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Malaria, FalciparumNCT01829737

Malaria Transmission Studies in Mali

An observational study of Malaria, Falciparum, run by National Institute of Allergy and Infectious Diseases (NIAID) at 1 site in United States.

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: Malaria is an illness caused by a parasite spread by mosquitoes. When a mosquito bites a person who is infected with a kind of parasite called a gametocyte, it is able to spread the infection to another person. Not everyone infected with parasites have gametocytes in their blood. Read more about this study

Who is it for?
Ages 6 months to 65 yearsHealthy volunteers can take part
Conditions the study is for
Malaria, Falciparum
How many people
534 participants
Where
1 siteUnited States
Study dates
20 Mar 2013to 20 Jan 2015
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
  • Healthy volunteers accepted
  • Child, Adult, Older adult

Who may be able to join

  • Age 6 months to 65 years, inclusive
  • Resident of Kenieroba with no plans to relocate away from Kenieroba for 1 year
  • Willingness to participate in the study as evidenced by informed consent (if <18 years, the informed consent of parent or guardian of the child, and assent from children 14 to 17 years old)
  • Age 18 to 65 years, inclusive
  • Hb level greater than or equal to 8.5 g/dL
  • Willingness to participate in the study as evidenced by informed consent
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  • Age 2 to 17 years, inclusive
  • Hb level greater than or equal to 8.5 g/dL
  • Previous enrollment in cohort study on protocol #08-I-N120
  • Uncomplicated malaria*
  • P. falciparum density greater than or equal to 10,000/microliters
  • Known hemoglobin type HbAA or HbAS
  • Not enrolled in this protocol s cohort study
  • Willingness to participate in the study as evidenced by informed consent and assent from children 14-17 years old)
  • Uncomplicated malaria: axillary temperature >37.5 degrees Celcius or history of fever in the past few days and no criteria of SM (see next paragraph) and no other etiologies of febrile illness (e.g., respiratory tract infection) on clinical examination.
  • Severe P. falciparum malaria: parasitemia of any density and any one of the following: coma
  • (Blantyre coma score less than or equal to 2), convulsions (witnessed by investigator), severe prostration, severe anemia (hemoglobin less than or equal to 6 g/dl), respiratory distress, hypoglycemia (serum glucose less than or equal to less than or equal to 40 mg/dl), jaundice/icterus, shock (systolic blood pressure less than or equal to 70 mmHg, rapid pulse, cool extremities), cessation of eating and drinking, repetitive vomiting.

Who cannot join

  • Any condition that in the opinion of the investigator would render the participant unable to comply with the protocol (e.g., psychiatric disease)
  • Any health condition that in the opinion of the investigator would confound data analysis or pose unnecessary exposure risks to study personnel (e.g., individuals who are known to be HIV-infected) or to the participant (e.g., severe malnutrition)
  • Pregnancy for venous blood collections (March 2013, October 2013, March 2014)
  • Pregnancy
  • Any condition that in the opinion of the investigator would render the participant unable to comply with the protocol (e.g., psychiatric disease)
  • Any health condition that in the opinion of the investigator would confound data analysis or pose unnecessary exposure risks to study personnel (e.g., individuals who are known to be HIV-infected) or to the participant (e.g., severe malnutrition)
Show all 9Show fewer
  • Pregnancy
  • Any condition that in the opinion of the investigator would render the participant unable to comply with the protocol (e.g., psychiatric disease)
  • Any health condition that in the opinion of the investigator would confound data analysis or pose unnecessary risks to study participants (e.g., severe malnutrition, acquired or inherited immunodeficiency)

Trial locations and contacts

1 site in 1 country.

United States1 site

  • National Institutes of Health Clinical Center, 9000 Rockville Pike

    Bethesda, Maryland, 20892

Other trials in United States

About this study

Official title: Epidemiologic Studies of Plasmodium Falciparum Gametocytemia and Transmission-blocking Immunity in Kenieroba, Mali

Background:

  • Malaria is an illness caused by a parasite spread by mosquitoes. When a mosquito bites a person who is infected with a kind of parasite called a gametocyte, it is able to spread the infection to another person. Not everyone infected with parasites have gametocytes in their blood. As a result, not everyone can spread malaria to others. Researchers are interested in learning more about why some healthy people have gametocytes in their blood and others do not. Identifying the people who have gametocytes in their blood can help target treatment and reduce the spread of malaria. This study will focus on the people of the village of Kenieroba in Mali, where malaria is common.
Read more

Objectives:

  • To study the relationship between gametocytes and malaria transmission in Mali.

Eligibility:

  • Individuals between 6 months and 65 years of age who live in Kenieroba, Mali, and will stay in the area for 1 year.

