Chagas disease overview: Difference between revisions
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Chagas disease is a pathogenic tropical disease transmitted by the [[protozoa]], ''[[Trypanosoma cruzi]]''. In the early, acute stage symptoms are mild and are usually no more than local swelling at the site of infection. As the disease progresses, over as much as twenty years, the serious chronic symptoms appear, such as heart disease and malformation of the intestines. If untreated, the chronic disease is often fatal. | Chagas disease is a pathogenic tropical disease transmitted by the [[protozoa]], ''[[Trypanosoma cruzi]]''. In the early, acute stage symptoms are mild and are usually no more than local swelling at the site of infection. As the disease progresses, over as much as twenty years, the serious chronic symptoms appear, such as heart disease and malformation of the intestines. If untreated, the chronic disease is often fatal. | ||
==Historical Perspective== | |||
The disease was named after the Brazilian [[physician]] and [[Infectology|infectologist]] [[Carlos Chagas]], who first described it in 1909<ref name=Chagas_1909>{{cite journal | author = Chagas C| title = Neue Trypanosomen | journal = Vorläufige Mitteilung. Arch. Schiff. Tropenhyg. | year = 1909 | volume = 13 | issue = | pages = 120–122 }}</ref><ref name=Redhead_2006>{{cite journal | author=Redhead SA, Cushion MT, Frenkel JK, Stringer JR | title=''Pneumocystis'' and ''Trypanosoma cruzi'': nomenclature and typifications | journal=J Eukaryot Microbiol | year=2006 | pages=2–11 | volume=53 | issue=1 | id=PMID 16441572}}</ref><ref name=WHO>WHO. [http://www.who.int/tdr/diseases/chagas/ Chagas.] Accessed 24 September 2006.</ref> but, the disease was not seen as a major [[public health]] problem in humans until the 1960s (the outbreak of Chagas' disease in Brazil in the 1920s went widely ignored<ref>{{cite web|url=http://links.jstor.org/sici?sici=0021-1753%28199906%2990%3A2%3C397%3AHAOAT%28%3E2.0.CO%3B2-H|title=Historical Aspects of American Trypanosomiasis (Chagas' Disease)}}</ref>). He discovered that the intestines of Triatomidae harbored a flagellate protozoan, a new species of the ''[[Trypanosoma]]'' genus, and was able to prove experimentally that it could be transmitted to marmoset monkeys that were bitten by the infected bug. Later studies showed that squirrel monkeys were also vulnerable to infection.<ref name=Hulsebos_1989>{{cite journal | author = Hulsebos LH| title = The effect of interleukin-2 on parasitemia and myocarditis in experimental Chagas' disease | journal = Journal of Protozoology | year = 1989 | volume = 36 | issue = 3 | pages = 293-298 }} </ref> | |||
==Pathophysiology== | |||
Chagas disease is caused by the protozoan [[Trypanosoma cruzi]]. T. cruzi is commonly transmitted to humans and other mammals by the [[hematophagy|blood-sucking]] "kissing bugs" of the subfamily [[Triatominae]] (family [[Reduviidae]]) most commonly species belonging to the [[Triatoma]], [[Rhodnius]], and [[Panstrongylus]] genera. It can also be transmitted through [[blood transfusions]], organ [[transplantation]], [[placenta|transplacentally]], [[breast milk]],<ref>Santos Ferreira C, Amato Neto V, Gakiya E, ''et al.'' "Microwave treatment of human milk to prevent transmission of Chagas disease." Rev Inst Med Trop São Paulo. 2003 Jan-Feb;45(1):41-2. PMID 12751321</ref> and in laboratory accidents. | |||
==Differentiating Chagas disease from other Diseases== | |||
Conditions like [[achalasia]], [[myocarditis]] and [[esophagitis]] can be confused with Chagas disease which affects the esophagus, heart and the colon. Hepatosplenomegaly is also common in Chagas disease making it one of the differential for enlarged liver and spleen. | |||
==Epidemiology and Demographics== | |||
Chronic Chagas' disease remains a major health problem in many Latin American countries, despite the effectiveness of hygienic and preventive measures, such as eliminating the transmitting insects, which have reduced to zero new infections in at least two countries of the region. | |||
==Risk Factors== | |||
Risk factors for Chagas disease include living in a hut where reduvid bugs live in the walls, living in Central or South America, poverty, receiving a [[blood transfusion]] from a person who carries the parasite but does not have active Chagas disease. | |||
==Natural History, Complications and Prognosis== | |||
About 30% of infected people who are not treated will develop chronic or symptomatic Chagas disease. It may take more than 20 years from the time of the original infection to develop heart or digestive problems. Abnormal heart rhythms ([[arrhythmias]], [[ventricular tachycardia]]) may cause sudden death. Once [[heart failure]] develops, death usually occurs within several years. | |||
==Diagnosis== | |||
===Symptoms=== | |||
The symptoms of Chagas' disease vary over the course of the infection. In the early, acute stage symptoms are mild and are usually no more than local swelling at the site of infection. As the disease progresses, over as much as twenty years, the serious chronic symptoms appear, such as heart disease and malformation of the intestines. If untreated, the chronic disease is often fatal. | |||
===Physical Examination=== | |||
The most recognized marker of acute Chagas disease is called Romaña's sign, which includes swelling of the eyelids on the side of the face near the bite wound or where the bug feces were deposited or accidentally rubbed into the eye. | |||
==Treatment== | |||
===Medical Therapy=== | |||
There are two approaches to therapy, both of which can be life saving. They include antiparasitic treatment to kill the parasite and symptomatic treatment to manage the symptoms and signs of infection. | |||
===Primary Prevention=== | |||
Methods of primary prevention of Chagas disease include vaccine, insecticides to control the vector and testing of donor blood . | |||
==References== | ==References== | ||
{{Reflist|2}} | {{Reflist|2}} | ||
Revision as of 19:20, 6 December 2012
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Raviteja Guddeti, M.B.B.S. [2]
Overview
Chagas disease is a pathogenic tropical disease transmitted by the protozoa, Trypanosoma cruzi. In the early, acute stage symptoms are mild and are usually no more than local swelling at the site of infection. As the disease progresses, over as much as twenty years, the serious chronic symptoms appear, such as heart disease and malformation of the intestines. If untreated, the chronic disease is often fatal.
