Severe malaria in children and adolescents in Southeast Gabon

Plasma Soluble Progenitor Cell Receptors as Biomarkers for Severe Anemia Among Malaria-Infected Pediatrics: A Prospective Study in Ghana

Background

Soluble forms of progenitor cell receptors may be implicated in the delayed erythropoietic response during severe anemia. In this study, plasma levels of soluble erythropoietin receptor (sEPO-R) and soluble granulocyte, macrophage-colony stimulating factor receptor (sGM-CSFR) were assessed in Plasmodium falciparum-infected children in Ghana.

Methods

This case-control study was conducted at Tamale Teaching Hospital, Ghana. One hundred and twenty P. falciparum-infected, and 60 uninfected children aged 12-144 months were recruited from April to July, 2023. About 4 mL of blood was collected for malaria microscopy, full blood count using a haematology analyser, and sEPO-R, sGM-CSFR and erythropoietin (EPO) estimation using enzyme-linked immunosorbent assays. Data were analyzed using SPSS version 26.0.

Results

Plasma levels of sEPO-R were higher among participants with severe malarial anemia (SMA) than those in the non-SMA and control groups (p < 0.001). Plasma sGM-CSFR levels were higher in P. falciparum-infected children than in controls, but the levels were similar between the SMA and non-SMA groups. Hemoglobin (r = -0.823, p < 0.001), RBC (r = -0.852, p < 0.001), HCT (r = -0.790, p < 0.001) and platelets (r = -0.810, p < 0.001) negatively correlated with sEPO-R. There was a strong positive correlation between sEPO-R and EPO in P. falciparum-infected children (r = 0.901, p < 0.001). Plasma sEPO-R better predicted severe anemia among malaria-infected children (cut-off point: 161.5 pg/mL, sensitivity: 96.0%, specificity: 82.9%, AUC: 0.964, p < 0.001).

Conclusion

P. falciparum-infected children had higher plasma levels of sGM-CSFR, sEPO-R and EPO. Plasma sEPO-R correlated negatively with erythrocyte parameters, suggesting a possible contribution of the endogenous receptor to the development of severe anemia in children with malaria. Further studies to investigate the neutralizing effects of sEPO-R on erythropoietic response during malaria are recommended.

Cerebral Malaria in Adults: A Retrospective Descriptive Analysis of 80 Cases in a Tertiary Hospital in The Gambia, 2020-2023

Background and Aim

Cerebral malaria in Gambian children has been studied but there is limited information on CM in adults. The study assesses the clinical features and outcome of CM in adult patients admitted at the Edward Francis Small Teaching Hospital.

Method

This was a retrospective review of all adult patients with malaria admitted to the internal medicine department from October 18, 2020 to February 2, 2022.

Results

A total number of 319 adults were admitted with malaria. Eighty (25%) patients met the criteria for CM. The median age of the CM patients was 19 years. CM patients were younger (p < 0.001), more likely to be of the adolescent age group (p < 0.001), more likely to be referred from a lower-level health facility (p < 0.001), and more likely to be admitted in intensive care p < 0.001) as compared to NSCM or UM patients. The total in-hospital mortality of CM patients was 23.8%. Ten (52.6%) out of the 19 patients died within the first 24 h of admission. In multivariate analysis, CM patients with acute kidney injury at presentation was an independent predictor of mortality in this study.

Conclusion

CM seems to affect the adolescent age group more than the older adults in The Gambia. The clinicians should be able to identify these high-risk patient group and institute prompt critical care interventions and/or treatment. The findings in this study also identify the need to expand access of critical care interventions and hemodialysis to help improve the prognosis of adult CM patients in The Gambia.

Epidemiological, Clinical and Paraclinical Profile of Paediatric Malaria at University Hospital Centre Amissa Bongo in Franceville, Gabon

BACKGROUND

Malaria remains the deadliest parasitic disease and continues to cause more than half a million deaths across the world each year, mainly victims are sub-Saharan children. Malaria is a common reason for paediatric hospitalisation.

OBJECTIVE

The objective was to characterise malaria and describe the evolution after treatment in the paediatric department of the University Hospital Centre Amissa Bongo de Franceville.

METHODS

This was a cross-sectional study conducted from 1 February 2023 to 15 May 2023. A clinical and biological diagnosis was made in febrile children aged from 6 months to 15 years.

RESULTS

A total of 306 patients were included. The mean age was 50.4 ± 44.3 months, 94.3% had consulted within ≥48 h and self-medication was practiced by 83.3%. The prevalence of malaria was 17.3%. Fever ˃39°8C (adjusted odds ratios [aOR] = 2.68; 95% confidence interval [CI] = [1.32-5.48]; P < 0.01), chills (aOR = 2.14; 95% CI = [1.13-4.11]; P < 0.01) and nausea-vomiting (aOR = 2.03; 95% CI = [1.06-3.83]; P = 0.03) were the factors associated with the occurrence of malaria. The majority of children were treated for simple malaria with artemisinin-based combination therapy. A total of 16/53 was seen in post-therapeutic consultation. Of them, 2 patients had a positive thick drop.

