MalariaNCT04704674
Community Dynamics of Malaria Transmission in Humans and Mosquitoes in Fleh-la and Marshansue, Salala District, Bong County, Liberia
An observational study of Malaria, run by National Institute of Allergy and Infectious Diseases (NIAID) at 1 site in Liberia.
Trial summary
Background: Malaria is a disease that affects many people in Liberia. It is caused by germs (parasites) that are spread by mosquito bites. Researchers want to gather data that may help them understand the best way to use a malaria vaccine in Liberia, which will be important in getting rid of the disease. Read more about this study
- Who is it for?
- Ages 6 months and older
- Conditions the study is for
- Malaria
- How many people
- 396 participants
- Where
- 1 siteLiberia
- Study dates
- 30 Sep 2021to 28 Feb 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 6 months and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: An estimated total of 400 volunteers from Fleh-la and Marshansue and surrounding villages will be enrolled. Participants above the age of six months will be approached to participate in the study; and will be followed for up to 3 years.
Who may be able to join
- Subject Inclusion Criteria:
- 6 months of age and above
- Known resident of Fleh-la and Marshansue or the surrounding villages and planning to remain for duration of study
- Willingness to allow stored laboratory specimens to be used for future research
- Acceptance and signature of the written informed consent and the assent for children aged 12-17 years who are not otherwise emancipated
- Household Inclusion Criteria:
Show all 10Show fewer
- To be eligible for participation, households must meet the following criteria:
- Household with at least 3 residents eligible for participation.
- Household with at least one compound member who is below 18 years of age whose parents or caretakers are willing to provide informed consent for the child to participate.
- Household members willing to accommodate mosquito sampling in their compound, both indoors and outdoors.
Who cannot join
- Subject Exclusion Criteria:
- Behavioral, cognitive, or psychiatric disease that in the opinion of the investigator affects the ability of the subject to understand and cooperate with the study protocol.
- Other condition that, in the opinion of the investigator, would jeopardize the safety or rights of a volunteer participating in the trial or would render the subject unable to comply with the protocol.
Trial locations and contacts
1 site in 1 country.
About this study
Background:
Malaria is a disease that affects many people in Liberia. It is caused by germs (parasites) that are spread by mosquito bites. Researchers want to gather data that may help them understand the best way to use a malaria vaccine in Liberia, which will be important in getting rid of the disease.
Read more
Objective:
To find out how often people of all ages who live in Fleh-la and Marshansue, Liberia, get malaria.
Eligibility:
Healthy people ages 6 months and older who live in Fleh-la and Marshansue in a household with adults and children.
Design:
Participants will be screened with a physical exam and questions about their health.
Participants will have monthly study visits. They will be asked about any symptoms of malaria and their use of bednets. Their vital signs, such as blood pressure and temperature, will be checked. Blood will be taken from the participant s arm or finger with a needle. If they have a fever, they will get a malaria test. If positive, they will get drugs to treat malaria.
Once a month, participants houses will be examined for mosquitoes. The team will remove all mosquitoes they collect. As part of this collection, participants houses will be sprayed with a chemical to kill mosquitoes and other insects. Participants will not be allowed in their house while the team is inside. The spray will not harm the participants.
Once a year, at the monthly visit, an additional blood sample will be taken.
Some of the participants blood samples will be used for genetic testing.
Participation will last for up to 3 years.
Read the detailed description
A vaccine that interrupts malaria transmission is critical to eradicate the disease, but improved assays are needed to measure the efficacy of vaccines. Transmission-blocking vaccines (TBVs) work by inducing antibodies that inhibit parasite development in the mosquito interrupting transmission. Efficacy of vaccines may be estimated by in vitro membrane feeding assays using immune sera and laboratory mosquitoes, but qualified assays that measure transmission in the field are needed to assess transmission-blocking interventions in natura. Clinical trials of TBVs have started elsewhere on the continent in Mali, and we have planned to expand TBV studies here in Liberia soon. This protocol is already being used for a longitudinal cohort to gather information of malaria transmission based on the rates of blood smear positive individuals by month, season and year in Fleh-la and Marshansue, in Salala, Bong County, Liberia. Individuals in the villages were approached first for participation, including permission to contact their household and neighbors of their compound for participation. Households were identified using census data and individuals who consented for participation are being enrolled. Malaria smears are obtained at monthly visits, in conjunction with mosquito collections in/around village residences. Parasite infection rates in locally caught mosquitoes will be assessed longitudinally for differences by season and year. A total of 400 volunteers from Fleh-la and Marshansue will be enrolled. Participants will be followed for at least one year, to collect data that will guide the design of future community-based trials of TBV for which this amendment is being submitted for approval.
- Conditions
- Malaria
- Keywords
- Assays, BLOOD SAMPLING, Parasites, Gametocyte, Infection, Natural History
- Medical subject headings
- Malaria, Infections
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 |
|---|---|---|
| 0.5 - 5 years | Age bracket for infants/children up to age five years | |
| 10 - 18 years | Age bracket for children 10 - 18 years | |
| 19 + years | Age bracket for adults over 19 years | |
| 5 - 10 years | Age bracket for children ages 5 - 10 years |
What is being measured
The primary outcome is the main question the study is designed to answer.
Measurement of Monthly rates of blood smear positive individuals by age
Rate of blood smear positive individuals
Measured: one year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Jan 2021
- Study start30 Sep 2021
- Primary completion28 Apr 2023
- Study completion28 Feb 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for MalariaStudies of the same condition, open and under way.
- More trials run by National Institute of Allergy and Infectious Diseases (NIAID)The sponsor's other registered studies.
- 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
- 396 participants (actual)
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Jennifer C Hume, Principal investigator, National Institute of Allergy and Infectious Diseases (NIAID)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04704674
- Sponsor's protocol ID
- 10000158
- Other IDs
- 000158-I
- Status last verified
- 6 Jan 2026
- First submitted
- 9 Jan 2021
- Last updated
- 16 Jan 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 16 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Community Dynamics of Malaria Transmission in Humans and Mosquitoes in Fleh-la and Marshansue, Salala District, Bong County, Liberia
- ClinicalTrials.gov ID
- NCT04704674
- Acronym / sponsor ID
- 10000158
- Conditions
- Malaria
- Keywords
- Assays, BLOOD SAMPLING, Parasites, Gametocyte, Infection, Natural History
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 396 participants (actual)
- Lead sponsor
- National Institute of Allergy and Infectious Diseases (NIAID)US National Institutes of Health
- Study start
- 30 Sep 2021 (actual)
- Primary completion
- 28 Apr 2023 (actual)
- Study completion
- 28 Feb 2026 (estimated)
- First posted
- 12 Jan 2021 (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.
Background:
Malaria is a disease that affects many people in Liberia. It is caused by germs (parasites) that are spread by mosquito bites. Researchers want to gather data that may help them understand the best way to use a malaria vaccine in Liberia, which will be important in getting rid of the disease.
Objective:
To find out how often people of all ages who live in Fleh-la and Marshansue, Liberia, get malaria.
Eligibility:
Healthy people ages 6 months and older who live in Fleh-la and Marshansue in a household with adults and children.
Design:
Participants will be screened with a physical exam and questions about their health.
Participants will have monthly study visits. They will be asked about any symptoms of malaria and their use of bednets. Their vital signs, such as blood pressure and temperature, will be checked. Blood will be taken from the participant s arm or finger with a needle. If they have a fever, they will get a malaria test. If positive, they will get drugs to treat malaria.
Once a month, participants houses will be examined for mosquitoes. The team will remove all mosquitoes they collect. As part of this collection, participants houses will be sprayed with a chemical to kill mosquitoes and other insects. Participants will not be allowed in their house while the team is inside. The spray will not harm the participants.
Once a year, at the monthly visit, an additional blood sample will be taken.
Some of the participants blood samples will be used for genetic testing.
Participation will last for up to 3 years.
Detailed description
A vaccine that interrupts malaria transmission is critical to eradicate the disease, but improved assays are needed to measure the efficacy of vaccines. Transmission-blocking vaccines (TBVs) work by inducing antibodies that inhibit parasite development in the mosquito interrupting transmission. Efficacy of vaccines may be estimated by in vitro membrane feeding assays using immune sera and laboratory mosquitoes, but qualified assays that measure transmission in the field are needed to assess transmission-blocking interventions in natura. Clinical trials of TBVs have started elsewhere on the continent in Mali, and we have planned to expand TBV studies here in Liberia soon. This protocol is already being used for a longitudinal cohort to gather information of malaria transmission based on the rates of blood smear positive individuals by month, season and year in Fleh-la and Marshansue, in Salala, Bong County, Liberia. Individuals in the villages were approached first for participation, including permission to contact their household and neighbors of their compound for participation. Households were identified using census data and individuals who consented for participation are being enrolled. Malaria smears are obtained at monthly visits, in conjunction with mosquito collections in/around village residences. Parasite infection rates in locally caught mosquitoes will be assessed longitudinally for differences by season and year. A total of 400 volunteers from Fleh-la and Marshansue will be enrolled. Participants will be followed for at least one year, to collect data that will guide the design of future community-based trials of TBV for which this amendment is being submitted for approval.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| 0.5 - 5 years | – | –Age bracket for infants/children up to age five years |
| 10 - 18 years | – | –Age bracket for children 10 - 18 years |
| 19 + years | – | –Age bracket for adults over 19 years |
| 5 - 10 years | – | –Age bracket for children ages 5 - 10 years |
Who may qualify
- Ages
- 6 months and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- An estimated total of 400 volunteers from Fleh-la and Marshansue and surrounding villages will be enrolled. Participants above the age of six months will be approached to participate in the study; and will be followed for up to 3 years.
Key inclusion criteria (10 listed)
- 6 months of age and above
- Known resident of Fleh-la and Marshansue or the surrounding villages and planning to remain for duration of study
- Willingness to allow stored laboratory specimens to be used for future research
- Acceptance and signature of the written informed consent and the assent for children aged 12-17 years who are not otherwise emancipated
- Household with at least 3 residents eligible for participation.
Key exclusion criteria (3 listed)
- Behavioral, cognitive, or psychiatric disease that in the opinion of the investigator affects the ability of the subject to understand and cooperate with the study protocol.
- Other condition that, in the opinion of the investigator, would jeopardize the safety or rights of a volunteer participating in the trial or would render the subject unable to comply with the protocol.
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
Measurement of Monthly rates of blood smear positive individuals by age
Time frame: one year
Rate of blood smear positive individuals
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Jan 2026.
- Individual participant dataSharing planned: No
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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.
Jennifer C Hume principal investigator
National Institute of Allergy and Infectious Diseases (NIAID)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Malaria, run by National Institute of Allergy and Infectious Diseases (NIAID) at 1 site in Liberia.
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 10 inclusion and 3 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: under way, not looking for participants, as of the sponsor's last update on 16 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Liberia. 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?
This study is still under way. Results are not available in the source record yet.
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?
Measurement of Monthly rates of blood smear positive individuals by age (time frame: one year). 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 16 Jan 2026.