Publications

@article{Soumah2024,

title = {Prevalence of dermal trypanosomes in suspected and confirmed cases of gambiense human African trypanosomiasis in Guinea},

author = {Alseny M’Mah Soumah and Mariame Camara and Justin Windingoudi Kabor\'{e} and Ibrahim Sadissou and Hamidou Ilboudo and Christelle Travaill\'{e} and Oumou Camara and Magali Tichit and Jacques Kabor\'{e} and Salimatou Boiro and Aline Crouzols and Jean Marc Tsagmo Ngoune and David Hardy and A\"{i}ssata Camara and Vincent Jamonneau and Annette Macleod and Jean Mathieu Bart and Mamadou Camara and Bruno Bucheton and Brice Rotureau},

url = {https://pubmed.ncbi.nlm.nih.gov/39159265/},

doi = {10.1371/JOURNAL.PNTD.0012436},

issn = {1935-2735},

year  = {2024},

date = {2024-01-01},

journal = {PLoS neglected tropical diseases},

volume = {18},

issue = {8},

publisher = {PLoS Negl Trop Dis},

abstract = {The skin is an anatomical reservoir for African trypanosomes, yet the prevalence of extravascular parasite carriage in the population at risk of gambiense Human African Trypanosomiasis (gHAT) remains unclear. Here, we conducted a prospective observational cohort study in the HAT foci of Forecariah and Boffa, Republic of Guinea. Of the 18,916 subjects serologically screened for gHAT, 96 were enrolled into our study. At enrolment and follow-up visits, participants underwent a dermatological examination and had blood samples and superficial skin snip biopsies taken for examination by molecular and immuno-histological methods. In seropositive individuals, dermatological symptoms were significantly more frequent as compared to seronegative controls. Trypanosoma brucei DNA was detected in the blood of 67% of confirmed cases (22/33) and 9% of unconfirmed seropositive individuals (3/32). However, parasites were detected in the extravascular dermis of up to 71% of confirmed cases (25/35) and 41% of unconfirmed seropositive individuals (13/32) by PCR and/or immuno-histochemistry. Six to twelve months after treatment, trypanosome detection in the skin dropped to 17% of confirmed cases (5/30), whereas up to 25% of unconfirmed, hence untreated, seropositive individuals (4/16) were still found positive. Dermal trypanosomes were observed in subjects from both transmission foci, however, the occurrence of pruritus and the PCR positivity rates were significantly higher in unconfirmed seropositive individuals in Forecariah. The lower sensitivity of superficial skin snip biopsies appeared critical for detecting trypanosomes in the basal dermis. These results are discussed in the context of the planned elimination of gHAT.},

keywords = {Adolescent, Adult, African* / diagnosis, African* / epidemiology, African* / parasitology, Alseny M'mah Soumah, Brice Rotureau, Child, DNA, doi:10.1371/journal.pntd.0012436, Female, Guinea / epidemiology, Humans, Male, Mariame Camara, MEDLINE, Middle Aged, National Center for Biotechnology Information, National Institutes of Health, National Library of Medicine, NCBI, NIH, NLM, Observational Study, PMC11361743, pmid:39159265, Prevalence, Prospective Studies, Protozoan / genetics, PubMed Abstract, Skin* / parasitology, Skin* / pathology, Trypanosoma brucei gambiense* / isolation \& purification, Trypanosomiasis, Young Adult},

pubstate = {published},

tppubtype = {article}

}

@article{Camara2023,

title = {Performance of clinical signs and symptoms, rapid and reference laboratory diagnostic tests for diagnosis of human African trypanosomiasis by passive screening in Guinea: a prospective diagnostic accuracy study},

author = {Oumou Camara and Mamadou Camara and Laura Cristina Falzon and Hamidou Ilboudo and Jacques Kabor\'{e} and Charlie Franck Alfred Compaor\'{e} and Eric Maurice F\`{e}vre and Philippe B\"{u}scher and Bruno Bucheton and Veerle Lejon},

