Malaria Research and Treatment最新文献

Background: Malaria is a protozoan disease caused by the Plasmodium species. Among the five Plasmodium species. Among the five Plasmodium falciparum and Plasmodium vivax malaria are by far the most predominant and widely distributed in Ethiopia. Malaria is one of the leading causes of morbidity and mortality globally, particularly in the sub-Saharan countries including Ethiopia. It is also a major obstacle to socio-economic development in the country.

Methods: Articles were searched from PubMed, Google Scholar, and Science Direct databases. The pooled prevalence estimates were analyzed using the DerSimonian-Laird random-effects model and the possible sources of heterogeneity were evaluated through subgroup analysis, metaregression, and sensitivity analysis. Publication bias was analyzed using funnel plots and Egger's test statistics. The data management and analysis were done using STATA 15.1 version software.

Results: Among 922 studies initially identified, thirty-five full-text articles fulfilled the inclusion criteria and included in the study. The combined, Plasmodium falciparum and Plasmodium vivax malaria are by far the most predominant and widely.

Conclusions: This systematic review and meta-analysis showed a high malaria prevalence in Ethiopia. Therefore, previous prevention and control measures should be revised and/or strengthened as appropriate and new strategies should be implemented. In addition, technical, financial and material support, and coordination of the regional capacity building and logistics should be adequately implemented.

Malaria is a protozoan parasitic infection of humans resulting from one or more of the five species of the genus Plasmodium and its burden across the world particularly in the tropics is well known. Blood transfusion on the other hand is a necessary intervention in saving lives. However, it can lead to transfusion transmitted infections including malaria if the blood was donated by an infected person. It is therefore important that the blood from donors in malaria prone environment be examined thoroughly for malaria parasites. The objective of this study was to investigate the incidence of malaria parasites in donor blood. A total of 1,500 samples from donors were examined using microscopy, rapid diagnostic test (RDT), and molecular method for malaria parasites. Malaria parasites were detected in forty-eight (48), 49 and 47 of the blood samples using microscopy, RDT, and molecular method respectively. This gave an average prevalence of 3.2%. All the blood groups examined had some malaria positivity except blood group O and A negative. In all the positive samples, the trophozoites of Plasmodium falciparum were detected. There was no association between blood group type and prevalence of the malaria parasites. There was also no association between age and prevalence of malaria parasite. The results attest to the potential risk of blood transfusion transmitted malaria and thus pose a great risk to blood recipients, especially the malaria vulnerable groups of children and pregnant women. Even though the prevalence in this study was not high enough, together with other results from elsewhere, it can be said that the screening of donated blood or donors for malaria parasites is necessary so that measures will be put in place not to transfuse patients at risk.

Malaria is the leading cause of morbidity in Ghana representing 40-60% of outpatient hospital attendance with about 10% ending up on admission. Microscopic examination of peripheral blood film remains the most preferred and reliable method for malaria diagnosis worldwide. But the level of skills required for microscopic examination of peripheral blood film is often lacking in Ghana. This study looked at determining the extent to which haematological parameters and demographic characteristics of patients could be used to predict malaria infection using logistic regression. The overall prevalence of malaria in the study area was determined to be 25.96%; nonetheless, 45.30% of children between the ages of 5 and 14 tested positive. The binary logistic model developed for this study identified age, haemoglobin, platelet, and lymphocyte as the most significant predictors. The sensitivity and specificity of the model were 77.4% and 75.7%, respectively, with a PPV and NPV of 52.72% and 90.51%, respectively. Similar to RDT this logistic model when used will reduce the waiting time and improve the diagnosis of malaria.

Background: Studying malaria parasites cross resistance to sulfadoxine-pyrimethamine (SP) and trimethoprim-sulfamethoxazole (cotrimoxazole, CTX) is necessary in areas coendemic for malaria and HIV. Polymorphism and frequency of drug resistance molecular markers, Pfdhfr and Pfdhps genes have been assessed in Plasmodium falciparum isolates from HIV-infected adults, in Gabon.

Materiel and methods: A cross-sectional study was conducted in three HIV care and treatment centers, at Libreville, the capital city of Gabon and at Oyem and Koulamoutou, two rural cities between March 2015 and June 2016. P. falciparum-infected HIV adults were selected. Analysis of Pfdhfr and Pfdhps genes was performed using high resolution melting (HRM) technique.

Results: Pfdhps A581G mutation was found in 23.5% (8/34) of the isolates. Triple Pfdhfr mutation (51I-59R-108N) was predominant (29.4%; n=10) while 17.6% (n=6) of the isolates carried a quadruple mutation (Pfdhfr 51I-59R-108N + Pfdhps 437G; Pfdhfr 51I-108N + Pfdhps 437G-Pfdhps581G; Pfdhfr 51I-59R-108N + Pfdhps 581G). Highly resistant genotype was detected in around 10% (n=3) of the isolates. The quintuple mutation (triple Pfdhfr 51I-59R-108N and double Pfdhps437-581) was only found in isolates from two patients who did not use CTX. The most frequent haplotypes were those with a single mutation (NCNIAKA) (36%) and a quadruple mutation (NCIIGKG, NRIIGKA, and NRIIAKG). Mixed unknown genotypes were found at codon 164 in three isolates. Mixed genotypes were more frequent at codons 51 (23.5%; n=8) and 59 (20.5%; n=7) (p<0.01).

Conclusion: Pfdhps A581G mutation as well as new combination of quintuple mutations is found for the first time in isolates from HIV-infected patients in Gabon in comparison to a previous study. The detection of these genotypes at a nonnegligible frequency underlines the need of a regular surveillance of antifolates drug resistance.

Background: Placental malaria is a leading global cause of low birth weight neonates, especially in first-time mothers. To better understand the role of innate immunity in placental malaria, we investigated the relationships between histopathological markers of placental malaria, fetal and maternal macrophage responses, and perinatal outcomes in a cross-sectional case control study of pregnant women presenting with symptomatic malaria at the time of delivery.

Results: Primigravidas showed increased hemozoin deposition in placental villi (p=0.02), syncytiotrophoblasts (p=0.01), and fetal Hofbauer cells (p=0.01). The percentage of hemozoin-positive villi negatively correlated with infant birth weight (regression coefficient [b] = -0.03 kg decrease in birth weight per % increase in hemozoin-positive villi, p=0.035). Malaria-infected placentas showed a twofold increase in Hofbauer cells (p<0.001) and maternal macrophages (p<0.001). Placental malaria was associated with a threefold increase in the percentage of M2 maternal macrophages (19.2% vs 6.4%, p=0.01). Primigravidas showed a significant decrease in the Hofbauer cell M2-percentage in placental malaria (92.7% vs. 97.0%, p=0.04), which was predictive of infant birth weight (b=0.08 kg increase in birth weight per % increase in M2 Hofbauer cells, p=0.001). There was no association between maternal macrophage response and infant birth weights.

Conclusions: Placentas with malarial infection had increased numbers of fetal Hofbauer cells in the villous stroma and maternal macrophages in the intervillous space. In primigravidas, decreased anti-inflammatory M2-type Hofbauer cells were predictive of lower birth weight. M2-type maternal macrophages were increased in placental malaria, but there was no association with gravidity or birth weight. These results suggested a protective role of M2 Hofbauer cells in fetal growth restriction.