Malaria and anemia

Evaluation of immunophenotypic alterations of peripheral blood lymphocytes and their sub-sets in uncomplicated P. Falciparum infection

BACKGROUND

Malaria is a life-threatening parasitic disease typically transmitted through the bite of an infected Anopheles mosquito. There is ample evidence showing the potential of malaria infection to affect the counts of lymphocyte subpopulations in the peripheral blood, but the extent of alteration might not be consistent in all geographical locations, due to several local factors. Although Ghana is among the malaria-endemic countries, there is currently no available data on the level of alterations that occur in the counts of lymphocyte subpopulations during P. falciparum malaria infection among adults.

AIM

The study was to determine the immunophenotypic alterations in the level of peripheral blood lymphocytes and their subsets in adults with uncomplicated P. falciparum malaria infection and apparently healthy participants.

METHODS

The study was a cross-sectional comparative study conducted in two municipalities of the Volta region of Ghana. Blood samples were collected from study participants and taken through serology (P. falciparum/Pan Rapid Diagnostic Kits), microscopy (Thick and thin blood films) and Haematological (Flow cytometric and Full blood count) analysis.

RESULTS

A total of 414 participants, comprising 214 patients with malaria and 200 apparently healthy individuals (controls) were recruited into this study. Parasite density of the malaria patients ranged from 75/µL to 84,364/µL, with a mean of 3,520/µL. It was also observed that the total lymphocytes slightly decreased in the P. falciparum-infected individuals (Mean ± SD: 2.08 ± 4.93 × 109/L) compared to the control group (Mean ± SD: 2.47 ± 0.80 × 109/L). Again, there was a significant moderate positive correlation between parasite density and haematocrit levels (r = 0.321, p < 0.001). Apart from CD45 + T-cells, more people in the control group had normal values for the lymphocyte subsets measured compared to the malaria patients.

CONCLUSIONS

From the results obtained, there was high parasite density among the malaria patients suggestive of high intensity of infection in the case group. The malaria patients again showed considerable haematological alterations in lymphocyte sub-sets and the parasite density appeared to be strongly associated with CD4 + T-cell reduction. Also, the parasite density significantly associated with decreasing haematocrit levels. This indicates that lymphocyte subset enumeration can be used to effectively support malaria diagnosis.

Modeling the shared risks of malaria and anemia in Rwanda

In sub-Saharan Africa, malaria and anemia contribute substantially to the high burden of morbidity and mortality among under-five children. In Rwanda, both diseases have remained public health challenge over the years in spite of the numerous intervention programs and policies put in place. This study aimed at understanding the geographical variations between the joint and specific risks of both diseases in the country while quantifying the effects of some socio-demographic and climatic factors. Using data extracted from Rwanda Demographic and Health Survey, a shared component model was conceived and inference was based on integrated nested Laplace approximation. The study findings revealed similar spatial patterns for the risk of malaria and the shared risks of both diseases, thus confirming the strong link between malaria and anaemia. The spatial patterns revealed that the risks for contracting both diseases are higher among children living in the districts of Rutsiro, Nyabihu, Rusizi, Ruhango, and Gisagara. The risks for both diseases are significantly associated with type of place of residence, sex of household head, ownership of bed net, wealth index and mother's educational attainment. Temperature and precipitation also have substantial association with both diseases. When developing malaria intervention programs and policies, it is important to take into account climatic and environmental variability in Rwanda. Also, potential intervention initiatives focusing on the lowest wealth index, children of uneducated mothers, and high risky regions need to be reinforced.

A Case Series: A Mother and Daughter with a Critically Low Hemoglobin Level Resulting from Severe Anemia Secondary to Malaria

Background

Malaria can lead to anemia, a condition marked by a reduction in red blood cells or lower than typical levels of hemoglobin. This condition mainly affects women and children and, in severe cases, can hinder the cognitive and motor development of children. It also poses significant risks for pregnant women and their unborn children.

Case presentation

An 18-month-old girl and her mother, referred from conflict-affected West Wollega, Ethiopia due to severe malaria, were admitted to Assosa General Hospital, Ethiopia, with critical health indicators. The daughter (case 1) had a hemoglobin level of 0.8 g/dL, a red blood cell count of 0.44 × 10^6u/L, an oxygen saturation of 90%, a body temperature of 36.6 °C, a heartbeat of 132 beats per minute, and a respiratory rate of 48 breaths per minute. She displayed signs of pale conjunctivitis and severe palmar paleness, and weighed 7 kg. The mother(case 2), aged 35, also had a history of severe malaria and presented with a critically low hemoglobin level of 2.5g/dL and a red blood cell count of 0.75 × 10^6u/L, with an oxygen saturation of 89%. Blood transfusion and malaria treatment were administered, and by the end of their hospital stay, both cases' symptoms had resolved, and they returned to normal baseline vital signs, including their hemoglobin levels.

