6 research outputs found
Transplacental Transmission of Plasmodium falciparum in a Highly Malaria Endemic Area of Burkina Faso
Malaria congenital infection constitutes a major risk in malaria endemic areas. In this study, we report the prevalence of transplacental malaria in Burkina Faso. In labour and delivery units, thick and thin blood films were made from maternal, placental, and umbilical cord blood to determine malaria infection. A total of 1,309 mother/baby pairs were recruited. Eighteen cord blood samples (1.4%) contained malaria parasites (Plasmodium falciparum). Out of the 369 (28.2%) women with peripheral positive parasitemia, 211 (57.2%) had placental malaria and 14 (3.8%) had malaria parasites in their umbilical cord blood. The umbilical cord parasitemia levels were statistically associated with the presence of maternal peripheral parasitemia (OR = 9.24, P âȘ 0.001), placental parasitemia (OR = 10.74, P âȘ 0.001), high-density peripheral parasitemia (OR = 9.62, P âȘ 0.001), and high-density placental parasitemia (OR = 4.91, P = 0.03). In Burkina Faso, the mother-to-child transmission rate of malaria appears to be low
Transplacental Transmission of Plasmodium falciparum in a Highly Malaria Endemic Area of Burkina Faso
Malaria congenital infection constitutes a major risk in malaria endemic areas. In this study, we report the prevalence of transplacental malaria in Burkina Faso. In labour and delivery units, thick and thin blood films were made from maternal, placental, and umbilical cord blood to determine malaria infection. A total of 1,309 mother/baby pairs were recruited. Eighteen cord blood samples (1.4%) contained malaria parasites (Plasmodium falciparum). Out of the 369 (28.2%) women with peripheral positive parasitemia, 211 (57.2%) had placental malaria and 14 (3.8%) had malaria parasites in their umbilical cord blood. The umbilical cord parasitemia levels were statistically associated with the presence of maternal peripheral parasitemia (OR = 9.24, P 0.001), placental parasitemia (OR = 10.74, P 0.001), high-density peripheral parasitemia (OR = 9.62, P 0.001), and high-density placental parasitemia (OR = 4.91, P = 0.03). In Burkina Faso, the mother-to-child transmission rate of malaria appears to be low
African-specific polymorphisms in Plasmodium falciparum serine repeat antigen 5 in Uganda and Burkina Faso clinical samples do not interfere with antibody response to BK-SE36 vaccination
Arisue N., Palacpac N.M.Q., Ntege E.H., et al. African-specific polymorphisms in Plasmodium falciparum serine repeat antigen 5 in Uganda and Burkina Faso clinical samples do not interfere with antibody response to BK-SE36 vaccination. Frontiers in Cellular and Infection Microbiology 12, 1058081 (2022); https://doi.org/10.3389/fcimb.2022.1058081.BK-SE36, based on Plasmodium falciparum serine repeat antigen 5 (SERA5), is a blood-stage malaria vaccine candidate currently being evaluated in clinical trials. Phase 1 trials in Uganda and Burkina Faso have demonstrated promising safety and immunogenicity profiles. However, the genetic diversity of sera5 in Africa and the role of allele/variant-specific immunity remain a major concern. Here, sequence analyses were done on 226 strains collected from the two clinical trial/follow-up studies and 88 strains from two cross-sectional studies in Africa. Compared to other highly polymorphic vaccine candidate antigens, polymorphisms in sera5 were largely confined to the repeat regions of the gene. Results also confirmed a SERA5 consensus sequence with African-specific polymorphisms. Mismatches with the vaccine-type SE36 (BK-SE36) in the octamer repeat, serine repeat, and flanking regions, and single-nucleotide polymorphisms in non-repeat regions could compromise vaccine response and efficacy. However, the haplotype diversity of SERA5 was similar between vaccinated and control participants. There was no marked bias or difference in the patterns of distribution of the SE36 haplotype and no statistically significant genetic differentiation among parasites infecting BK-SE36 vaccinees and controls. Results indicate that BK-SE36 does not elicit an allele-specific immune response
Inherited Disorders of Hemoglobin and <em>Plasmodium falciparum</em> Malaria
An estimated 300,000 babies are born each year with severe Inherited Disorders of Hemoglobin (IDH). Despite major advances in the understanding of the molecular pathology, control, and management of the IDH thousands of infants and children with these diseases are dying due to the accessibility to appropriate medical care. In addition, as malaria has been the principal cause of early mortality in several parts of the world for much of the last 5000Â years, as a result, it is the strongest force for selective pressure on the human genome. That is why, in the world, there is an overlap of malaria endemicity and IDH. Over the past twenty years several studies have shown that IDH such us hemoglobin and/or red cell membrane abnormalities confer resistance to malaria reducing hence the mortality during the first years of life. This has led to the selection of populations with IDH in malaria-endemic areas. This may explain the overlap between these two pathologies. This chapter aims to present the relationship between IDH and malaria susceptibility, make an overview of the current state of knowledge and the burden of IDH, and highlight steps that require to be taken urgently to improve the situation
The ABO Blood Group System and <em>Plasmodium falciparum</em> (<em>Pfâ</em>) Infection in Three Ethnic Groups Living in the Stable and Seasonal Malaria Transmission Areas of Burkina Faso (BF)
Genetic factors, including red blood cell polymorphisms, influence the severity of disease due to infection with Plasmodium falciparum (Pf). Studies show that these genetic factors associated with malaria susceptibility or resistance vary geographically, ethnically, and racially. We performed cross-sectional surveys in population living in rural villages from three ethnic groups. The blood group (BG) was determined genetically using two polymorphisms (rs8176719 and rs8176746). Out of 548 participants, 29.7% were Mossi, 38.2% were Fulani, and 32.1% were Rimaibe. The distribution of BG was, respectively, A: 25.5%, B: 26.6%, AB: 7.3%, and O: 40.5%. BG O was not only the common blood type overall, but was higher in Fulani (52.6%) than others. Fulani was associated with a reduced risk of infection and lower parasite densities than sympatric populations. The subjects with non-O blood were less susceptible to malaria infection. An association between ethnicity and malaria infection during the high transmission season as well as an association between the non-O blood group and malaria infections according to ethnicity was found. This was also true when ethnic groups were considered separately. Our results have demonstrated that the Fulani are not only less susceptible to Pf malaria infection, but when infected have lower parasite densities. Individuals with non-O blood are at lower risk of infection
Persistence of Anti-SE36 Antibodies Induced by the Malaria Vaccine Candidate BK-SE36/CpG in 5â10-Year-Old Burkinabe Children Naturally Exposed to Malaria
Information on the dynamics and decline/persistence of antibody titres is important in vaccine development. A recent vaccine trial in malaria-exposed, healthy African adults and children living in a malaria hyperendemic and seasonal area (Ouagadougou, Burkina Faso) was the first study in which BK-SE36/CpG was administered to different age groups. In 5- to 10-year-old children, the risk of malaria infection was markedly lower in the BK-SE36/CpG arm compared to the control arm. We report here data on antibody titres measured in this age-group after the high malaria transmission season of 2021 (three years after the first vaccine dose was administered). At Year 3, 83% of children had detectable anti-SE36 total IgG antibodies. Geometric mean antibody titres and the proportion of children with detectable anti-SE36 antibodies were markedly higher in the BK-SE36/CpG arm than the control (rabies) arm. The information obtained in this study will guide investigators on future vaccine/booster schedules for this promising blood-stage malaria vaccine candidate