Improved detection of Trypanosoma brucei by lysis of red blood cells, concentration and LED fluorescence microscopy

Biéler, Sylvain; Matovu, Enock; Mitashi, Patrick; Ssewannyana, E.; Shamamba, Stomy Karhemere Bi; Bessell, Paul R.; Ndung’u, Joseph Mathu

doi:10.1016/j.actatropica.2011.10.016

Cited by 33 publications

(34 citation statements)

References 14 publications

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“…Confirmatory diagnosis of HAT has been improved following development of the Primo Star iLED fluorescence microscope (FM) by FIND and Carl Zeiss Microimaging [14]. Unlike classical fluorescence microscopes, this microscope does not require a dark room, can be powered using small solar panels, and the light source lasts for more than 10,000 hours.…”

Section: Introductionmentioning

confidence: 99%

“…Unlike classical fluorescence microscopes, this microscope does not require a dark room, can be powered using small solar panels, and the light source lasts for more than 10,000 hours. A number of techniques for preparing and staining samples with acridine orange, then examining them using the LED FM have been developed [14,15]. This has been shown to improve sensitivity when used alongside existing techniques such as gland puncture (GP), and the microhaematocrit centrifugation technique (mHCT, CTC or Woo test), that are routinely used to confirm HAT [16].…”

Section: Introductionmentioning

confidence: 99%

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Enhanced passive screening and diagnosis for gambiense human African trypanosomiasis in north-western Uganda – Moving towards elimination

Wamboga

Matovu

Bessell³

et al. 2017

PLoS ONE

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IntroductionThe incidence of gambiense human African trypanosomiasis (gHAT) in Uganda has been declining, from 198 cases in 2008, to only 20 in 2012. Interruption of transmission of the disease by early diagnosis and treatment is core to the control and eventual elimination of gHAT. Until recently, the format of available screening tests had restricted screening and diagnosis to central health facilities (passive screening). We describe a novel strategy that is contributing to elimination of gHAT in Uganda through expansion of passive screening to the entire population at risk.Methodology / Principal findingsIn this strategy, patients who are clinically suspected of having gHAT at primary health facilities are screened using a rapid diagnostic test (RDT), followed by parasitological confirmation at strategically located microscopy centres. For patients who are positive with the RDT and negative by microscopy, blood samples undergo further testing using loop-mediated isothermal amplification (LAMP), a molecular test that detects parasite DNA. LAMP positive patients are considered strong suspects, and are re-evaluated by microscopy. Location and upgrading of facilities to perform microscopy and LAMP was informed by results of georeferencing and characterization of all public healthcare facilities in the 7 gHAT endemic districts in Uganda. Three facilities were upgraded to perform RDTs, microscopy and LAMP, 9 to perform RDTs and microscopy, and 200 to screen patients with RDTs. This reduced the distance that a sick person must travel to be screened for gHAT to a median distance of 2.5km compared to 23km previously. In this strategy, 9 gHAT cases were diagnosed in 2014, and 4 in 2015.ConclusionsThis enhanced passive screening strategy for gHAT has enabled full coverage of the population at risk, and is being replicated in other gHAT endemic countries. The improvement in case detection is making elimination of the disease in Uganda an imminent possibility.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Enhanced passive screening and diagnosis for gambiense human African trypanosomiasis in north-western Uganda – Moving towards elimination

Wamboga

Matovu

Bessell³

et al. 2017

PLoS ONE

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“…Recently, more serological tests with improved sensitivity and specificity have been developed, namely, T. brucei gambiense -specific SD Bioline HAT test [7, 8] and HAT sero-k-seT [9, 10], although further improvement is still required. Other recently launched tests include the T. brucei specific simple LED fluorescence microscope [11] and nucleic acid detecting RIME loop-mediated isothermal amplification (LAMP) test [12]. In addition, other experimental subgenus Trypanozoon LAMP tests have been reported [13–15] as well as more recently a T. brucei gambiense LAMP test [16].…”