Conclusions

Severely low hemoglobin levels, worsened by severe malaria, present a significant danger in cases of anemia. As far as I am aware, this might be the lowest hemoglobin level recorded. Promoting awareness, economic empowerment initiatives, alongside routine provision of iron supplements and Prompt malaria diagnosis and treatment to create a comprehensive approach that addresses the multifaceted challenges posed by anemia, ultimately leading to improved health outcomes for vulnerable populations.

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.

Shared component modelling of early childhood anaemia and malaria in Kenya, Malawi, Tanzania and Uganda

Background

Malaria and anaemia contribute substantially to child morbidity and mortality. In this study, we sought to jointly model the residual spatial variation in the likelihood of these two correlated diseases, while controlling for individual-level, household-level and environmental characteristics.

Methods

A child-level shared component model was utilised to partition shared and disease-specific district-level spatial effects.

Results

The results indicated that the spatial variation in the likelihood of malaria was more prominent compared to that of anaemia, for both the shared and specific spatial components. In addition, approximately 30% of the districts were associated with an increased likelihood of anaemia but a decreased likelihood of malaria. This suggests that there are other drivers of anaemia in children in these districts, which warrants further investigation.

Conclusions

The maps of the shared and disease-specific spatial patterns provide a tool to allow for more targeted action in malaria and anaemia control and prevention, as well as for the targeted allocation of limited district health system resources.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03694-4.

Do maternal grandmothers influence breastfeeding duration and infant nutrition? Evidence from Merida, Mexico

OBJECTIVES

Breast-feeding is sensitive to somatic, hormonal, behavioral and psychological components of maternal capital. However, through grandmothering, older women may also influence breast-feeding by transferring informational resources to their daughters. We hypothesized that mothers with prolonged instrumental support from their own mother are more likely to have received advice and to have favorable attitudes/practices regarding breastfeeding, compared to those lacking such support, with implications for the grandchild's somatic capital.

METHODS

We recruited 90 mother-infant dyads (52 with grandmaternal support, 38 without) in Merida, Yucatan, Mexico. All children were first-borns, aged ~2 years. Anthropometry and body composition were assessed. Data on grandmother's breastfeeding advice and maternal breastfeeding duration were obtained by questionnaire. Maternal attitudes to breast-feeding were assessed using the Iowa Infant Feeding Attitude Scale.

RESULTS

Women with instrumental support were more likely to have received grandmaternal advice during pregnancy/infancy on exclusive breast-feeding duration (60% vs. 37%, p = 0.033) and the type of first complementary food (81% vs. 47%, p = 0.001). However, women with support had a less favorable attitude to breastfeeding than those without and breastfed their children for less time (median 5 vs. 10.5 months, p = 0.01). No group differences were found in children's length, weight, skinfolds or lean mass z-score.

DISCUSSION

Although grandmothers providing instrumental support provided advice regarding breastfeeding, their attitudes may reflect issues beyond nutritional health. Advice of maternal grandmothers did not promote extended breastfeeding, however the differences in breastfeeding attitudes were not associated with the children's nutritional status. Grandmothers should be included in public health interventions promoting breastfeeding.

Bayesian spatio-temporal modelling and mapping of malaria and anaemia among children between 0 and 59 months in Nigeria

BACKGROUND/M&M

A vital aspect of disease management and policy making lies in the understanding of the universal distribution of diseases. Nevertheless, due to differences all-over host groups and space-time outbreak activities, data are subject to intricacies. Herein, Bayesian spatio-temporal models were proposed to model and map malaria and anaemia risk ratio in space and time as well as to ascertain risk factors related to these diseases and the most endemic states in Nigeria. Parameter estimation was performed by employing the R-integrated nested Laplace approximation (INLA) package and Deviance Information Criteria were applied to select the best model.

RESULTS

In malaria, model 7 which basically suggests that previous trend of an event cannot account for future trend i.e., Interaction with one random time effect (random walk) has the least deviance. On the other hand, model 6 assumes that previous event can be used to predict future event i.e., (Interaction with one random time effect (ar1)) gave the least deviance in anaemia.

DISCUSSION

For malaria and anaemia, models 7 and 6 were selected to model and map these diseases in Nigeria, because these models have the capacity to receive strength from adjacent states, in a manner that neighbouring states have the same risk. Changes in risk and clustering with a high record of these diseases among states in Nigeria was observed. However, despite these changes, the total risk of malaria and anaemia for 2010 and 2015 was unaffected.

CONCLUSION

Notwithstanding the methods applied, this study will be valuable to the advancement of a spatio-temporal approach for analyzing malaria and anaemia risk in Nigeria.

Individual-and community-level factors associated with anemia among children aged 6–23 months in sub-Saharan Africa: evidence from 32 sub-Saharan African countries

Background

Anemia among children aged 6–23 months is a major public health problem worldwide specifically in sub-Saharan Africa (SSA). Anemia during the childhood period causes significant short-and long-term health consequences. However, there is a paucity of evidence on Anemia among children aged 6–23 months in SSA. Therefore, this study examined the individual- and community-level factors associated with anemia among children aged 6–23 months in sub-Saharan Africa.

Methods

A secondary data analysis was done based on the most recent Demographic and Health Survey (DHS) of 32 sub-Saharan African countries. A total weighted sample of 51,044 children aged 6–23 months was included for analysis. We have used a multilevel proportional odds model to identify predictors of severity levels of anemia. Variables with p < 0.2 in the bivariable analysis were considered for the multivariable analysis. In the multivariable multilevel proportional odds model, the Adjusted Odds Ratio (AOR) with the 95% Confidence Interval (CI) was reported to declare the statistical significance and strength of the association.

Results

In this study, about 76.6% (95% CI: 76.2%, 76.9%) of children aged 6–23 months in sub-Saharan Africa were anemic. In the multivariable multilevel proportional odds model, being female, being aged 18–23 months, higher level of maternal education, being larger size at birth, belonging to a wealthier household, getting four ANC visits and above, advanced maternal age, and belonging to a community with high maternal education were significantly associated with lower odds of higher levels of anemia. On the other hand, being twin birth, being smaller size at birth, being of a higher order of birth, having fever in the last two weeks, and distance to a health facility were significantly associated with higher odds of higher levels of anemia.

Conclusion

The study found that more than three-fourths of children aged 6–23 months in sub-Saharan Africa were anemic. This finding proved that the severity levels of anemia among children in sub-Saharan Africa remain a serious public health concern. Therefore, to curve this problem enhancing maternal education, promoting maternal health service utilization, and improving health care access is crucial. In addition, health care providers better give special emphasis to twin births, higher-order birth, and those belonging to poor households to reduce the incidence of anemia among children aged 6–23 months in SSA.

Safety of Treating Malaria with Artemisinin-Based Combination Therapy in the First Trimester of Pregnancy

There have been recent calls for the use of artemisinin-based combination therapies (ACTs) for uncomplicated malaria in the first trimester of pregnancy. Nevertheless, the 2021 WHO Guidelines for Malaria reaffirmed their position that there is not adequate clinical safety data on artemisinins to support that usage. The WHO's position is consistent with several issues with the existing clinical data. First, first trimester safety results from multiple ACTs were lumped in a meta-analysis which does not demonstrate that each of the included ACTs is equally safe. Second, safety results from all periods of the first trimester were lumped in the meta-analysis which does not demonstrate the same level of safety for all subperiods, particularly gestational Weeks 6 to 8 which is likely to be the most sensitive period. Third, even if there is evidence of a lack of an effect on miscarriage for a particular ACT, it does not follow then there are no developmental effects for any ACT. In monkeys, artesunate caused marked embryonal anemia leading to embryo death but the long-term consequences of lower levels of embryonal anemia are not known. Fourth, there have been advances in the sensitivity and usage of rapid diagnostic tests that will lead to diagnoses of malaria earlier in gestation which is less well studied and more likely sensitive to artemisinins. Any clinical studies of the safety of ACTs in the first trimester need to evaluate the results of treatment with individual ACTs during different 1- to 2-week periods of the first trimester.

Geographic weighted regression analysis of hot spots of anemia and its associated factors among children aged 6-59 months in Ethiopia: A geographic weighted regression analysis and multilevel robust Poisson regression analysis

INTRODUCTION

Anemia among children aged 6-59 months remains a major public health problem in low-and high-income countries including Ethiopia. Anemia is associated with significant consequences on the health of children such as under-five morbidity and mortality, increased risk of infection, and poor academic performance. The prevalence of anemia in Ethiopia has varied across areas. Therefore, this study aimed to investigate the geographic weighted regression analysis of anemia and its associated factors among children aged 6-59 months in Ethiopia.

METHODS

This study was based on the 2016 Ethiopian Demographic and Health Survey (EDHS) data. A total weighted sample of 8482 children aged 6-59 months was included. For the spatial analysis, Arc-GIS version 10.7 and SaTScan version 9.6 statistical software were used. Spatial regression was done to identify factors associated with the hotspots of anemia and model comparison was based on adjusted R2 and Corrected Akaike Information Criteria (AICc). For the associated factors, the multilevel robust Poisson regression was fitted since the prevalence of anemia was greater than 10%. Variables with a p-value < 0.2 in the bi-variable analysis were considered for the multivariable analysis. In the multivariable multilevel robust Poisson regression analysis, the adjusted prevalence ratio with the 95% confidence interval was reported to declare the statistical significance and strength of association.

RESULTS

The prevalence of anemia among children aged 6-59 months was 57.56% (95%CI: 56.50%, 58.61%) with significant spatial variation across regions in Ethiopia. The significant hot spot areas of anemia among children aged 6-59 months were detected in the central, west, and east Afar, Somali, Dire Dawa, Harari, and northwest Gambella regions. Mothers who had anemia, a child aged 23-59 months, mothers aged 15-19 years, and coming from a household with a poorer or poorest household were significant predictors of the spatial variations of anemia among children aged 6-59 months. In the multilevel robust Poisson analysis, born to mothers aged 30-39 (APR = 0.84, 95% CI: 0.76, 0.92) and 40-49 years (APR = 0.73, 95% CI: 0.65, 0.83), mothers who didn't have formal education (APR = 1.10, 95% CI: 1.00, 1.20), Children in the poorest household wealth index (APR = 1.17, 95% CI: 1.06, 1.29), being 4-6 (APR = 1.08, 95% CI: 1.02, 1.13) and above 6 order of birth (APR = 1.15, 95% CI: 1.07, 1.23), children born to anemic mothers (APR = 1.24, 95% CI: 1.19, 1.29), children aged 24-59 months (APR = 0.70, 95% CI: 0.68, 0.73), stunted children (APR = 1.09, 95% CI: 1.04, 1.13) and underweight children (APR = 1.07, 95% CI: 1.03, 1.13) were significantly associated with anemia among children aged 6-59 months.

CONCLUSION AND RECOMMENDATION

Anemia is still a public health problem for children in Ethiopia. Residing in a geographic area where a high proportion of children born to mothers aged 15-19 years, a child aged 6-23 months, coming from a household with poorer or poorest wealth index, and mothers with anemia increased the risk of experiencing anemia among children aged 6-59 months. Maternal education, maternal age, child age, household wealth, stunting, underweight, birth order, and maternal anemia were significant predictors of anemia among children. The detailed map of anemia hot spots among children aged 6-59 months and its predictors could assist program planners and decision-makers to design targeted public health interventions.

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.

The "Double Burden of Malnutrition" in the Amazon: dietary change and drastic increases in obesity and anemia over 40 years among the Awajún

Undernutrition and overnutrition are interconnected. Yet few studies have examined the "double burden of malnutrition" (DBM) over time in indigenous communities. We investigated changes in the food systems and nutritional health of Awajún communities in the Peruvian Amazon in the 1970s and in 2013. Methods included ethnography, 24 hr food recalls, and biological measures. In 2013, the number of traditional foods consumed decreased to 10% of levels in the 1970s and the number of market foods consumed increased 40-fold. Rates of anemia and obesity were also substantially higher in 2013 compared to the 1970s (23% vs 6% for anemia and 30% vs. 0% for obesity) indicating a DBM has emerged. Examining the predictors of hemoglobin levels and body mass indices in the 2013 sample reveals that this DBM is differentially impacting women and that risk for obesity among the Awajún is associated with multiple proxies of market integration beyond just the consumption of market foods. These findings highlight the complex pathways by which rapid lifestyle changes are creating gendered health inequalities within indigenous communities over time.

Intervention of standardized ethanol leaf extract of Annickia polycarpa, (DC.) Setten and Maas ex I.M. Turner. (Annonaceae), in Plasmodium berghei infested mice produced anti-malaria action and normalized gross hematological indices

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria is a global public health burden due to large number of annual infections and casualties caused by its hematological complications. The bark of Annickia polycarpa is an effective anti-malaria agent in African traditional medicine. However, there is no standardization parameters for A. polycarpa. The anti-malaria properties of its leaf are also not known.

AIM OF THE STUDY

To standardize the ethanol leaf extract of A. polycarpa (APLE) and investigate its anti-malaria properties and the effect of its treatment on hematological indices in Plasmodium berghei infected mice in the Rane's test.

MATERIALS AND METHODS

Malaria was induced by inoculating female ICR mice with 1.0 × 107P. berghei-infected RBCs in 0.2 mL (i.p.) of blood. Treatment was commenced 3 days later with APLE 50, 200, 400 mg/kg p.o., Quinine 30 mg/kg i.m. (Standard drug) or sterile water (Negative control) once daily per group for 4 successive days. Anti-malarial activity and gross malaria indices such as hyperparasitemia, mean change in body weight and mean survival time (MST) were determined for each group. Changes in white blood cells (WBCs), red blood cells (RBCs), platelets (PLT) counts, hemoglobin (HGB) concentration, hematocrit (HCT) and mean corpuscular volume (MCV) were also measured in the healthy mice before infection as baseline and on day 3 and 8 after inoculation using complete blood count. Standardization was achieved by UHPLC-MS chemical fingerprint analysis and quantitative phytochemical tests.

RESULTS

APLE, standardized to its total alkaloids, phenolics and saponin contents, produced significant (P < 0.05) dose-dependent clearance of mean hyperparasitemia of 22.78 ± 0.93% with the minimum parasitemia level of 2.01 ± 0.25% achieved at 400 mg/kg p.o. on day 8. Quinine 30 mg/kg i.m. achieved a minimum parasitemia level of 6.15 ± 0.92%. Moreover, APLE (50-400 mg/kg p.o.) evoked very significant anti-malaria activity of 89.22-95.50%. Anti-malaria activity of Quinine 30 mg/kg i.m. was 86.22%. APLE also inverse dose-dependently promotes weight gain with the effect being significant (P < 0.05) at 50 mg/kg p.o. Moreover, APLE dose-dependently increased the MST of malaria infested mice with 100% survival at 400 mg/kg p.o. Quinine 30 mg/kg i.m. also produce 100% survival rate but did not promote (P > 0.05) weight gain. Hematological studies revealed the development of leukocytopenia, erythrocytosis, microcytic anemia and thrombocytopenia in the malaria infected mice which were reverted with the treatment of APLE 50-400 mg/kg p.o. or Quinine 30 mg/kg i.m. but persisted in the negative control. The UHPLC-MS fingerprint analysis of APLE led to identification of one oxoaporphine and two aporphine alkaloids (1-3). Alkaloids 1 and 3 are being reported in this plant for the first time.

CONCLUSION

These results indicate that APLE possessed significant anti-malaria, immunomodulatory, erythropoietic and hematinic actions against malaria infection. APLE also has the ability to revoke deleterious physiological alteration produced by malaria and hence, promote clinical cure. These properties of APLE are due to its constituents especially, aporphine and oxoaporphine alkaloids.

Anemia in preschool children from Angola: a review of the evidence

Angola is one of the southern African countries with the highest prevalence of anemia, and despite the high geographic heterogeneity of its distribution across the country, it was reported to be indicative of a severe public health problem in some areas, mainly in children. Despite the relevance of this condition in the country there is still an important gap regarding scientific evidences and knowledge systematization in the indexed literature, that could be used to inform and optimize national public health policies willing to address it. Furthermore, the changes in anemia epidemiology among African preschool children and the late updates in nutrition-specific and nutrition-sensitive preventive strategies in the continent are of imperative relevance, as they could contribute to design context-specific national approaches to reduce anemia's morbidity and mortality. In this study we intent to perform a systematic review regarding the sparse evidence available on the country regarding the prevalence of anemia, its associated factors, the prevention, and/or control strategies with potential to reduce anemia that were implemented, and to discuss interventions targeting infections and/or nutrition conducted in other African countries.

Predictors of outcome in childhood Plasmodium falciparum malaria

Plasmodium falciparum malaria is classified as either uncomplicated or severe, determining clinical management and providing a framework for understanding pathogenesis. Severe malaria in children is defined by the presence of one or more features associated with adverse outcome, but there is wide variation in the predictive value of these features. Here we review the evidence for the usefulness of these features, alone and in combination, to predict death and other adverse outcomes, and we consider the role that molecular biomarkers may play in augmenting this prediction. We also examine whether a more personalized approach to predicting outcome for specific presenting syndromes of severe malaria, particularly cerebral malaria, has the potential to be more accurate. We note a general need for better external validation in studies of outcome predictors and for the demonstration that predictors can be used to guide clinical management in a way that improves survival and long-term health.

Teratogen update: Malaria in pregnancy and the use of antimalarial drugs in the first trimester

Malaria is a particular problem in pregnancy because of enhanced sensitivity, the possibility of placental malaria, and adverse effects on pregnancy outcome. Artemisinin-containing combination therapies (ACTs) are the most effective antimalarials known. WHO recommends 7-day quinine therapy for uncomplicated Plasmodium falciparum malaria in the first trimester despite the superior tolerability and efficacy of 3-day ACT regimens because artemisinins caused embryolethality and/or cardiovascular malformations at relatively low doses in rats, rabbits, and monkeys. The developmental toxicity of artesunate, artemether, and DHA were similar in rats but artesunate was embryotoxic at lower doses in rabbits (5 mg/kg/day) than artemether (no effect level = 25 mg/kg/day). In clinical studies in Africa, treatment with artemether-lumefantrine in the first trimester was observed to be highly efficacious and the miscarriage rate (≤3.1%) was similar to no antimalarial treatment (2.6%). When data from the first-trimester use of largely artesunate-based therapies in Thailand were pooled together, there was no difference in miscarriage rate compared to quinine. However, individually, artesunate-mefloquine was associated with a higher miscarriage rate (15/71 = 21%) compared to other artemisinin-based therapies including 7-day artesunate + clindamycin (2/50 = 4%) and quinine (92/842 = 11%). Thus, appropriate statistical comparisons of individual ACT groups are needed prior to assuming that they all have the same risk for developmental toxicity. Current limitations in the assessment of the safety of ACTs in the first trimester are a lack of exposures early in gestation (gestational weeks 6-7), limited postnatal evaluation for cardiovascular malformations, and the pooling of all ACTs for the assessment of risk.

Relative Contributions of Malaria, Inflammation, and Deficiencies of Iron and Vitamin A to the Burden of Anemia during Low and High Malaria Seasons in Rural Zambian Children

OBJECTIVE

To estimate the burden of anemia attributable to malaria, inflammation, and deficiency of iron or vitamin A during low and high malaria seasons among Zambian children.

STUDY DESIGN

From a cohort of children (n = 820), 4-8 years of age participating in a randomized controlled trial of pro-vitamin A, we estimated attributable fractions for anemia (hemoglobin of <110 or 115 g/L, by age) owing to current malaria or inflammation (C-reactive protein of >5 mg/L, or α-1 acid glycoprotein of >1 g/L, or both), and current or prior iron deficiency (ID; defined as low ferritin [<12 or 15 μg/L for age <5 or >5 years] or functional ID [soluble transferrin receptor of >8.3 mg/L] or both) and vitamin A deficiency (retinol of <0.7 μmol/L), during low and high malaria seasons, using multivariate logistic regression. Serum ferritin, soluble transferrin receptor, and retinol were adjusted for inflammation.

RESULTS

The burden of anemia independently associated with current malaria, inflammation, ID, and vitamin A deficiency in the low malaria season were 12% (P < .001), 6% (P = .005), 14% (P = .001), and 2% (P = .07), respectively, and 32% (P < .001), 15% (P < .001), 10% (P = .06), and 2% (P = .06), respectively, in the high malaria season. In both seasons, functional ID was independently associated with more anemia (approximately 11%) than low ferritin (approximately 4%). Anemia and ID in the low malaria season, accounted for 20% (P < .001) and 4% (P = .095) of the anemia in the subsequent high malaria season.

CONCLUSIONS

Anemia in this population is strongly linked to malaria, inflammation, and functional ID, and to a lesser extent, low iron stores. Integrated control strategies are needed.

Genesis of placental sequestration in malaria and possible targets for drugs for placental malaria

Malaria during pregnancy results in intrauterine growth restriction, fetal anemia, and infant mortality. Women are more susceptible to malaria during pregnancy due to malaria‐induced inflammation and the sequestration of infected red blood cells in the placenta, which bind to the chondroitin sulfate portion of syndecan‐1 on the syncytiotrophoblast and in the intervillous space. Syndecan‐1 is a dimeric proteoglycan with an extracellular ectodomain that is cleaved from the transmembrane domain (referred to as “shedding”) by matrix metalloproteinases (MMPs), likely the secreted MMP‐9. The ectodomain includes four binding sites for chondroitin sulfate, which are proximal to the transmembrane domain, and six distal binding sites primarily for heparan sulfate. This “shedding” of syndecan‐1 is inhibited by the presence of the heparan sulfate chains, which can be removed by heparanase. The intervillous space contains fibrin strands and syndecan‐1 ectodomains free of heparan sulfate. The following is proposed as the sequence of events that leads to and is primarily responsible for sequestration in the intervillous space of the placenta. Inflammation associated with malaria triggers increased heparanase activity that degrades the heparan sulfate on the membrane‐bound syndecan‐1. Inflammation also upregulates MMP‐9 and the removal of heparan sulfate gives MMP‐9 access to cleave syndecan‐1, thereby releasing dimeric syndecan‐1 ectodomains with at least four chondroitin sulfate chains attached. These multivalent ectodomains bind infected RBCs together leading to their aggregation and entrapment in intervillous fibrin. This mechanism suggests possible new targets for anti‐placental malaria drugs such as the inhibition of MMP‐9. Doxycycline is an antimalarial drug which inhibits MMP‐9.

Molecular Principles of Intrauterine Growth Restriction in Plasmodium Falciparum Infection

Malaria in pregnancy still constitutes a particular medical challenge in tropical and subtropical regions. Of the five Plasmodium species that are pathogenic to humans, infection with Plasmodium falciparum leads to fulminant progression of the disease with massive impact on pregnancy. Severe anemia of the mother, miscarriage, stillbirth, preterm delivery and intrauterine growth restriction (IUGR) with reduced birth weight are frequent complications that lead to more than 10,000 maternal and 200,000 perinatal deaths annually in sub-Saharan Africa alone. P. falciparum can adhere to the placenta via the expression of the surface antigen VAR2CSA, which leads to sequestration of infected erythrocytes in the intervillous space. This process induces a placental inflammation with involvement of immune cells and humoral factors. Especially, monocytes get activated and change the release of soluble mediators, including a variety of cytokines. This proinflammatory environment contributes to disorders of angiogenesis, blood flow, autophagy, and nutrient transport in the placenta and erythropoiesis. Collectively, they impair placental functions and, consequently, fetal growth. The discovery that women in endemic regions develop a certain immunity against VAR2CSA-expressing parasites with increasing number of pregnancies has redefined the understanding of malaria in pregnancy and offers strategies for the development of vaccines. The following review gives an overview of molecular processes in P. falciparum infection in pregnancy which may be involved in the development of IUGR.

The RANI Project: A socio-normative intervention to reduce anemia in Odisha, India: A formative research protocol

Background: More than half of women of reproductive age in India are anemic. Anemia is associated with increased risk of preterm delivery, higher maternal mortality and contributes to fatigue, which affects women’s work productivity. The World Health Organization (WHO) recommends daily oral iron and folic acid (IFA) supplements during pregnancy and weekly supplements for women of reproductive age. Government programs and global donors have distributed and promoted IFA supplements in India for over four decades. However, initial intake and compliance remain inadequate.

Objectives: This protocol describes the formative research phase of a larger study, called the Reduction in Anemia through Normative Innovations (RANI) Project, which will test, through a randomized controlled trial, the hypothesis that a social norms-based behavioral intervention in Odisha, India will improve uptake of IFA supplements and reduce anemia among reproductive age women as compared to usual care. The focus of this paper is on the formative research required to develop a sound intervention. We will examine socio-normative barriers to and facilitators of IFA supplement uptake.

Methods and analysis: Based on the Theory of Normative Social Behavior, we will adopt a mixed-method, multilevel approach. We will collect data using focus groups, in-depth interviews, observations, Rapid Participatory Ethnographic Evaluation and Research (PEER) techniques, and perceptual mapping methods. Our sample includes reproductive age women (pregnant and not pregnant), their husbands, their mothers/in law and key stakeholders. Before collecting the data, and after analyzing the results, we will hold convenings in India to engage key stakeholders in collaborative design. Following the intervention design, we will test components of the intervention, gather user feedback and fine-tune as necessary.

Impact: This study will contribute to the social norms and behavioral intervention research and inform policymakers about the value of adopting a socio-normative approach.

Inhibition of ex vivo erythropoiesis by secreted and haemozoin-associated Plasmodium falciparum products

It has been estimated that up to a third of global malaria deaths may be attributable to malarial anaemia, with children and pregnant women being those most severely affected. An inefficient erythropoietic response to the destruction of both infected and uninfected erythrocytes in infections with Plasmodium spp. contributes significantly to the development and persistence of such anaemia. The underlying mechanisms, which could involve both direct inhibition of erythropoiesis by parasite-derived factors and indirect inhibition as a result of modulation of the immune response, remain poorly understood. We found parasite-derived factors in conditioned medium (CM) of blood-stage Plasmodium falciparum and crude isolates of parasite haemozoin directly to inhibit erythropoiesis in an ex vivo model based on peripheral blood haematopoietic stem cells. Erythropoiesis-inhibiting activity was detected in a fraction of CM that was sensitive to heat inactivation and protease digestion. Erythropoiesis was also inhibited by crude parasite haemozoin but not by detergent-treated, heat-inactivated or protease-digested haemozoin. These results suggest that the erythropoiesis-inhibiting activity in both cases is mediated by proteins or protein-containing biomolecules and may offer new leads to the treatment of malarial anaemia.

