Objectives: The new red blood cell (RBC) parameters from automated haematology analyzers, such as reticulocyte haemoglobin content and percentage of hypochromic red cells or equivalent, are useful in the laboratory assessment of iron deficiency anaemia (IDA). However, the clinical utility of these parameters are confounded by thalassaemia trait (TT) especially in geographical areas of high thalassaemia prevalence. We aimed to evaluate the new formula derived from some red cell parameters on the Beckman Coulter DxH800 in distinguishing between IDA and TT in Hong Kong population. Methods: A total of 246 normal subjects, 102 patients with IDA and 115 subjects with TT were accrued for the study. Concurrent chronic disorder and ovelapped IDA and TT cases were excluded. The new red cell parameters studied were red blood cell size factor (RSF), low haemoglobin density (LHD%), microcytic anaemia factor (MAF), standard deviation of conductivity of the non-reticulocyte population (SD-C-NRET) and unghosted cell (UGC). Comparison between groups was performed by student t-test and the diagnostic performance of the parameters was determined by receiver operating characteristic (ROC) curve analysis. Results: Both LHD% and RSF were significantly higher in IDA than TT, whereas MAF was significantly lower. Although the biological basis was uncertain, SD-C-NRET was significantly lower in IDA than TT and showed the best diagnostic performance as a single parameter. A formula ((RBC+HB)*(HCT+SD-C-NRET))/(RDW-SD ) was devised to distinguish between IDA and TT. With a cutoff value of 23, the area under curve (AUC) was 0.995 (95% CI of 0.99 – 1.00), the sensitivity was 97% and the specificity was 99.1%. This formula was superior to other discriminant functions in the literature. The UGC number was not significantly different between alpha- and beta-TT. Conclusions: The new RBC parameters on Beckman Coulter DxH800 provided useful information in distinguishing between IDA and TT, which is important for clinical decision making and streamlining further laboratory testing. This index can be used to screen patients who are likely to be IDA or TT for further hematological studies to confirm diagnosis. / published_or_final_version / Pathology / Master / Master of Medical Sciences

published_or_final_version / Medicine / Master / Doctor of Medicine

published_or_final_version / Medicine / Master / Doctor of Medicine

Horses have been domesticated for thousands of years. Through selection practices horses have been separated into groups that pass on desired traits. We have viewed what the breeders have done at the genotypic level to accomplish their breeds. By using a relatively new technique, DNA fingerprinting, Thoroughbred inbreeding and eight other breeds (Standardbreds, Quarter horses, American Saddlebreds, National Show Horses, Arabians, Morgans, Mustangs and Belgians) have been studied. The probes CAC5 and YNZ 132 gave the best probability (ranging from 1.9x10⁻¹⁰ to 4.8x10⁻¹⁵) that two unrelated individuals would not have the same DNA fingerprint out of the probes screened. The level of inbreeding in Thoroughbreds has been estimated by comparing the number of bands shared among these animals to a quasi-natural population (Mustang) and a theoretically known genetic relationship (a sire and his offspring). Using the probes CAC5 and YNZ 132 Thoroughbreds share 20% more bands than the Mustang and 30-50% less than the sire and offspring. To compare the nine breeds, blood from ten horses from nine different breeds was mixed and DNA fingerprinted. Each lane on the autoradiograph therefore represents one breed. The two probes produced data with a rank correlation of .75 (Kendall's tau) (Ostle,B., 1963). Selection practices have been divided into, narrow selection regimes (where one or two traits have been selected for) and broad selection regimes (where numerous traits have been selected for). The amount of bands shared between the breeds was calculated and applied to a computer program named Gendiv (Gentzbittel and Nicolas, 1989,1991). Three consensus trees were derived showing that the narrow selection regime breeds, Thoroughbreds and Standardbreds, were the most genetically distanced from broad selection regime breeds, Mustangs and Morgans. / Master of Science

