Submicroscopic placental infection by non-falciparum Plasmodium spp.

Abstract

BackgroundAmong 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 findingsUsing 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 observedConclusionsOverall 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.

False-negative malaria rapid diagnostic test results and their impact on community-based malaria surveys in sub-Saharan Africa

“…RDT LODs widely vary, sometimes even within the same country as has been observed in Angola 6. Second, non- P. falciparum malaria is not detected by commonly used PfHRP2-based RDTs 7. Third, improper RDT storage, including prolonged exposure to hot or humid conditions, can impair RDT performance 8.…”

Selective whole genome amplification of Plasmodium malariae DNA from clinical samples reveals insights into population structure

“…Molecular surveillance has demonstrated that non-falciparum malaria has been underestimated by microscopy diagnosis [2][3][4][5] , and rapid diagnostic tests (RDT), which are unable to diagnose non-falciparum malaria to the species level 6,7 . Molecular studies are beginning to demonstrate alarmingly high levels (4-24%) of P. malariae mono-and co-infections across continents 2,[8][9][10][11][12] . P. malariae infections commonly present with mild or no symptoms, however, severe disease, including anaemia, renal pathologies, and splenomegaly [13][14][15][16][17] can occur, complications which can prove fatal 16 .…”

A Molecular Investigation of Malaria Infections From High-Transmission Areas of Southern Togo Reveals Different Species of Plasmodium Parasites

“…Among the five known species of Plasmodium that infect humans, Pf infection (and to a lesser extent Po and Pm) is the essential cause of malaria burden in tropical Africa ( World Health Organization [WHO], 2018b ). In West Africa, both Po and Pm malaria cases have been identified in Benin, Ghana, and Senegal ( Browne et al, 2000 ; Roucher et al, 2014 ; Trape et al, 2014 ; Doritchamou et al, 2018 ), as well as Po in Cote d’Ivoire and Comoros Islands ( Bauffe et al, 2012 ), to mention a few. However, there have been no information publicly reported yet on Po and Pm from Togo.…”