Dataset Information

Validation of rK39 immunochromatographic test and direct agglutination test for the diagnosis of Mediterranean visceral leishmaniasis in Spain.

ABSTRACT: Visceral leishmaniasis (VL), the most severe form of leishmaniasis, is endemic in Europe with Mediterranean countries reporting endemic status alongside a worrying northward spread. Serological diagnosis, including immunochromatographic test based on the recombinant antigen rK39 (rK39-ICT) and a direct agglutination test (DAT) based on the whole parasite antigen, have been validated in regions with high VL burden, such as eastern Africa and the Indian subcontinent. To date, no studies using a large set of patients have performed an assessment of both methods within Europe.We selected a range of clinical serum samples from patients with confirmed VL (including HIV co-infection), Chagas disease, malaria, other parasitic infections and negative samples (n = 743; years 2009-2015) to test the performance of rK39-ICT rapid test (Kalazar Detect Rapid Test; InBios International, Inc., USA) and DAT (ITM-DAT/VLG; Institute of Tropical Medicine Antwerp, Belgium). An in-house immunofluorescence antibody test (IFAT), was included for comparison. Estimated sensitivities for rK39-ICT and DAT in HIV-negative VL patients were 83.1% [75.1-91.2] and 84.2% [76.3-92.1], respectively. Sensitivity was reduced to 67.3% [52.7-82.0] for rK39 and increased to 91.3% [82.1-100.0] for DAT in HIV/VL co-infected patients. The in-house IFAT was more sensitive in HIV-negative VL patients, 84.2% [76.3-92.1] than in HIV/VL patients, 79.4% [73.3-96.2]. DAT gave 32 false positives in sera from HIV-negative VL suspects, compared to 0 and 2 for rK39 and IFAT, respectively, but correctly detected more HIV/VL patients (42/46) than rK39 (31/46) and IFAT (39/46).Though rK39-ICT and DAT exhibited acceptable sensitivity and specificity a combination with other tests is required for highly sensitive diagnosis of VL cases in Spain. Important variation in the performance of the tests were seen in patients co-infected with HIV or with other parasitic infections. This study can help inform the choice of serological test to be used when screening or diagnosing VL in a European Mediterranean setting.

SUBMITTER: Bangert M

PROVIDER: S-EPMC5849364 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Validation of rK39 immunochromatographic test and direct agglutination test for the diagnosis of Mediterranean visceral leishmaniasis in Spain.

Bangert Mathieu M Flores-Chávez María D MD Llanes-Acevedo Ivonne P IP Arcones Carolina C Chicharro Carmen C García Emilia E Ortega Sheila S Nieto Javier J Cruz Israel I

PLoS neglected tropical diseases 20180301 3

<h4>Background</h4>Visceral leishmaniasis (VL), the most severe form of leishmaniasis, is endemic in Europe with Mediterranean countries reporting endemic status alongside a worrying northward spread. Serological diagnosis, including immunochromatographic test based on the recombinant antigen rK39 (rK39-ICT) and a direct agglutination test (DAT) based on the whole parasite antigen, have been validated in regions with high VL burden, such as eastern Africa and the Indian subcontinent. To date, no ...[more]

PMID: 29494596

Similar Datasets

Project description:BackgroundThe development of rK39-based immunochromatographic rapid diagnostic tests represents an important advance for serodiagnosis of visceral leishmaniasis, being cheap and easy to use at the point of care (POC). Although the use of rK39 have considerably improved the sensitivity and specificity of serological tests compared with total antigens, great variability in sensitivity and specificity was reported. This study aimed at the evaluation of "Kalazar Detect™ Rapid Test, Whole Blood" (Kalazar Detect RDT) for Visceral Leishmaniasis (VL) diagnosis using oral fluid, whole blood and serum specimens collected at different endemic areas of VL of Brazil.MethodologyTo evaluate Kalazar Detect RDT, oral fluid, whole blood and serum specimens from 128 VL patients, 85 healthy individuals, 22 patients with possible cross-reactivity diseases and 20 VL/aids coinfected patients were collected and assayed at the POC.Principal findings and conclusionsThe performance of Kalazar Detect RDT in whole blood and serum was similar; however, using oral fluid, the sensitivity was low. Particularly in samples from the city of Natal, Rio Grande do Norte state in Northeastern Brazil, we observed low sensitivity, 80.0% (95% CI: 62.7-90.5), using whole blood and serum, and poor sensitivity, 43.3% (95% CI: 27.4-60.8) with oral fluid. Those values were much lower than in the other regions, where sensitivity ranged from 92.7-96.3% in whole blood and serum, and 80.0-88.9% in oral fluid. Besides, in VL/aids coinfected patients, lower sensitivity was achieved compared with VL patients. In samples from Natal, the sensitivity was 0.0% (95% CI: 0.0-49.0) and 25.0% (95% CI: 4.6-69.9), using oral fluid and serum/whole blood, respectively; in samples from the other regions, the sensitivity ranged from 40.0-63.6% and 80.0-81.8%, respectively. As for specificity, high values were observed across the fluids, 100.0% (95% CI: 96.5-100.0) in whole blood, 96.3% (95% CI: 90.8-98.5) in serum, and 95.3% (95% CI: 89.5-98.0) in oral fluid; across localities, specificity ranged from 85.7-100.0%. Serum samples sent by the collaborating centers to Instituto de Medicina Tropical (n = 250) were tested by Kalazar Detect RDT, Direct Agglutination Test, Indirect immunofluorescence assay, Enzyme-linked immunosorbent assay, and IT-Leish® RDT. The regional difference in the performance of rK39-based RDT and lower sensitivity in Leishmania/HIV coinfected patients raise concern on the routine use of these products for the diagnosis of VL.

Dataset Information

Validation of rK39 immunochromatographic test and direct agglutination test for the diagnosis of Mediterranean visceral leishmaniasis in Spain.

Publications

Validation of rK39 immunochromatographic test and direct agglutination test for the diagnosis of Mediterranean visceral leishmaniasis in Spain.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets