An observational study in Severe Malaria, Uncomplicated Malaria and Asyptomatic Plasmodium Infection, sponsored by Institute of Tropical Medicine, Belgium. Completed at 3 sites in 3 countries. Open to participants aged 1 Year and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-03-11.
Sponsored by Institute of Tropical Medicine, Belgium · Observational
Understanding the sexual conversion of the malaria parasite is essential to interrupt malaria transmission. A new tool is developed that, based on expression analysis of sexual stage biomarkers, will estimate sexual conversion rates in natural infections.
Understanding the sexual conversion of the malaria parasite is essential to interrupt malaria transmission. At each replicating cycle within erythrocytes, a proportion of asexual parasites converts into non-replicative sexual stages, which are the only forms able to infect mosquitos. The rate at which sexual stages are produced, is known as basal sexual conversion rate. Changes in the host immune and metabolic environment associated with the development of malaria disease, such as depletion of lysophosphatidylcholine in plasma, have been associated with increased sexual conversion rates in vitro. It is hypothesised that immune and metabolite factors that are altered during malaria infection induce sexual conversion in Plasmodium falciparum parasites. In this project, a new tool is developed that, based on expression analysis of sexual stage biomarkers, will estimate sexual conversion rates in natural infections. The aim is to identify immune factors and metabolites that induce sexual conversion using in-house developed sexual conversion assays, and experimental mosquito infections. Finally, transcriptional mechanisms are explored driving parasite sexual conversion in the host environment during disease using single-cell RNA-sequencing approaches. This research will provide essential knowledge on the factors that affect sexual conversion in the host and potentially inform novel strategies to interrupt transmission.
1,184 studies on the registry are indexed under Malaria; 79 are open to participants now.
This study's enrollment of 458 is below the median of 582 across 204 observational studies indexed under Malaria.
Browse Malaria studies →Institute of Tropical Medicine, Belgium is the lead sponsor of 104 studies on the registry; 21 are open to participants now.
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Pilot:
This study will be performed at the policlinic of ITM, in Antwerp, Belgium.
WP1 Recruitment screenings will be organized in Nanoro village, within the catchment area of the existing health demographic surveillance system (HDSS) of Nanoro Health district (NHD), Burkina Faso.
WP2 The study will include pediatric patients with uncomplicated and severe malaria (aged ≥ 1 and ≤ 12 years, male and female) visiting Chókwè Rural Hospital, Mozambique, and the peripheral health centers in Chókwè district.
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.
Pilot:
-symptomatic for P. falciparum
-/Travel to P. falciparum endemic area within the last month
WP1:
WP2:
I. Severe malaria by infection with P. falciparum is defined in the presence of P. falciparum asexual parasitemia, and as one or more of the following:
II. Uncomplicated malaria by infection with P. falciparum is defined as a patient who presents with lethargic profile (e.g. fever) and a positive parasitological test for P. falciparum, but with no features of severe malaria.
Exclusion Criteria:
WP1:
WP2:
x Antimalarial drug treatment or other medication during the past week x If the patient had a meal within 4 hours before admission x Patients with acute meningitis (as clinically evaluated according to the local guidelines) x Patients with developmental delay or history of chronic illness x Vaccination during the past week
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.
Patients (P. falciparum-infected) No intervention 6 ml of venous blood sampled at one time point
Control non-infected individuals No intervention 6 ml of venous blood sampled at one time point
Asymptomatic (P. falciparum-infected) No intervention Venous blood sample (maximum of 8 ml) at 1 time point. 300µl of finger prick blood at four follow-up visits 24, and 48 and 72h and day 10 after the enrollment.
uncomplicated patients (P. falciparum-infected) No intervention Venous blood sample (maximum of 8 ml) at 1 time point.
Control non-infected individuals No intervention Venous blood sample (maximum of 6 ml) at 1 time point.
Uncomplicated malaria patients No intervention Venous blood sample (maximum of 6 ml) at 1 time point.
Severe malaria patients No intervention Venous blood sample (maximum of 6 ml) at 1 time point.
To validate a Sexual Conversion Estimator tool
To validate a Sexual Conversion Estimator tool to accurately estimate SC rates and future transmission potential in epidemiological samples. First, the investigators will measure expression levels of SRBs and directly determine SC rates in samples from malaria asymptomatic patients. Second, the investigators will use a machine learning classifier to determine the combination of SRBs that best predicts SC rates; and third, the investigators will measure the predictive value of the Estimator tool for future transmission potential
Time frame: 2023-2025
To investigate in malaria patients associations between host immune and metabolic factors and P. falciparum sexual conversion and infection potential
In patients with uncomplicated and severe malaria, the investigators will investigate associations between host inflammatory molecules, parasite-specific Ab and metabolic factors, with parasite SC rates. The investigators hypothesize that SC rates will be higher in severe malaria patients and associated with specific molecules and metabolites.
Time frame: 2023-2025
To validate associations between sexual conversion and host immune and metabolic factors in vitro
An in vitro assay, based on recently described gametocyte-reporter parasite lines 16 will be used to validate candidate associations identified in Objective 2. First, the effect of patient serum samples and specific metabolites and inflammatory factors via in vitro SC assays is tested. Next, in vitro cultures with significantly induced SC will be fed to Anopheles stephensi mosquitoes to assess infection potential via standard membrane feeding assays. It is hypothesized that plasma/factors identified in Objective 2, induce SC in vitro and increase mosquito infections.
Time frame: 2024-2026
To explore transcriptional mechanisms driving parasite sexual conversion in the host environment during uncomplicated and severe malaria disease
Use of a single cell RNA-sequencing (scRNA-seq) approaches to generate the first in-depth characterization of gene expression patterns of very early sexual stages in the host circulation during natural infections in uncomplicated and severe clinical presentations (samples collected in Objective 2).
Time frame: 2024-2026
This study is completed, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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