Diagnostic Accuracy and Feasibility of Serological Tests on Filter Paper Samples for Outbreak Detection of T.b. gambiense Human African Trypanosomiasis

Abstract

Abstract. Control of human African trypanosomiasis (HAT) in the Democratic Republic of Congo is based on mass population screening by mobile teams; a costly and labor-intensive approach. We hypothesized that blood samples collected on filter paper by village health workers and processed in a central laboratory might be a cost-effective alternative. We estimated sensitivity and specificity of micro-card agglutination test for trypanosomiasis (micro-CATT) and enzymelinked immunosorbent assay (ELISA)/ T.b. gambiense on filter paper samples compared with parasitology-based case classification and used the results in a Monte Carlo simulation of a lot quality assurance sampling (LQAS) approach. Conditional on high sample size per lot (≥ 60%), both tests could reliably distinguish a 2% from a zero prevalence at village level. Alternatively, these tests could be used to identify individual HAT suspects for subsequent confirmation.

Human African Trypanosomiasis Diagnosis in First-Line Health Services of Endemic Countries, a Systematic Review

“…In one study CATT on filter paper lost its sensitivity rapidly when the filter papers were stored at ambient temperature [17]. Reproducibility of CATT on filter paper is excellent (Kappa = 0·84) [12], [14]. The micro-CATT does not meet the ASSURED criteria of robustness, being equipment free and user- friendly (table 1).…”

“…ELISA is an antibody detection test that uses the same antigens as the Latex/ T.b.gambiense (LiTat 1.3+1.5+1.6) but fixed in an ELISA plate [14]. Test sample may be serum, plasma or saliva, either fresh or on filter paper.…”

“…Test sample may be serum, plasma or saliva, either fresh or on filter paper. Reported sensitivity with different kinds of samples ranges from 82·8% to 100%, specificity from 94·7% to 100% [13], [14], [20], [36], [37]. Performing ELISA tests is time-consuming, technically demanding and expensive; moreover ELISA tests are not an individual format tests but are performed in batches of at least 50 samples.…”

“…The need of sophisticated equipment, electricity, trained personnel and large volumes of purified water remain serious drawbacks for wide spread application of the tests. For surveillance purposes ELISA could be used on eluates of dried blood from filter papers in a reference laboratory, provided the optimal cut off has been determined [14]. ELISA does fail however on several of the ASSURED criteria, in particular due the fact that it requires sophisticated equipment and skilled staff (table 1).…”

Sleep and Rhythm Changes at the Time ofTrypanosoma bruceiInvasion of the Brain Parenchyma in the Rat

“…The currently available drugs effective in the otherwise fatal second stage of both forms of HAT are highly toxic, which makes early diagnosis and treatment essential. Yet, in spite of recent advances (Amin et al, 2009(Amin et al, , 2010Boda et al, 2009;Hainard et al, 2009Hainard et al, , 2011, effective tools to distinguish early second stage from the first stage are not currently available (Barrett, 2010;WHO, 2010), and diagnostic criteria for HAT staging and severity monitoring are debated (Hasker et al, 2010;Lejon & Büscher, 2005). It is, therefore, crucial to develop accurate procedures and standards for the determination of the clinical progression of the disease.…”