African trypanosomiasis laboratory findings: Difference between revisions
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The diagnosis of African trypanosomiasis rests upon demonstrating [[trypanosomes]] by microscopic examination of chancre fluid, [[lymph node]] aspirates,[[blood]], [[bone marrow]], or, in the late stages of infection, [[cerebrospinal fluid]]. | The diagnosis of African trypanosomiasis rests upon demonstrating [[trypanosomes]] by microscopic examination of chancre fluid, [[lymph node]] aspirates,[[blood]], [[bone marrow]], or, in the late stages of infection, [[cerebrospinal fluid]]. | ||
==Laboratory Findings== | ==Laboratory Findings== | ||
The diagnosis of African trypanosomiasis rests upon demonstrating trypanosomes by microscopic examination of chancre fluid, lymph node aspirates,blood, bone marrow, or, in the late stages of infection, cerebrospinal fluid. | |||
===Blood smear=== | |||
*Acute Chagas disease is often diagnosed by visual detection of the ''T.b. rhodesiense '' parasite on peripheral blood smear. | |||
*Peripheral blood smears are usually stained with Giemsa stain for adequate visualization of the parasite. | |||
===Electrolyte and Biomarker Studies=== | ===Electrolyte and Biomarker Studies=== | ||
Three serological tests are available for detection of the parasite; the micro-CATT, wb-CATT, and wb-LATEX. The first uses dried blood while the other two use whole blood samples. A 2002 study found the wb-CATT to be the most efficient for diagnosis, while the wb-LATEX is a better exam for situations where greater sensitivity is required.<ref>{{cite journal |author=Truc P, Lejon V, Magnus E, ''et al.'' |title=Evaluation of the micro-CATT, CATT/Trypanosoma brucei gambiense, and LATEX/T b gambiense methods for serodiagnosis and surveillance of human African trypanosomiasis in West and Central Africa |journal=Bull. World Health Organ. |volume=80 |issue=11 |pages=882–6 |year=2002 |pmid=12481210 |pmc=2567684 |doi= |url=}}</ref> | Three serological tests are available for detection of the parasite; the micro-CATT, wb-CATT, and wb-LATEX. The first uses dried blood while the other two use whole blood samples. A 2002 study found the wb-CATT to be the most efficient for diagnosis, while the wb-LATEX is a better exam for situations where greater sensitivity is required.<ref>{{cite journal |author=Truc P, Lejon V, Magnus E, ''et al.'' |title=Evaluation of the micro-CATT, CATT/Trypanosoma brucei gambiense, and LATEX/T b gambiense methods for serodiagnosis and surveillance of human African trypanosomiasis in West and Central Africa |journal=Bull. World Health Organ. |volume=80 |issue=11 |pages=882–6 |year=2002 |pmid=12481210 |pmc=2567684 |doi= |url=}}</ref> |
Revision as of 19:37, 26 June 2017
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African trypanosomiasis laboratory findings On the Web |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Pilar Almonacid; Jesus Rosario Hernandez, M.D. [2]
Overview
The diagnosis of African trypanosomiasis rests upon demonstrating trypanosomes by microscopic examination of chancre fluid, lymph node aspirates,blood, bone marrow, or, in the late stages of infection, cerebrospinal fluid.
Laboratory Findings
The diagnosis of African trypanosomiasis rests upon demonstrating trypanosomes by microscopic examination of chancre fluid, lymph node aspirates,blood, bone marrow, or, in the late stages of infection, cerebrospinal fluid.
Blood smear
- Acute Chagas disease is often diagnosed by visual detection of the T.b. rhodesiense parasite on peripheral blood smear.
- Peripheral blood smears are usually stained with Giemsa stain for adequate visualization of the parasite.
Electrolyte and Biomarker Studies
Three serological tests are available for detection of the parasite; the micro-CATT, wb-CATT, and wb-LATEX. The first uses dried blood while the other two use whole blood samples. A 2002 study found the wb-CATT to be the most efficient for diagnosis, while the wb-LATEX is a better exam for situations where greater sensitivity is required.[1]
Microscopy
A wet preparation should be examined for the motile trypanosomes, and in addition a smear should be fixed, stained with Giemsa (or Field), and examined. Concentration techniques can be used prior to microscopic examination. For blood samples, these include centrifugation followed by examination of the buffy coat; mini anion-exchange/centrifugation; and the Quantitative Buffy Coat (QBC) technique. For other samples such as spinal fluid, concentration techniques include centrifugation followed by examination of the sediment. Isolation of the parasite by inoculation of rats or mice is a sensitive method, but its use is limited to T. b. rhodesiense. Antibody detection has sensitivity and specificity that are too variable for clinical decisions. In addition, in infections with T. b. rhodesiense, seroconversion occurs after the onset of clinical symptoms and thus is of limited use.
Gallery
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African trypanosomiasis. Adapted from Public Health Image Library (PHIL). [2]
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African trypanosomiasis. Adapted from Public Health Image Library (PHIL). [2]
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African trypanosomiasis. Adapted from Public Health Image Library (PHIL). [2]
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African trypanosomiasis. Adapted from Public Health Image Library (PHIL). [2]
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African trypanosomiasis. Adapted from Public Health Image Library (PHIL). [2]
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African trypanosomiasis. Adapted from Public Health Image Library (PHIL). [2]
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African trypanosomiasis. Adapted from Public Health Image Library (PHIL). [2]
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African trypanosomiasis. Adapted from Public Health Image Library (PHIL). [2]
References
- ↑ Truc P, Lejon V, Magnus E; et al. (2002). "Evaluation of the micro-CATT, CATT/Trypanosoma brucei gambiense, and LATEX/T b gambiense methods for serodiagnosis and surveillance of human African trypanosomiasis in West and Central Africa". Bull. World Health Organ. 80 (11): 882–6. PMC 2567684. PMID 12481210.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 "Public Health Image Library (PHIL)".