Development of a New Rapid Diagnostic Test to Support Onchocerciasis Elimination

Not Applicable

Recruiting

• Conditions: Mansonelliasis; Loiasis; Onchocerciasis; Healthy Volunteers
• Interventions: Biological: Biological samples collection (blood drawing + feces)

• Registration Number: NCT06350851
• Lead Sponsor: Bioaster

Brief Summary

Onchocerciasis, also known as river blindness, is one of the disease targeted for elimination by the World Health Organization (WHO) in the group of Neglected Tropical Diseases. Existing diagnostic tools for onchocerciasis have limitations that make mapping, epidemiological assessments and verification of elimination of onchocerciasis difficult. It is in this context that WHO, in its 2021-2030 roadmap for onchocerciasis, has identified the development of new diagnostic tests, or the improvement of existing diagnostic tests, as a critical condition for achieving the goal of eliminating onchocerciasis transmission.

To this end, a series of cross-sectional studies will be carried out in Cameroun over a one year period to collect and characterize biological samples for the development and evaluation of a new rapid diagnostic test for onchocerciasis. The study will target individuals aged 18 and over, mono-infected with one of the filarial species Onchocerca volvulus, Loa loa or Mansonella perstans; and non-infected.

At the end of this study, data on the endemicity of onchocerciasis, loiasis and mansonellosis in the selected communities will be updated. More importantly, a new rapid diagnostic test will be developed, which can then be used to monitor the activities of onchocerciasis control programs.

Detailed Description

Onchocerciasis, also known as river blindness, stands as the second leading cause of infectious blindness worldwide. According to estimates by the World Health Organization (WHO), approximately 25 million people are infected globally, with another 90 million at risk. Over 99% of these cases occur in Africa, and vision loss affects around 1.15 million individuals. The primary strategy for combating onchocerciasis currently is Community Directed Treatment with Ivermectin (CDTI), requiring a minimum of 80% therapeutic coverage for 10 -15 years.

Areas of West and Central Africa endemic for loiasis and mansonellasis, where ivermectin may trigger severe side effects, pose a significant challenge in the battle against onchocerciasis. Existing diagnostic tools for onchocerciasis have limitations that make mapping, epidemiological assessments and verification of elimination of onchocerciasis difficult. This situation underscores the importance of improving the specificity of onchocerciasis diagnosis to reduce cross-reactivity and false results due to other parasitic helminths in co-endemic regions. It is in this context that WHO, in its 2021-2030 roadmap for onchocerciasis, has identified the development of new diagnostic tests, or the improvement of existing diagnostic tests, as a critical condition for achieving the goal of eliminating onchocerciasis transmission.

To this end, a series of cross-sectional studies will be carried out to build up a bank of well-characterized biological samples for the development and evaluation of a new rapid diagnostic test for onchocerciasis. These studies will take place in the Centre, Littoral, West and South regions of Cameroon over a one year period. The study will target individuals aged 18 and over, mono-infected with one of the filarial species Onchocerca volvulus, Loa loa or Mansonella perstans; and non-infected. The study will begin with a screening phase during which potential participants will be diagnosed for the different filariasis. Following this screening phase, individuals meeting the inclusion criteria will be selected. Once consent has been obtained, blood samples will be taken for test development and validation of the onchocerciasis RDT. In fact, venous blood sample (in a tube containing EDTA) will be taken for each participant, by venipuncture. After collection, the tube(s) containing the blood will be stored in a cooler containing ice and transported to the laboratory within 6 hours of collection. Once at the laboratory, the plasma will be immediately prepared, then aliquoted and stored at -80ºC until transfer to BIOASTER for development and evaluation of the new diagnostic test for onchocerciasis.

At the end of this study, data on the endemicity of onchocerciasis, loiasis and mansonellosis in the selected communities will be updated. More importantly, a new rapid diagnostic test will be developed, which can then be used to monitor the activities of onchocerciasis control programs.

Study Timeline

• Study First Submitted: 2024-03-22
• Study First Submitted QC: 2024-03-29
• Study First Posted: 2024-04-05
• Study Start: 2024-04-15
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-05
• Last Update Posted: 2025-03-07
• Primary Completion: 2025-12
• Study Completion: 2025-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 400

Inclusion Criteria

• Subjects informed of the objectives of the study and who signed a consent form
• Subjects without filariasis (for control subjects), or
• Subjects mono-infected with Onchocerca volvulus, or
• Subjects mono-infected with Loa loa, or
• Subjects mono-infected with Mansonella perstans or alternatively co-infected with Mansonella perstans and Loa loa

Exclusion Criteria

• Pregnant or breast-feeding women
• Subjects having taken antihelminthic treatment less than 6 months before the inclusion date

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Group 3: Subjects mono-infected with Loa loa	Biological samples collection (blood drawing + feces)	Blood drawing + feces sample collection
Group 4: Subjects mono-infected with Mansonella perstans (alternatively co-infected with Loa loa)	Biological samples collection (blood drawing + feces)	Blood drawing + feces sample collection
Group1: Control subjects (non-infected with filariasis)	Biological samples collection (blood drawing + feces)	Blood drawing + feces sample collection
Group 2: Subjects mono-infected with Onchocerca volvulus	Biological samples collection (blood drawing + feces)	Blood drawing + feces sample collection

Primary Outcome Measures

Name	Time	Method
Evaluation of the performance of the prototype diagnostic test	Up to 52 weeks	The prototype will be evaluated with all plasma samples in order to determine the dynamic range of the test and the associated variability, as well as its performance in terms of sensitivity and specificity in relation to non-infected samples, and the absence of cross-reactivity with samples infected by Loa loa and Mansonella perstans.

Trial Locations

Locations (1)

Higher Institute for Scientific and Medical Research; 🇨🇲 Yaounde, Cameroon