Effect of malarial infection on haematological parameters in population near Thailand-Myanmar border

Evaluation of the antimalarial and CD4+ T-cell modulatory effects of leaf methanol extract of Phyllanthus muellerianus (Kuntze) Exell (Phyllanthaceae) in Plasmodium berghei-infected mice

ETHNOPHARMACOLOGICAL RELEVANCE

Phyllanthus muellerianus (Kunze) Exell, a member of the Phyllanthaceae family, is a medicinal plant widely distributed in Africa. Decoctions from the leaves are used in Nigeria to treat fevers, convulsions, some neurological disorders and malaria.

AIM OF THE STUDY

This study is to evaluate the anti-malarial properties of methanol extract of Phyllanthus muellerianus (MEPM) leaves and its ethyl acetate fraction using a murine malaria model infected with Plasmodium berghei. Additionally, we seek to investigate the potential modulatory effects of this extract and fraction on CD4+ T-cell populations in the context of malaria infection.

MATERIALS AND METHODS

The anti-malarial effects of the leaf methanol extract of Phyllanthus muellerianus (MEPM) were screened using three established in vivo models of anti-plasmodial screening namely the curative, suppressive and prophylactic models. The methanol extract (MEPM) was afterwards fractionated into hexane (HFPM), ethyl acetate (EAFPM), and methanol (MFPM) fractions. In the pilot anti-malarial screening of the fractions, EAFPM exhibited the best antiparasitic activity. Subsequently, EAFPM was screened for anti-malarial activity using the three models above. The effects of the MEPM and EAFPM on haematological indices (Hb and PCV) of the inoculated animals were further screened and the mean survival time (MST) of the animals was monitored. CD4+ T cells of various groups were counted before and after treatment using a flow cytometer. The EAFPM was further subjected to HPLC analysis for identification of its major compounds.

RESULTS

The EAFPM (100 and 200 mg/kg) elicited 88% and 93% cure respectively in the curative model, while artesunate (5 mg/kg,- the positive control) gave 87% protection. The MEPM and EAFPM also gave significant suppression of parasitemia in the suppressive model. The treated groups survived beyond 28 days as against 11 days by the control group (infected but not treated). The treated groups also prevented anaemia seen in the negative control. The EAFPM group significantly modulated the CD4+ T cell. Compounds identified were Gallocatechin, Quercetin -3-O-gallate, Ellagic acid, and Methylellagic acid rhamnoside).

CONCLUSION

The study established that the leaf of Phyllanthus muellerianus possesses antimalarial activity, thus lending support to its use in the folkloric treatment of malaria.

Association between asymptomatic Plasmodium falciparum malaria infection, anaemia and mean corpuscular volume of school children in the Volta Region of Ghana

Background

Although, several studies have reported abnormal Mean Corpuscular Volume (MCV) values and anaemia associated with malaria infections with a focus on Plasmodium falciparum among patients with complicated and uncomplicated malaria, none has looked at the association with asymptomatic malaria. This study aimed to assess this association.

Methods

We conducted a cross-sectional study using 3 mL of blood samples from 549 children aged 5-17 years attending 5 schools selected in the Volta Region. Semi-structured questionnaires were administered to the children to obtain demographic data. Blood samples were collected to estimate the children's full blood count (FBC) and malaria status. Data obtained were analysed using STATA 15 software. P-values of less than 0.05 were considered statistically significant.

Results

Most of the children in this study (49.9%) had normal MCV (81.3-91.3 fL) with an overall malaria prevalence of 55.6 % (95% CI: 51.3-59.8) and anaemia prevalence of 48.6% (95% CI 44.4-52.9). Most anaemic children had normal MCV (81.3-91.3 fL) (49.8, 95% CI 43.7-56.0). The predicted probability of malaria was highly likely among children with normal MCV (81.3-91.3 fL) but with high variability and uncertainty among those with low MCV (<81.3 fL) and high MCV (>91.3 fL).

Conclusion

This study shows a reduced predicted probability of malaria among children with low and high MCV, playing a protective function against malaria. Further studies are required to elucidate the interaction.

Alteration of prothrombin time in Plasmodium falciparum and Plasmodium vivax infections with different levels of severity: a systematic review and meta-analysis

Malaria infection leads to hematological abnormalities, including deranged prothrombin time (PT). Given the inconsistent findings regarding PT in malaria across different severities and between Plasmodium falciparum and P. vivax, this study aimed to synthesize available evidence on PT variations in clinical malaria. A systematic literature search was performed in PubMed, Embase, Scopus, Ovid, and Medline from 27 November 2021 to 2 March 2023 to obtain studies documenting PT in malaria. Study quality was evaluated using the Joanna Briggs Institute checklist, with data synthesized through both qualitative and quantitative methods, including meta-regression and subgroup analyses, to explore heterogeneity and publication bias. From 2767 articles, 21 studies were included. Most studies reported prolonged or increased PT in malaria patients compared to controls, a finding substantiated by the meta-analysis (P < 0.01, Mean difference: 8.86 s, 95% CI 5.32-12.40 s, I2: 87.88%, 4 studies). Severe malaria cases also showed significantly higher PT than non-severe ones (P = 0.03, Hedges's g: 1.65, 95% CI 0.20-3.10, I2: 97.91%, 7 studies). No significant PT difference was observed between P. falciparum and P. vivax infections (P = 0.88, Mean difference: 0.06, 95% CI - 0.691-0.8, I2: 65.09%, 2 studies). The relationship between PT and malaria-related mortality remains unclear, underscoring the need for further studies. PT is typically prolonged or increased in malaria, particularly in severe cases, with no notable difference between P. falciparum and P. vivax infections. The inconsistency in PT findings between fatal and non-fatal cases highlights a gap in current understanding, emphasizing the need for future studies to inform therapeutic strategies.

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.

Predictors of Comorbidity of Malaria and Septicemia in Children Living in Malaria-Endemic Communities in Nigeria

PURPOSE

The study attempted to identify possible overlap between serum cell-reactive proteins (C-rp) and hematological indices as predictors of comorbidity of malaria and septicemia among children attending primary healthcare facilities in Ilorin, Nigeria.

METHODS

One hundred and ninety-three children (aged: ≤ 1-15 years) presenting with symptoms suggestive of malaria were enrolled. Blood specimens were collected and screened for: Romanowsky, culture, serum C-RP and hematological indices.

RESULTS

One hundred and fifteen (59.6%) children had Plasmodium falciparum infections (female 69.0% and male 34.1%). Septicemia was common among 52 (26.9%), but malaria and septicemia co-infection was 42 (36.5%). C-rp levels were low (< 10 mg/L) in 41 (35.7%, OR 4.594, CI 2.463-8.571) and high (> 10 mg/L) in 74 (64.3%, OR 2.519, CI 1.681-3.775) among the malaria positives (p < 0.05). Children with low C-rp, 8 (15.4%, OR 9.413, CI 4.116-21.531) were positive for septicemia and high C-RP 44 (84.6%, OR 1.694, CI 1.396-2.055), but without malaria, respectively. Similarly, increased C-rp levels were significantly associated with clinical malaria; > 10,000 parasites/μL (OR 1.486, CI 1.076-2.054, P < 0.001). Malaria-positive versus negative showed that PCV, C-rp, hemoglobin, platelet, WBC, and neutrophil were statistically significant (P < 0.05). Two bacteria species were identified, viz; Staphylococcus aureus 39 (54.9%) and Escherichia coli 32 (45.1%). The trade-off between sensitivity and specificity occurred at 16.475 cut-off using C-rp and degree of malaria severity as the standard for AUROC.

CONCLUSION

C-rp are inflammatory markers, though non-specificity may be associated with malaria prognosis and severity during malaria-septicemia co-infection.

Higher platelet counts and platelet factors are associated with a reduction in Plasmodium falciparum parasite density in young Malian children

OBJECTIVES

The association between thrombocytopenia and parasite density or disease severity is described in numerous studies. In recent years, several studies described the protective role of platelets in directly killing Plasmodium parasites, mediated by platelet factor 4 (PF4) binding to Duffy antigen. This study aimed to evaluate the protective role of platelets in young children who are Duffy antigen-negative, such as those in sub-Saharan Africa.

METHODS

A zero-inflated negative binomial model was used to relate platelet count and parasite density data collected in a longitudinal birth cohort. Platelet factors were measured by enzyme-linked immunosorbent assay in samples collected from malaria-infected children who participated in a cross-sectional study.

RESULTS

We described that an increase of 10,000 platelets/μl was associated with a 2.76% reduction in parasite count. Increasing levels of PF4 and CXCL7 levels were also significantly associated with a reduction in parasite count.

CONCLUSIONS

Platelets play a protective role in reducing parasite burden in Duffy-negative children, possibly mediated through activation of the innate immune system.

Elevation of free triiodothyronine (fT3) levels by Plasmodium falciparum independent of thyroid stimulating hormone (TSH) in children with uncomplicated malaria

BACKGROUND

Malaria parasites have a devastating effect on the infected host. However, there is a paucity of data on the effect of Plasmodium falciparum on thyroid hormones.

METHODS

This case-control study (1:1) involved children <16 years of age with uncomplicated malaria. Hematological parameters were determined using the URIT-5380 hematology analyzer (China). Later, levels of thyroid hormones, namely free triiodothyronine (fT3), free tetraiodothyronine (fT4), and thyroid-stimulating hormone (TSH), were determined using human ELISA kits (DiaSino ELISA kit, Zhengzhou, China).

RESULTS

Ninety children with malaria and ninety matched control group were studied. Overall, compared to the control group, lower TSH (3.43 ± 1.25 vs. 3.84 ± 1.34, p = 0.035) and elevated levels of fT3 levels (5.85 ± 1.79 vs. 3.89 ± 1.19, p < 0.001) were observed in patients with malaria. However, fT4 levels were comparable between cases and control group (16.37 ± 2.81 vs 17.06 ± 3.5, p = 0.150). Free T3 levels were significantly higher in children <10 years (p < 0.001) and higher among male children with malaria (p < 0.001). Overall, there was a significant positive relationship between parasite counts and fT3 (R = 0.95, p < 0.001). Furthermore, body temperature was positively correlated with fT3 (R = 0.97, p < 0.001).

CONCLUSIONS

Isolated fT3 thyrotoxicosis was observed in falciparum malaria, especially in children <10 years and male malaria patients, independent of TSH. This observation could explain the severity of malaria in children.

CO-INFECTION WITH MALARIA AND INTESTINAL PARASITES AND ITS ASSOCIATION WITH ANEMIA IN CHILDREN (ZERO TO TEN YEARS OLD) IN TIKO SUBDIVISION, CAMEROON

Concomitant infections with malaria and intestinal parasitic infections may be associated with anemia in children (0-10 yr). This study determined the prevalence of co-infection with malaria and intestinal parasitic infections and determined its association with anemia in children (0-10 yr) in Tiko, Cameroon. A hospital-based cross-sectional study was carried out whereby venous blood and stool samples were collected from 377 febrile children. Blood was used to perform a full blood count. Thick and thin blood films were prepared and stained with Giemsa for malaria parasite diagnosis. The formol ether concentration technique was used to analyze the stools. Pearson's chi-square test, Student's t-test, and other statistical analyses were performed. Of the 377 participants, 139 (36.9%) were positive for malaria, 21 (5.6%) had intestinal helminths, 8 (2%) had co-infection, and 79 (21.0%) were anemic. Malaria and anemia were prevalent among the children and were significantly associated (P = 0.025). There was no statistically significant difference (P > 0.05) among age groups. Girls were more often infected with malaria (69, 37.3%), and boys were more often infected with intestinal parasites (13, 7.0%), but there was no statistical association for both malaria and intestinal parasitic infections (IPIs) for both sexes (P > 0.05). Hookworms, Ascaris lumbricoides, and Trichuris trichiura were the intestinal parasites found in this study. There was a significant association between anemia and parasitic co-infection in children (P = 0.003). Malaria and IPIs are prevalent in the Tiko municipality. They play a great role in anemia especially when there is a co-infection. Public education and awareness campaigns are necessary in this municipality.

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.

An Observational Study Comparing the Effects of Chloroquine and Artemisinin-Based Combination Therapy on Hematological Recovery in Patients With Plasmodium vivax Malaria

Introduction Malaria, a common parasitic disease in tropical regions, produces hematological changes in patients. In the present study, we compare hematologic recovery between the chloroquine and artemether-lumefantrine treatment groups of patients with Plasmodium vivax malaria. Methodology This was a cross-sectional observational study comparing hematological parameters, including total and differential white blood cell counts, and platelet counts between two patient groups: one group with 48 patients receiving chloroquine, and the other with 47 patients receiving the artemether-lumefantrine combination. Both groups received primaquine to combat the hypnozoite stage. Results The rate of platelet count recovery was significantly faster in patients treated with the artemether-lumefantrine combination (p-value 0.002). Rates of recovery of the total white blood cell count and neutrophil count were faster with the artemether-lumefantrine combination, while the recovery of the lymphocyte count was faster in patients treated with chloroquine. However, these changes were statistically insignificant (p-values = 0.69, 0.42, and 0.65, respectively). Conclusion Based on hematological recovery, artemisinin combination therapy may be preferred over treatment with chloroquine in cases of P. vivax malaria. However, factors such as the adverse effect profile, cost-effectiveness, and chloroquine resistance need to be considered for the practical applicability of the same.

Pre-vaccination monocyte-to-lymphocyte ratio as a biomarker for the efficacy of malaria candidate vaccines: A subgroup analysis of pooled clinical trial data

BACKGROUND

Pre-vaccination monocyte-to-lymphocyte ratio was previously suggested as a marker for malaria vaccine effectiveness. We investigated the potential of this cell ratio as a marker for malaria vaccine efficacy and effectiveness. Effectiveness was investigated by using clinical malaria endpoint, and efficacy was investigated by using surrogate endpoints of Plasmodium falciparum prepatent period, parasite density, and multiplication rates in a controlled human malaria infection trial (CHMI).

METHODS

We evaluated the correlation between monocyte-to-lymphocyte ratio and RTS,S vaccine effectiveness using Cox regression modeling with clinical malaria as the primary endpoint. Of the 1704 participants in the RTS,S field trial, data on monocyte-to-lymphocyte ratio was available for 842 participants, of whom our analyses were restricted. We further used Spearman Correlations and Cox regression modeling to evaluate the correlation between monocyte-to-lymphocyte ratio and Whole Sporozoite malaria vaccine efficacy using the surrogate endpoints. Of the 97 participants in the controlled human malaria infection vaccine trials, hematology and parasitology information were available for 82 participants, of whom our analyses were restricted.

RESULTS

The unadjusted efficacy of RTS,S malaria vaccine was 54% (95% CI: 37%-66%, p <0.001). No correlation was observed between monocyte-to-lymphocyte ratio and RTS,S vaccine efficacy (Hazard Rate (HR):0.90, 95%CI:0.45-1.80; p = 0.77). The unadjusted efficacy of Whole Sporozoite malaria vaccine in the appended dataset was 17.6% (95%CI:10%-28.5%, p<0.001). No association between monocyte-to-lymphocyte ratio and the Whole Sporozoite malaria vaccine was found against either the prepatent period (HR = 1.16; 95%CI:0.51-2.62, p = 0.72), parasite density (rho = 0.004, p = 0.97) or multiplication rates (rho = 0.031, p = 0.80).

CONCLUSION

Monocyte-to-lymphocyte ratio alone may not be an adequate marker for malaria vaccine efficacy. Further investigations on immune correlates and underlying mechanisms of immune protection against malaria could provide a clearer explanation of the differences between those protected in comparison with those not protected against malaria by vaccination.

A systematic review and meta-analysis of inflammatory biomarkers associated with malaria infection and disease severity

Inflammatory biomarkers; C-reactive protein (CRP), Interleukin 6 (IL-6), and tumor necrosis factor- alpha (TNF-α) play a very crucial role in disease pathogenesis. Studies conducted earlier showed the associativity of these biomarkers with malaria severity. Meta-analysis of individual biomarkers was done in many studies, while in a few others, all these candidates were estimated, but the findings were inconclusive. Therefore, a systematic review and meta-analyses were performed to evaluate differences in biomarkers mentioned above in complicated and uncomplicated malaria patients. Studies focussed on CRP, IL-6, and TNF-α with quantitative data on complicated and uncomplicated malaria patients were searched on PubMed, Scopus, and Google Scholar. The quality of the studies selected for this review was checked following Newcastle-Ottawa Scale guidelines. The standard mean difference and confidence interval of biomarkers in the targeted groups were calculated using the random effects model. Egger's test and funnel plot asymmetry were performed to assess the publication bias. Thirteen studies that qualified the inclusion criteria were considered for this meta-analysis. CRP levels were higher in complicated malaria patients than uncomplicated ones (P < 0.00001, pooled SMD: 0.90 mg/L, 95 % CI: 0.51 to 1.30 mg/L, I2: 80 %, six studies). IL-6 levels were elevated in complicated cases (P < 0.00001, pooled SMD: 0.89 pg/ml, 95 % CI: 0.66 to 1.12, I2: 99 %, four studies) and TNF-α also showed an increase in severe complicated patients (P < 0.00001, pooled SMD: 1.18 pg/ml, 95 % CI: 1 to 1.36, I2: 99 %, six studies). In most of the included studies, CRP, IL-6, and TNF-α were higher in complicated malaria patients. Nevertheless, the results of a few studies were not convincing. Due to the lack of specificity in all individual biomarkers, none had adequate diagnostic accuracy. Considering the role of pro-inflammatory cytokines in the CRP activation pathway in malaria progression, the combination of these biomarkers should be used in monitoring the disease severity.

Association between hemoglobin variants and laboratory outcomes in patients infected with P. falciparum from South West Uganda

Aims

We assess the relationship between various hemoglobin variants and some hematological parameters packed cell volume, white blood cells (PCV, WBC) and parasitemia level of patients with malaria in the southwestern, Uganda.

Methods

Patient were enrolled by rapid diagnostic tests (RDTs), confirmed by microscopy, and laboratory outcomes were determined.

Results

Patients positive for malaria RDTs were 155, microscopic-confirmed P. falciparum parasites were 95 (61.29%) having hemoglobin variants HbAA and HbAS; 75 (78.95%) and 13 (13.68%), respectively. The laboratory outcomes showed mean, PCV (32.19 ± 4.83), WBC (5831.66 ± 2888.29) and P. falciparum parasitaemia density (32,605.45 ± 14031), while the hemoglobin variants mean values AA (39,008.85 ± 31,261.56), AC (15908 ± 10173.48), AS (16,561.46 ± 15,380.93), SC (30,524 ± 0.000) and SS(1652 ± 0.000) were significantly different from the total population (34,321.5 ± 21,924.26) parasite-density.

Conclusion

Patients with hemoglobin variants HbAA had a significantly higher parasite-carrying capacity and PCV levels.

Increased Neutrophil Percentage and Neutrophil-T Cell Ratio Precedes Clinical Onset of Experimental Cerebral Malaria

Newly emerging data suggest that several neutrophil defense mechanisms may play a role in both aggravating and protecting against malaria. These exciting findings suggest that the balance of these cells in the host body may have an impact on the pathogenesis of malaria. To fully understand the role of neutrophils in severe forms of malaria, such as cerebral malaria (CM), it is critical to gain a comprehensive understanding of their behavior and functions. This study investigated the dynamics of neutrophil and T cell responses in C57BL/6 and BALB/c mice infected with Plasmodium berghei ANKA, murine models of experimental cerebral malaria (ECM) and non-cerebral experimental malaria, respectively. The results demonstrated an increase in neutrophil percentage and neutrophil-T cell ratios in the spleen and blood before the development of clinical signs of ECM, which is a phenomenon not observed in the non-susceptible model of cerebral malaria. Furthermore, despite the development of distinct forms of malaria in the two strains of infected animals, parasitemia levels showed equivalent increases throughout the infection period evaluated. These findings suggest that the neutrophil percentage and neutrophil-T cell ratios may be valuable predictive tools for assessing the dynamics and composition of immune responses involved in the determinism of ECM development, thus contributing to the advancing of our understanding of its pathogenesis.

Clinico-Serological Profile of Infective Causes of Acute Hepatitis in Children Admitted to a Tertiary Care Centre

BACKGROUND

Hepatitis is a major cause of healthcare burden in India. Hepatitis A is the most common cause of acute viral hepatitis in the pediatric population whereas hepatitis E virus (HEV) is the most important cause of epidemic hepatitis. Various other causes of acute infective hepatitis in children are dengue, malaria, and enteric fever. The aim of the present study is to understand the clinico-serological profile in cases of acute infective hepatitis in children.  Methodology: The present study is a cross-sectional study that was carried out from 1 September 2017 to 31 March 2019. A total of 89 children in the age group 1-18 years with clinically suspected acute infective hepatitis and subsequent confirmation on laboratory tests were included in the study.

RESULTS

Hepatitis A (48.3%) was found to be the most common aetiology followed by dengue (22.5%) and hepatitis E (12.4%). No cases of hepatitis B or hepatitis C were found. The most common presenting complaint was fever (90%) and the most common clinical finding was icterus (69.7%). The sensitivity of icterus for the diagnosis of hepatitis was found to be 70%. Lab investigations showed a significant association between different etiologies of infective hepatitis with packed cell volume (PCV), white blood cell (WBC) count, and platelet count. Levels of aspartate aminotransferase (AST) and alanine transaminase (ALT) were raised in samples of patients with hepatitis A, hepatitis E, and combined hepatitis A and E infection as compared to other causes. All cases of hepatitis A and E were diagnosed with positive IgM antibody tests to the respective viral antigens. The most common complication was hepatic encephalopathy which was seen in patients with hepatitis A, dengue, and septicemia. Around 99% of patients recovered well and were discharged. One death occurred in a case of septicemia with septic shock with multiple organ dysfunction syndrome (MODS).

CONCLUSION

The most common cause of infective hepatitis in children is hepatitis A. Other causes like dengue, malaria, and typhoid should also be kept in mind. The absence of icterus does not rule out hepatitis. Lab investigations including serology are important to confirm the diagnosis of various causes of hepatitis. Timely immunization against hepatitis is strongly recommended.

Key cytokines and hematological parameters in patients with uncomplicated falciparum malaria in Hodeidah, Yemen

Immunity to malaria has a major role in controlling disease and pathogenesis with cytokine production being involved in almost every phase of the immune response. The present study aimed to assess hematological variables and to measure plasma levels of TNFα, IFNγ and IL10, their ratios, and their relation to parasitemia among patients with uncomplicated falciparum malaria in Hodeidah, Yemen. Forty patients with uncomplicated P. falciparum monoinfection and 40 healthy age and sex-matched controls were enrolled in the study. Parasitological diagnosis was confirmed, and parasite density was estimated. Plasma cytokine levels, hematologic parameters, and the presence of gametocytes were determined. Results revealed higher TNFα, IFNγ and IL10 in patients than in controls. A relatively higher IL10 production was demonstrated by the significantly lower TNFα/IL10 and IFNγ/IL10 ratios in patients than in controls. TNFα and IL10 correlated positively with parasite density. Lower Hb levels, RBC, lymphocyte and platelet counts, and higher neutrophil and reticulocyte counts were observed in patients compared to controls. Reticulocyte count was higher and IFNγ level was lower in the presence of gametocytes. Conclusively, uncomplicated falciparum malaria is associated with the ability to regulate the production of pro-inflammatory and anti-inflammatory cytokines. This mediates parasite clearance while simultaneously avoiding severe pathology.

Thrombocytopenia a predictor of malaria: how far?

Malaria is an acute febrile illness. It is a dangerous disease that contributes to millions of hospital visits and hundreds of thousands of deaths, especially in children residing in sub-Saharan Africa. In a non-immune individual, symptoms usually appear 10-15 days after the infective mosquito bite. The first symptoms-fever, headache, and chills-may be mild and difficult to recognize as malaria. If not treated within 24 h, P. falciparum malaria can progress to severe illness, often leading to death. Children with severe malaria frequently develop one or more of the following symptoms: severe anaemia, respiratory distress in relation to metabolic acidosis, or cerebral malaria. In adults, multi-organ involvement is also frequent. In malaria endemic areas, people may develop partial immunity, allowing asymptomatic infections to occur. Haematological changes are well-recognised with malarial infection however background haemoglobinopathy, nutritional status, demographic factors and malaria immunity play a major role in specific changes in that geographical region. Artemisinin derivatives are new generation antimalarial drugs they are used in the treatment of acute attacks of severe malaria including cerebral malaria. Information on the safety of these new antimalarial drugs on body function is still scanty. Haematological parameters are well studied in P. falciparum infection, but now recent studies have indicated that these changes do occur in P. vivax infection also. Hematological profile together with microscopy will enable rapid diagnosis, prompt treatment and further complications can be avoided. This current review is aimed at providing an up-to-date information on the role of malaria and anti-malarial drugs on haematological parameters especially thrombocytopenia.

Prevalence of malaria and associated clinical manifestations and myeloperoxidase amongst populations living in different altitudes of Mezam division, North West Region, Cameroon

BACKGROUND

Malaria is a growing problem in Africa, with prevalence varies from areas to areas due to several factors including the altitude. This study aimed to investigate the malaria distribution and its relationship with level of some blood parameters and plasma myeloperoxidase (MPO) in population of three localities with different altitudes.

METHODS

A total of 150 participants were recruited in each locality and facial body temperature of each was measured using a forehead digital thermometer. Blood samples were collected and used diagnose malaria parasite using the rapid test followed by Giemsa stain microscopy and have the full blood count and MPO level using a colorimetric method.

RESULTS

The overall prevalence of falciparum malaria was 34.7%, with no difference between the three communities, but Bambili of high altitude had the highest prevalence (70.7%). A majority of the infected persons had mild malaria, with most cases being asymptomatic (temperature < 37.5 ºC). Patients had significant increase of geometric mean malaria parasite density (GMPD) in Bambili (1755 ± 216 parasites/µL) and Bamenda (1060 ± 2515 parasites/µL of blood) than patients in Santa (737 ± 799 parasites/µL). There was a significant risk to have malaria infection in Bambili (OR = 33.367, p = 0.021) than in Santa (OR = 2.309, p = 0.362). Bambili' participants of 6-10 years showed a high prevalence of malaria (85.7%). GMPD was significantly different between males (p = 0.010) as well as females (p = 0.000). Participants from Santa (11.2 ± 3.2 g/dL) and Bambili (12.6 ± 2.4 g/dL) had a high haemoglobin concentration than those from Bamenda (10.6 ± 2.1 g/dL). There was a significant difference in the WBC counts and platelet counts among infected participants in the study areas. MPO level had an increasing trend among infected participants in Santa (2.378 ± 0.250), Bambili (2.582 ± 0.482) and Bamenda (2.635 ± 0.466).

CONCLUSION

The results of the present study demonstrated that altitudinal variations significant impact the risk of population to have malaria with high parasitaemia and may contribute to the malaria prevalence and severity by affecting the haemoglobin concentration, WBC and platelet level and plasma MPO in population.

Platelet Parameters and Their Correlation with Parasitemia Levels Among Malaria Infected Adult Patients at Jinella Health Center, Harar, Eastern Ethiopia: Comparative Cross-Sectional Study

Background

Malaria is a major public health problem with the highest morbidity and mortality in developing countries. Hematological changes play a great role in malaria pathogenesis through platelets and platelet parameters. However, the changes in platelet parameters are not clearly described in Ethiopia. Therefore, this study aimed to compare platelet parameters and their correlation with parasitemia among malaria-infected adult patients and healthy adults.

Methods

An institutional-based comparative cross-sectional study was conducted involving 186 (93 malaria-infected patients and 93 healthy adults) study participants using a convenient sampling technique at Jinella health center, Harar, Eastern Ethiopia, from July 10-August 10, 2022. Five milliliters of venous blood were collected from each study participant, and platelet parameters were analyzed using a Unicel (DxH 800) automated hematologic analyzer. A drop of blood was taken from malaria-suspected patients for blood film preparation. Results between two groups were compared using the Mann-Whitney U-test. Spearman's rank correlation coefficient was used to evaluate the relationships between two continuous variables. A P-value of < 0.05 was considered statistically significant.

Results

Platelet, plateletcrit, and mean platelet volume of malaria-infected patients were significantly lower as compared with healthy adults (103 x10³cells/μL vs 268 x10³cells/μL, 0.13 fl vs 0.23 fl, and 9.6 fl vs 15.3 fl), respectively). Conversely, platelet distribution width and platelet large cell ratio were higher in malaria-infected patients than healthy adults (19.2% vs 15.3% and 0.35% vs 0.29%), respectively). Parasitemia levels had a moderately inverse correlation with platelet count (r= -0.419) and a weakly positive correlation with mean platelet volume (r=0.278).

Conclusion

The platelet, plateletcrit, and mean platelet volume of malaria-infected patients were significantly lower as compared with healthy adults. Malaria parasitemia had a moderate inverse correlation with platelet count and a weak positive correlation with mean platelet volume. Thrombocytopenia and alteration of platelet parameters should be considered in malaria patients.

Serum anti-erythropoietin antibodies among pregnant women with Plasmodium falciparum malaria and anaemia: A case-control study in northern Ghana

BACKGROUND

Anaemia in pregnancy is common in underdeveloped countries, and malaria remains the predominant cause of the condition in Ghana. Anti-erythropoietin (anti-EPO) antibody production may be implicated in the pathogenesis of Plasmodium falciparum malaria-related anaemia in pregnancy. This study ascertained the prevalence of anti-EPO antibody production and evaluated the antibodies' relationship with Plasmodium falciparum malaria and malaria-related anaemia in pregnancy.

METHODS

This hospital-based case-control study recruited a total of 85 pregnant women (55 with Plasmodium falciparum malaria and 30 controls without malaria). Venous blood was taken from participants for thick and thin blood films for malaria parasite microscopy. Complete blood count (CBC) analyses were done using an automated haematology analyzer. Sandwich enzyme-linked immunosorbent assay (ELISA) was used to assess serum erythropoietin (EPO) levels and anti-EPO antibodies. Data were analyzed using IBM SPSS version 22.0.

RESULTS

Haemoglobin (p<0.001), RBC (p<0.001), HCT (p = 0.006) and platelet (p<0.001) were significantly lower among pregnant women infected with Plasmodium falciparum. Of the 85 participants, five (5.9%) had anti-EPO antibodies in their sera, and the prevalence of anti-EPO antibody production among the Plasmodium falciparum-infected pregnant women was 9.1%. Plasmodium falciparum-infected pregnant women with anti-EPO antibodies had lower Hb (p<0.001), RBC (p<0.001), and HCT (p<0.001), but higher EPO levels (p<0.001). Younger age (p = 0.013) and high parasite density (p = 0.004) were significantly associated with Plasmodium falciparum-related anti-EPO antibodies production in pregnancy. Also, younger age (p = 0.039) and anti-EPO antibody production (p = 0.012) related to the development of Plasmodium falciparum malaria anaemia in pregnancy.

CONCLUSION

The prevalence of anti-EPO antibodies among pregnant women with Plasmodium falciparum malaria was high. Plasmodium falciparum parasite density and younger age could stimulate the production of anti-EPO antibodies, and the antibodies may contribute to the development of malarial anaemia in pregnancy. Screening for anti-EPO antibodies should be considered in pregnant women with P. falciparum malaria.

The effect of malaria on childhood anemia in a quasi-experimental study of 7,384 twins from 23 Sub-Saharan African countries

Background

Young children in Sub-Saharan Africa (SSA), particularly those from resource-limited settings, are heavily burdened by anemia and malaria. While malaria infected children frequently become anemic (hemoglobin < 110 g/L), anemia is a strongly multifactorial disease with many other risk factors than malaria. Due to the complex and often overlapping contributors to anemia, it remains challenging to isolate the true impact of malaria on population level hemoglobin concentrations.

Methods

We quantified the malaria-induced effect on hemoglobin levels in children under 5 years of age, leveraging data from 7,384 twins and other multiples, aged 6 to 59 months, from 57 nationally representative Demographic and Health Surveys (DHSs) from 23 SSA countries from 2006 to 2019. The quasi-experimental twin fixed-effect design let us minimize the impact of potential confounders that do not vary between twins.

Results

Our analyses of twins revealed a malaria-induced hemoglobin decrease in infected twins of 9 g/L (95% CI -10; -7, p<0.001). The relative risk of severe anemia was higher (RR = 3.01, 95% CI 1.79; 5.1, p<0.001) among malaria positive children, compared to malaria negative children. Conversely, malaria positive children are only half as likely to be non-anemic (RR = 0.51, 95% CI 0.43; 0.61, p<0.001).

Conclusion

Even after rigorous control for confounding through a twin fixed-effects study design, malaria substantially decreased hemoglobin levels among SSA twins, rendering them much more susceptible to severe anemia. This effect reflects the population-level effect of malaria on anemia.

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.

Evolutionary consequences of vector-borne transmission: how using vectors shapes host, vector and pathogen evolution

Transmission mode is a key factor that influences host–parasite coevolution. Vector-borne pathogens are among the most important disease agents for humans and wildlife due to their broad distribution, high diversity, prevalence and lethality. They comprise some of the most important and widespread human pathogens, such as yellow fever, leishmania and malaria. Vector-borne parasites (in this review, those transmitted by blood-feeding Diptera) follow unique transmission routes towards their vertebrate hosts. Consequently, each part of this tri-partite (i.e. parasite, vector and host) interaction can influence co- and counter-evolutionary pressures among antagonists. This mode of transmission may favour the evolution of greater virulence to the vertebrate host; however, pathogen–vector interactions can also have a broad spectrum of fitness costs to the insect vector. To complete their life cycle, vector-borne pathogens must overcome immune responses from 2 unrelated organisms, since they can activate responses in both vertebrate and invertebrate hosts, possibly creating a trade-off between investments against both types of immunity. Here, we assess how dipteran vector-borne transmission shapes the evolution of hosts, vectors and the pathogens themselves. Hosts, vectors and pathogens co-evolve together in a constant antagonistic arms race with each participant's primary goal being to maximize its performance and fitness.

Malaria and anemia in children under 7 years of age in the western region of Côte d’Ivoire

Background

Anemia is a major public health problem, affecting nearly one-quarter of the world’s population. It is defined as a reduction in the hemoglobin level in the peripheral blood to below the normal threshold set for a particular population. Very often in the subtropics, helminths or malaria co-infect an individual, causing morbidities that vary by age and region. This study aims to characterize the type of anemia observed in children under 7 years of age infected with malaria in the western region of Côte d’Ivoire, to recommend a better strategy of care.

Methods

The study was carried out from March 2020 to May 2021 in 22 villages in Man, Tonkpi Region, with a cohort of 451 children, both male and female, aged from 3 months to 6 years. The children provided venous blood samples for the diagnosis and characterization of anemia (full blood count), and Giemsa staining (GS) (thick and thin smears) and rapid diagnostic tests (RDTs) were used for the diagnosis of malaria. Risk factors and morbidity profiles were assessed using a questionnaire. Logistic regressions models were employed to identify independent risk factors and morbidity patterns associated with Plasmodium falciparum mono-infection and co-infections.

Results

Of the 451 children who completed the study, 221 (49.0%) were female and 230 (51.0%) were male. The prevalence of anemia was 55.0%, distributed as 30.7% mild, 66.1% moderate, and 3.2% severe anemia. The characterization of anemia revealed that hypochromic microcytic anemia (HMA) was the predominant type, being found in 195 (78.63%) children. It was followed by normochromic microcytic anemia (29 children, 11.69%), normochromic normocytic anemia (14 children, 5.65%), and, finally, hypochromic normocytic anemia (10 children, 4.03%). The prevalence of malaria was 66.7% and 78.3% based on GS and RDTs, respectively. The closed association between malaria (Plasmodium) and anemia led to P. falciparum alone causing 56.7% of mild, 51.3% of moderate, and 37.5% of severe anemia in children.

Conclusion

Malaria infection was highly prevalent among children aged ≤ 7 years in both sex and in different age groups, although the number of Plasmodium parasites present during infections was greatest in younger children. Similarly, the prevalence of anemia was high, with moderate anemia and HMA being more prevalent in children ≤ 7 years of age in the western region of Côte d’Ivoire.

Evaluation of anti-malarial potency of new pyrazole-hydrazine coupled to Schiff base derivatives

Background

The search for pharmacologically effective agents among molecules bearing multiple functionalities is commonly practiced. In continuation of the search for new anti-malarial agents, new pyrazole-hydrazine coupled Schiff-base derivatives previously synthesized were screened for anti-malarial property.

Methods

Here, in vivo prophylactic and curative activities of the compounds were assessed while their binding affinity for falcipain-2, a crucial enzyme in Plasmodium survival, was done using computational techniques.

Results

The two derivatives (BepINH and BepBeH) respectively led to a significant (p < 0.05) reduction in parasitaemia count (0.76 ± 1.11 and 0.79 ± 1.19) at day 3 post-treatment relative to the negative control (16.37 ± 1.25). For the prophylactic study, it was observed that the highest parasitaemia suppression level of 95.35% and 95.17% for BepINH and BepBeH at 15 mg/kg was slightly comparable to that obtained for ACT-Lonart (99.38%). In addition, their haematological profiles indicate that they are potentially beneficial in suppressing haemolytic damage to RBC, thereby protecting the body against infection-induced anaemia. Docking calculations on the derivatives toward the Plasmodium falciparum falcipain-2 revealed that they favourably interacted with a binding affinity higher than that of a known cocrystallized inhibitor.

Conclusion

This study confirms the relevance of multi-functional molecules in the search for new and effective anti-plasmodial agent and lay the foundation for further development of these compound series to potent anti-plasmodial agent that interacts with falcipain-2.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04266-8.

Evaluation of blood cell count parameters as predictors of treatment failure of malaria in Angola: An observational study

Background

Despite the guidelines provided by the World Health Organization for the treatment of malaria, treatment failure occurs in many hospitalized patients.

Objective

Evaluate whether blood cell count parameters may serve as predictors for malaria treatment.

Methodology

A cross-sectional study with a quantitative approach.

Results

Of the 219 patients, 21.5% showed failure to antimalarial treatment, Patient with 21 and 40 years (72.6%), male (53.4%), from peri-urban area (47.5%), with high parasitemia (59.8%), treated with Arthemeter (90.9%) and the mortality were 5.9%. Significant associations were observed between occupation, level of parasitemia and outcome with resistance to antimalarial treatment (p<0.05). Patients with normal Hb [OR: 0.75 (95% CI: 0.39–1.44), p = 0.393], RBC [OR: 0.83 (95% CI: 0.40–1.72), p = 0.632], RDW [OR: 0.54 (95% CI: 0.27–1.09), p = 0.088], MCV [OR: 0.61 (95% CI: 0.28–1.31), p = 0.204] were less likely to have malaria treatment failures after artemisinin-based therapy failure. In contrast, those with normal values of segmented neutrophils [OR: 0.32 (95% CI: 0.11–0.96), p = 0.042] and lymphocyte counts [OR: 0.24 (95% CI: 0.05–1.04), p = 0.055]. We also found that patients with significant low levels of Hct [OR: 0.31 (95% CI: 0.15–0.64) p = 0.002], and high leukocytes [OR: 8.88 (95% CI: 2.02–37.2), p = 0.004] and normal platelet values [OR: 1.42 (95% CI: 0.73–2.95), p = 0.280] demonstrated high probability of treatment failure.

Conclusion

The importance of blood cell count parameters in monitoring malaria therapy necessitates the urgent need to re-evaluate Artemether-based therapy. Future studies involving more participants in different settings are needed to provide further evidence.

Association between vitamin D serum levels and clinical, laboratory, and parasitological parameters in patients with malaria from an endemic area of the Amazon

Background:

Some studies have suggested the importance of vitamin D [25(OH)D] in malaria clinical practice. The prevalence of 25(OH)D deficiency in the Amazon population is not well known, and there are few studies in patients with malaria. This study aimed to evaluate 25(OH)D serum levels in patients with malaria and determine their relationships with epidemiological, clinical, laboratory, and parasitemia data.

Methods:

An analytical cross-sectional study of 123 patients with malaria and 122 individuals without malaria was performed in Itaituba, Pará, Brazil, from January 2018 to October 2019, by evaluating sociodemographic, clinical-epidemiological, parasitological, and laboratory data and adopting a 5% significance level. Parametric tests (Student's t-test), non-parametric tests (Mann-Whitney U), and Spearman’s correlation ([r_s], for non-parametric variables) were used according to the nature of the distribution of the variables. For the qualitative variables, Pearson's chi-square test, Fisher's exact test, and the G test were used. Spearman's correlation was used to compare the results of the 25(OH)D levels and blood counts performed among patients and the control group.

Results:

Malaria patients residing in a mining area had 25(OH)D serum levels that were significantly lower than those in the control group residing in the mining area, though both were within normal levels. Red blood cell counts had an inverse correlation with parasitemia (Plasmodium falciparum), and platelet levels had an inverse correlation with parasitemia (Plasmodium vivax). 25(OH)D deficiency was evidenced in Itaituba, in the state of Pará, which is an endemic area of malaria in the Amazon region.

The roles of betulinic acid on circulating concentrations of creatine kinase and immunomodulation in mice infected with chloroquine-susceptible and resistant strains of Plasmodium berghei

Complete malarial therapy depends largely on the immunological and inflammatory response of the host to the invading potentials of malarial parasite. In this study, we evaluated the roles of betulinic acid on immunological response, anti-inflammatory potentials, cardiac and skeletal muscle tissue damage in mice infected with chloroquine susceptible (NK 65) and resistant (ANKA) strains of Plasmodium berghei. Serum Interleukins 1β and 6 (IL-1β, IL-6), tumour necrosis factor alpha (TNF-α), immunoglobulins G and M (IgG and IgM), C-reactive protein (CRP) and creatine kinase (CK) were determined using ELISA technique. Aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma glutammyl transferase (GGT) were determined using ELISA technique. The results showed that betulinic acid decreased the levels of IL-1β, IL-6, TNF-α and CRP relative to the infected control. The IgG and IgM levels significantly increased in both models while CK did not decrease significantly in both models although serum AST, ALT and GGT significantly decreased compared to the infected control. These results showed that betulinic acid possessed anti-inflammatory, immunomodulatory and remediating effects on tissue damage. Furthermore, the decrease in activity of CK brought about by betulinic acid is indicative of decrease in cardiac and skeletal muscle injury which is a major pathological concern in Plasmodium infection and treatment.

Promising New Antimalarial Combination Drugs: Garlic And Arteether in Pregnant Mice Infected with Plasmodium berghei

BACKGROUND

Antimalarial prescription remains a challenge in pregnant women because of maternal and fetal complications. Recently, garlic and α-β-arteether combination treatment in malaria-infected mice conferred protection. The purpose of this study is to evaluate the efficacy of these drugs during pregnancy malaria and its safety measures.

OBJECTIVE

The study is to evaluate the efficacy of arteether and garlic combination drugs in protection against malaria infected pregnant mice.

METHODS

Plasmodium berghei-infected pregnant mouse model was used to assess the combination drug efficacy and the outcome of abnormalities of the disease after drug treatment. After optimizing the dose and gestation period, maternal protection was confirmed by parasite clearance in smear and mortality observation. In addition, maternal hematological parameters, different organ histopathology and IgG levels were documented along with the fetal and infant outcomes.

RESULTS

Arteether monotherapy led to spontaneous fetal abortion or resorption but after the dose optimization and with garlic combination has resulted in completion of the pregnancy and protection against malaria. The derangements observed in the histoarchitecture of organs and hematological parameters caused by malaria infection revealed improvement after drug treatment and the smear observation confirms the clearance of malaria parasite in the peripheral blood, but IgG level was maintained at the same higher level as in malaria-infected mice.

CONCLUSIONS

The first report of arteether and garlic combination promising high efficacy in protection against malaria-infected pregnant mice ascertain their safety and an effective alternative for pregnancy-associated malaria.

Alteration of Platelet Count in Patients with Severe Non-Plasmodium falciparum Malaria: A Systematic Review and Meta-Analysis

The understanding of platelet biology under physiological and pathological conditions like malaria infection is critical importance in the context of the disease outcome or model systems used. The importance of severe thrombocytopenia (platelet count < 50,000 cells (µL) and profound thrombocytopenia (platelet count < 20,000 cells/µL) in malaria patients remains unclear. This study aimed to synthesize evidence regarding the risks of severe and profound thrombocytopenia in patients with severe non-Plasmodium falciparum malaria. Our overall aim was to identify potential indicators of severe non-P. falciparum malaria and the Plasmodium species that cause severe outcomes. This systematic review was registered at the International Prospective Register of Systematic Reviews (PROSPERO) under registration ID CRD42020196541. Studies were identified from previous systematic reviews (n = 5) and the MEDLINE, Scopus, and Web of Science databases from 9 June 2019 to 9 June 2020. Studies were included if they reported the outcome of severe non-Plasmodium species infection, as defined by the World Health Organization (WHO) criteria, in patients with known platelet counts and/or severe and profound thrombocytopenia. The risk of bias was assessed using the Newcastle–Ottawa Scale (NOS). Data were pooled, and pooled prevalence (PP) and pooled odds ratios (ORs) were calculated using random effects models. Of the 118 studies identified from previous meta-nalyses, 21 met the inclusion criteria. Of the 4807 studies identified from the databases, three met the inclusion criteria. Nine studies identified from reference lists and other sources also met the inclusion criteria. The results of 33 studies reporting the outcomes of patients with severe P. vivax and P. knowlesi infection were pooled for meta-analysis. The PP of severe thrombocytopenia (reported in 21 studies) was estimated at 47% (95% confidence interval (CI): 33–61%, I2: 96.5%), while that of profound thrombocytopenia (reported in 13 studies) was estimated at 20% (95% CI: 14–27%, 85.2%). The pooled weighted mean difference (WMD) in platelet counts between severe uncomplicated Plasmodium infections (reported in 11 studies) was estimated at −28.51% (95% CI: −40.35–61%, I2: 97.7%), while the pooled WMD in platelet counts between severe non-Plasmodium and severe P. falciparum infections (reported in eight studies) was estimated at −3.83% (95% CI: −13.90–6.25%, I2: 85.2%). The pooled OR for severe/profound thrombocytopenia comparing severe to uncomplicated Plasmodium infection was 2.92 (95% CI: 2.24–3.81, I2: 39.9%). The PP of death from severe and profound thrombocytopenia was estimated at 11% (95% CI: 0–22%). These results suggest that individuals with severe non-P. falciparum infection (particularly P. vivax and P. knowlesi) who exhibit severe or profound thrombocytopenia should be regarded as high risk, and should be treated for severe malaria according to current WHO guidelines. In addition, severe or profound thrombocytopenia coupled with other clinical and microscopic parameters can significantly improve malaria diagnosis, enhance the timely treatment of malaria infections, and reduce the morbidity and mortality of severe non-P. falciparum malaria.

C-reactive protein as an early biomarker for malaria infection and monitoring of malaria severity: a meta-analysis

This study investigated whether C-reactive protein (CRP) can be used as a marker for the early detection and monitoring of malaria severity. Potentially relevant studies were searched in Medline (PubMed), Scopus, and Web of Science. Differences in CRP between (1) severe malaria and uncomplicated malaria, (2) uncomplicated malaria and asymptomatic malaria, (3) uncomplicated malaria and febrile/healthy controls, and (4) asymptomatic malaria and febrile/healthy controls were estimated using random-effects models. Twenty-nine studies were included for meta-analysis. The results of meta-analysis demonstrated higher mean CRP levels in (1) patients with severe malaria compared with uncomplicated malaria (p < 0.001, standard mean difference [SMD]: 1.52, 95% confidence interval [CI]: 0.91-2.12, I2: 95.1%), (2) patients with uncomplicated malaria than in those with asymptomatic malaria (p: 0.001, SMD: 1.65, 95% CI: 0.67-2.62, I2: 96.7%), (3) patients with uncomplicated malaria compared with febrile/healthy controls (p < 0.001, SMD: 2.38, 95% CI: 1.37-3.40, I2: 98.5%), and (4) patients with asymptomatic malaria compared with febrile/healthy controls (p < 0.001, SMD: 2.55, 95% CI: 1.60-3.50, I2: 99.2%). This study demonstrated CRP levels are a biomarker for the early detection and monitoring of malaria severity.

The effect of malaria on haemoglobin concentrations: a nationally representative household fixed-effects study of 17,599 children under 5 years of age in Burkina Faso

Background

Although the association between malaria and anaemia is widely studied in patient cohorts, the population-representative causal effects of malaria on anaemia remain unknown. This study estimated the malaria-induced decrease in haemoglobin levels among young children in malaria-endemic Burkina Faso.

Methods

The study was based on pooled individual-level nationally representative health survey data (2010–2011, 2014, 2017–2018) from 17 599 children under 5 years of age. This data was used to estimate the effects of malaria on haemoglobin concentration, controlling for household fixed-effects, age, and sex in a series of regression analyses. The fixed-effects controlled for observed and unobserved confounding on the household level and allowed to determine the impact of malaria infection status on haemoglobin levels and anaemia prevalence. Furthermore, the diagnostic results from microscopy and rapid diagnostic tests were leveraged to provide a quasi-longitudinal perspective of acute and prolonged effects after malaria infection.

Results

The prevalence of both malaria (survey prevalence ranging from 17.4% to 65.2%) and anaemia (survey prevalence ranging from 74% to 88.2%) was very high in the included surveys. Malaria was estimated to significantly reduce haemoglobin levels, with an overall effect of − 7.5 g/dL (95% CI − 8.5, − 6.5). Acute malaria resulted in a − 7.7 g/dL (95% CI − 8.8, − 6.6) decrease in haemoglobin levels. Recent malaria without current parasitaemia decreased haemoglobin concentration by − 7.1 g/dL (95% CI − 8.3, − 5.9). The in-sample predicted prevalence of severe anaemia was 9.4% among malaria positives, but only 2.2% among children without malaria.

Conclusion

Malaria infection has a strong detrimental effect on haemoglobin levels among young children in Burkina Faso. This effect seems to carry over even after acute infection, indicating prolonged haemoglobin reductions even after successful parasite-elimination. The quasi-experimental fixed-effect approach adds a population level perspective to existing clinical evidence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-021-03948-z.

Prevalence and characteristics of malaria among COVID-19 individuals: A systematic review, meta-analysis, and analysis of case reports

BACKGROUND

The world population is currently at a very high risk of Coronavirus disease-2019 (COVID-19), caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). People who live in malaria-endemic areas and get infected by SARS-CoV-2 may be at increased risk of severe COVID-19 or unfavorable disease outcomes if they ignore their malaria status. Therefore, the present study aimed to synthesize, qualitatively and quantitatively, information on the prevalence and characteristics of malaria infection among COVID-19-infected individuals. The findings will help us better understand this particular comorbidity during the COVID-19 pandemic.

METHODS

The systematic review protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) with the identification number: CRD42021247521. We searched for studies reporting on the coinfection of COVID-19 and malaria in PubMed, Web of Science, and Scopus from inception to March 27, 2021 using Medical Subject Headings (MeSH) terms. The study's methodological quality in the search output was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Tools for cross-sectional study. The pooled prevalence of Plasmodium spp. infection among patients infected with COVID-19 was estimated using the random effect model and then graphically presented as forest plots. The heterogeneity among the included studies was assessed using Cochrane Q and I2 statistics. The characteristics of patients co-infected with COVID-19 and malaria were derived from case reports and series and were formally analyzed using simple statistics.

RESULTS

Twelve of 1,207 studies reporting the coinfection of COVID-19 and malaria were selected for further analysis. Results of quantitative synthesis show that the pooled prevalence of Plasmodium spp. infection (364 cases) among COVID-19 individuals (1,126 cases) is 11%, with a high degree of heterogeneity (95% CI: 4%-18%, I2: 97.07%, 5 studies). Most of the coinfections were reported in Nigeria (336 cases), India (27 cases), and the Democratic Republic of Congo (1 case). Results of qualitative synthesis indicate that patients with coinfection are typically symptomatic at presentation with mild or moderate parasitemia. An analysis of case reports and series indicates that co-infected individuals often display thrombocytopenia, lymphopenia, and elevated bilirubin levels. Among four patients (30%) who required treatment with intravenous artesunate, one experienced worsened clinical status after administering the drug. One serious outcome of coinfection involved a pregnant woman who experienced fetal abortion due to the initial misdiagnosis of malaria.

CONCLUSIONS

All individuals in malaria-endemic regions who are febrile or display symptoms of COVID-19 should be evaluated for malaria to avoid serious complications. Further prospective studies are required to investigate the burden and outcomes of COVID-19 in malaria-endemic regions. Prompt management is required to prevent serious outcomes in individuals co-infected with COVID-19 and malaria.

The utility of basic blood counts, WBC histogram and C-reactive protein in detecting malaria

Background

Hematology analyzers display abnormal parameters during malaria infection providing insightful information for suspecting and assessing malaria infection. The goal of this study is to demonstrate the potential of a three-part differential hematology analyzer to assess malaria, provide information about the parasitemia, and discuss the importance of combining C-reactive protein (CRP) with hematology parameters to obtain further information about the malaria infection.

Methods

The present study shows the results of a case–control study during the monsoon season of years 2018 and 2019 in Mumbai, India. The study considers 1008 non-malaria febrile cases, 209 P. vivax and 31 P. falciparum positive malaria samples, five cases of mixed P. vivax and P. falciparum infection, and three co-infection cases of P. vivax and dengue. Raw data from the three-part analyzer LC-667G CRP (HORIBA) and the corresponding microscopic findings (golden standard for diagnosis of malaria) were obtained for each sample.

Results

The medians of platelet counts (PLT) were 102.5, 109.0, and 223.0 × 10³/µL, while CRP medians were 67.4, 81.4 and 10.4 mg/L in P. vivax, P. falciparum and control groups respectively (p < 0.001 in Mann–Whitney U tests between malaria and control groups). Compared with negative samples, platelets counting less than 161.5 × 10³/µL were observed on malaria patients (OR 19.12, 95% CI 11.89–30.75). Especially in P. vivax cases, an abnormal peak was frequently observed in the white blood cells (WBC) histogram around the 37fL channel. The events counted around that channel showed a linear correlation with the counting of red blood cells infected predominantly with larger parasitic forms. Parameters like CRP (rs = 0.325, p < 0.001), WBC (rs = 0.285, p < 0.001) and PLT (rs = − 0.303, p < 0.001) were correlated with the parasitemia of P. vivax samples. Between the malaria and dengue groups, the highest area under the receiver operating characteristic curve was observed on CRP (0.867, CRP ≥ 26.85 mg/L).

Conclusions

A three-part differential hematology analyzer has the potential to not only trigger malaria diagnosis confirmation but also assess the severity of the infection when CRP is considered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06704-5.

ln vitro inhibition of beta-hematin formation and in vivo effects of Diospyros mespiliformis and Mondia whitei methanol extracts on chloroquine-susceptible Plasmodium berghei-induced malaria in mice

Background and aim

This study was carried out to investigate antiplasmodial activities of Diospyros mespiliformis (DM) and Mondia whitei (MW) in Plasmodium berghei-infected mice.

Materials and methods

Air-dried stem of DM and root of MW were soaked in methanol, decanted and concentrated to give extracts. Parts of these extracts were partitioned successively to give dichloromethane, ethylacetate and methanol fractions. Mice (18 ± 3 g) were infected with Plasmodium berghei-infected erythrocytes from a donor mouse and were treated with the extracts, while the drug control group received 10 mg/kg body weight of artesunate and the parasitized control received the vehicle (5% v/v DMSO). Percentage parasitemia and clearance were estimated from thin films of blood smear. Hematological parameters were determined using standard methods. Both extracts were also tested on in vitro inhibition of β-hematin formation.

Results, discussion and conclusion

Results showed that DM had the least percentage parasitemia (0.67%) and highest percentage parasite clearance (84.7%) while the MW had 0.89% percentage parasitemia and 79.7% clearance at the highest dose used after the seventh day relative to untreated control. The cell free antiplasmodial activity of the fractions and extracts of both DM and MW revealed that DM significantly inhibited β-hematin formation than MW. The packed cell volume, white blood cell count, Lymphocyte, Eosinophil, Monocyte and Neutrophil significantly increased in the treated groups compared with the control. The results showed that the DM had higher antiplasmodial activity.

Insecticide-treated net ownership, utilization and knowledge of malaria in children residing in Batoke-Limbe, Mount Cameroon area: effect on malariometric and haematological indices

Background

Insecticide-treated nets (ITNs) are the most widely used interventions for malaria control in Africa. The aim of this study was to assess the ownership and utilization of ITNs and the knowledge of malaria and their effects on malariometric and haematological indices in children living in the Mount Cameroon area.

Methods

A community-based cross-sectional study involving a total of 405 children aged between 6 months and 14 years living in Batoke–Limbe was carried out between July and October 2017. A semi-structured questionnaire was used to document demographic status, knowledge on malaria and ITN ownership and usage. Venous blood sample was collected from each child to determine the prevalence and intensity of parasitaemia by Giemsa-stained microscopy and full blood count by auto haematology analysis to obtain white blood cell (WBC) and red blood cell (RBC) counts, haemoglobin (Hb) level, haematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC). A multilinear regression model was used to determine the relationship between haematological parameter as dependent variable and the independent variables.

Results

The overall prevalence of parasitaemia, anaemia, knowledge about malaria, ITN ownership, usage and effective usage was 46.7%, 54.7%, 40.7%, 78.8%, 50.9% and 29.9%, respectively. The prevalence of parasitaemia was significantly higher (P < 0.001) in children who ineffectively utilized ITNs (54.9%) than effective users (27.3%). Having knowledge of malaria, negatively correlated with WBC counts (P = 0.005), but positively correlated with Hb levels (P < 0.001), RBC counts (P < 0.001), Hct (P < 0.001), MCV (P < 0.001) and MCH (P < 0.001). ITN use positively correlated with WBC counts (P = 0.005) but negatively with Hb levels (P = 0.004), RBC counts (P = 0.006), and MCH (P < 0.001). Meanwhile, parasitaemia negatively correlated with Hb levels (P = 0.004), RBC counts (P = 0.01), Hct (P = 0.04) and MCHC (P = 0.015).

Conclusion

There is need for more sensitization on the benefits of using the ITNs to meet up with the intended and expected impact of the free distribution of ITNs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-021-03860-6.

Uncovering the effects of heterogeneity and parameter sensitivity on within-host dynamics of disease: malaria as a case study

Background

The fidelity and reliability of disease model predictions depend on accurate and precise descriptions of processes and determination of parameters. Various models exist to describe within-host dynamics during malaria infection but there is a shortage of clinical data that can be used to quantitatively validate them and establish confidence in their predictions. In addition, model parameters often contain a degree of uncertainty and show variations between individuals, potentially undermining the reliability of model predictions. In this study models were reproduced and analysed by means of robustness, uncertainty, local sensitivity and local sensitivity robustness analysis to establish confidence in their predictions.

Results

Components of the immune system are responsible for the most uncertainty in model outputs, while disease associated variables showed the greatest sensitivity for these components. All models showed a comparable degree of robustness but displayed different ranges in their predictions. In these different ranges, sensitivities were well-preserved in three of the four models.

Conclusion

Analyses of the effects of parameter variations in models can provide a comparative tool for the evaluation of model predictions. In addition, it can assist in uncovering model weak points and, in the case of disease models, be used to identify possible points for therapeutic intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-021-04289-z.

Hematological indices and abnormalities among patients with uncomplicated falciparum malaria in Kosti city of the White Nile state, Sudan: a comparative study

BACKGROUND

Hematological abnormalities are common features in falciparum malaria but vary among different populations across countries. Therefore, we compared hematological indices and abnormalities between Plasmodium falciparum-infected patients and malaria-negative subjects in Kosti city of the White Nile State, Sudan.

METHODS

A comparative, cross-sectional study was conducted at the Clinical Laboratory Unit of Kosti Teaching Hospital from June to December 2018. A total of 392 participants (192 P. falciparum-infected patients and 200 malaria-negative subjects) were recruited in the study. Hematological indices of hemoglobin (Hb), red blood cells (RBCs), white blood cells (WBCs) and platelets were measured, and their median values were statistically compared.

RESULTS

The majority of P. falciparum-infected patients (67.6%) showed a low-level parasitemia. The median values of Hb concentration, RBC count, mean corpuscular volume (MCV), mean corpuscular Hb (MCH) and mean corpuscular Hb concentration (MCHC) were significantly lower in P. falciparum-infected patients, while the median red cell distribution width (RDW) was significantly higher in the patients compared to malaria-negative subjects. Anemia, low MCV, low MCH, low MCHC and high RDW were significantly associated with falciparum malaria, but parasitemia level was not significantly associated with anemia severity. The median total WBC count was non-significantly higher in P. falciparum-infected patients, with neutropenia being significantly associated with falciparum malaria. The median platelet count was significantly lower in P. falciparum-infected patients, with thrombocytopenia being significantly associated with falciparum malaria.

CONCLUSIONS

Falciparum malaria among patients in Kosti city of the White Nile State, Sudan is predominantly of low-level parasitemia. It is significantly associated with anemia, low MCV, low MCH, low MCHC, high RDW, thrombocytopenia and neutropenia. However, parasitemia level is not a significant predictor of anemia severity. On the other hand, leucopenia is not useful to predict falciparum malaria. Further large-scale studies in community and healthcare settings and inclusion of patients with complicated or severe malaria and those with high parasite densities are recommended.

Confounding influences of malnutrition and Plasmodium falciparum and Schistosoma haematobium infections on haematological parameters in school children in Muyuka, Cameroon

Background

School-aged children (SAC) are a high-risk demographic group for infectious diseases and malnutrition. The objective of this study was to assess the burden and the effect of Plasmodium falciparum and Schistosoma haematobium infections on the haematological indices in SAC and the confounding influence of malnutrition on the outcomes.

Methods

This cross-sectional study was conducted in SAC 4–14 years old living in Ikata, Bafia and Mile 14-Likoko in Muyuka, Cameroon. Anthropometric measures of malnutrition were obtained and blood samples collected were used for detection of malaria parasites by Giemsa-stained blood films using light microscopy and complete blood count analysis using an automated haematology analyser. Urine samples collected were used to detect micro haematuria with the aid of reagent strips and the eggs of S. haematobium by urine filtration technique. Multiple linear regression model was used to examine influence of independent variables on haematological parameters.

Results

Out of the 606 SAC examined, the prevalence of single infections with Plasmodium or S. haematobium and co-infection with both parasites was 16.2, 16.3 and 8.3%, respectively. Overall, malaria parasite (MP), urogenital schistosomiasis, malnutrition, anaemia, haematuria, microcytosis and thrombocytopenia was prevalent in 24.4, 24.6, 25.9, 74.4, 12.2, 45.4 and 11.1% of SAC, respectively. A significant linear decline (P = 0.023) in prevalence of P. falciparum infection with the severity of stunting was observed. Factors that significantly influenced haematological parameters included haemoglobin: age, stunting and MP; haematocrit: age and MP; white blood cell count: age; red blood cell count; age and MP; lymphocyte counts: stunting; mean cell volume: age; mean cell haemoglobin: age and stunting; mean cell haemoglobin concentration: sex, stunting and red cell distribution width-coefficient of variation: sex, age and stunting.

Conclusions

Malnutrition, Plasmodium and S. haematobium infections are common while anaemia is a severe public health problem in Muyuka, Cameroon. The interaction between haematological parameters with malaria parasites as well as linear growth index was negative and other interactions indicate systemic inflammation. While findings provide contextual intervention targets to ensure the judicious use of the limited resources, there is need for regular monitoring and proper treatment to improve the health of the underserved population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06201-9.

Insights into Plasmodium and SARS-CoV-2 co-infection driven neurological manifestations

In malaria-endemic regions, people often get exposed to various pathogens simultaneously, generating co-infection scenarios. In such scenarios, overlapping symptoms pose serious diagnostic challenges. The delayed diagnosis may lead to an increase in disease severity and catastrophic events. Recent coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected various areas globally, including malaria-endemic regions. The Plasmodium and SARS-CoV-2 co-infection and its effect on health are yet unexplored. We present a case report of a previously healthy, middle-aged individual from the malaria-endemic area who suffered SARS-CoV-2 and Plasmodium falciparum co-infection. The patient developed severe disease indications in a short time period. The patient showed neurological symptoms, altered hematological as well as liver-test parameters, and subsequent death in a narrow time span. We hereby discuss the various aspects of this case regarding treatment and hematological parameters. Further, we have put forward perspectives related to the mechanism behind severity and neurological symptoms in this fatal parasite-virus co-infection case. In malaria-endemic regions, due to overlapping symptoms, suspected COVID-19 patients should also be monitored for diagnosis of malaria without any delay. The SARS-CoV-2 and Plasmodium co-infection could increase the disease severity in a short time span. In treatment, dexamethasone may not help in severe cases having malaria as well as COVID-19 positive status and needs further exploration.

Thrombocytopenia as a Diagnostic Marker for Malaria in Patients with Acute Febrile Illness

BACKGROUND

Thrombocytopenia is the most common hematological abnormality in patients with acute malaria. This study aimed to determine the role of thrombocytopenia as a diagnostic marker for malaria in patients with acute febrile illness.

METHOD

A cross-sectional health facility-based study was conducted on 423 consecutively selected acute febrile patients at Ataye District Hospital from February to May 2019 GC. A complete blood count and malaria microscopy were performed for each acute febrile patient. ROC curve analysis was performed to calculate sensitivity, specificity, positive predictive value, and negative predictive value of platelet count in predicting malaria. A P ≤ 0.05 was considered statistically significant.

RESULT

Out of the 423 acute febrile patients, 73 (17.3%) were microscopically confirmed malaria cases and the rest 350 (82.7%) patients had negative blood film results. Of the microscopically confirmed malaria cases, 55 (75.34%) were P. vivax and 18 (24.66%) were P. falciparum. The prevalence of thrombocytopenia among malaria patients (79.5%) was significantly higher than those in malaria negative acute febrile patients (13.7%), P < 0.001. About 67% malaria-infected patients had mild to moderate thrombocytopenia and 12.3% had severe thrombocytopenia. The ROC analysis demonstrated platelet counts <150,000/μl as an optimal cutoff value with 0.893 area under the curve, 79.5% sensitivity, 86.3% specificity, 95.3% negative predictive value, and 54.7% positive predictive value to predict malaria.

CONCLUSION

Malaria is still among the major public health problems in the country. Thrombocytopenia is a very good discriminatory test for the presence or absence of malaria with 79.5% sensitivity and 86.3% specificity. Therefore, this may be used in addition to the clinical and microscopic parameters to heighten the suspicion of malaria.

Haematological abnormalities in children with sickle cell disease and non-severe malaria infection in western Kenya

Background

In Plasmodium falciparum infection, clinical conditions such as anaemia, thrombocytopenia and leukocytosis are common. Mutation in haemoglobin sub-unit beta gene (HBB) may be a genetic factor responsible for these haematological changes during infection. However, the contributions of the carriage of different HBB genotypes on these changes remain largely unknown.

Methodology

In this cross-sectional study, we evaluated haematological abnormalities in P. falciparum-infected children (n = 217, aged 1–192 months) with different haemoglobin sub-unit beta (HBB) genotypes (HbAA, HbAS and HbSS). Children with acute febrile conditions were recruited at Jaramogi Oginga Odinga Teaching and Referral Hospital at the outpatient clinic. Haematological parameters were determined using Beckman Coulter counter ACTdiff2™ while HBB genotyping was done using TaqMan® SNP genotyping assay. Chi-square (χ²) was used to determine differences between proportions. Differences in haematological parameters were compared across groups using Kruskal Wallis test and between groups using Mann Whitney U test. Partial correlation test was used to determine correlation between haematological parameters and sickle cell genotypes while controlling for age and sex.

Results

Haemoglobin (Hb), [median (IQR); 7.3 (1.3), P = 0.001], haematocrit (HCT), [median (IQR); 26.4 (4.4), P = 0.009], red blood cells (RBC), [median (IQR); 3.2 (1.7), P = 0.048] were markedly reduced in HbSS, however, red cell distribution with (RDW) [median (IQR); 14.9 (3.3), P = 0.030] was increased in malaria infected children with HbSS. Severe anaemia was highest in HbSS (23.1%) followed by HbAA (8.6%) and HbAS (7.1%). There were no differences in platelet count (P = 0.399) hence no severe thrombocytopeania across the genotypes. Leukocytosis was highest in HbSS (69.2%), 42% in HbAS and 31% in HbAA. The RBC, HCT and Hb had negative correlation with RDW in HbSS in malarial-infected children (r = − 0.725, P = 0.008), (r = − 0.718, P = 0.009) and (r = − 0.792, P = 0.002), respectively.

Conclusion

Our study reveals that anaemia is the most common abnormality in malaria-infected children with carriage of HbSS. The RBC, HCT and Hb concentration decrease with increase in RDW levels in infected children with carriage of HbSS compared to other HBB genotypes. Therefore, carriage of HbSS genotype is correlated with severity of haematological abnormalities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06025-7.

Studies on the mitochondrial, immunological and inflammatory effects of solvent fractions of Diospyros mespiliformis Hochst in Plasmodium berghei-infected mice

The use of medicinal plants in the treatment of malaria is gaining global attention due to their efficacy and cost effectiveness. This study evaluated the bioactivity-guided antiplasmodial efficacy and immunomodulatory effects of solvent fractions of Diospyros mespiliformis in mice infected with a susceptible strain of Plasmodium berghei (NK 65). The crude methanol extract of the stem of D. mespiliformis (DM) was partitioned between n-hexane, dichloromethane, ethyl acetate and methanol. Male Swiss mice (20 ± 2 g) infected with P. berghei were grouped and treated with vehicle (10 mL/kg, control), Artemether lumefantrine (10 mg/kg), 100, 200 and 400 mg/kg of n-hexane, dichloromethane, ethyl acetate and methanol fractions of D. mespiliformis for seven days. Blood was obtained for heme and hemozoin contents while serum was obtained for inflammatory cytokines and immunoglobulins G and M assessments. Liver mitochondria were isolated for mitochondrial permeability transition (mPT), mitochondrial F1F0 ATPase (mATPase) and lipid peroxidation (mLPO) assays. The GC-MS was used to identify the compounds present in the most potent fraction. The dichloromethane fraction had the highest parasite clearance and improved hematological indices relative to the drug control. The heme values increased, while the hemozoin content significantly (P < 0.05) decreased compared with the drug control. The highest dose of HF and MF opened the mPT pore while the reversal effects of DF on mPT, mATPase and mLPO were dose-dependent. The levels of IgG, IgM and TNFα in the DF group were significantly higher than the drug control, while the IL-1β and IL-6 values did not vary linearly with the dose. Lupeol and Stigmastan-3,5-diene were the most abundant phytochemicals in the DF. The outcome of this study showed that the DF has immunomodulatory effects in infected mice, reduced proliferation of the malaria parasite and thus protect liver cells.

Comparison of Plasmodium ovale curtisi and Plasmodium ovale wallikeri infections by a meta-analysis approach

Malaria caused by Plasmodium ovale species is considered a neglected tropical disease with limited information about its characteristics. It also remains unclear whether the two distinct species P. ovale curtisi and P. ovale wallikeri exhibit differences in their prevalence, geographic distribution, clinical characteristics, or laboratory parameters. Therefore, this study was conducted to clarify these differences to support global malaria control and eradication programs. Studies reporting the occurrence of P. ovale curtisi and P. ovale wallikeri were explored in databases. Differences in proportion, clinical data, and laboratory parameters between the two species were estimated using a random-effects model and expressed as pooled odds ratios (ORs), mean difference (MD), or standardized MD depending on the types of extracted data. The difference in geographical distribution was visualized by mapping the origin of the two species. A total of 1453 P. ovale cases extracted from 35 studies were included in the meta-analysis. The p-value in the meta-analyses provided evidence favoring a real difference between P. ovale curtisi malaria cases (809/1453, 55.7%) and P. ovale wallikeri malaria cases (644/1453, 44.3%) (p: 0.01, OR 1.61, 95% CI 0.71-3.63, I2: 77%). Subgroup analyses established evidence favoring a real difference between P. ovale curtisi and P. ovale wallikeri malaria cases among the imported cases (p: 0.02, 1135 cases). The p value in the meta-analyses provided evidence favoring a real difference in the mean latency period between P. ovale curtisi (289 cases) and P. ovale wallikeri malaria (266 cases) (p: 0.03, MD: 27.59, 95% CI 1.99-53.2, I2: 94%), total leukocyte count (p < 0.0001, MD: 840, 95% CI 610-1070, I2: 0%, two studies) and platelet count (p < 0.0001, MD: 44,750, 95% CI 2900-60,500, I2: 32%, three studies). Four continents were found to have reports of P. ovale spp., among which Africa had the highest number of reports for both P. ovale spp. in its 37 countries, with a global proportion of 94.46%, and an almost equal distribution of both P. ovale spp., where P. ovale curtisi and P. ovale wallikeri reflected 53.09% and 46.90% of the continent's proportion, respectively. This is the first systematic review and meta-analysis to demonstrate the differences in the characteristics of the two distinct P. ovale species. Malaria caused by P. ovale curtisi was found in higher proportions among imported cases and had longer latency periods, higher platelet counts, and higher total leukocyte counts than malaria caused by P. ovale wallikeri. Further studies with a larger sample size are required to confirm the differences or similarities between these two species to promote malaria control and effective eradication programs.

Haematological profile of children with malaria in Sorong, West Papua, Indonesia

Background

Malaria remains a major public health problem in Indonesian Papua, with children under five years of age being the most affected group. Haematological changes, such as cytopenia that occur during malaria infection have been suggested as potential predictors and can aid in the diagnosis of malaria. This study aimed to assess the haematological alterations associated with malaria infection in children presenting with signs and symptoms of malaria.

Methods

A retrospective study was performed by collecting data from the medical records of malaria patients at Sorong Regional General Hospital, Sorong, West Papua, Indonesia, both from outpatient and inpatient clinics, from January 2014 until December 2017. The laboratory profile of children suffering from malaria was evaluated.

Results

One hundred and eighty-two children aged 1 month to 18 years old were enrolled. The subjects were mostly male (112, 61.5%) with a mean age of 6.45 years (SD = 4.3 years). Children below 5 years of age suffered the most from malaria in this study (77, 42.3%). One hundred two subjects (56%) were infected with Plasmodium falciparum. Half of the enrolled subjects (50%) had haemoglobin level (Hb) between 5.1 and 10 gr/dL. A total of 41 children (53.2%) less than 5 years old suffered from P. falciparum infection. In the age group of 5–10 years, there were 34 children (57.6%) who suffered from P. falciparum, and in the age group > 10 years, 27 children (58.7%) suffered from P. falciparum infection. Only 4 subjects (5.2%) in the less than 5 years old age group had mixed malaria infection. Among eight predictors of the haematological profile, there were five predictors that were significantly associated with the diagnostic criteria, namely haemoglobin, haematocrit, leukocytes, platelets and monocytes (p < 0.05). Generally, clinical symptoms are not significantly associated with a malaria diagnosis, and only one variable showed a significant relationship, pale, with a P value of 0.001.

Conclusions

Children with malaria had changes in some haematological markers, with anaemia, low platelet count, white blood count, and lymphocyte count being the most important predictors of malaria infection in the study area. These markers could be used to raise suspicion of malaria in children living in high endemic areas, such as West Papua.

Antrocaryon micraster (A. Chev. And Guillaumin) stem bark extract demonstrated anti-malaria action and normalized hematological indices in Plasmodium berghei infested mice in the Rane's test

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria is caused by infection with some species of Plasmodium parasite which leads to adverse alterations in physical and hematological features of infected persons and ultimately results in death. Antrocaryon micraster is used to treat malaria in Ghanaian traditional medicine. However, there is no scientific validation of its anti-malaria properties. The plant does not also have any chemical fingerprint or standardization parameters.

AIM OF THE STUDY

This study sought to evaluate the anti-malaria activity of standardized A. micraster stem bark extract (AMSBE) and its effect on mean survival time (MST) and body weight reduction of Plasmodiumberghei infested mice. And to study the effect of treatment of AMSBE on hematological indices of the P. berghei infested mice in order to partly elucidate its anti-malarial mechanism of action.

MATERIALS AND METHODS

Malaria was induced in female ICR mice by infecting them with 0.2 mL of blood (i.p.) containing 1.0 × 10⁷P. berghei-infested RBCs from a donor mouse and leaving them without treatment for 3 days. AMSBE or Lonart (standard control) was then orally administered at 50, 200 and 400 mg/kg or 10 mg/kg once daily for 4 consecutive days. The untreated control received sterile water. Malaria parasitemia reduction, anti-malarial activity, mean change in body weight and MST of the parasitized mice were evaluated. Furthermore, changes in white blood cells (WBCs), red blood cells (RBCs), platelets count, hemoglobin (HGB), hematocrit (HCT) and mean corpuscular volume (MCV) were also determined in the healthy animals before infection as baseline and on days 3, 5 and 8 after infection by employing complete blood count. Standardization of AMSBE was achieved by quantification of its constituents and chemical fingerprint analysis using UHPLC-MS.

RESULTS

Administration of AMSBE, standardized to 41.51% saponins and 234.960 ± 0.026 mg/g of GAE phenolics, produced significant (P < 0.05) reduction of parasitemia development, maximum anti-malaria activity of 46.01% (comparable to 32.53% produced by Lonart) and significantly (P < 0.05) increased body weight and MST of P. berghei infected mice compared to the untreated control. Moreover, there were significant (P > 0.05) elevation in WBCs, RBCs, HGB, HCT and platelets in the parasitized-AMSBE (especially at 400 mg/kg p.o.) treated mice compared to their baseline values. Whereas, the non-treated parasitized control recorded significant reduction (P < 0.05) in all the above-mentioned parameters compared to its baseline values. The UHPLC-MS fingerprint of AMSBE revealed four compounds with their retention times, percentage composition in their chromatograms and m/z of the molecular ions and fragments in the spectra.

CONCLUSIONS

These results show that A. micraster stem bark possessed significant anti-malaria effect and also has the ability to abolish body weight loss, leucopenia, anemia and thrombocytopenia in P. berghei infected mice leading to prolonged life span. The UHPLC-MS fingerprint developed for AMSBE can be used for rapid authentication and standardization of A. micraster specimens and herbal preparations produced from its hydroethanolic stem bark extract to ensure consistent biological activity. The results justify A. micraster's use as anti-malaria agent.