The objective of this study was to evaluate copper sulphate densitometry as a screening method for anaemia in children. The accuracy of copper sulphate densitometry was also compared to clinical assessment for the presence of pallor and haemoglobin measurement with a BMS-haemoglobinometer. Different observers performed these three screening tests independently. For the purposes of this study, anaemia was defined as a laboratory haemoglobin (Hb) concentration below 10 g/dl. A cross-sectional screening study was undertaken, where the results of the different screening tests were compared to laboratory haemoglobin determination (gold standard). The study sample consisted of one hundred consecutive children, aged between 6 months and 6 years, whose parents had given informed written consent for participation. The study was conducted in the Paediatric Outpatient Department of Pretoria Academic Hospital (73 children) and a local creche (27 children). In this study sample, the prevalence of anaemia (Hb < 10 g/dl) was 17% (95% Confidence Interval (95%CI) 10.2; 25.8). Clinical assessment by students for the presence of pallor had a sensitivity of 41.2% (95%CI 19.4; 66.5), specificity of 81.9% (95%CI 71.6; 89.2), positive predictive value of 31.8% (95% CI14.7; 54.9) and negative predictive value of 87.2%(95%CI 77.2; 93.3). The likelihood ratio for detection of anaemia by clinical assessment was 2.3. Copper sulphate densitometry had a sensitivity of 88.2% (95%CI 62.3; 97.9), specificity of 89.2% (95%CI 79.9; 94.6), positive predictive value of 62.5% (95% CI 40.8; 80.5) and negative predictive value of 97.4% (95%CI 90.0; 99.5) to screen for anaemia. The Likelihood Ratio of a positive copper sulphate-screening test was 8.17. On average, haemoglobin concentration was underestimated by 0.29 g/dl with the BMS-haemoglobinometer, with the 95% limits of agreement ranging from underestimation by 1.3 g/dl to over-estimation by 1.9 g/dl. Logistic regression analysis revealed that both the copper sulphate test and measurements with the BMS-haemoglobinometer predicted anaemia accurately. The area under the Receiver Operating Characteristic (ROC) curve for the haemoglobinometer was 0.94 (95%CI 0.87; 1), while the area under the curve for copper sulphate densitometry was 0.89 (95% CI 0.73; 1). Used together, the area under the ROC curve was 0.95 (95% CI 0.89; 1). In resource-poor settings, copper sulphate densitometry could be an accurate, inexpensive and simple screening method for anaemia in children. / Dissertation (MSc (Clinical Epidemiology))--University of Pretoria, 2005. / Clinical Epidemiology / unrestricted

The purpose of this research project was to evaluate the role of the community pharmacist in screening, identifying, and referring ambulatory patients with high total blood cholesterol (TBC) in a community pharmacy. Fifty seven patients, out of 241 initially screened individuals, met the study inclusion criteria and were accepted into this study. Of these 57 patients, 51 patients completed the six month study period. The normal population group consisted of 164 participants with TBC < 200 mgjdL at the initial cholesterol testing (visit 1). The drop out group represented six patients who failed to continue attending the two follow up tests (visit 2 and 3). For screening purposes, a non-fasting whole blood sample was used to measure TBC using the Boehringer Mannheim Reflotron analyzer. The project was evaluated based on mean TBC levels obtained during the initial screening and the two follow up tests, pre-test and post-test scores, behavior and lifestyle changes, and the number of patients who received a physician's order for lipid analysis as a result of initial screening results. In addition, influence of age and educational background on lowering TBC in visits 2 and 3, patient acceptance of blood screening in a community pharmacy and willingness to pay for this service in the future were also determined. To assess the level of significance among the means of the tested parameters, both parametric (one-way analysis of variance, Scheffe's post hoc test and two sample t-test) and non-parametric statistics (Mann-Whitney and chi-square test) were used at a probability level of less than 0.05. There was a significant difference in