External quality assessment of the laboratory diagnosis of tropical infectious diseases

The present PhD focuses the quality management of the diagnosis of malaria and human immunodeficiency virus at the level of the end-user by means of External Quality Assessment. Chapter I assesses the quality of microscopic diagnosis of malaria countrywide in the Democratic Republic of the Congo by an External Quality Assessment (EQA) session organised through the combined networks of the national malaria and tuberculosis control programs. The study documents the competence of the microscopic diagnosis of malaria among 174 laboratories in DRC and assesses the quality and procurement policy of the Giemsa stain solutions. Chapters II addresses quality control issues of malaria rapid diagnostic test (RDT) as evaluated by EQA in a non-endemic setting (Belgium and Luxembourg, 123 participants). In addition to evaluating the analytical competence of the participants and the performance of the RDT kits, RDT package instructions are evaluated and the place of RDTs in the diagnostic strategy is assessed. Chapter III assesses the competence of reading and interpretation of malaria and HIV RDTs by endusers in an endemic setting by means of EQA. Short cases with high-resolution pictures are presented to end-users, who are asked to reply by SMS. The cases focus on problems and errors in reading and interpretation of malaria and HIV tests, as well as on the use of the diagnostic algorithm for the HIV tests. Chapter IV assesses the visual acuity of end-users of malaria and HIV RDTs in an African field setting. Poor visual acuity from the end-users may affect RDT reading, especially since up to a third of malaria RDTs show faint and weak lines. Simple but unnoticed and uncorrected presbyopia (an accommodation deficit resulting in near vision failure) has been reported to be more frequent in African population as compared to Western populations. The prevalence and degree of presbyopia and its effect on RDT readings will be assessed among end-users in RDC field settings. Chapter V describes the adaptation and validation of the Dried Tube Spot technique (DTS, used to prepare control samples for HIV RDT evaluation) to other applications in RDT testing including malaria, leishmaniasis and human African trypanosomiasis. The DTS system will be converted to the use of whole blood samples, assessed for heat and humidity stabilisation, and subjected to pilot EQA sessions in field settings.

Trefwoorden:B780-tropische-geneeskunde