BackgroundMalaria infection during pregnancy can result in placental malaria and is associated with adverse pregnancy outcomes particularly among primigravidae. The aim of this study was to assess the prevalence and risk factors for placental malaria and its effect on pregnancy outcomes in Blue Nile state, Sudan.MethodsA cross-sectional hospital-based study was conducted consecutively during January 2012–December 2015 in three main hospitals in Blue Nile State, Sudan. At delivery, peripheral and placental blood samples were collected from consenting women. Finger prick blood was used for preparation of peripheral smears and for haemoglobin measurement. Smears were stained with Giemsa and examined microscopically for malaria parasites. Pregnancy outcomes in association to placental malaria were investigated.ResultsA total of 1149 mothers and their newborns were recruited. The mean (SD) of the age was 23.3 (5.2) years. Detection of malaria parasites was confirmed in 37.8% of the peripheral blood films and 59.3% of the placental films with Plasmodium falciparum as the only species detected. In multivariate analysis, younger age ≤23.2 years old (AOR = 3.2, 95% CI 1.9–5.5; P < 0.001), primiparae (AOR = 3.9, CI 2.1–7.6; P < 0.001), secundiparae (AOR = 2.8, 95% CI 1.5–5.1; P < 0.001, no antenatal care (ANC) visits (AOR = 11.9, 95% CI 7.8–18.1; P < 0.001) and not using bed nets (AOR = 3.5, 95% CI 1.7–6.8; P < 0.001) were risk factors for placental malaria. Education and residence were not associated with placental malaria infection. Placental malaria was significantly associated with maternal anaemia (AOR = 41.6, 95% CI 23.3–74.4; P < 0.001) and low birth weight (LBW) (AOR = 25.2, 95% CI 15.1–41.3; P < 0.001).ConclusionDuring the study, there was a high prevalence of placental malaria in Blue Nile State-Sudan, as the enhanced control activities were not practiced, leading to adverse pregnancy outcomes, such as maternal anaemia and LBW.

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Background Malaria control efforts in Sudan rely heavily on case management. In 2004, health authorities adopted artemisinin-based combination therapies (ACTs) for the treatment of uncomplicated malaria. However, some recent surveys have reported ACT failure and a prevalent irrational malaria treatment practice. Here we examine whether the widespread use of ACT and failure to adhere to national guidelines have led to the evolution of drug resistance genes. Methods We genotyped known drug resistance markers (Pfcrt, Pfmdr-1, Pfdhfr, Pfdhps, Pfk13 propeller) and their flanking microsatellites among Plasmodium falciparum isolates obtained between 2009 and 2016 in different geographical regions in Sudan. Data were then compared with published findings pre-ACT (1992–2003). Results A high prevalence of Pfcrt76T, Pfmdr-1-86Y, Pfdhfr51I, Pfdhfr108N, Pfdhps37G was observed in all regions, while no Pfk13 mutations were detected. Compared with pre-ACT data, Pfcrt-76T and Pfmdr-1-86Y have decayed, while Pfdhfr-51I, Pfdhfr-108N and Pfdhps-437G strengthened. Haplotypes Pfcrt-CVIET, Pfmdr-1-NFSND/YFSND, Pfdhfr-ICNI and Pfdhps-SGKAA predominated in all sites. Microsatellites flanking drug resistance genes showed lower diversity than neutral ones, signifying high ACT pressure/selection. Conclusions Evaluation of P. falciparum drug resistance genes in Sudan matches the drug deployment pattern. Regular monitoring of these genes, coupled with clinical response, should be considered to combat the spread of ACT resistance.

Background Accurate diagnosis of malaria infection is essential for successful control and management of the disease. Both microscopy and rapid diagnostic tests (RDTs) are recommended for malaria diagnosis, however, RDTs are more commonly used. The aim of the current study was to assess the performance of microscopy and RDTs in the diagnosis of Plasmodium falciparum infection using a nested polymerase chain reaction (PCR) assay as the gold standard. Methods A cross-sectional study was carried out in Kassala Hospital, eastern Sudan. A total of 341 febrile participants of all ages were recruited. Blood specimens were collected and malaria testing was performed using an RDT (SD Bioline Malaria Ag Pf), microscopy and nested PCR. The sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively) of microscopy and the RDT were investigated. Results The prevalence of P. falciparum malaria infections in this study was 22.9%, 24.3% and 26.7% by PCR, microscopy and RDT, respectively. Compared with microscopy, the RDT had slightly higher sensitivity (80.7% vs 74.3%; p=0.442), equivalent specificity (89.3% vs 90.4%), a similar PPV (69.2% vs 69.8%) and a higher NPV (94.0% vs 92.2%). Conclusions The diagnostic performance of the RDT was better than that of microscopy in the diagnosis of P. falciparum malaria when nested PCR was used as the gold standard.

The aim of the present study was to investigate the prevalence of submicroscopic infections and to assess its impact on maternal anaemia and low birth weight. A cross-sectional study was carried out with 1149 consented pregnant women who delivered at 3 main hospitals in the Blue Nile State, between January 2012 and December 2015. From a matched maternal peripheral, placental maternal side, and cord blood sample, blood films and dried spots were prepared for microscopic examination and nested polymerase chain reaction (n-PCR), respectively. 107 out of 447 negative blood films were found to have submicroscopic infection detected using n-PCR in any of the three compartments. Placental samples had a significantly higher prevalence (142) of submicroscopic infections compared with the peripheral (6.5%) and cord (8.1%) samples. The mean (SD) of the maternal haemoglobin (Hb) was significantly lower in cases with submicroscopic parasitaemia (10.9 (0.8) vs. 12.1 (0.7) g/dl, P<0.001) compared with those who had no submicroscopic parasitaemia. Submicroscopic malaria infection was associated with anaemia (OR 19.7, (95% CI, 10.3–37.8)). Thirty-eight babies born to women with submicroscopic infections were low birth weight (LBW) and was significantly lower in submicroscopic parasitaemia (2.663 (0.235) vs. 2.926 (0.341) kg, P<0.001). Submicroscopic malaria infection was associated with LBW (OR = 2.7, (95% CI, 1.2–5.6)). There is a high incidence of submicroscopic infections in any of the three compartments regardless of age or parity. Submicroscopic infection is a risk of maternal anaemia and low birth weight in women in this area of high seasonal malaria transmission.

