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

Sponsor
National Institute of Allergy and Infectious Diseases (NIAID) (NIH)
Overall Status
Completed
CT.gov ID
NCT03304704
Collaborator
(none)
1,928
1
29.4
65.5

Study Details

Study Description

Brief 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. Researchers want to learn more about the disease so they can develop new approaches to malaria control.

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.

Condition or Disease Intervention/Treatment Phase

    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.

    Study Design

    Study Type:
    Observational
    Actual Enrollment :
    1928 participants
    Observational Model:
    Cohort
    Time Perspective:
    Prospective
    Official Title:
    Community Dynamics of Malaria Transmission and Mosquito Feeding in Bancoumana and Doneguebougou, Mali
    Actual Study Start Date :
    Jan 28, 2018
    Actual Primary Completion Date :
    Jul 12, 2020
    Actual Study Completion Date :
    Jul 12, 2020

    Arms and Interventions

    Arm Intervention/Treatment
    DSF Cohort

    Accrual/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 Cohort

    Accrual/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 Cohort

    Accrual/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

    Outcome Measures

    Primary Outcome Measures

    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) [Up to 3 years]

      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)

    Eligibility Criteria

    Criteria

    Ages Eligible for Study:
    6 Months to 65 Years
    Sexes Eligible for Study:
    All
    Accepts Healthy Volunteers:
    No
    • INCLUSION CRITERIA:

    • 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

    • 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

    EXCLUSION CRITERIA:
    • 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

    • 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

    Contacts and Locations

    Locations

    Site City State Country Postal Code
    1 Univ of Sciences, Techniques and Technology Bamako Mali

    Sponsors and Collaborators

    • National Institute of Allergy and Infectious Diseases (NIAID)

    Investigators

    • Principal Investigator: Jennifer C Hume, National Institute of Allergy and Infectious Diseases (NIAID)

    Study Documents (Full-Text)

    None provided.

    More Information

    Publications

    Responsible Party:
    National Institute of Allergy and Infectious Diseases (NIAID)
    ClinicalTrials.gov Identifier:
    NCT03304704
    Other Study ID Numbers:
    • 999917180
    • 17-I-N180
    First Posted:
    Oct 9, 2017
    Last Update Posted:
    Aug 1, 2022
    Last Verified:
    Jun 13, 2022
    Studies a U.S. FDA-regulated Drug Product:
    No
    Studies a U.S. FDA-regulated Device Product:
    No
    Keywords provided by National Institute of Allergy and Infectious Diseases (NIAID)
    Additional relevant MeSH terms:

    Study Results

    No Results Posted as of Aug 1, 2022