mean TBC levels between visit 1 and 2, and between visit 1 and 3 (P< 0.01). However, no statistically significant difference was found between visit 2 and 3 (P= 0.48). In addition, there was no significant difference in the incidence of high blood cholesterol in terms of gender or age difference at the initial screening. Further, mean TBC levels between males and females remained statistically insignificant during the two follow up tests. However, younger patients were able to lower their mean TBC level in visit 2 and 3 compared with older patients (P=< 0.031). The one-way analysis of variance results showed that there was no statistically significant difference in TBC changes during the three visits by subjects categorized by educational background levels. Patient's attitude toward the idea of blood test measurement in community pharmacies was positive. Ninety eight percent of the study group stated that they strongly liked such an idea, 92.16% expressed a willingness to pay an average of $4.55 (range $3 or less to $10), and all agreed that it was a convenient service for them. It was concluded that cholesterol screening in this community pharmacy was effective and acceptable, and may prove to be financially feasible when effectively planned and marketed. This service provides the community pharmacist with an opportunity to offer a unique patient-oriented public service.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

RESUME La Trypanosomiase Humain Africaine (THA) demeure un problème de santé publique pour plusieurs pays en Afrique subsaharienne. Le contrôle de la THA est basé essentiellement sur la stratégie de dépistage actif suivi du traitement des personnes infectées. Le dépistage actif est réalisé par des unités mobiles spécialisées, bien que les services de santé fixes jouent un rôle important en détectant « passivement » des cas. Le dépistage reposait jadis sur la palpation ganglionnaire mais, depuis le développement du test d’agglutination sur carte (CATT), trois possibilités se sont offertes aux programmes de contrôle à savoir: i) continuer avec la palpation ganglionnaire ii) combiner la palpation ganglionnaire avec le CATT iii) recourir au CATT seul. Certains programmes comme celui de la République Démocratique du Congo (RDC) ont opté pour la combinaison en parallèle de la palpation ganglionnaire avec le CATT. Toute personne ayant une hypertrophie ganglionnaire cervicale et/ou un CATT positif est considéré comme suspecte de la THA. Elle sera soumise aux tests parasitologiques de confirmation à cause de la toxicité des médicaments anti-THA. Les tests parasitologiques classiques sont l’examen du suc ganglionnaire (PG), l’examen du sang à l’état frais (SF), la goutte épaisse colorée (GE). La sensibilité de cette séquence a été estimée insuffisante par plusieurs auteurs et serait à la base d’une grande perte de l’efficacité de la stratégie dépistage-traitement. D’autres techniques de concentration ont été développées comme la mini-Anion Exchange Concentration Technique (mAECT), la Centrifugation en Tube Capillaire (CTC) et le Quantitative Buffy Coat (QBC), mais ces techniques de concentration ne sont pas utilisées en routine. En RDC, une interruption des activités de contrôle en 1990 a eu comme conséquence une réémergence importante de la maladie du sommeil. Depuis 1998 les activités de contrôle ont été refinancées de manière structurée. Ce travail vise deux buts à savoir le plaidoyer pour la continuité des activités de contrôle et la rationalisation des stratégies de contrôle. Nous avons évalué l’évolution de la maladie du sommeil en rapport avec le financement, son impact sur les ménages ainsi que la communauté. L’exercice de rationalisation a porté sur les outils de dépistage et de confirmation. Nous avons d’abord évalué la validité des tests, leur faisabilité ainsi que les coûts et ensuite nous avons effectué une analyse décisionnelle formelle pour comparer les algorithmes de dépistage et pour les tests de confirmation. Pendant la période de refinancement structurel de la lutte contre la THA en RDC (1998-2003), le budget alloué aux activités a été doublé lorsqu’on le compare à la période précédente (1993-1997). Le nombre des personnes examinées a aussi doublé mais par contre le nombre des nouveaux cas de THA est passé d’un pic de 26 000 cas en 1998 à 11 000 en 2003. Le coût par personne examinée a été de 1,5 US$ et celui d’un cas détecté et sauvé à 300 US$. Pendant cette période, les activités ont été financées par l’aide extérieure à plus de 95%. Cette subvention pourrait laisser supposer que l’impact de la THA au niveau des ménages et des communautés est réduit mais lorsque nous avons abordé cet aspect, il s’est avéré que le coût de la THA au niveau des ménages équivaut à un mois de leur revenu et que la THA fait perdre 2145 DALYs dans la communauté. L’intervention par la stratégie de dépistage-traitement a permis de sauver 1408 DALYs à un coût de 17 US$ par DALYs sauvé. Ce coût classe l’intervention comme « good value for money ». Le recours au CATT seul s’est avéré comme la stratégie la plus efficiente pour le dépistage actif. Le gain marginal lorsque l’on ajoute la palpation ganglionnaire en parallèle est minime et n’est pas compensé par le coût élevé lié à un nombre important des suspects soumis aux tests parasitologiques. Les techniques de concentration ont une bonne sensibilité et leur faisabilité est acceptable. Leur ajout à l’arbre classique améliore la sensibilité de 29 % pour la CTC et de 42% pour la mAECT. Le coût de la CTC a été de 0,76 € et celui de la mAECT de 2,82 €. Le SF a été estimé très peu sensible. L’algorithme PG- GE-CTC-mAECT a été le plus efficient avec 277 € par vie sauvée et un ratio de coût-efficacité marginal de 125 € par unité de vie supplémentaire sauvée. L’algorithme PG-GE-CATT titration avec traitement des personnes avec une parasitologie négative mais un CATT positif à un seuil de 1/8 devient compétitif lorsque la prévalence de la THA est élevée. Il est donc possible dans le contexte actuel de réduire la prévalence de la THA mais à condition que les activités ne soient pas interrompues. Le recours à un algorithme recourant au CATT dans le dépistage actif et à la séquence PG-GE-CTC-mAECT est le plus efficient et une efficacité de 80%. La faisabilité et l’efficacité peut être différent d’un endroit à l’autre à cause de la focalisation de la THA. Il est donc nécessaire de réévaluer cet algorithme dans un autre foyer de THA en étude pilote avant de décider d’un changement de politique. Le recours à cet algorithme implique un financement supplémentaire et une volonté politique. SUMMARY Human African Trypanosomiasis (HAT) remains a major public health problem affecting several countries in sub-Saharan Africa. HAT control is essentially based on active case finding conducted by specialized mobile teams. In the past the population screening was based on neck gland palpation, but since the development of the Card Agglutination Test for Trypanosomiasis (CATT) three control options are available to the control program: i) neck gland palpation ii) CATT iii) neck gland palpation and CATT done in parallel . Certain programs such as the one in DRC opted for the latter, combining CATT and neck gland palpation. All persons having hypertrophy of the neck gland and/or a positive CATT test are considered to be a HAT suspect. Confirmation tests are necessary because the screening algorithms are not 100 % specific and HAT drugs are very toxic. The classic parasitological confirmation tests are lymph node puncture (LNP), fresh blood examination (FBE) and thick blood film (TBF). The sensitivity of this combination is considered insufficient by several authors and causes important losses of efficacy of the screening-treatment strategy. More sensitive concentration methods were developed such as the mini Anion Exchange Concentration Techniques (mAECT), Capillary Tube Centrifugation (CTC) and the Quantitative Buffy Coat (QBC), but they are not used on a routine basis. Main reasons put forward are low feasibility, high cost and long time of execution. In the Democratic Republic of Congo, HAT control activities were suddenly interrupted in 1990 and this led to an important re-emergence or the epidemic. Since 1998 onwards, control activities were financed again in a structured way. This works aims to be both a plea for the continuation of HAT control as well as a contribution to the rationalization of the control strategies. We analyzed the evolution of sleeping sickness in the light of its financing, and we studied its