Severe MalariaIMMETASEXNCT06064591
Host Immune and Metabolic Determinants of Sexual Conversion in Plasmodium Parasites IMMETASEX
An observational study of Severe Malaria and Uncomplicated Malaria, run by Institute of Tropical Medicine, Belgium at 3 sites in 3 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 1 year and olderHealthy volunteers can take part
- Conditions the study is for
- Severe Malaria, Uncomplicated Malaria, Asyptomatic Plasmodium Infection
- How many people
- 458 participants
- Where
- 3 sitesin 3 countries
- Study dates
- 13 Dec 2023to 9 Dec 2025
- How long will I take part?
- 10 Days
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 1 year and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Study population: 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.
Who may be able to join
- Age: ≥ 1 year
- Willing and able to provide written informed consent (or assent for minors with written informed consent by parent(s) and/or guardian(s).
- Pilot:
- -symptomatic for P. falciparum
- -/Travel to P. falciparum endemic area within the last month
- WP1:
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- Resident in Nanoro district
- non-symptomatic individuals
- WP2:
- Positive for P. falciparum infection via Rapid Diagnostic Tests (RDT)
- Age: ≥ 1 and ≤ 12 years
- Patients are included when suspected of the following conditions:
- 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:
- Impaired consciousness: A Blantyre coma score < 3 (when patients are ≤ 6 years) or Glasgow coma score < 10 (when patients are ≥ 6 years).
- Prostration: Generalized weakness so that the person is unable to sit, stand or walk without assistance.
- Multiple convulsions: More than two episodes within 24 hours.
- Clinical manifestation of respiratory distress (e.g., rapid, deep and labored breathing).
- Diagnosis through exclusion: absence of an identified alternative cause.
- 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.
Who cannot join
- Delayed developmental status or history of chronic illness
- Participation in another study
- Previous malaria treatment or prophylaxis in the last week
- Inability or unwillingness of the parents or guardians to provide informed consent
- WP1:
- Symptoms of malaria, as defined by presence of fever (body temperature >37.5 °C or history of fever during the past 48 hours) with a positive RDT (RDT are performed always when there is presence of fever)
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- Any plans to leave the study are in the coming 10 days
- WP2:
- Severe anemia (will be determined via clinical examination), since blood samples can hardly be withdrawn, co-morbidities.
- A questionnaire will be used during the clinical assessment that addresses following exclusion criteria:
- 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
Trial locations and contacts
3 sites in 3 countries.
3 sites in 3 countries
Burkina Faso1 site
Institut de Recherche en Sciences de la Santé - Clinical Research Unit of Nanoro
Nanoro
About this study
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.
Read the detailed description
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.
- Medical subject headings
- Malaria
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Pilot study Belgium Patients | Patients (P. falciparum-infected) No intervention 6 ml of venous blood sampled at one time point | |
| Pilot study Belgium Controls | Control non-infected individuals No intervention 6 ml of venous blood sampled at one time point | |
| Work package 1 Burkina Faso Asymptomatic | 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. | |
| Work package 1 Burkina Faso uncomplicated patients | uncomplicated patients (P. falciparum-infected) No intervention Venous blood sample (maximum of 8 ml) at 1 time point. | |
| Work package 1 Burkina Faso Uncomplicated Malaria Patients | Control non-infected individuals No intervention Venous blood sample (maximum of 6 ml) at 1 time point. | |
| Work package 2 Mozambique Uncomplicated malaria patients | Uncomplicated malaria patients No intervention Venous blood sample (maximum of 6 ml) at 1 time point. | |
| Work package 2 Burkina Faso Severe malaria patients | Severe malaria patients No intervention Venous blood sample (maximum of 6 ml) at 1 time point. |
What is being measured
The primary outcome is the main question the study is designed to answer.
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
Measured: 2023-2025
Secondary outcomes (3)
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.
Measured: 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.
Measured: 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).
Measured: 2024-2026
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Oct 2023
- Study start13 Dec 2023
- Primary completion9 Dec 2025
- Study completion9 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Severe MalariaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 458 participants (actual)
- Target duration
- 10 Days
Sponsor and investigators
- Lead sponsor
- Institute of Tropical Medicine, Belgium
- Sponsor type
- University, hospital or other
- Collaborators
- Instituto Nacional de Saúde, Mozambique, Clinical Research Unit of Nanoro, Barcelona Institute for Global Health, Leiden University Medical Center, KU Leuven
- Responsible party
- Sponsor
- Investigators
- Anna Rosanas-Urgell, Prof, Principal investigator, ITM
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06064591
- Sponsor's protocol ID
- IMMETASEX 1704/23
- Other IDs
- G067823N
- Acronym
- IMMETASEX
- Status last verified
- Mar 2026
- First submitted
- 26 Sep 2023
- Last updated
- 11 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Host Immune and Metabolic Determinants of Sexual Conversion in Plasmodium Parasites IMMETASEX
- ClinicalTrials.gov ID
- NCT06064591
- Acronym / sponsor ID
- IMMETASEX / IMMETASEX 1704/23
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 458 participants (actual)
- Lead sponsor
- Institute of Tropical Medicine, BelgiumUniversity, hospital or other
- Collaborators
- Instituto Nacional de Saúde, Mozambique, Clinical Research Unit of Nanoro, Barcelona Institute for Global Health, Leiden University Medical Center, KU Leuven
- Study start
- 13 Dec 2023 (actual)
- Primary completion
- 9 Dec 2025 (actual)
- Study completion
- 9 Dec 2025 (actual)
- First posted
- 3 Oct 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 10 Days
- Number of arms
- 7
| Arm | Type | Receives |
|---|---|---|
| Pilot study Belgium Patients | – | –Patients (P. falciparum-infected) No intervention 6 ml of venous blood sampled at one time point |
| Pilot study Belgium Controls | – | –Control non-infected individuals No intervention 6 ml of venous blood sampled at one time point |
| Work package 1 Burkina Faso Asymptomatic | – | –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. |
| Work package 1 Burkina Faso uncomplicated patients | – | –uncomplicated patients (P. falciparum-infected) No intervention Venous blood sample (maximum of 8 ml) at 1 time point. |
| Work package 1 Burkina Faso Uncomplicated Malaria Patients | – | –Control non-infected individuals No intervention Venous blood sample (maximum of 6 ml) at 1 time point. |
| Work package 2 Mozambique Uncomplicated malaria patients | – | –Uncomplicated malaria patients No intervention Venous blood sample (maximum of 6 ml) at 1 time point. |
| Work package 2 Burkina Faso Severe malaria patients | – | –Severe malaria patients No intervention Venous blood sample (maximum of 6 ml) at 1 time point. |
Who may qualify
- Ages
- 1 year and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
- Study population
- 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.
Key inclusion criteria (19 listed)
- Age: ≥ 1 year
- Willing and able to provide written informed consent (or assent for minors with written informed consent by parent(s) and/or guardian(s).
- -symptomatic for P. falciparum
- -/Travel to P. falciparum endemic area within the last month
- Resident in Nanoro district
Key exclusion criteria (11 listed)
- Delayed developmental status or history of chronic illness
- Participation in another study
- Previous malaria treatment or prophylaxis in the last week
- Inability or unwillingness of the parents or guardians to provide informed consent
- Symptoms of malaria, as defined by presence of fever (body temperature >37.5 °C or history of fever during the past 48 hours) with a positive RDT (RDT are performed always when there is presence of fever)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
To validate a Sexual Conversion Estimator tool
Time frame: 2023-2025
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
3 secondary outcomes
To investigate in malaria patients associations between host immune and metabolic factors and P. falciparum sexual conversion and infection potential
Time frame: 2023-2025
To validate associations between sexual conversion and host immune and metabolic factors in vitro
Time frame: 2024-2026
To explore transcriptional mechanisms driving parasite sexual conversion in the host environment during uncomplicated and severe malaria disease
Time frame: 2024-2026
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Mar 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Anna Rosanas-Urgell, Prof principal investigator
ITM
3 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Severe Malaria and Uncomplicated Malaria, run by Institute of Tropical Medicine, Belgium at 3 sites in 3 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 19 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Belgium, Burkina Faso, Mozambique. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To validate a Sexual Conversion Estimator tool (time frame: 2023-2025). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Mar 2026.