Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05650502 |
| Other study ID # |
University of Parakou |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
June 1, 2021 |
| Est. completion date |
May 30, 2022 |
Study information
| Verified date |
December 2022 |
| Source |
Université de Parakou |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational [Patient Registry]
|
Clinical Trial Summary
This study aims to evaluate the effects of SMC (Seasonal malaria chemoprevention) with
Sulfadoxine-Pyrimethamine (SP) and Amodiaquine (AQ) on the evolution of anti-malarial
immunity of children and their susceptibility to malarial infection.
This is a cross-sectional study on children aged 6 to 59 months with/without SMC in two
villages in northern Benin. Sociodemographic and clinical data as well as repeated blood
samples will be collected from 440 children (before, during and after treatment). Samples
will be analyzed using a Luminex assay to investigate antibody responses to MSP (merozoite
surface protein) , Glurp (Glutamate-Rich Protein) and a panel of PfEMP1. qPCR (quantitative
polymerase chain reaction) will be used to detect the prevalence of malaria at this period
and parasites infecting children will be characterize during the follow up.
Description:
Study location and population The study was conducted in parallel in two different sites, the
health districts of Cobly and Tchaourou (two villages) located in northern Benin. These two
districts have been chosen based on the Ministry of Health's programming for the
implementation of SMC. The two sites were very similar in terms of malaria transmission
characteristics and epidemiology, with the difference that SMC was implemented in Cobly but
not in Tchaourou. Participants will be informed on the importance of SMC. A written informed
consent was collected from parent or guardian of each child. Participation was entirely
voluntary.
Study Design and procedures This is a case control study focuses on the follow-up over 12
months of children aged 6 to 59 months in northern Benin. The study was conducted in
collaboration with National Malaria Control Program (NMCP). Demographic data generated by the
NMCP had allow us for a random selection of children from random households. In both
intervention and control sites, equal numbers of children were included. The study team
visited each selected household to inform members. A monthly visit has been set up for
monitoring. Children of consenting parents or guardians were recruited and parents/guardians
were taken through a questionnaire administered by the researcher or an assistant
(clinician). 1 ml of peripheral venous blood was collected into collection tubes and
transferred to the Center for Expertise and Enhancing Research in Epidemiology and Public
Health (CEEREPH) at the University of Parakou where a blood smear was prepared from each
sample. Fifty microliters of blood have been transferred to Whatman 3MM filter paper and
stored at room temperature for DNA extraction. The remaining whole blood have been
centrifuged. The plasma and red blood cells were aliquoted. Samples was collected at 4 times
during the 12 months follow-up period. The first samples were collected at the beginning of
SMC implimentation (before children receive the first SMC dose), the second blood sample were
collected at the day of the third dose of SMC, the third, at three month after the last dose
of SMC and the fourth, six months after the last dose of SMC).
Malaria prevalence Thick and thin blood smears whave been prepared from all samples at all
four times. Thick smears will be fixed in methanol. All slides were air dried and stained
using Giemsa stain 3% for 45-60 min. Once dry, the stained thick and thin blood films were
examined microscopically using a routine procedure. Parasite densities was recorded as the
number of parasites/μl of blood assuming an average leukocyte count of 8,000/μl of blood.
Dried blood spots were air dried and stored individually in small Ziploc bags with a
desiccant. Plasmodium spp detection was performed using a real time polymerase chain reaction
(qPCR).
Anti-PfEMP1 antibody response Plasmodium falciparum-encoded variant surface antigens (VSA)
are expressed on the surface of infected erythrocytes (IE) and mediate binding to a range of
endothelial cell receptors. The best characterized VSA are the var gene-encoded P. falciparum
erythrocyte membrane protein 1 (PfEMP1) family in two exon units. Exon I codes for the
extracellular and variable part of the protein as well as a transmembrane region and Exon II
encodes the intracellular and relatively conserved acidic terminal segment (ATS). The most
variable part of the protein contains a N-terminal segment followed by segments composed of
three domain types; Duffy binding-like domains (DBL-domains): Cysteine-rich inter-domain
regions (CIDRs) and C2. In this study, a panel of plasma antibody was quantified using
microsphere bead-coupled proteins comprising 28 P. falciparum-derived antigens and tetanus
toxoid, using the Luminex platform. The panel includes VAR2CSA (the VSA associated to
placental malaria) and 25 HIS-tagged CIDR proteins representing all three main groups of
PfEMP1, merozoite surface protein 1 (MSP1) and apical membrane antigen 1 (AMA1).
