Evaluation to Assess the Usability of rK28 for the Diagnosis of Visceral Leishmaniasis in Kenya (rK28-AccDemo)

Evaluation of rK28 RDT for the Diagnosis of Visceral Leishmaniasis in Kenya, Towards Strengthening Recommendations for Its Use and Access in Eastern Africa

Visceral leishmaniasis (VL) is a fatal disease caused by Leishmania parasites and transmitted by female phlebotomine sandflies. The disease is a serious public health problem in eastern Africa; including Kenya where an estimated 4000 cases occur annually and 5 million people are at risk of infection. Accurate diagnosis of VL is critical for appropriate treatment. Currently, VL diagnosis in Kenya is based on testing suspected patients with the IT-Leish rK39 rapid diagnostic test (RDT) followed by other tests such as the Direct Agglutination Tests (DAT) and microscopy of tissue aspirates (splenic, bone marrow, lymph node) on rK39-negative patients. However, these diagnostic tools present several challenges including; the need for expertise, equipment and low diagnostic sensitivity of (85%) for DAT and rK39. Alternative VL diagnostic tools that are readily available, easy to use with increased sensitivity are needed to improve VL surveillance and control in Kenya. In the present study, we will assess rK28 as a diagnostic tool including performance with increased sensitivity when used together with IT-Leish rK39 and its potential for inclusion in VL diagnosis algorithms and evaluate Kala-azar Detect rK39 for potential use in Kenya. Suspected patients presenting at VL testing facilities in Marsabit, Turkana and Wajir Counties will be recruited prospectively and tested using IT-Leish rK39 followed by DAT for case confirmation according to the national guidelines. Alongside the case confirmation, samples from participants will also be tested using the rK28 and Kala-azar Detect rK39 in whole blood and serum. The collected data will be analyzed and compared separately between the RDTs as well as in combination, and the performance of the algorithms determined retrospectively. This design will enable the assessment of the sensitivity of combining rK28 and rK39 (Kala-azar Detect) compared to rK39 (IT-Leish/Kala-azar Detect) alone. Microscopy will be used as confirmatory test. We will also assess the feasibility, usefulness, and cost-effectiveness of rK28 in the VL diagnostic algorithm, through sensitivity analyses. The improved understanding of rK28 as a VL diagnostic tool and its potential for inclusion in the VL diagnosis algorithm could enable faster and more effective management of cases and accelerate elimination of VL.

Study Overview

• Status: Recruiting
• Conditions: Visceral Leishmaniasis
• Intervention / Treatment: Diagnostic test: rK28

• Study Type: Observational
• Enrollment (Anticipated): 625

Contacts and Locations

• Study Contact: Name: Dawn K Maranga; Phone Number: +254722554641; Email: Dawn.Maranga@finddx.org

Study Locations

• Kenya
  • Lodwar, Kenya
    • Recruiting
    • Turkana County
    • Sub-Investigator: Jimmy Loree
  • Marsabit, Kenya
    • Recruiting
    • Marsabit County
    • Sub-Investigator: Abduba Liban
  • Nairobi, Kenya
    • Active, not recruiting
    • Kenya Medical Research Institute
  • Wajir, Kenya
    • Recruiting
    • Wajir County
    • Sub-Investigator: Rukia Abdullahi

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 1 year and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Individuals presenting at health facilities in the participating sites or referred from peripheral health centres with suspicion of VL.

Description

Inclusion Criteria:

• All patients ≥ 1 year, with clinical signs and symptoms compatible with VL (fever > 2 weeks, splenomegaly, wasting, malaria negative)
• Participants for whom written informed consent has been obtained (if aged 18 years and over) or signed by parents(s) or legal guardian for participants under 18 years of age. In the case of minors 12 - 17 years, assent from the children will to be obtained in addition to parental consent.

Exclusion Criteria:

• Relapse cases of VL (recrudescent infection 6-12 month after treatment).
• Participants with post-kala-azar dermal leishmaniasis
• Participants from whom, for any reason, the blood sample needed for the evaluation cannot be taken

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic performance	Sensitivity, Specificity, the negative and positive predictive values (NPV, PPV) along with their confidence intervals.	12 months
Diagnostic performance	Diagnostic odd ratio (DOR) or balanced Accuracy (BA).	12 months
Use cases	Use cases for the different combination of tests.	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cost effectiveness	Cost estimates per test/algorithm	12 months
Access to diagnosis (optimum placement of RDTs)	Distance to the primary healthcare facility and to the referral facility.	12 months

Collaborators and Investigators

• Sponsor: Foundation for Innovative New Diagnostics, Switzerland
• Collaborators: Kenya Medical Research Institute

Study record dates

Study Major Dates

• Study Start (Actual): December 31, 2022
• Primary Completion (Anticipated): December 31, 2023
• Study Completion (Anticipated): June 30, 2024

Study Registration Dates

• First Submitted: April 21, 2022
• First Submitted That Met QC Criteria: May 18, 2022
• First Posted (Actual): May 23, 2022

Study Record Updates

• Last Update Posted (Actual): April 7, 2023
• Last Update Submitted That Met QC Criteria: April 6, 2023
• Last Verified: April 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Skin Diseases; Infections; Vector Borne Diseases; Parasitic Diseases; Protozoan Infections; Skin Diseases, Parasitic; Skin Diseases, Infectious; Euglenozoa Infections; Leishmaniasis; Leishmaniasis, Visceral
• Other Study ID Numbers: NT012

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No