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Transmission Dynamics of Residual and Re-emerging Malaria in the Amazon: Defining a Roadmap to Malaria Elimination

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT03689036
Recruitment Status : Active, not recruiting
First Posted : September 28, 2018
Last Update Posted : May 12, 2022
Sponsor:
Collaborator:
University of Sao Paulo
Information provided by (Responsible Party):
Simone Ladeia, Oswaldo Cruz Foundation

Brief Summary:

A population baseline longitudinal study in a major residual malaria hotspot in Brazil to: 1. identify risk factors for residual malaria infection and disease at individual and household level, 2. identify and quantify population changes in P. vivax and P. falciparum to detect reintroductions and to estimate parasite population complexity at baseline and after interventions and 3. describe changing dynamics of malaria incidence and parasitemia prevalence over time, and to assess potential effects of combinations of interventions on malaria control and elimination using mathematical models.

The study will be developed in Mâncio Lima, a residual malaria hotspot in northwestern Brazil. The population of study is approximately 2,000 subjects aged 3 months and up, who correspond to all the residents of 20% of the households of the urban area of Mâncio Lima.

Will be made Active (ACD) and Passive Case Detection (PCD) every 6 months, over 5 years. (symptom based surveying; microscopy-based diagnosis).

Each visit will include interview, physical examination and collection of 100 μL of blood (finger prick) to malaria diagnosis by smear, RDT and qPCR. If the subject will be positive by smear or RDT (rapid diagnostic test for malaria), despite of presence of symptoms, ≥ 20 mL of venous blood will be draw of them to immunology and parasite genetics study and the immediate treatment per MOH(Ministry of Health) guidelines will be performed.

Subjects with smear or RDT negative, will be followed for symptoms over the next 6 months. If it is subsequently found to be smear/RDT-positive by PCD, the treatment will be performed.

Clinical and epidemiological characteristics of malaria, genetic characteristics of the population of Plasmodium and changing dynamics of malaria transmission will be analyzed.


Condition or disease
Malaria

Detailed Description:

Cross-sectional surveys will be carried out in order to identify risk factors for residual malaria infection and disease at both the individual and household level, to supply parasite samples for detailed population-level molecular analyses and to supply epidemiological data for parameterization of new mathematical models of malaria transmission.

SPECIFIC AIMS:

  • Aim 1: Longitudinally determine malaria dynamics in a major residual malaria hotspot in Brazil.
  • Aim 2: Identify and quantify population changes in P. vivax and P. falciparum to detect reintroductions, and to estimate parasite population complexity at baseline and potentially after interventions.
  • Aim 3: Develop and apply mathematical models to describe changing dynamics of malaria incidence and parasitemia prevalence over time, and to assess potential effects of combinations of interventions on malaria control and elimination.

    • The study will be developed in the urban area of Mâncio Lima, northwestern of Brazil.

A census performed by our field team between Nov 2015 and Apr 2016 identified ~ 10,000 inhabitants in the urban area of Mâncio Lima. At the site preparation phase, a random sample of 20% of the households enumerated during our census will be visited by our field teams and all dwellers aged 3 months or up (or their parents/guardians) will be invited to participate in the cohort study.

We expect to enroll ~ 2,000 subjects who will participate in 10 cross-sectional surveys (every six months) over five years (total of 20,000 observations), and contribute 120,000 person-months of follow-up. Because of the open-cohort design of this study, subjects who are lost for follow-up are replaced with newcomers, without affecting significantly the number of person-months of follow-up.

At each visit, the subjects will be interviewed and 100ul of blood will be collected to Active (ACD) and Passive Case Detection (PCD) (symptom based surveying; microscopy-based diagnosis). Each visit will include an interview, physical examination and collection of 100 μL of blood (finger prick) to malaria diagnosis by smear, RDT and qPCR.

When the subjects are positive by smear or RDT (rapid diagnostic test for malaria), despite of presence of symptoms, ≥ 20 mL of venous blood will be draw of them to immunology and parasite genetics study and the immediate treatment per Ministry of Health of Brazil guidelines will be performed.

