Validation of an In-House ELISA Method in the Diagnosis of Cutaneous Leishmaniasis Caused by <i>Leishmania donovani</i> in Hambantota District, Sri Lanka
Clinical diagnosis has become a challenge amidst a surge of cutaneous leishmaniasis in Southern Sri Lanka. The routine diagnostic method, slit-skin smear (SSS), has variable sensitivity, leading to undiagnosed cases. Improved diagnostics are urgently needed. We assessed a new in-house ELISA method f...
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MDPI AG
2022-04-01
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| author | Nirmitha Lalindi De Silva Viraji Nefertiti Hiromel De Silva Arachchige Theja Hemapala Deerasinghe Upeksha Lakmini Rathnapala Hirotomo Kato Makoto Itoh Hidekazu Takagi Mirani Vasanthamala Weerasooriya Thishan Channa Yahathugoda |
| author_facet | Nirmitha Lalindi De Silva Viraji Nefertiti Hiromel De Silva Arachchige Theja Hemapala Deerasinghe Upeksha Lakmini Rathnapala Hirotomo Kato Makoto Itoh Hidekazu Takagi Mirani Vasanthamala Weerasooriya Thishan Channa Yahathugoda |
| author_sort | Nirmitha Lalindi De Silva |
| collection | DOAJ |
| description | Clinical diagnosis has become a challenge amidst a surge of cutaneous leishmaniasis in Southern Sri Lanka. The routine diagnostic method, slit-skin smear (SSS), has variable sensitivity, leading to undiagnosed cases. Improved diagnostics are urgently needed. We assessed a new in-house ELISA method for its diagnostic capabilities against ITS-1 nested PCR (gold standard—Gs). A cohort of 190 clinical CL cases was examined by SSS microscopy, anti-rKRP42 IgG ELISA (serum- and urine-based), and rK39-Immunochromatographic strip test. Validation was done using non-endemic sera, and cutoffs were developed using the receiver operating curve. The sensitivity of SSS for case detection was 77.9% (authors) and 76.3% (technicians). ELISA vs. Gs demonstrated sensitivity (Sn) = 94.4%; specificity (Sp) = 50.0%; positive predictive value (PPV) = 97.1%; negative predictive value (NPV) = 33.3%; Kappa agreement (Kp) = 0.39/<i>p</i> < 0.01. Comparison of the combination method (SSS by technicians and ELISA) vs. Gs showed: Sn = 98.9%; Sp = 30.0; PPV = 96.2; NPV 60.0%; Kp = 0.378/<i>p</i> < 0.01. All methods performed better compared to SSS (29.4%) where the clinical diagnosis was doubtful (PCR = 94.15%; serum ELISA = 88.2%; combination = 94.1%; <i>p</i> < 0.01 for all). High serum anti-rKRP42 titers were seen in those with multiple lesions. Anti-rKRP42 urine ELISA was suboptimal as a diagnostic test. A 9% rate of positivity was seen for rk39-ICT, and positives recorded high anti-rKRP42 titers. The diagnostic accuracy can be increased above the level of the Gs by combining SSS and ELISA. Advanced studies are required to understand the association between rk39-ICT positivity and high anti-rKRP42 titers. |
| first_indexed | 2024-03-10T03:23:25Z |
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| language | English |
| last_indexed | 2024-03-10T03:23:25Z |
| publishDate | 2022-04-01 |
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| series | Microorganisms |
| spelling | doaj.art-bc17f03dfab648f98b25f8030b078b632023-11-23T12:15:02ZengMDPI AGMicroorganisms2076-26072022-04-0110592110.3390/microorganisms10050921Validation of an In-House ELISA Method in the Diagnosis of Cutaneous Leishmaniasis Caused by <i>Leishmania donovani</i> in Hambantota District, Sri LankaNirmitha Lalindi De Silva0Viraji Nefertiti Hiromel De Silva1Arachchige Theja Hemapala Deerasinghe2Upeksha Lakmini Rathnapala3Hirotomo Kato4Makoto Itoh5Hidekazu Takagi6Mirani Vasanthamala Weerasooriya7Thishan Channa Yahathugoda8Department of Parasitology, Faculty of Medicine, University of Ruhuna, Galle 80000, Sri LankaBase Hospital Tangalle, Tangalle 82200, Sri LankaDistrict General Hospital Hambantota, Hambantota 82000, Sri LankaSchool of Biosciences, University of Melbourne, Melbourne, VIC 3010, AustraliaDivision of Medical Zoology, Department