impact on the household and the community. We aimed at a rationalization of the use of the screening and confirmation tools. We first evaluated the validity of the tests, their feasibility and the cost and we did a formal decision analysis to compare screening and confirmation algorithms. The budget allocated to control activities was doubled during the period when structural aid funding was again granted (1998-2003) compared with the period before (1993-1997). The number of persons examined per year doubled as well but the number of cases found peaked at 26 000 in 1998 and dropped to 11 000 in the period afterwards. The cost per person examined was 1.5 US$ and per case detected and saved was 300 US$. The activities were financed for 95 % by external donors during this period. This subvention could give the impression that the impact of HAT on the household and the household was limited but when we took a closer look at this aspect we found that the cost at household level amounted to one month of income and that HAT caused the loss of 2145 DALYs in the community. The intervention consisting of active case finding and treatment allowed to save 1408 DALY’s at a cost of 17 US$ per DALY, putting the intervention in the class of “good value for money”. The use of CATT alone as screening test emerged as the most efficient strategy for active case finding. The marginal gain when neck gland palpation is added is minor and is not compensated by the high cost of doing the parasitological confirmation test on a high number of suspected cases. The concentration methods have a good sensitivity and acceptable feasibility. Adding them to the classical tree improves its sensitivity with 29 % for CTC and with 42 % for mAECT. The cost of CTC was 0.76 US$ and of mAECT was 2.82 US$. Sensitivity of fresh blood examination was poor. The algorithm LNP-TBF-CTC-mAECT was the most efficient costing 277 Euro per life saved and a marginal cost effectiveness ratio of 125 Euro per supplementary life saved. The algorithm LNP-TBF-CATT titration with treatment of persons with a negative parasitology but a CATT positive at a dilution of 1/8 and more becomes competitive when HAT prevalence is high. We conclude that it is possible in the current RDC context to reduce HAT prevalence on condition that control activities are not interrupted. Using an algorithm that includes CATT in active case finding and the combination LNP-TBF-CTC-mAECT is the most efficient with an efficacy of 80 %. Feasibility and efficacy may differ from one place to another because HAT is very focalized, so it is necessary to test this novel algorithm in another HAT focus on a pilot basis, before deciding on a policy change. Implementation of this algorithm will require additional financial resources and political commitment.

RESUME<p>La Trypanosomiase Humain Africaine (THA) demeure un problème de santé publique pour plusieurs pays en Afrique subsaharienne. Le contrôle de la THA est basé essentiellement sur la stratégie de dépistage actif suivi du traitement des personnes infectées. Le dépistage actif est réalisé par des unités mobiles spécialisées, bien que les services de santé fixes jouent un rôle important en détectant « passivement » des cas. Le dépistage reposait jadis sur la palpation ganglionnaire mais, depuis le développement du test d’agglutination sur carte (CATT), trois possibilités se sont offertes aux programmes de contrôle à savoir: i) continuer avec la palpation ganglionnaire ii) combiner la palpation ganglionnaire avec le CATT iii) recourir au CATT seul. Certains programmes comme celui de la République Démocratique du Congo (RDC) ont opté pour la combinaison en parallèle de la palpation ganglionnaire avec le CATT. Toute personne ayant une hypertrophie ganglionnaire cervicale et/ou un CATT positif est considéré comme suspecte de la THA. Elle sera soumise aux tests parasitologiques de confirmation à cause de la toxicité des médicaments anti-THA. Les tests parasitologiques classiques sont l’examen du suc ganglionnaire (PG), l’examen du sang à l’état frais (SF), la goutte épaisse colorée (GE). La sensibilité de cette séquence a été estimée insuffisante par plusieurs auteurs et serait à la base d’une grande perte de l’efficacité de la stratégie dépistage-traitement. D’autres