CONCLUSION

Non-compliance with preventive measures and the misuse of antimalarials further complicate the clinical picture, requiring parenteral management for the most part.

Pro- and anti-inflammatory cytokines mediate the progression of severe anemia in malaria-infected children: A prospective study

BACKGROUND

Severe Plasmodium falciparum malarial anemia is still the principal cause of death in children in underdeveloped countries. An imbalance between proinflammatory and anti-inflammatory cytokines is associated with malaria progression. This study evaluated circulating levels of selected inflammatory cytokines among malaria-infected children in Ghana.

METHODS

This case-control study was conducted at Tamale Teaching Hospital, Ghana. One hundred and twenty children with malaria and 60 controls, aged 12-144 months were selected from April to July, 2023 for the study. Malaria was diagnosed through microscopy, full blood count was measured using hematology analyzer, and cytokines were measured using enzyme-linked immunosorbent assay.

RESULTS

Malaria-infected children had higher tumor necrosis factor alpha (TNF-α) (p < .001), interferon-gamma (IFN-ɣ) (p < .001), interleukin (IL)-1β (p < .001), IL-6 (p < .001), granulocyte macrophage-colony stimulating factor (GM-CSF) (p < .001), and IL-10 (p < .001) levels than controls. Participants with high parasitemia had raised TNF-α (p < .001), IFN-ɣ (p < .001), IL-1β (p < .001), IL-6 (p < .001), GM-CSF (p < .001), and IL-10 (p < .001), but reduced IL-3 (p < .001) and TGF-β (p < .001) than those with low parasitemia. Severe malarial anemic children had elevated TNF-α (p < .001), IFN-ɣ (p < .001), IL-1β (p < .001), IL-6 (p < .001), GM-CSF (p < .001), and IL-10 (p < .001), but lower IL-3 (p < .001) and TGF-β (p < .001) than those with uncomplicated malaria.

CONCLUSION

Parasite density was the principal predictor of the cytokine levels, as parasitemia positively associated with IL-10, GM-CSF, IL-6, IL-1β, IFN-ɣ, and TNF-α, but negatively associated with IL-3 and TGF-β. Malaria is associated with enhanced secretion of pro- and anti-inflammatory cytokines in Ghanaian children. Inflammatory cytokines may be involved in the development of severe malarial anemia in children. However, IL-3 and TGF-β may offer protection against severe malarial anemia.

Assessment of environmental and spatial factors influencing the establishment of Anopheles gambiae larval habitats in the malaria endemic province of Woleu-Ntem, northern Gabon

BACKGROUND

This study aimed to assess the spatial distribution of Anopheles mosquito larval habitats and the environmental factors associated with them, as a prerequisite for the implementation of larviciding.

METHODS

The study was conducted in December 2021, during the transition period between the end of the short rainy season (September-November) and the short dry season (December-February). Physical, biological, and land cover data were integrated with entomological observations to collect Anopheles larvae in three major towns: Mitzic, Oyem, and Bitam, using the "dipping" method during the transition from rainy to dry season. The collected larvae were then reared in a field laboratory established for the study period. After the Anopheles mosquitoes had emerged, their species were identified using appropriate morphological taxonomic keys. To determine the influence of environmental factors on the breeding of Anopheles mosquitoes, multiple-factor analysis (MFA) and a binomial generalized linear model were used.

RESULTS

According to the study, only 33.1% out of the 284 larval habitats examined were found to be positive for Anopheles larvae, which were primarily identified as belonging to the Anopheles gambiae complex. The findings of the research suggested that the presence of An. gambiae complex larvae in larval habitats was associated with various significant factors such as higher urbanization, the size and type of the larval habitats (pools and puddles), co-occurrence with Culex and Aedes larvae, hot spots in ambient temperature, moderate rainfall, and land use patterns.

CONCLUSIONS

The results of this research mark the initiation of a focused vector control plan that aims to eradicate or lessen the larval habitats of An. gambiae mosquitoes in Gabon's Woleu Ntem province. This approach deals with the root causes of malaria transmission through larvae and is consistent with the World Health Organization's (WHO) worldwide objective to decrease malaria prevalence in regions where it is endemic.

Microfilariae Prevalence and its Association with Anemia Among First-time Blood Donors in Lambaréné, Gabon

Background

Anemia remains a significant public health concern in Gabon, particularly among children, adolescents, and females. Gabon is also home to two major species of filarial worms, Loa and Mansonella spp., which cause microfilaremia. The epidemiological nexus between hemoglobin (Hb) concentrations and microfilaremia in Gabonese first-time blood donors remains unknown.

