Submicroscopic placental infection by non-falciparum Plasmodium spp

PLoS Negl Trop Dis. 2018 Feb 12;12(2):e0006279. doi: 10.1371/journal.pntd.0006279. eCollection 2018 Feb.

Abstract

Background: Among the Plasmodium species that infect humans, adverse effects of P. falciparum and P. vivax have been extensively studied and reported with respect to poor outcomes particularly in first time mothers and in pregnant women living in areas with unstable malaria transmission. Although, other non-falciparum malaria infections during pregnancy have sometimes been reported, little is known about the dynamics of these infections during pregnancy.

Methods and findings: Using a quantitative PCR approach, blood samples collected from Beninese pregnant women during the first antenatal visit (ANV) and at delivery including placental blood were screened for Plasmodium spp. Risk factors associated with Plasmodium spp. infection during pregnancy were assessed as well as the relationships with pregnancy outcomes. P. falciparum was the most prevalent Plasmodium species detected during pregnancy, irrespective either of parity, of age or of season during which the infection occurred. Although no P. vivax infections were detected in this cohort, P. malariae (9.2%) and P. ovale (5.8%) infections were observed in samples collected during the first ANV. These non-falciparum infections were also detected in maternal peripheral blood (1.3% for P. malariae and 1.2% for P. ovale) at delivery. Importantly, higher prevalence of P. malariae (5.5%) was observed in placental than peripheral blood while that of P. ovale was similar (1.8% in placental blood). Among the non-falciparum infected pregnant women with paired peripheral and placental samples, P. malariae infections in the placental blood was significantly higher than in the peripheral blood, suggesting a possible affinity of P. malariae for the placenta. However, no assoctiation of non-falciparum infections and the pregnancy outcomes was observed.

Conclusions: Overall this study provided insights into the molecular epidemiology of Plasmodium spp. infection during pregnancy, indicating placental infection by non-falciparum Plasmodium and the lack of association of these infections with adverse pregnancy outcomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benin / epidemiology
  • Blood / parasitology
  • Female
  • Humans
  • Malaria / epidemiology*
  • Molecular Epidemiology
  • Placenta / parasitology*
  • Placenta Diseases / epidemiology*
  • Plasmodium / classification
  • Plasmodium / genetics
  • Plasmodium / isolation & purification*
  • Pregnancy
  • Pregnancy Complications, Infectious / epidemiology*
  • Pregnancy Outcome
  • Real-Time Polymerase Chain Reaction
  • Risk Factors

Grants and funding

STOPPAM is collaborative project supported by the European 7th Framework Programme (contract no. 200889). JYAD is supported by the Division of Intramural Research, National Institute of Allergy and Infectious Diseases of the National Institutes of Health. RAA is supported by PhD studentship from WHO/TDR postgraduate program in Implementation Science. AMo was supported by PhD studentship from Islamic Development Bank. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.