techniques de concentration ont été développées comme la mini-Anion Exchange Concentration Technique (mAECT), la Centrifugation en Tube Capillaire (CTC) et le Quantitative Buffy Coat (QBC), mais ces techniques de concentration ne sont pas utilisées en routine. <p>En RDC, une interruption des activités de contrôle en 1990 a eu comme conséquence une réémergence importante de la maladie du sommeil. Depuis 1998 les activités de contrôle ont été refinancées de manière structurée. <p>Ce travail vise deux buts à savoir le plaidoyer pour la continuité des activités de contrôle et la rationalisation des stratégies de contrôle. Nous avons évalué l’évolution de la maladie du sommeil en rapport avec le financement, son impact sur les ménages ainsi que la communauté. L’exercice de rationalisation a porté sur les outils de dépistage et de confirmation. Nous avons d’abord évalué la validité des tests, leur faisabilité ainsi que les coûts et ensuite nous avons effectué une analyse décisionnelle formelle pour comparer les algorithmes de dépistage et pour les tests de confirmation.<p>Pendant la période de refinancement structurel de la lutte contre la THA en RDC (1998-2003), le budget alloué aux activités a été doublé lorsqu’on le compare à la période précédente (1993-1997). Le nombre des personnes examinées a aussi doublé mais par contre le nombre des nouveaux cas de THA est passé d’un pic de 26 000 cas en 1998 à 11 000 en 2003. Le coût par personne examinée a été de 1,5 US$ et celui d’un cas détecté et sauvé à 300 US$. Pendant cette période, les activités ont été financées par l’aide extérieure à plus de 95%. Cette subvention pourrait laisser supposer que l’impact de la THA au niveau des ménages et des communautés est réduit mais lorsque nous avons abordé cet aspect, il s’est avéré que le coût de la THA au niveau des ménages équivaut à un mois de leur revenu et que la THA fait perdre 2145 DALYs dans la communauté. L’intervention par la stratégie de dépistage-traitement a permis de sauver 1408 DALYs à un coût de 17 US$ par DALYs sauvé. Ce coût classe l’intervention comme « good value for money ».<p>Le recours au CATT seul s’est avéré comme la stratégie la plus efficiente pour le dépistage actif. Le gain marginal lorsque l’on ajoute la palpation ganglionnaire en parallèle est minime et n’est pas compensé par le coût élevé lié à un nombre important des suspects soumis aux tests parasitologiques. Les techniques de concentration ont une bonne sensibilité et leur faisabilité est acceptable. Leur ajout à l’arbre classique améliore la sensibilité de 29 % pour la CTC et de 42% pour la mAECT. Le coût de la CTC a été de 0,76 € et celui de la mAECT de 2,82 €. Le SF a été estimé très peu sensible. L’algorithme PG- GE-CTC-mAECT a été le plus efficient avec 277 € par vie sauvée et un ratio de coût-efficacité marginal de 125 € par unité de vie supplémentaire sauvée. L’algorithme PG-GE-CATT titration avec traitement des personnes avec une parasitologie négative mais un CATT positif à un seuil de 1/8 devient compétitif lorsque la prévalence de la THA est élevée.<p>Il est donc possible dans le contexte actuel de réduire la prévalence de la THA mais à condition que les activités ne soient pas interrompues. Le recours à un algorithme recourant au CATT dans le dépistage actif et à la séquence PG-GE-CTC-mAECT est le plus efficient et une efficacité de 80%. La faisabilité et l’efficacité peut être différent d’un endroit à l’autre à cause de la focalisation de la THA. Il est donc nécessaire de réévaluer cet algorithme dans un autre foyer de THA en étude pilote avant de décider d’un changement de politique. Le recours à cet algorithme implique un financement supplémentaire et une volonté politique. <p><p><p>SUMMARY<p>Human African Trypanosomiasis (HAT) remains a major public health problem affecting several countries in sub-Saharan Africa. HAT control is essentially based on active case finding conducted by specialized mobile teams. In the past the population screening was based on neck gland palpation, but since the development of the Card Agglutination Test for Trypanosomiasis (CATT) three control options are available to the control program: i) neck gland palpation ii) CATT iii) neck gland palpation and CATT done in parallel .Certain programs such as the one in