Aims

To understand better the epidemiological relationship between anemia and microfilaremia to improve donor selection and management protocols.

Study Design

A retrospective cohort study.

Methods

This study was conducted among first-time blood donors in Lambaréné between March 2018 and October 2019. Participants aged 16-65 years old and weighing a minimum of 50 kg were enrolled using standard donor selection criteria. An automatic hematological analyzer was used to quantify Hb concentrations, and microscopy techniques were used to detect the presence of microfilariae.

Results

Microfilariae were found in 4.8% (35/723) of the 723 first-time blood donors from Lambaréné. Anemia was classified as mild in 35.5% (257/723) and moderate in 1% (7/723). No significant associations were found between the distribution of microfilariae and variables such as age, sex, socioprofessional classification, marital status, or residence. Blood group O donors had a higher prevalence of microfilariae (6%) than non-O donors (2.7%). However, the observed difference was not statistically significant (AOR =2.3, p = 0.052). Furthermore, microfilariae were associated with increased moderate anemia (3.7% vs. 29%, AOR =15.6, p = 0.003).

Conclusion

Our findings highlight microfilaremia as a possible etiological cause of anemia among Gabonese blood donors, emphasizing the need for further research and a potential review of donor management strategies.

Methemoglobin levels in malaria: a systematic review and meta-analysis of its association with Plasmodium falciparum and Plasmodium vivax infections and disease severity

Reports indicate that Plasmodium infections influence methemoglobin levels. However, findings have been inconclusive or have varied across different geographic and demographic contexts. This systematic review and meta-analysis aimed to consolidate existing data regarding the association between Plasmodium infections and alterations in methemoglobin levels related to the severity of the infection. A comprehensive literature search of several databases, including Ovid, ProQuest, Embase, Scopus, MEDLINE, and PubMed, was conducted to identify relevant studies that examined methemoglobin levels in patients with malaria. Qualitative synthesis and meta-analysis of the pooled standardized mean difference were conducted to synthesize the differences in methemoglobin levels between: (1) patients with malaria and those without malaria and (2) patients with severe malaria and those with uncomplicated malaria based on various themes including publication year, study design, study area, Plasmodium species, age group, symptomatic status, severity status, and method of malaria detection. Of the 1846 studies that were initially identified from the main databases and additional searches on Google Scholar, 10 studies met the eligibility criteria and were selected for this review. The systematic review distinctly highlighted an association between malaria and elevated methemoglobin levels, an observation consistent across diverse geographical regions and various Plasmodium species. Furthermore, the meta-analysis confirmed this by demonstrating increased methemoglobin levels in patients with malaria compared to those without malaria (P < 0.001, Hedges' g 2.32, 95% CI 1.36-3.29, I2 97.27, 8 studies). Moreover, the meta-analysis found elevated methemoglobin levels in patients with severe malaria compared to those with uncomplicated malaria (P < 0.001, Hedges' g 2.20, 95% CI 0.82-3.58, I2 96.20, 5 studies). This systematic review and meta-analysis revealed increased methemoglobin levels in patients with P. falciparum and P. vivax infections, with a notable association between elevated methemoglobin levels and severe malaria. Future research should focus on elucidating the specific mechanisms by which changes in methemoglobin levels are related to infections by P. falciparum and P. vivax, particularly in terms of severity, and how these alterations could potentially impact patient management and treatment outcomes.

Therapeutic efficacy and safety of artesunate + amodiaquine and artemether + lumefantrine in treating uncomplicated Plasmodium falciparum malaria in children on the rainy south-east coast of Madagascar

Malaria is a major public health problem in Madagascar, particularly in coastal areas. We conducted a randomized, controlled, parallel-group study of artemisinin-based combination therapy (ACT) in Mananjary and Farafangana, two localities on the rainy south-east coast of Madagascar, from March to September 2018. The efficacy and safety of artesunate + amodiaquine (ASAQ) and artemether + lumefantrine (AL) were assessed according to the WHO protocol with a 28-day follow-up. Children aged 6 months to 14 years with uncomplicated Plasmodium falciparum malaria were randomized to receive ASAQ or AL for three days (1:1). 347/352 (98.5%) randomized patients reached the study endpoint on day 28. Crude adequate clinical and parasitological response (ACPR) rates were 100% (95% CI: 98.8-100%) in the ASAQ group and 96% (95% CI: 93.1-98.9%) in the AL group (per protocol population). However, the PCR-corrected ACPR rate was 97.7% (95% CI: 95.4-100%) in the AL group. Two cases of recrudescence and three of re-infection were observed. Mild and moderate adverse events, including gastrointestinal and/or nervous disorders, were reported in 11.9% (42/352) of patients. We found that ASAQ and AL were safe and efficacious for treating uncomplicated P. falciparum malaria. They may be used for treatment at health facilities and at the community level, and for mass drug administration campaigns.