Design:

  • For 1 year, participants will have study visits once every 2 weeks (twice a month, for a total of 24 visits). The visits will last 30 minutes each.
  • At each visit, participants will provide a small blood sample. They will report any symptoms of malaria such as fever, headache, and body aches. Participants will be encouraged to seek medical treatment if they experience malaria symptoms between visits.
  • Participants who have malaria symptoms will have a blood test for malaria parasites. Those who have parasites in the blood will receive antimalarial treatment.
  • Three times over 1 year, a larger blood sample will be collected. These blood samples will be taken once in the dry season, once in the wet season, and once in the next dry season.
  • Women between 14 and 45 years of age will also provide urine samples to test for pregnancy. Pregnant women will not be asked to give blood samples.
Read the detailed description

Plasmodium falciparum malaria continues to evade control efforts in part through the complexity of its life cycle, which involves both humans and mosquitoes. While it is known that the gametocyte form of the parasite transmits disease, it is unclear which individuals constitute the primary gametocyte reservoir in a given human population. It is also unclear how an individual s asexual parasite density, acquired immune responses, and red blood cell (RBC) polymorphisms affect the presence and transmission of gametocytes. Investigating these effects has been limited in part because gametocytes are often present in peripheral blood at densities below the limit of microscopic detection. Recent technical advances in the molecular detection of gametocytes have set the stage for a better understanding of gametocyte epidemiology and biology in humans. In a setting of highly seasonal transmission, we are conducting an epidemiological study to estimate gametocyte prevalence over 1 year in the village of Kenieroba, Mali. In a cohort of 500 individuals that represents the age-distribution of the entire village population, we will explore how age, asexual parasite prevalence, season, and RBC polymorphisms affect variation in gametocyte prevalence (detected by a sensitive molecular method). From these same individuals, we will purify plasma IgG and compare its transmission-blocking activity by age group and season. These assessments will provide a foundation for future studies of gametocytemia dynamics within individuals as well as the impact of host immunity on gametocyte infectivity in our study population. Such information will enable us to identify those individuals that are primarily responsible for malaria transmission in Kenieroba. Incorporation of such findings into new or existing computer-based models of parasite infection and transmission may improve our evaluation of existing malaria control strategies.

Keywords
Asymptomatic Parasitemia, RBC Polymorphism, Acquired Immunity
Medical subject headings
Malaria, Falciparum

What is being measured

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

  1. Determine gametocytemia prevalence at each time point relative to age group, asexual parasitemia prevalence, season, and red blood cell polymorphisms, for all cohort enrollees residing in Kenieroba and not treated for malaria during the previous...

    Measured: 1 year

Timeline

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

  1. First posted11 Apr 2013 (estimated)
  2. Study start20 Mar 2013
  3. Primary completion20 Jan 2015
  4. Study completion20 Jan 2015

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Time perspective
Prospective
Enrolment
534 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01829737
Sponsor's protocol ID
999913107
Other IDs
13-I-N107
Status last verified
20 Jan 2015
First submitted
9 Apr 2013
Last updated
2 Aug 2018
Results posted
No

Publications

  • Baker DA. Malaria gametocytogenesis. Mol Biochem Parasitol. 2010 Aug;172(2):57-65. doi: 10.1016/j.molbiopara.2010.03.019. Epub 2010 Apr 8.

    PubMed 20381542

  • Sachs J, Malaney P. The economic and social burden of malaria. Nature. 2002 Feb 7;415(6872):680-5. doi: 10.1038/415680a.

    PubMed 11832956

  • Marsh K. Research priorities for malaria elimination. Lancet. 2010 Nov 13;376(9753):1626-7. doi: 10.1016/S0140-6736(10)61499-7. Epub 2010 Oct 28. No abstract available.

    PubMed 21035843

  • Willcox AC, Huber AS, Diouf A, Barrett JR, Silk SE, Pulido D, King LDW, Alanine DGW, Minassian AM, Diakite M, Draper SJ, Long CA, Miura K. Antibodies from malaria-exposed Malians generally interact additively or synergistically with human vaccine-induced RH5 antibodies. Cell Rep Med. 2021 Jun 21;2(7):100326. doi: 10.1016/j.xcrm.2021.100326. eCollection 2021 Jul 20.

    PubMed 34337556

Questions about this trial

What is this clinical trial studying?

An observational study of Malaria, Falciparum, run by National Institute of Allergy and Infectious Diseases (NIAID) at 1 site in United States.

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 9 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 2 Aug 2018. 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 United States. 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?

Determine gametocytemia prevalence at each time point relative to age group, asexual parasitemia prevalence, season, and red blood cell polymorphisms, for all cohort enrollees residing in Kenieroba and not treated for malaria during the previous... (time frame: 1 year). 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 NCT01829737, which also lists 4 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 2 Aug 2018.

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