DRC opted for the latter, combining CATT and neck gland palpation. All persons having hypertrophy of the neck gland and/or a positive CATT test are considered to be a HAT suspect. Confirmation tests are necessary because the screening algorithms are not 100 % specific and HAT drugs are very toxic. The classic parasitological confirmation tests are lymph node puncture (LNP), fresh blood examination (FBE) and thick blood film (TBF). The sensitivity of this combination is considered insufficient by several authors and causes important losses of efficacy of the screening-treatment strategy. More sensitive concentration methods were developed such as the mini Anion Exchange Concentration Techniques (mAECT), Capillary Tube Centrifugation (CTC) and the Quantitative Buffy Coat (QBC), but they are not used on a routine basis. Main reasons put forward are low feasibility, high cost and long time of execution. <p>In the Democratic Republic of Congo, HAT control activities were suddenly interrupted in 1990 and this led to an important re-emergence or the epidemic. Since 1998 onwards, control activities were financed again in a structured way.<p>This works aims to be both a plea for the continuation of HAT control as well as a contribution to the rationalization of the control strategies. We analyzed the evolution of sleeping sickness in the light of its financing, and we studied its impact on the household and the community. We aimed at a rationalization of the use of the screening and confirmation tools. We first evaluated the validity of the tests, their feasibility and the cost and we did a formal decision analysis to compare screening and confirmation algorithms. <p>The budget allocated to control activities was doubled during the period when structural aid funding was again granted (1998-2003) compared with the period before (1993-1997). The number of persons examined per year doubled as well but the number of cases found peaked at 26 000 in 1998 and dropped to 11 000 in the period afterwards. The cost per person examined was 1.5 US$ and per case detected and saved was 300 US$. The activities were financed for 95 % by external donors during this period. This subvention could give the impression that the impact of HAT on the household and the household was limited but when we took a closer look at this aspect we found that the cost at household level amounted to one month of income and that HAT caused the loss of 2145 DALYs in the community. The intervention consisting of active case finding and treatment allowed to save 1408 DALY’s at a cost of 17 US$ per DALY, putting the intervention in the class of “good value for money”. <p>The use of CATT alone as screening test emerged as the most efficient strategy for active case finding. The marginal gain when neck gland palpation is added is minor and is not compensated by the high cost of doing the parasitological confirmation test on a high number of suspected cases. The concentration methods have a good sensitivity and acceptable feasibility. Adding them to the classical tree improves its sensitivity with 29 % for CTC and with 42 % for mAECT. The cost of CTC was 0.76 US$ and of mAECT was 2.82 US$. Sensitivity of fresh blood examination was poor. The algorithm LNP-TBF-CTC-mAECT was the most efficient costing 277 Euro per life saved and a marginal cost effectiveness ratio of 125 Euro per supplementary life saved. The algorithm LNP-TBF-CATT titration with treatment of persons with a negative parasitology but a CATT positive at a dilution of 1/8 and more becomes competitive when HAT prevalence is high. <p>We conclude that it is possible in the current RDC context to reduce HAT prevalence on condition that control activities are not interrupted. Using an algorithm that includes CATT in active case finding and the combination LNP-TBF-CTC-mAECT is the most efficient with an efficacy of 80 %. Feasibility and efficacy may differ from one place to another because HAT is very focalized, so it is necessary to test this novel algorithm in another HAT focus on a pilot basis, before deciding on a policy change. Implementation of this algorithm will require additional financial resources and political commitment.<p><p> / Doctorat en Sciences de la santé publique / info:eu-repo/semantics/nonPublished