Section: Introductionmentioning

confidence: 99%

Loop-Mediated Isothermal Amplification Test forTrypanosoma gambienseGroup 1 with Stem Primers: A Molecular Xenomonitoring Test for Sleeping Sickness

Njiru

Mbae

Mburugu

2017

Journal of Tropical Medicine

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The World Health Organization has targeted Human African Trypanosomiasis (HAT) for elimination by 2020 with zero incidence by 2030. To achieve and sustain this goal, accurate and easy-to-deploy diagnostic tests for Gambian trypanosomiasis which accounts for over 98% of reported cases will play a crucial role. Most needed will be tools for surveillance of pathogen in vectors (xenomonitoring) since population screening tests are readily available. The development of new tests is expensive and takes a long time while incremental improvement of existing technologies that have potential for xenomonitoring may offer a shorter pathway to tools for HAT surveillance. We have investigated the effect of including a second set of reaction accelerating primers (stem primers) to the standard T. brucei gambiense LAMP test format. The new test format was analyzed with and without outer primers. Amplification was carried out using Rotorgene 6000 and the portable ESE Quant amplification unit capable of real-time data output. The stem LAMP formats indicated shorter time to results (~8 min), were 10–100-fold more sensitive, and indicated higher diagnostic sensitivity and accuracy compared to the standard LAMP test. It was possible to confirm the predicted product using ESE melt curves demonstrating the potential of combining LAMP and real-time technologies as possible tool for HAT molecular xenomonitoring.

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“…DNA was extracted from 200 μl of blood of each animal according to the protocol of Bruford et al (1998) following red blood cell (RBC) lysis ( Biéler et al , 2012). The procedure for DNA amplification and diagnosis of T. vivax infection has been described elsewhere ( Ganyo, 2014).…”

Section: Methodsmentioning

confidence: 99%

Haematology of N’Dama and West African Short Horn cattle herds under natural Trypanosoma vivax challenge in Ghana

et al. 2018

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Animal trypanosomosis is a major cause of economic loss in Background: livestock production in Africa. A suggested control measure is to use breeds with traits of trypanotolerance. The study examines the effect of natural challenge on haematological parameters in two Trypanosoma vivax trypanotolerant cattle [N'Dama and West African Short Horn (WASH)] herds.-specific primers were used to diagnose infection in Methods: T. vivax T. vivax an N'Dama herd at Cape Coast in southern Ghana and a WASH herd at Chegbani in northern Ghana from May to July 2011 in a cross-sectional study. Levels of haematological parameters comprising packed cell volume (PCV), haemoglobin (Hb) concentration and total red blood cell (RBC) and white blood cell (WBC) counts; differential WBC counts (neutrophils, lymphocytes, eosinophils, monocytes and basophils); and RBC indices of mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were determined in blood samples and then compared between infected and uninfected cattle.We found that haematological indices for infected and uninfected Results: animals in both breeds were within the normal range. However, the mean PCV values for -infected WASH and N'Dama were lower in infected T. vivax compared to uninfected animals. The difference was significant ( < 0.05) in p N'Dama but not in WASH. The RBC indices were higher in infected N'Dama compared to infected WASH with a significant difference in total RBC ( < p 0.05).We conclude from our findings that despite the presence of Conclusion: infection by , N'Dama and WASH cattle maintained their T. vivax haematological parameters within acceptable normal ranges, and this underscores the need for routine diagnosis and treatment so that such trypanotolerant cattle do not serve as potential reservoirs of trypanosome parasites.

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Improved detection of Trypanosoma brucei by lysis of red blood cells, concentration and LED fluorescence microscopy

Cited by 33 publications

References 14 publications

Enhanced passive screening and diagnosis for gambiense human African trypanosomiasis in north-western Uganda – Moving towards elimination

Enhanced passive screening and diagnosis for gambiense human African trypanosomiasis in north-western Uganda – Moving towards elimination

Loop-Mediated Isothermal Amplification Test forTrypanosoma gambienseGroup 1 with Stem Primers: A Molecular Xenomonitoring Test for Sleeping Sickness

Haematology of N’Dama and West African Short Horn cattle herds under natural Trypanosoma vivax challenge in Ghana

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