Background:Control of malaria during pregnancy remains a major public health challenge in developing countries. Microscopic parasite detection represents a pivotal step in malaria control, while modern molecular techniques are deemed to improve detection rates markedly.Aims:This study aimed to investigate the frequency of submicroscopic and multiple Plasmodium falciparum (P. falciparum) infections during pregnancy, using the P. falciparum merozoite surface protein1 (MSP-1) gene as a polymorphic marker.Materials and Methods:The study was a cross-sectional, analytical study that was conducted at Omdurman Maternity Hospital, Sudan, between July 2003 and December 2004. Following informed consent, 836 pregnant women between the ages of 16-47 years with different gestational ages were enrolled in the study. Thin and thick blood films were stained with Giemsa and examined by experienced microscopists. Parasite DNA was extracted using Chelex method. Nested polymerase chain reaction (PCR) assays specific for P. falciparum were carried out to detect infections below the threshold of microscopy and to genotype different strains in the samples using merozoite surface protein-1.Results:More than a quarter of the study participants (219/836; 26.2%) were smear-positive for malaria infection. The results of the PCR-based assays showed that 41.8 % (257/617) of the smear-negative women were PCR positive and therefore had submicroscopic infections. The mean number of genetically different P. falciparum parasites detected was 2.7 (range 1–9). The multiplicity of infection identified by at least two alleles of MSP-1 was significantly higher among paucigravidae (45.6%) compared to multigravidae (28.9%), with mean number of alleles of 2.4 and 1.9, respectively (p=0.009). This likely indicates the gradual acquisition of immunity.Conclusion:Conventional microscopy underestimates the actual extent of malaria infections during pregnancy in endemic regions. Multiplicity of infection may be an important factor in the gradual acquisition of strain-specific immunity.

Background The sequestration of Plasmodium falciparum infected cells in the placenta results in placental malaria (PM). It activates the mother's immune cells and induces secretion of inflammatory cytokines, which might influence pregnancy outcomes. This study aims to investigate the cytokines (levels IL-4, IL-6, IL-10, IL-17A, and INF γ) in maternal peripheral, placental, and umbilical cord blood in response to PM and the extent to which this may influence maternal haemoglobin levels and birth weight. Methods A total of 185 consenting Sudanese women from Blue Nile State were enrolled at delivery time in a cross-sectional study conducted between Jan 2012-Dec 2015. Malaria infection in the collected maternal peripheral, placental, umbilical cord samples was determined microscopically, and ELISA was used to measure the plasma levels IL-4, IL-6, IL-10, IL-17A, and INF γ in the collected positive and negative malaria samples. Results Elevated levels of IL-4 and IL-10 and reduced levels of IL-6 were detected in the malaria positive samples in comparison to the negative ones in the three types of the samples investigated. Maternal, IL-4 and IL-10 were significantly higher in the samples collected from the PM infected group compared to the non-infected control (P < 0.001). While the absence of PM was significantly associated with the IL-6 and maternal IFN-γ levels, maternal IL-17A, placental and umbilical cord IFN-γ levels showed no significant difference (P = 0.214, P = 0.065, P = 0.536, respectively) due to infection. Haemoglobin level and birth weight were increased in the group with high levels of IL-6 and IL-17A, but not in the group with IL-4 and IL-10 levels. While significantly negative correlation was found between IFN-γ levels and birth weight for all three types of samples, only maternal peripheral IFN-γ level was significantly positively correlated with maternal haemoglobin (r = 0.171, P = 0.020). Conclusion These results suggest that PM induces mother’s immune response and impairs her cytokine profile, which might alter maternal haemoglobin levels and the baby's birth weight.

Diagnosis of congenital malaria is complicated by the low density of the parasite circulating in the cord blood and/or the peripheral blood of the newborns. Molecular techniques are significantly more sensitive than blood smears in detecting low-level parasitemia. This study investigated the prevalence of congenital malaria by the use of the real-time polymerase chain reaction (real-time PCR) in 102 babies born to mothers with microscopically confirmed infected placenta from Blue Nile state, Sudan. At delivery time, placental, maternal peripheral and cord blood samples in addition to samples collected from the newborns’ peripheral blood were examined for malaria infection using Giemsa-stained thick smear and parasite DNA detection by real-time PCR. The overall prevalence of congenital malaria includes the total babies with cord blood parasitaemia and peripheral blood parasitaemia was 18.6 and 56.8% using microscopy and real-time PCR, respectively. Even though all the neonates were aparasitaemic by microscopy, 19 (18.6%) of the babies had congenital malaria detected by real-time PCR, 15 (25.9%) of the babies with congenital malaria were born to mothers with both placental and peripheral blood malaria infections detected using the two techniques. Congenital malaria was significantly associated with cord blood malaria infections, maternal age and maternal haemoglobin level (p &lt; 0.001). This first study investigating congenital malaria in Blue Nile state, Sudan shows that malaria-infected placenta resulted in infant and cord blood infections.