axonemes and cysts that are ellipsoidal to ovoidal in shape. Nitroimidazoles lamblia trophozoites Trophozoites Cells or feeding stage in the life cycle of sporozoan protozoa. In the malarial parasite, the trophozoite develops from the merozoite and then splits into the schizont. Trophozoites that are left over from cell division can go on to form gametocytes. Amebicides
Image: “ Trophozoites Trophozoites Cells or feeding stage in the life cycle of sporozoan protozoa. In the malarial parasite, the trophozoite develops from the merozoite and then splits into the schizont. Trophozoites that are left over from cell division can go on to form gametocytes. Amebicides of Giardia Giardia A genus of flagellate intestinal eukaryotes parasitic in various vertebrates, including humans. Characteristics include the presence of four pairs of flagella arising from a complicated system of axonemes and cysts that are ellipsoidal to ovoidal in shape. Nitroimidazoles lamblia” by Eva NohĂ˝nková, Department of Tropical Medicine, 1st Faculty of Medicine, Charles University in Prague and Hospital Bulovka, Czech Republic. License: CC BY 4.0Giemsa stain Giemsa stain Borrelia of Leishmania Leishmania Leishmania species are obligate intracellular parasites that are transmitted by an infected sandfly. The disease is endemic to Asia, the Middle East, Africa, the Mediterranean, and South and Central America. Clinical presentation varies, dependent on the pathogenicity of the species and the host’s immune response. Leishmania/Leishmaniasis promastigotes
Image: “ Giemsa stain Giemsa stain Borrelia” by Arriyadh Community College, King Saud University, P.O. Box 28095, Riyadh 11437, Saudi Arabia. License: CC BY 3.0Blood smear Blood smear Myeloperoxidase Deficiency demonstrating Trypanosoma trypomastigotes Trypomastigotes Trypanosoma brucei/African trypanosomiasis
Image by Lecturio. License: CC BY-NC-SA 4.0Microscopic images of Trichomonas Trichomonas A genus of parasitic flagellate eukaryotes distinguished by the presence of four anterior flagella, an undulating membrane, and a trailing flagellum. Nitroimidazoles vaginalis trophozoites Trophozoites Cells or feeding stage in the life cycle of sporozoan protozoa. In the malarial parasite, the trophozoite develops from the merozoite and then splits into the schizont. Trophozoites that are left over from cell division can go on to form gametocytes. Amebicides
Image: “ Trichomonas Trichomonas A genus of parasitic flagellate eukaryotes distinguished by the presence of four anterior flagella, an undulating membrane, and a trailing flagellum. Nitroimidazoles protozoa Protozoa Nitroimidazoles” by isis325. License: CC BY 2.0.