of Infection and Immunity, Jichi Medical University, Tochigi 329-0498, JapanDepartment of Microbiology and Immunology, Aichi Medical University School of Medicine, Aichi 480-1195, JapanDepartment of Microbiology and Immunology, Aichi Medical University School of Medicine, Aichi 480-1195, JapanDepartment of Parasitology, Faculty of Medicine, University of Ruhuna, Galle 80000, Sri LankaDepartment of Parasitology, Faculty of Medicine, University of Ruhuna, Galle 80000, Sri LankaClinical diagnosis has become a challenge amidst a surge of cutaneous leishmaniasis in Southern Sri Lanka. The routine diagnostic method, slit-skin smear (SSS), has variable sensitivity, leading to undiagnosed cases. Improved diagnostics are urgently needed. We assessed a new in-house ELISA method for its diagnostic capabilities against ITS-1 nested PCR (gold standard—Gs). A cohort of 190 clinical CL cases was examined by SSS microscopy, anti-rKRP42 IgG ELISA (serum- and urine-based), and rK39-Immunochromatographic strip test. Validation was done using non-endemic sera, and cutoffs were developed using the receiver operating curve. The sensitivity of SSS for case detection was 77.9% (authors) and 76.3% (technicians). ELISA vs. Gs demonstrated sensitivity (Sn) = 94.4%; specificity (Sp) = 50.0%; positive predictive value (PPV) = 97.1%; negative predictive value (NPV) = 33.3%; Kappa agreement (Kp) = 0.39/<i>p</i> < 0.01. Comparison of the combination method (SSS by technicians and ELISA) vs. Gs showed: Sn = 98.9%; Sp = 30.0; PPV = 96.2; NPV 60.0%; Kp = 0.378/<i>p</i> < 0.01. All methods performed better compared to SSS (29.4%) where the clinical diagnosis was doubtful (PCR = 94.15%; serum ELISA = 88.2%; combination = 94.1%; <i>p</i> < 0.01 for all). High serum anti-rKRP42 titers were seen in those with multiple lesions. Anti-rKRP42 urine ELISA was suboptimal as a diagnostic test. A 9% rate of positivity was seen for rk39-ICT, and positives recorded high anti-rKRP42 titers. The diagnostic accuracy can be increased above the level of the Gs by combining SSS and ELISA. Advanced studies are required to understand the association between rk39-ICT positivity and high anti-rKRP42 titers.https://www.mdpi.com/2076-2607/10/5/921cutaneous leishmaniasisdiagnosisELISArKRP42rK39serology |
| spellingShingle | Nirmitha Lalindi De Silva Viraji Nefertiti Hiromel De Silva Arachchige Theja Hemapala Deerasinghe Upeksha Lakmini Rathnapala Hirotomo Kato Makoto Itoh Hidekazu Takagi Mirani Vasanthamala Weerasooriya Thishan Channa Yahathugoda Validation of an In-House ELISA Method in the Diagnosis of Cutaneous Leishmaniasis Caused by <i>Leishmania donovani</i> in Hambantota District, Sri Lanka Microorganisms cutaneous leishmaniasis diagnosis ELISA rKRP42 rK39 serology |
| title | Validation of an In-House ELISA Method in the Diagnosis of Cutaneous Leishmaniasis Caused by <i>Leishmania donovani</i> in Hambantota District, Sri Lanka |
| title_full | Validation of an In-House ELISA Method in the Diagnosis of Cutaneous Leishmaniasis Caused by <i>Leishmania donovani</i> in Hambantota District, Sri Lanka |
| title_fullStr | Validation of an In-House ELISA Method in the Diagnosis of Cutaneous Leishmaniasis Caused by <i>Leishmania donovani</i> in Hambantota District, Sri Lanka |
| title_full_unstemmed | Validation of an In-House ELISA Method in the Diagnosis of Cutaneous Leishmaniasis Caused by <i>Leishmania donovani</i> in Hambantota District, Sri Lanka |
| title_short | Validation of an In-House ELISA Method in the Diagnosis of Cutaneous Leishmaniasis Caused by <i>Leishmania donovani</i> in Hambantota District, Sri Lanka |
| title_sort | validation of an in house elisa method in the diagnosis of cutaneous leishmaniasis caused by i leishmania donovani i in hambantota district sri lanka |
| topic | cutaneous leishmaniasis diagnosis ELISA rKRP42 rK39 serology |
| url | https://www.mdpi.com/2076-2607/10/5/921 |
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