Historical Perspective
The disease was named after the Brazilian physician and infectologist Carlos Chagas, who first described it in 1909[1][2][3] but, the disease was not seen as a major public health problem in humans until the 1960s (the outbreak of Chagas' disease in Brazil in the 1920s went widely ignored[4]). He discovered that the intestines of Triatomidae harbored a flagellate protozoan, a new species of the Trypanosoma genus, and was able to prove experimentally that it could be transmitted to marmoset monkeys that were bitten by the infected bug. Later studies showed that squirrel monkeys were also vulnerable to infection.[5]
Pathophysiology
Chagas disease is caused by the protozoan Trypanosoma cruzi. T. cruzi is commonly transmitted to humans and other mammals by the blood-sucking "kissing bugs" of the subfamily Triatominae (family Reduviidae) most commonly species belonging to the Triatoma, Rhodnius, and Panstrongylus genera. It can also be transmitted through blood transfusions, organ transplantation, transplacentally, breast milk,[6] and in laboratory accidents.
Differentiating Chagas disease from other Diseases
Conditions like achalasia, myocarditis and esophagitis can be confused with Chagas disease which affects the esophagus, heart and the colon. Hepatosplenomegaly is also common in Chagas disease making it one of the differential for enlarged liver and spleen.
Epidemiology and Demographics
Chronic Chagas' disease remains a major health problem in many Latin American countries, despite the effectiveness of hygienic and preventive measures, such as eliminating the transmitting insects, which have reduced to zero new infections in at least two countries of the region.
Risk Factors
Risk factors for Chagas disease include living in a hut where reduvid bugs live in the walls, living in Central or South America, poverty, receiving a blood transfusion from a person who carries the parasite but does not have active Chagas disease.
Natural History, Complications and Prognosis
About 30% of infected people who are not treated will develop chronic or symptomatic Chagas disease. It may take more than 20 years from the time of the original infection to develop heart or digestive problems. Abnormal heart rhythms (arrhythmias, ventricular tachycardia) may cause sudden death. Once heart failure develops, death usually occurs within several years.
Diagnosis
Symptoms
The symptoms of Chagas' disease vary over the course of the infection. In the early, acute stage symptoms are mild and are usually no more than local swelling at the site of infection. As the disease progresses, over as much as twenty years, the serious chronic symptoms appear, such as heart disease and malformation of the intestines. If untreated, the chronic disease is often fatal.
Physical Examination
The most recognized marker of acute Chagas disease is called Romaña's sign, which includes swelling of the eyelids on the side of the face near the bite wound or where the bug feces were deposited or accidentally rubbed into the eye.
Treatment
Medical Therapy
There are two approaches to therapy, both of which can be life saving. They include antiparasitic treatment to kill the parasite and symptomatic treatment to manage the symptoms and signs of infection.
Primary Prevention
Methods of primary prevention of Chagas disease include vaccine, insecticides to control the vector and testing of donor blood .
References
- ↑ Chagas C (1909). "Neue Trypanosomen". Vorläufige Mitteilung. Arch. Schiff. Tropenhyg. 13: 120–122.
- ↑ Redhead SA, Cushion MT, Frenkel JK, Stringer JR (2006). "Pneumocystis and Trypanosoma cruzi: nomenclature and typifications". J Eukaryot Microbiol. 53 (1): 2–11. PMID 16441572.
- ↑ WHO. Chagas. Accessed 24 September 2006.
- ↑ "Historical Aspects of American Trypanosomiasis (Chagas' Disease)".
- ↑ Hulsebos LH (1989). "The effect of interleukin-2 on parasitemia and myocarditis in experimental Chagas' disease". Journal of Protozoology. 36 (3): 293–298.
- ↑ Santos Ferreira C, Amato Neto V, Gakiya E, et al. "Microwave treatment of human milk to prevent transmission of Chagas disease." Rev Inst Med Trop São Paulo. 2003 Jan-Feb;45(1):41-2. PMID 12751321