Passive surveillance of human African trypanosomiasis in Côte d'Ivoire: Understanding prevalence, clinical symptoms and signs, and diagnostic test characteristics.

Koné, Minayégninrin, Kaba, Dramane, Kaboré, Jacques, Thomas, Lian Francesca ORCID: 0000-0001-8447-1210, Falzon, Laura Cristina ORCID: 0000-0002-4043-1644, Koffi, Mathurin, Kouamé, Cyrille Mambo, Ahouty, Bernardin, Compaoré, Charlie Franck Alfred, N'Gouan, Emmanuel Kouassi
et al (show 5 more authors) (2021) Passive surveillance of human African trypanosomiasis in Côte d'Ivoire: Understanding prevalence, clinical symptoms and signs, and diagnostic test characteristics. PLoS neglected tropical diseases, 15 (8). e0009656-e0009656.

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<h4>Background</h4>Little is known about the diagnostic performance of rapid diagnostic tests (RDTs) for passive screening of human African trypanosomiasis (HAT) in Côte d'Ivoire. We determined HAT prevalence among clinical suspects, identified clinical symptoms and signs associated with HAT RDT positivity, and assessed the diagnostic tests' specificity, positive predictive value and agreement.<h4>Methods</h4>Clinical suspects were screened with SD Bioline HAT, HAT Sero-K-Set and rHAT Sero-Strip. Seropositives were parasitologically examined, and their dried blood spots tested in trypanolysis, ELISA/Tbg, m18S-qPCR and LAMP. The HAT prevalence in the study population was calculated based on RDT positivity followed by parasitological confirmation. The association between clinical symptoms and signs and RDT positivity was determined using multivariable logistic regression. The tests' Positive Predictive Value (PPV), specificity and agreement were determined.<h4>Results</h4>Over 29 months, 3433 clinical suspects were tested. The RDT positivity rate was 2.83%, HAT prevalence 0.06%. Individuals with sleep disturbances (p<0.001), motor disorders (p = 0.002), convulsions (p = 0.02), severe weight loss (p = 0.02) or psychiatric problems (p = 0.04) had an increased odds (odds ratios 1.7-4.6) of being HAT RDT seropositive. Specificities ranged between 97.8%-99.6% for individual RDTs, and 93.3-98.9% for subsequent tests on dried blood spots. The PPV of the individual RDTs was below 14.3% (CI 2-43), increased to 33.3% (CI 4-78) for serial RDT combinations, and reached 67% for LAMP and ELISA/Tbg on RDT positives. Agreement between diagnostic tests was poor to moderate (Kappa ≤ 0.60), except for LAMP and ELISA/Tbg (Kappa = 0.66).<h4>Conclusion</h4>Identification of five key clinical symptoms and signs may simplify referral for HAT RDT screening. The results confirm the appropriateness of the diagnostic algorithm presently applied, with screening by SD Bioline HAT or HAT Sero-K-Set, supplemented with trypanolysis. ELISA/Tbg could replace trypanolysis and is simpler to perform.<h4>Trial registration</h4>, ID NCT03356665.

Item Type: Article
Uncontrolled Keywords: Animals, Humans, Trypanosoma brucei gambiense, Trypanosomiasis, African, Seizures, Weight Loss, Antigens, Protozoan, Diagnostic Tests, Routine, Prevalence, Logistic Models, Sensitivity and Specificity, Predictive Value of Tests, Adult, Middle Aged, Cote d'Ivoire, Female, Male, Sleep Wake Disorders, Motor Disorders
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences
Depositing User: Symplectic Admin
Date Deposited: 13 Sep 2021 07:35
Last Modified: 18 Jan 2023 21:28
DOI: 10.1371/journal.pntd.0009656
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