An observational study in Loiasis and Lymphatic Filariasis, sponsored by Washington University School of Medicine. Completed at 1 site in Cameroon. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-21.
Sponsored by Washington University School of Medicine · Observational
This prospective study will enroll and follow 60 loiasis patients with high worm burden to monitor the spontaneous release of filarial antigen in peripheral blood. This study will define the cross-reactive antigen profile of persons with spontaneous loiasis antigenemia, and determine whether it varies with time.
Global efforts to eradicate lymphatic filariasis (LF) depend on rapid diagnostic tests (RDTs) that detect Wuchereria bancrofti circulating filarial antigen but these tests are unreliable in African nations where Loa loa is co-endemic because they yield false-positive results in some individuals with loiasis. The goals of this project are to define the cross-reactive antigen profile of persons with spontaneous antigenemia, how it varies over time, and to determine which L. loa antigens in cross-reactive sera best distinguish loiasis cross-reactivity from LF.
This prospective study will prospectively enroll 50 adults who presented with cross-reactive antigenemia at screening and 10 negative controls. Participants will followed for one year and tested every three months for persistence of antigenemia.
42 studies on the registry are indexed under Elephantiasis, Filarial; 5 are open to participants now.
This study's enrollment of 86 is below the median of 12,930 across 13 observational studies indexed under Elephantiasis, Filarial.
Browse Elephantiasis, Filarial studies →Washington University School of Medicine is the lead sponsor of 1,803 studies on the registry; 271 are open to participants now.
Of its 329 completed or terminated interventional studies of FDA-regulated products, 216 (66%) have results posted.
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The study will be conducted in the Okola health district (Lékié Division, Centre Region, Cameroon), situated about 40km northeast of Yaoundé, the political capital city of Cameroon. The Okola health district is highly endemic for loiasis. Participant will be recruited among those excluded from an Onchocerciasis study due to high Mf counts >20,000/mL.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This cohort will prospectively enroll 50 adults (age 18+) with cross-reactive antigenemia based on a positive filariasis test strip (FTS) and L. loa Mf counts \>20,000 Mf/mL.
Other: No intervention
This cohort will prospectively enroll 10 adults (age 18+) with a negative filariasis test strip (FTS) and L. loa Mf counts \>20,000 Mf/mL.
Patients in these cohorts will not be given anti-filariasis therapies because these drugs are not approved for use in patients with high worm burdens (\>20,000 Mf/mL)
prevalence of specific cross-reactive L. loa antigens at baseline
Prevalence of filariasis test strip (FTS) positive individuals at screening. Cross-reactive proteins in plasma will be identified by mass-spectrometry to identify a cross-reactive biomarker
Time frame: 1 day
Recurrence of cross-reactive antigenemia
To determine if the same antigens are present at each follow up
Time frame: quarterly for 1 year
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — The deidentified IPD for all primary and secondary outcomes will be made publicly available either as a supplementary file in a research publication and/or made publicly available in a data repository maintained by the Becker Biomedical Library at Washington University.
Time frame: The data will be made available following publication. It will remain available indefinitely.
Access criteria: The data will be made publicly available.
Ran from Jan 2020 to primary completion in May 2021, 16 months.
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This study is completed, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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