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MalariaNCT03304704

Community Dynamics of Malaria Transmission and Mosquito Feeding in Bancoumana, Mali

An observational study of Malaria, run by National Institute of Allergy and Infectious Diseases (NIAID) at 3 sites in Mali.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Background: Half of the world's population is at risk of malaria. Malaria is a disease that affects many people in Mali and other parts of Africa. It is caused by germs spread by mosquito bites. Malaria may be mild. But it can also be serious or can lead to death if it is not diagnosed and treated promptly. Read more about this study

Who is it for?
Ages 6 months to 65 years
Conditions the study is for
Malaria
How many people
1,928 participants
Where
3 sitesMali
Study dates
28 Jan 2018to 12 Jul 2020
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 6 months to 65 years
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Study population: Known resident of Bancoumana, Doneguebougou or the surrounding villages; and Willingness to allow stored laboratory specimens to be used for future research@@@@@@

Who may be able to join

  • GENOTYPE ONLY COHORT
  • Any age
  • Known resident of Bancoumana or the surrounding villages
  • Acceptance and signature of the written informed consent and the assent for children aged 12-17 years
  • Willingness to allow stored laboratory specimens to be used for future research
  • PARASITE SURVEILLANCE COHORT
Show all 17Show fewer
  • 6 months to 65 years of age
  • Known resident of Bancoumana or the surrounding villages
  • 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
  • DSF COHORT
  • Aged between 5 and 65 years, inclusive
  • Good general health as determined by review of medical history and/or clinical testing at the time of screening
  • Known resident of Bancoumana or the surrounding villages
  • Willingness to allow stored laboratory specimens to be used for future research
  • Willingness to undergo DSF
  • Acceptance and signature of the written informed consent and the assent for children aged 12-17 years

Who cannot join

  • GENOTYPE ONLY COHORT
  • 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
  • PARASITE SURVEILLANCE CHORT
  • 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
Show all 12Show fewer
  • Currently enrolled participant in protocol 17-I-N006 or another active LMIV/MRTC vaccine clinical trial
  • DSF COHORT
  • 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
  • Currently enrolled participant in protocol 17-I-N006 or another LMIV/MRTC vaccine clinical trial
  • History of severe reaction to mosquito bites

Trial locations and contacts

3 sites in 1 country.

Mali3 sites
  • Bancoumana Malaria Vaccine Center

    Bamako

  • Univ of Sciences, Techniques and Technology

    Bamako

  • Doneguebougou Facility

    Donéguébougou

Other trials in Mali

About this study

Official title: Community Dynamics of Malaria Transmission and Mosquito Feeding in Bancoumana and Doneguebougou, Mali

Background:

Half of the world's population is at risk of malaria. Malaria is a disease that affects many people in Mali and other parts of Africa. It is caused by germs spread by mosquito bites. Malaria may be mild. But it can also be serious or can lead to death if it is not diagnosed and treated promptly. Researchers want to learn more about the disease so they can develop new approaches to malaria control.

Read more

Objective:

To collect data on how mosquitoes spread malaria and how many people get malaria in the community by comparing different areas, seasons, and years.

Eligibility:

Residents of a certain area of Mali who are of any age

Design:

Participants will be screened with a physical exam and medical history.

All participants will have at least 1 visit. They will answer questions about their health and malaria. They may have a physical exam. They will have blood collected.

Some participants will have 1 visit every month for 3 years. They will repeat the procedures above.

These participants will have mosquitoes collected in their home monthly. They may be able to catch some of the mosquitoes alive or may need to use a spray to kill the mosquitoes. Participants in this part of the study can be up to 65 years old.

Some participants will also have about 60 mosquitoes directly feed on their arm or leg for 15-20 minutes each month. These participants must be 5-65 years old.

...

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 in vaccinees 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 TBV have started in Bancoumana and Doneguebougou, and we expect to expand TBV studies here and in adjacent areas in the future. This protocol will use a longitudinal cohort to gather information on mosquito feeding and infection patterns in Bancoumana, Doneguebougou and surrounding villages in Mali. Individuals actively participating in LMIV vaccine trials will be approached first for participation, including permission to contact their household and neighbors of their compound for participation. Households will be identified using census data and individuals will be consented for participation. Malaria smears will be obtained at monthly visits, in conjunction with mosquito collections in/around village residences and with direct skin feeds (DSFs) using insectary-raised mosquitoes. Parasite transmission to mosquitoes will be assessed longitudinally for differences by season and year, and compared between wild-caught and laboratory-raised mosquitoes. Data will also be obtained on gametocyte and parasite carriage rates by season and year. Genotyping of individual subjects will be performed to pair with the bloodmeals of wild-caught mosquitoes.

