Effect of Plasmodium falciparum malaria parasites on haematological parameters in Ghanaian children

Altered haematological parameters in children with malaria infection, a systematic review and meta-analysis

OBJECTIVE

This study aimed to illustrate the effect of malaria infection on red blood cell parameters in children and evaluate the diagnostic relevance of haematological parameters in predicting malaria.

METHODS

The studies were identified through databases like PubMed, Google Scholar, and Scopus to retrieve related articles. Fourteen studies were selected by literature search based on inclusion and exclusion criteria, and a meta-analysis on different red blood cell parameters was performed.

RESULTS

Haematocrit, haemoglobin concentration, and RBC count show statistically significant findings with p values of (<0.00001), (p<0.00001) and (p=0.0004), respectively. Other parameters like MCV, MCH, and MCHC show statistically non-significant results with p values of 0.21, 0.36, and 0.63, respectively.

CONCLUSION

Considering the above findings, the combination of haemoglobin concentration, haematocrit, and RBC counts could be used as reliable parameters to predict the presence of infection and included in the diagnostic strategy for malaria in children.

Estimation of parasitaemia in imported falciparum malaria using the results of a combined rapid diagnostic test. No big help from haematological parameters

BACKGROUND

Microscopy continues to be the mainstay for the evaluation of parasitaemia in malaria but requires laboratory support and microbiological experience. Other fast and simple methods are necessary.

METHODS

A retrospective observational study of imported malaria treated from July-2007 to December-2020 was carried out to evaluate the association between the degree of parasitaemia and both rapid diagnostic tests (RDT) reactivity patterns and haematological parameters. Plasmodium falciparum monoinfections diagnosed by peripheral blood smear and/or polymerase chain reaction (PCR),which also had a positive RDT result in the same blood sample, were included in the study.

RESULTS

A total of 273 patients were included. Most of them were male (n = 256; 93.8%) and visiting friends and relatives (VFR) travellers (n = 252; 92.3%). Patients with plasmodial lactate dehydrogenase (pLDH) or aldolase and histidine-rich protein 2 (HRP-2) co-reactivity (Pan/Pf pattern) had a parasitaemia range between 0 and 37% while those with just HRP-2 reactivity (P. falciparum pattern) had ranges between 0 and 1%. Not a single case of P. falciparum pattern was found for parasitaemia ranges greater than 1%, showing a negative predictive value of 100% for high parasitaemia. All the correlations between haematological parameters and parasitaemia resulted to be weak, with a maximum rho coefficient of -0.35 for lymphocytes and platelets, and of 0.40 for neutrophils-to-lymphocytes count ratio. Multivariate predictive models were constructed reflecting a poor predictive capacity.

CONCLUSIONS

The reactivity pattern of RDT allows a rapid semi-quantitative assessment of P. falciparum parasitaemia in travellers with imported malaria, discriminating patients with lower parasite loads. Haematological parameters were not able to estimate parasitaemia with sufficient precision.

Variability in white blood cell count during uncomplicated malaria and implications for parasite density estimation: a WorldWide Antimalarial Resistance Network individual patient data meta-analysis

BACKGROUND

The World Health Organization (WHO) recommends that when peripheral malarial parasitaemia is quantified by thick film microscopy, an actual white blood cell (WBC) count from a concurrently collected blood sample is used in calculations. However, in resource-limited settings an assumed WBC count is often used instead. The aim of this study was to describe the variability in WBC count during acute uncomplicated malaria, and estimate the impact of using an assumed value of WBC on estimates of parasite density and clearance.

METHODS

Uncomplicated malaria drug efficacy studies that measured WBC count were selected from the WorldWide Antimalarial Resistance Network data repository for an individual patient data meta-analysis of WBC counts. Regression models with random intercepts for study-site were used to assess WBC count variability at presentation and during follow-up. Inflation factors for parasitaemia density, and clearance estimates were calculated for methods using assumed WBC counts (8000 cells/µL and age-stratified values) using estimates derived from the measured WBC value as reference.

RESULTS

Eighty-four studies enrolling 27,656 patients with clinically uncomplicated malaria were included. Geometric mean WBC counts (× 1000 cells/µL) in age groups < 1, 1-4, 5-14 and ≥ 15 years were 10.5, 8.3, 7.1, 5.7 and 7.5, 7.0, 6.5, 6.0 for individuals with falciparum (n = 24,978) and vivax (n = 2678) malaria, respectively. At presentation, higher WBC counts were seen among patients with higher parasitaemia, severe anaemia and, for individuals with vivax malaria, in regions with shorter regional relapse periodicity. Among falciparum malaria patients, using an assumed WBC count of 8000 cells/µL resulted in parasite density underestimation by a median (IQR) of 26% (4-41%) in infants < 1 year old but an overestimation by 50% (16-91%) in adults aged ≥ 15 years. Use of age-stratified assumed WBC values removed systematic bias but did not improve precision of parasitaemia estimation. Imprecision of parasite clearance estimates was only affected by the within-patient WBC variability over time, and remained < 10% for 79% of patients.

CONCLUSIONS

Using an assumed WBC value for parasite density estimation from a thick smear may lead to underdiagnosis of hyperparasitaemia and could adversely affect clinical management; but does not result in clinically consequential inaccuracies in the estimation of the prevalence of prolonged parasite clearance and artemisinin resistance.

Renal and hepatic dysfunction parameters correlate positively with gender among patients with recurrent malaria cases in Birnin Kebbi, Northwest Nigeria

Background

Simultaneous increase in transaminases and bilirubin is an indicator of hepatic dysfunction in malaria. Malaria-induced hyperbilirubinemia has been associated with acute kidney injury and pathogenesis of cerebral malaria which are significantly associated with mortality in malaria infection. This retrospective study was designed to assess the lipid profile, and hematological, renal and hepatic function data of malaria patients in Sir Yahaya Memorial hospital Birnin Kebbi from 2016 to 2020 who are 18 years and above.

Methods

The data of all patients between 2016 and 2020 who are 18 years and above were collected. Complete data of 370 subjects who met the inclusion criteria which consist of 250 malaria subjects and 120 control subjects were analyzed.

Results

The results showed that females constitute 65.2% of malaria patients with complete records while the remaining 34.8% were males. Age distribution of the patients showed that the infection was more prevalent among 26–45 years and least among 65 years and above. Anemia and thrombocytopenia were prevalent among the female malaria patients compared to the male patients. Liver and kidney function parameters analyzed correlate positively with the gender. The infected male showed higher dysfunction in liver parameters while infected female patients showed significant dysfunction in kidney function parameters and lipid profile.

Conclusions

In conclusion, to prevent the potential widespread of acute renal and hepatic failure with the attendant morbidity and mortality among malaria patients, it is recommended that liver and kidney function tests be mandated for patients with recurring malaria and those with a history of treatment failure in the endemic area to ensure early diagnosis of malarial induced kidney and liver injury among malaria patients.

Machine learning approaches classify clinical malaria outcomes based on haematological parameters

BACKGROUND

Malaria is still a major global health burden, with more than 3.2 billion people in 91 countries remaining at risk of the disease. Accurately distinguishing malaria from other diseases, especially uncomplicated malaria (UM) from non-malarial infections (nMI), remains a challenge. Furthermore, the success of rapid diagnostic tests (RDTs) is threatened by Pfhrp2/3 deletions and decreased sensitivity at low parasitaemia. Analysis of haematological indices can be used to support the identification of possible malaria cases for further diagnosis, especially in travellers returning from endemic areas. As a new application for precision medicine, we aimed to evaluate machine learning (ML) approaches that can accurately classify nMI, UM, and severe malaria (SM) using haematological parameters.

METHODS

We obtained haematological data from 2,207 participants collected in Ghana: nMI (n = 978), SM (n = 526), and UM (n = 703). Six different ML approaches were tested, to select the best approach. An artificial neural network (ANN) with three hidden layers was used for multi-classification of UM, SM, and uMI. Binary classifiers were developed to further identify the parameters that can distinguish UM or SM from nMI. Local interpretable model-agnostic explanations (LIME) were used to explain the binary classifiers.

RESULTS

The multi-classification model had greater than 85% training and testing accuracy to distinguish clinical malaria from nMI. To distinguish UM from nMI, our approach identified platelet counts, red blood cell (RBC) counts, lymphocyte counts, and percentages as the top classifiers of UM with 0.801 test accuracy (AUC = 0.866 and F1 score = 0.747). To distinguish SM from nMI, the classifier had a test accuracy of 0.96 (AUC = 0.983 and F1 score = 0.944) with mean platelet volume and mean cell volume being the unique classifiers of SM. Random forest was used to confirm the classifications, and it showed that platelet and RBC counts were the major classifiers of UM, regardless of possible confounders such as patient age and sampling location.

CONCLUSION

The study provides proof of concept methods that classify UM and SM from nMI, showing that the ML approach is a feasible tool for clinical decision support. In the future, ML approaches could be incorporated into clinical decision-support algorithms for the diagnosis of acute febrile illness and monitoring response to acute SM treatment particularly in endemic settings.

Reduction in total leukocytes in malaria patients compared to febrile controls: A systematic review and meta-analysis

BACKGROUND

Leukocyte alterations are a common hematological alteration among malaria patients.

OBJECTIVES

This systematic review and meta-analysis aimed to provide data and evidence comparing alterations in total leukocyte counts in malaria patients compared to febrile/healthy subjects at baseline before treatment. A systematic review was conducted by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement for reporting systematic reviews and meta-analyses.

DATA SOURCES

Web of Science (ISI), Scopus, and Medline.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

All published articles reporting a total leukocyte count of patients infected with malaria, non-malaria (febrile or healthy group) at baseline before treatment before August 27, 2019, were retrieved, and data were extracted by two main reviewers independently.

STUDY APPRAISAL AND SYNTHESIS METHODS

We used a forest plot, heterogeneity test (Cochran's Q), and the degree of heterogeneity (I2) to test whether the included studies were heterogeneous. The quality of the included studies was determined by a quality assessment guide based on the quality assessment tool developed by the Newcastle-Ottawa Scale (NOS). Cochran's Q (Chi-square) and Moran's I2 were used to evaluate heterogeneity. Meta-regression using STATA software was conducted to find the source of heterogeneity. A funnel plot with Egger's test was used to examine the significance of publication bias among the included studies. The mean differences were estimated using a random-effects model.

RESULTS

Out of the 2,261 articles screened, 29 articles were included in this systematic review and meta-analysis. The heterogeneity test indicated that there was heterogeneity among the included studies with no publication bias. The meta-analysis demonstrated that the total leukocyte count was significantly lower in patients with malaria (n = 4,619) than in those without malaria (n = 10,056) (Z = 4.0, P-value < 0.00001, mean difference = -1.38, 95% CI = -2.06-(-0.71)). Leukocyte differential alterations, low lymphocyte counts (P-value <0.0001, mean difference = -1.03, 95% CI = -1.53-(-0.53)) and a high NL ratio were found in the malaria group (n = 1,579) compared to the non-malaria group (n = 4,991) (P-value <0.0001, mean difference = 0.6, 95% CI = 0.32-0.88). The subgroup analysis indicated that there was a significantly lower total leukocyte count in the malaria group (n = 3,545) than in the febrile group (n = 8,947) (Z = 1.33, P-value < 0.0001, mean difference = -1.76, 95% CI = -2.56-(-0.96)), but no significant difference was found between the malaria group (n = 1,232) and the healthy group (n = 1,679) (P-value > 0.05).

LIMITATIONS

As the specific diagnoses in the febrile groups were not reported in the included studies so that the results of the present study need to be carefully interpreted.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

This systematic review demonstrated that the total leukocyte count was affected by malarial infection at baseline despite the heterogeneity of the included studies. Future work must aim to understand the treatment-related total leukocyte reduction during follow-up or post-treatment outcomes in malaria-endemic settings.

Haematological Profile of Adults with Malaria Parasitaemia Visiting the Volta Regional Hospital, Ghana

Background

Malaria is known to cause severe health consequences due to its marked effects and alteration on the haematological parameters of infected individuals. This study evaluated the haematological profile of adult individuals infected with the malaria parasite.

Methods

A retrospective study was conducted using archived data of malaria positive cases from January 2017 to March 15, 2019. Data retrieved included subjects' demographics, malaria parasite count, malaria parasite species, and full blood count parameters. A total of 236 malaria positive subjects were included in the study.

Results

The study showed that more females were infected with the malaria parasite than males (69.07% and 30.93%, respectively). A total of 87.3% of the study population were infected with Plasmodium falciparum as compared to 12.7% infected with Plasmodium malariae. The commonest haematological abnormalities that were seen in this study were lymphopenia (56.78%), anaemia (55.51%), thrombocytopenia (47.46%), eosinopenia (45.76%), neutropenia (29.24%), monocytosis (21.19%), and leucocytosis (17.37%) in the infected subjects. The mean platelet count of P. falciparum-infected subjects was decreased as compared to the mean platelet count of P. malariae-infected subjects. There was a significant (P value <0.05) decrease in the number of platelet count with every unit increase in parasite density.

Conclusion

Study participants infected with malaria demonstrated vital changes in haematological parameters with anaemia, thrombocytopenia, lymphopenia, monocytosis, and eosinopenia being the most important predictors of malaria infection especially with P. falciparum species.P. falciparum-infected subjects was decreased as compared to the mean platelet count of.

Neutrophil extracellular traps drive inflammatory pathogenesis in malaria

Neutrophils are essential innate immune cells that extrude chromatin in the form of neutrophil extracellular traps (NETs) when they die. This form of cell death has potent immunostimulatory activity. We show that heme-induced NETs are essential for malaria pathogenesis. Using patient samples and a mouse model, we define two mechanisms of NET-mediated inflammation of the vasculature: activation of emergency granulopoiesis via granulocyte colony-stimulating factor production and induction of the endothelial cytoadhesion receptor intercellular adhesion molecule-1. Soluble NET components facilitate parasite sequestration and mediate tissue destruction. We demonstrate that neutrophils have a key role in malaria immunopathology and propose inhibition of NETs as a treatment strategy in vascular infections.

High-Sensitivity C-Reactive Protein: A Potential Ancillary Biomarker for Malaria Diagnosis and Morbidity

Background

Malaria remains an important cause of morbidity and mortality in Africa. Previous studies that assessed C-reactive protein (CRP) have centered on the conventional method. This study evaluated the usefulness of high-sensitivity CRP (hs-CRP) in malaria diagnosis and morbidity in a pediatric population in Ghana.

Methodology

A total of 267 subjects (100 microscopically proven nonmalarial parasitaemics as controls and 167 plasmodium parasitaemic subjects as cases), between the ages of 7 months and 18 years, were recruited for this case-control study. Blood samples were collected for malaria parasite density by microscopic examination; full blood count, electrolytes, and liver function tests using an automated analyzer; and hs-CRP levels by sandwich ELISA method.

Results

The median hs-CRP concentration was lowest in the control group and increased significantly from low to high parasitaemia. The median hs-CRP level was significantly higher in high malaria parasitaemia compared to moderate and low malaria parasitaemia. Increasing hs-CRP cutoff (3.12-4.64 mg/L) presented with increasing specificity (79.3-93.1%) and sensitivity (96.4%-97.4%), except for moderate parasitaemia where a decline in sensitivity (80.9%) was observed. However, hs-CRP had relatively lower PPV but high NPV at low parasitaemia while both the PPV and NPV were moderate in moderate parasitaemia.

Conclusion

hs-CRP yielded a high sensitivity, specificity, and accuracy for low, moderate, and high-grade malaria, respectively, and thus may serve as an effective supplementary diagnostic and prognostic biomarker for Plasmodium parasite infection. However, hs-CRP might not be readily useful yet for diagnostic purposes in hospitals due to the relatively low PPV and NPV for low and moderate parasitaemia and thus necessitates further studies in larger cohorts.

Antierythropoietin Antibody Production Is Not Associated with Malaria and Malaria-Related Anaemia in Humans

Introduction

The pathophysiology of malaria-related anaemia is not fully understood although increased destruction of parasitized and nonparasitized erythrocytes, as well as inadequate erythropoiesis, has been proposed. Circulating antierythropoietin (anti-EPO) antibodies have also been implicated in malaria and malaria-related anaemia in mice. However, studies on this association have not been investigated in humans. This study therefore determined the prevalence of anti-EPO antibody production and assessed its association with malaria and malaria-related anaemia in humans.

Methods

A total of 86 children aged 1-10 years (57 children with malaria serving as the case group and 29 healthy children serving as control), all residents of Duayaw Nkwanta, Ghana, were recruited for this case-control study. Venous blood was collected for thick and thin films for malaria microscopy, full blood count by automated haematology analyzer, and antierythropoietin antibody and erythropoietin estimation by sandwich ELISA method.

Results

Out of the 86 participants recruited, only 3 (3.5%) were positive for anti-EPO antibody; 2.3% of the case group; and 1.2% of the control group. There was no association between the cases and the controls in the production of anti-EPO antibodies. Erythropoietin concentration was significantly higher in malaria-related anaemic subjects (p=0.032).

Conclusion

Antierythropoietin antibodies are not associated with malaria infection and malaria-related anaemia in humans. Erythropoietin concentration is associated with malaria-related anaemia.

Correlation of malaria parasitaemia with peripheral blood monocyte to lymphocyte ratio as indicator of susceptibility to severe malaria in Ghanaian children

Background

Even though malaria is generally on the decline due extensive control and elimination efforts, it still remains a public health problem for over 40% of the world’s population. During the course of malaria infection, parasites and red blood cells come under oxidative stress and there is host immune response in an attempt to protect the red blood cells. The frequency of monocytes and lymphocytes in peripheral blood might, therefore, be expected to reflect the state of an individual’s immune response to the infection. Circulating monocytes and lymphocytes could therefore serve as an index in relation to malaria parasitaemia. The purpose of this study was to determine whether the relative count of monocytes to lymphocytes in peripheral blood (M:L ratio) can predict parasitaemia and, therefore, the severity of malaria infection.

