Maternal Placental Infection with Plasmodium falciparum and Malaria Morbidity during the First 2 Years of Life

Abstract

In areas endemic for malaria, pregnant women frequently present with a placenta that has been parasitized by Plasmodium falciparum, an infection associated with a reduction in the birth weight of the offspring. However, the impact of placental infection on malaria-related morbidity during the infant's first years of life has not been investigated. Between 1993 and 1995, 197 children in southern Cameroon were followed weekly clinically and monthly parasitologically. The dates of first positive blood smear and the evolution of the parasite prevalence rates were compared between infants born to mothers presenting with (n = 42) and without (n = 155) P. falciparum infection of the placenta. Infants born to placenta-infected mothers were more likely to develop a malaria infection between 4 and 6 months of age; then the difference progressively disappeared. Similarly, parasite prevalence rates were higher in placenta-infected infants from 5 to 8 months of age. Thus, malarial infection of the placenta seems to result in a higher susceptibility of infants to the parasite. This was not related to maternally transmitted antibodies, as specific antibody levels were similar in both groups of infants. A better understanding of the involved mechanisms may have important implications for the development of malaria control strategies.

ASSOCIATION OF INTERFERON-γ RESPONSES TO PRE-ERYTHROCYTIC STAGE VACCINE CANDIDATE ANTIGENS OF PLASMODIUM FALCIPARUM IN YOUNG KENYAN CHILDREN WITH IMPROVED HEMOGLOBIN LEVELS: XV. ASEMBO BAY COHORT PROJECT

“…[34][35][36][37] Although this study was not able to identify the major factor that leads to the susceptibility to the first malaria infection, the relationship between longer time to the first malaria infection and subsequent lymphocyte proliferation we observed may reflect the overall good status of cellular immunity.…”

The effect of placental malaria infection on cord blood and maternal immunoregulatory responses at birth

“…The fact that no immunological effects were observed in acute PM suggests that a certain amount of PM exposure time is required for the immunological effects to occur, and demonstrates the value of analyzing by histological group. FOXP3 1 regulatory T-cell induction could explain why PM infected children are more susceptible to malaria infections in early life [4,5], since we have shown that those with higher ex vivo Treg levels are more susceptible to subsequent infections [42]. Indeed, a recent study shows that malaria exposure in utero can lead to immune tolerance induction in some newborns characterized by a decrease in the number of individuals mounting a pro-inflammatory response and increased numbers with malaria Ag driven IL-10 production [43].…”

“…PM leads to poor fetal outcomes, including premature delivery and low birth weight. Furthermore, infants born of malaria infected mothers/ placentas are more susceptible to malaria in the first few years of life than those whose mothers were not infected, through unknown mechanisms [4,5].…”

Cost-effectiveness of sulfadoxine-pyrimethamine for the prevention of malaria-associated low birth weight.

“…There have also been concerns about whether prevention of malaria in the mother will render the newborn and young infant more susceptible to malaria infection, though limited evidence to date argues against this. 49 Finally, we limited our analysis to women in their first and second pregnancies because malaria-associated LBW is primarily a problem of primigravidae and secundigravidae in areas of high malaria transmission. In addition, most of the available published data on the efficacy of SP in reducing rates of placental malaria in HIV-positive compared with HIV-negative women focuses on primigravidae and secundigravidae.…”