A total of 3,200 volunteers from Bancoumana, Doneguebougou and surrounding areas will be enrolled into three distinct cohorts. The Genotype Only Cohort (n=1000), which will include the vaccine trial participants, will complete a single visit to obtain a blood sample for genotyping with no additional follow up. The DSF Cohort (n=1200) will enroll subjects aged 5 to 65 years for monthly blood sampling, DSF, and mosquito collection at their household. The Parasite Surveillance Cohort (n=1000) will enroll subjects under the age of 5 years (as young as 6 months) and subjects of any age who are unwilling to participate in DSF; they will have monthly blood sampling and mosquito collection at their household. Enrollment into the Genotype and Parasite Surveillance Cohorts will be linked to full enrollment of the DSF Cohort. Participants in the Parasite Surveillance and DSF cohorts, will be followed for up to 3 years, to collect data that will guide the design of future community-based trials of TBV.

Conditions
Malaria
Keywords
Assays, Direct Skin Feeds, Infection, Parasite, Gametocyte, 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 groups in NCT03304704
Study groupRoleWhat they receive
DSF CohortAccrual/Screening up to 1800 will include volunteers between the ages of 5 and 17 years and will be enrolled for genotyping and monthly blood sampling
Genotype CohortAccrual/Screening up to 1500 will complete a single visit with blood draw for genotyping for future fidelity assessments with blood-fed, spray wild-caught mosquitoes.
Parasite Surveillance CohortAccrual/Screening up to 1500 will be enrolled for genotyping and a minimum of six monthly blood sampling and mosquito wild catches wild-caught mosquitoes within their compound

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Measurement of estimated rates of Infection rate in mosquitoes by DSF measured as the rate (per blood-fed mosquito) of malaria transmission (human to mosquito)

    Infection rate in mosquitoes by DSF measured as the rate (per blood-fed mosquito) of malaria transmission (human to mosquito; and Infection rate in live wild-caught mosquitoes measured as the rate (per blood-fed mosquito) of malaria transmission (human to mosquito)

    Measured: Up to 3 years

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted9 Oct 2017
  2. Study start28 Jan 2018
  3. Primary completion12 Jul 2020
  4. Study completion12 Jul 2020

Resources

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
1,928 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03304704
Sponsor's protocol ID
999917180
Other IDs
17-I-N180
Status last verified
Feb 2025
First submitted
6 Oct 2017
Last updated
10 Feb 2025
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • Toure YT, Doumbo O, Toure A, Bagayoko M, Diallo M, Dolo A, Vernick KD, Keister DB, Muratova O, Kaslow DC. Gametocyte infectivity by direct mosquito feeds in an area of seasonal malaria transmission: implications for Bancoumana, Mali as a transmission-blocking vaccine site. Am J Trop Med Hyg. 1998 Sep;59(3):481-6. doi: 10.4269/ajtmh.1998.59.481.

    PubMed 9749648
  • Diallo M, Toure AM, Traore SF, Niare O, Kassambara L, Konare A, Coulibaly M, Bagayogo M, Beier JC, Sakai RK, Toure YT, Doumbo OK. Evaluation and optimization of membrane feeding compared to direct feeding as an assay for infectivity. Malar J. 2008 Dec 2;7:248. doi: 10.1186/1475-2875-7-248.

    PubMed 19055715
  • Drakeley C, Sutherland C, Bousema JT, Sauerwein RW, Targett GA. The epidemiology of Plasmodium falciparum gametocytes: weapons of mass dispersion. Trends Parasitol. 2006 Sep;22(9):424-30. doi: 10.1016/j.pt.2006.07.001. Epub 2006 Jul 17.

    PubMed 16846756

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 3 sites in Mali.

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 17 inclusion and 12 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 10 Feb 2025. 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 Mali. 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?

Measurement of estimated rates of Infection rate in mosquitoes by DSF measured as the rate (per blood-fed mosquito) of malaria transmission (human to mosquito) (time frame: Up to 3 years). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03304704, which also lists 3 linked publications.

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 10 Feb 2025.

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