Methods

Two millilitre of venous blood sample were taken from participants by venisection into anticoagulant tubes. Thick and thin blood films were made and stained with Giemsa and examined for malaria parasites. Whole blood specimen were analysed for full blood count using ABX Pentra 60 C+ automated haematological analyzer. Data was entered into Microsoft Word and analysed using Statistical Package for Social Sciences (SPSS, Version 20.0) and Graphpad prism. Spearman’s correlation was used to determine correlation between occurrences of clinical malaria and the monocytes and lymphocytes ratio. Statistical significance was taken as p ≤ 0.05 with 95% confidence interval.

Results

The study comprised of 1629 (m = 896; f = 733) children up to 5 years presenting with clinical malaria as cases and 445 (m = 257; f = 188) apparently healthy children as controls. The results indicated that there was a significant positive correlation between the monocytes to lymphocytes ratio and the presence of parasites (p = 0.04) and the level of parasitaemia within the age group of 0–3 years (p = 0.02) and 4–5 years (p = 0.03).

Conclusions

The monocyte to lymphocyte ratio obtained correlated positively with the presence of malaria as well as the level of parasitaemia. The outcome of this work implies that monocyte to lymphocyte ratio can be used to predict the level of parasitaemia and together with other factors, the development of severe malaria.

Hematological abnormalities in patients with malaria and typhoid in Tamale Metropolis of Ghana

Objective

Anemia, Leukopenia, and thrombocytopenia are commonly observed hematological abnormalities in malaria and typhoid patients. In this study, we evaluated the prevalence of cytopenias in patients with mono-infections of plasmodium parasites (malaria group) or salmonella bacteria (typhoid group). Full blood counts from 79 patients (age ranging from 18 to 77 years) categorized into malaria and typhoid groups at the Tamale Central Hospital were assessed.

Results

Data generated were entered and analyzed using SPSS version 20 and Graphpad Prism 6. Values were observed to be significant at p < 0.05. The prevalence of cytopenias were; 29.6, 48.0% for anemia, 38.9, 12.0% for thrombocytopenia, 20.4, 12.0% for leukopenia, 13.0, 8.0% for bicytopenia and 5.6, 4.0% for pancytopenia in both malaria and typhoid groups respectively. Between the two groups of patients, thrombocytopenia was significantly associated with those in the malaria group (χ² = 5.84, p < 0.016). No association was found between cytopenias and gender in patients in the malaria group; however, the middle aged group, 36–55 years, was significantly associated with anemia (χ² = 12.97, p < 0.002). Cytopenias were not associated with gender, and with different age categories in patients in the typhoid group.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3456-9) contains supplementary material, which is available to authorized users.

Evaluation of hematological indices of childhood illnesses in Tamale Metropolis of Ghana

BACKGROUND

Although hematological indices cannot in entirety be used to diagnose diseases or defects, the appropriate interpretation of these indices could complement diagnostics such as microscopy and serology for numerous illnesses in children. This study sought to evaluate distinct hematological indices characterizing different childhood illnesses.

METHODS

Full blood counts from 150 children (age range from 1 to 15 year) presenting different disease conditions at the Tamale Central Hospital were assessed. The hematological indices were compared between disease categories, and relationships between disease indicators were determined.

RESULTS

The prevalence of the diagnosed childhood illness were: 50.7% malaria, 20.0% diarrhea, 13.3% typhoid fever, 10.0% Sickle Cell Disease (SCD), and 6.0% malaria-typhoid co-infection. Fever was diagnosed in a majority (66.0%) of the children, but was independent of each disease group, (χ²  = 9.18, P = .057). Of the 24 hematological indices analyzed, eight; red blood cell (RBC) (P < .001), hemoglobin (Hb) (P < .001), mean cell volume (MCV) (P = .002), mean cell hemoglobin (MCH) (P < .001; lowest and below normal range for SCD), red cell distribution width (RDW_CV) (P < .001), eosinophil percentage [EOS (%)] (P = .001), eosinophil number [EOS#] (P = .002), and platelets (PLT) (P = .001; lowest for malaria) differed significantly across the different disease groups. Levels of Hb and/or MCV were below the normal reference ranges for most of the diagnosed diseases. In addition, low PLT and MCH were respectively distinct for children with malaria and SCD.

CONCLUSION

Hematological indices including Hb, MCV and PLT, or MCH may be useful indices that could incite further diagnostic tests for malaria or SCD among children in Ghana.