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Study Type : Observational
Estimated Enrollment : 2000 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Transmission Dynamics of Residual and Re-emerging Malaria in the Amazon: Defining a Roadmap to Malaria Elimination_Part A: Acre, Brazil
Actual Study Start Date : April 2, 2018
Estimated Primary Completion Date : October 31, 2023
Estimated Study Completion Date : July 31, 2024

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Malaria




Primary Outcome Measures :
  1. Risk factors for residual malaria infection and disease [ Time Frame: 2023 ]
    Determining sociodemographic variables that are significantly associated with malaria infection (regardless of symptoms) and clinical illness by multilevel multiple regression analysis


Secondary Outcome Measures :
  1. Genetic characterization of locally circulating malaria parasites over space and time [ Time Frame: 2023 ]
    Determination of multilocus genotypes (using microsatellite markers) and complete genomes of Plasmodium vivax and Plasmodium falciparum isolates obtained from georeferenced households over the study period (5 years).

  2. Estimating the impact of interventions to control and eliminate malaria. [ Time Frame: 2023 ]
    Development and parametrization of mathematical models that incorporate risk heterogeneity in hosts to recapitulate major features of malaria transmission in the study site and estimate the impact of control measures (e.g., insecticide-treated bednet distribution, larviciding or improved antirelapse therapy for vivax malaria).


Biospecimen Retention:   Samples With DNA
Plasmodium vivax and Plasmodium falciparum


Information from the National Library of Medicine

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Ages Eligible for Study:   3 Months and older   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
A census performed by our field team between Nov 2015 and Apr 2016 identified ~ 10,000 inhabitants in the urban area of Mâncio Lima. At the site preparation phase, a random sample of 20% of the households enumerated during our census will be visited by our field teams and all dwellers aged 3 months or up (or their parents/guardians) will be invited to participate in the cohort study. We expect to enroll ~ 2,000 subjects who will participate in 10 cross-sectional surveys over five years (total of 20,000 observations), and contribute 120,000 person-months of follow-up. Because of the open-cohort design of this study, subjects who are lost for follow-up are replaced with newcomers, without affecting significantly the number of person-months of follow-up.
Criteria

INCLUSION CRITERIA:

  • Any subject aged 3 or more months old living in the study sites and providing written informed consent, or with parental written informed consent and assent when age-appropriate;
  • Plans to remain in the study site for the next five years.

Adults and children will both contribute to the data and study goals. Adults and children will both contribute to the data and study goals. Children less than three months of age will be excluded from the study because the heel or finger prick procedures to draw blood may be perceived by the parents as inappropriate for this age group. Children aged three months or more are eligible as long as they are members of the randomly chosen households and their parents/guardians provide informed consent. Inclusion of children is essential for the study goals, since different age groups may differ in acquired immunity and therefore in the risk of having symptoms when carrying malaria parasites

EXCLUSION CRITERIA:

  • any chronic or acute condition that, in the opinion of the field clinician or nurse, may affect the results of the study or the ability of providing informed consent.
  • Less then 3 months old
  • Do not have permanent residence in the study area

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03689036


Locations
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Brazil
Marcelo Urbano Ferreira
São Paulo, Brazil, 05508900
Sponsors and Collaborators
Oswaldo Cruz Foundation
University of Sao Paulo
Investigators
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Study Director: Marcelo U Ferreira, PhD MD University of Sao Paulo
Study Chair: simone l andrade, Phd MD Oswaldo Cruz Foundation
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: Simone Ladeia, Investigator, Oswaldo Cruz Foundation
ClinicalTrials.gov Identifier: NCT03689036    
Other Study ID Numbers: DMID 17-0037-A
First Posted: September 28, 2018    Key Record Dates
Last Update Posted: May 12, 2022
Last Verified: May 2022
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Simone Ladeia, Oswaldo Cruz Foundation:
malaria
transmission
Asymptomatic infeccion
malaria elimination
residual malaria
Amazon
Additional relevant MeSH terms:
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Malaria
Protozoan Infections
Parasitic Diseases
Infections
Vector Borne Diseases