url = {https://pubmed.ncbi.nlm.nih.gov/36941656/},

doi = {10.1186/S40249-023-01076-1},

issn = {2049-9957},

year  = {2023},

date = {2023-01-01},

journal = {Infectious diseases of poverty},

volume = {12},

issue = {1},

publisher = {Infect Dis Poverty},

abstract = {Background: Passive diagnosis of human African trypanosomiasis (HAT) at the health facility level is a major component of HAT control in Guinea. We examined which clinical signs and symptoms are associated with HAT, and assessed the performance of selected clinical presentations, of rapid diagnostic tests (RDT), and of reference laboratory tests on dried blood spots (DBS) for diagnosing HAT in Guinea. Method: The study took place in 14 health facilities in Guinea, where 2345 clinical suspects were tested with RDTs (HAT Sero-K-Set, rHAT Sero-Strip, and SD Bioline HAT). Seropositives underwent parasitological examination (reference test) to confirm HAT and their DBS were tested in indirect enzyme-linked immunoassay (ELISA)/Trypanosoma brucei gambiense, trypanolysis, Loopamp Trypanosoma brucei Detection kit (LAMP) and m18S quantitative PCR (qPCR). Multivariable regression analysis assessed association of clinical presentation with HAT. Sensitivity, specificity, positive and negative predictive values of key clinical presentations, of the RDTs and of the DBS tests for HAT diagnosis were determined. Results: The HAT prevalence, as confirmed parasitologically, was 2.0% (48/2345, 95% CI: 1.5\textendash2.7%). Odds ratios (OR) for HAT were increased for participants with swollen lymph nodes (OR = 96.7, 95% CI: 20.7\textendash452.0), important weight loss (OR = 20.4, 95% CI: 7.05\textendash58.9), severe itching (OR = 45.9, 95% CI: 7.3\textendash288.7) or motor disorders (OR = 4.5, 95% CI: 0.89\textendash22.5). Presence of at least one of these clinical presentations was 75.6% (95% CI: 73.8\textendash77.4%) specific and 97.9% (95% CI: 88.9\textendash99.9%) sensitive for HAT. HAT Sero-K-Set, rHAT Sero-Strip, and SD Bioline HAT were respectively 97.5% (95% CI: 96.8\textendash98.1%), 99.4% (95% CI: 99.0\textendash99.7%) and 97.9% (95% CI: 97.2\textendash98.4%) specific, and 100% (95% CI: 92.5\textendash100.0%), 59.6% (95% CI: 44.3\textendash73.3%) and 93.8% (95% CI: 82.8\textendash98.7%) sensitive for HAT. The RDT’s positive and negative predictive values ranged from 45.2\textendash66.7% and 99.2\textendash100% respectively. All DBS tests had specificities ≥ 92.9%. While LAMP and m18S qPCR sensitivities were below 50%, trypanolysis and ELISA/T.b. gambiense had sensitivities of 85.3% (95% CI: 68.9\textendash95.0%) and 67.6% (95% CI: 49.5\textendash82.6%). Conclusions: Presence of swollen lymph nodes, important weight loss, severe itching or motor disorders are simple but accurate clinical criteria for HAT referral in HAT endemic areas in Guinea. Diagnostic performances of HAT Sero-K-Set and SD Bioline HAT are sufficient for referring positives to microscopy. Trypanolysis on DBS may discriminate HAT patients from false RDT positives. Trial registration The trial was registered under NCT03356665 in clinicaltrials.gov (November 29, 2017, retrospectively registered https://clinicaltrials.gov/ct2/show/NCT03356665) Graphical Abstract: [Figure not available: see fulltext.].},

keywords = {African*, Animals, Clinical Trial, Diagnostic Tests, doi:10.1186/s40249-023-01076-1, Guinea, Humans, Mamadou Camara, MEDLINE, National Center for Biotechnology Information, National Institutes of Health, National Library of Medicine, NCBI, NIH, NLM, Oumou Camara, PMC10026442, pmid:36941656, Prospective Studies, PubMed Abstract, Routine, Sensitivity and Specificity, Trypanosomiasis, Veerle Lejon},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Analytical sensitivity of loopamp and quantitative real-time PCR on dried blood spots and their potential role in monitoring human African trypanosomiasis elimination.},

author = {Charlie Franck Alfred Compaor\'{e} and Hamidou Ilboudo and Jacques Kabor\'{e} and Justin Windingoudi Kabor\'{e} and Oumou Camara and Mohamed Bamba and Hassane Sakande and Minay\'{e}gninrin Kon\'{e} and Mamadou Camara and Dramane Kaba and Adrien Marie Gaston Belem and Stijn Deborggraeve and Philippe B\"{u}scher and Bruno Bucheton and Veerle Lejon and Vincent Jamonneau},

doi = {10.1016/j.exppara.2020.108014},

issn = {1090-2449 0014-4894},

year  = {2020},

date = {2020-12-01},

urldate = {2020-12-01},

journal = {Experimental parasitology},

volume = {219},

pages = {108014},

address = {United States},

abstract = {The objective set by WHO to reach elimination of human African trypanosomiasis (HAT) as a public health problem by 2020 is being achieved. The next target is the interruption of gambiense-HAT transmission in humans by 2030. To monitor progress towards this target, in areas where specialized local HAT control capacities will disappear, is a major challenge. Test specimens should be easily collectable and safely transportable such as dried blood spots (DBS). Monitoring tests performed in regional reference centres should be reliable, cheap and allow analysis of large numbers of specimens in a high-throughput format. The aim of this study was to assess the analytical sensitivity of Loopamp, M18S quantitative real-time PCR (M18S qPCR) and TgsGP qPCR as molecular diagnostic tests for the presence of Trypanosoma brucei gambiense in DBS. The sensitivity of the Loopamp test, with a detection limit of 100 trypanosomes/mL, was in the range of parasitaemias commonly observed in HAT patients, while detection limits for M18S and TgsGP qPCR were respectively 1000 and 10,000 trypanosomes/mL. None of the tests was entirely suitable for high-throughput use and further development and implementation of sensitive high-throughput molecular tools for monitoring HAT elimination are needed.},

keywords = {African/blood/diagnosis/*prevention \& control, Algorithms, Animals, Blood Specimen Collection/methods/standards, Diagnosis, DNA, Dried blood spots, Feasibility, High-Throughput Screening Assays/methods/standards, Humans, Loopamp, Mice, Molecular Diagnostic Techniques/*standards, Nucleic Acid Amplification Techniques/*standards, Protozoan/isolation \& purification, Quantitative real-time PCR, Real-Time Polymerase Chain Reaction/methods/*standards, Sensitivity, Sensitivity and Specificity, Specimen Handling/methods/standards, Trypanosoma brucei gambiense, Trypanosoma brucei gambiense/genetics/*isolation \& purification, Trypanosomiasis},

pubstate = {published},

tppubtype = {article}

}