Enteroparasite and vivax malaria co-infection on the Brazil-French Guiana border: Epidemiological, haematological and immunological aspects

Malaria-enteroparasitic co-infections are known for their endemicity. Although they are prevalent, little is known about their epidemiology and effect on the immune response. This study evaluated the effect of enteroparasite co-infections with malaria caused by Plasmodium vivax in a border area between Brazil and French Guiana. The cross sectional study took place in Oiapoque, a municipality of Amapá, on the Amazon border. Malaria was diagnosed using thick blood smears, haemoglobin dosage by an automated method and coproparasitology by the Hoffman and Faust methods. The anti-PvMSP-1₁₉ IgG antibodies in the plasma were evaluated using ELISA and Th1 (IFN-γ, TNF-α and IL-2), and Th2 (IL-4, IL-5 and IL-10) cytokine counts were performed by flow cytometry. The participants were grouped into those that were monoinfected with vivax malaria (M), vivax malaria-enteroparasite co-infected (CI), monoinfected with enteroparasite (E) and endemic controls (EC), who were negative for both diseases. 441 individuals were included and grouped according to their infection status: [M 6.9% (30/441)], [Cl 26.5% (117/441)], [E 32.4% (143/441)] and [EC 34.2% (151/441)]. Males prevailed among the (M) 77% (23/30) and (CI) 60% (70/117) groups. There was a difference in haemoglobin levels among the different groups under study for [EC-E], [EC-Cl], [E-M] and [Cl-M], with (p < 0.01). Anaemia was expressed as a percentage between individuals [CI-EC (p < 0.05)]. In terms of parasitaemia, there were differences for the groups [CI-M (p < 0.05)]. Anti-PvMSP-1₁₉ antibodies were detected in 51.2% (226/441) of the population. The level of cytokines evaluation revealed a large variation in TNF-α and IL-10 concentrations in the co-infected group. In this study we did not observe any influence of coinfection on the acquisition of IgG antibodies against PvMSP119, as well as on the profile of the cytokines that characterize the Th1 and Th2 patterns. However, co-infection increased TNF-α and IL-10 levels.

Mechanism of splenic cell death and host mortality in a Plasmodium yoelii malaria model

Malaria is a fatal disease that displays a spectrum of symptoms and severity, which are determined by complex host-parasite interactions. It has been difficult to study the effects of parasite strains on disease severity in human infections, but the mechanisms leading to specific disease phenotypes can be investigated using strains of rodent malaria parasites that cause different disease symptoms in inbred mice. Using a unique mouse malaria model, here we investigated the mechanisms of splenic cell death and their relationship to control of parasitemia and host mortality. C57BL/6 mice infected with Plasmodium yoelii nigeriensis N67C display high levels of pro-inflammatory cytokines and chemokines (IL-6, IFN-γ, TNF-α, CXCL1, and CCL2) and extensive splenic damage with dramatic reduction of splenic cell populations. These disease phenotypes were rescued in RAG2^−/−, IFN-γ^−/−, or T cell depleted mice, suggesting IFN-γ and T cell mediated disease mechanisms. Additionally, apoptosis was one of the major pathways involved in splenic cell death, which coincides with the peaks of pro-inflammatory cytokines. Our results demonstrate the critical roles of T cells and IFN-γ in mediating splenic cell apoptosis, parasitemia control, and host lethality and thus may provide important insights for preventing/reducing morbidity associated with severe malaria in humans.

Transdermal delivery of oleanolic acid attenuates pro-inflammatory cytokine release and ameliorates anaemia in P. berghei malaria

Malaria remains a major health problem in many tropical areas. Severe malaria infection is associated with secondary complications including anaemia leading to a need for the search of affordable antimalarial agents that can clear the parasitaemia and ameliorate anaemia during infection. The current study investigated the effects of transdermally delivered OA on malaria parasites, HCT and selected plasma cytokine concentrations in P. berghei-infected male Sprague-Dawley rats. The study was carried out over a period of 21days, divided into pre-treatment (day 0-7), treatment (day 8-12) and post-treatment (day 13-21) periods. Parasitaemia, HCT, RBC count, Hgb, plasma TNF-α, IL-6 and IL-10 concentrations were monitored in non-infected and infected rats following a once-off application of an OA-pectin patch (34mg/kg). Animals treated with drug-free pectin and CHQ (30mg/kg, p.o) twice daily for 5 consecutive days acted as negative and positive controls respectively. Infected control animals exhibited increased percentage parasitaemia, TNF-α, IL-6, IL-10 and a reduction in HCT. Interestingly, OA-pectin patch application cleared the malaria parasites and increased HCT values back to normalcy. Furthermore, TNF-α, IL-6 and IL-10 were reduced by day 12 of the study. These findings suggest that the OA-pectin patch delivers therapeutic doses of OA which are able to attenuate cytokine release and ameliorate anaemia during malaria infection. Therefore, transdermally delivered OA may be a potent therapeutic agent for malaria and amelioration of anaemia.

Factors associated with malaria parasitaemia among children under 5 years in Uganda: a secondary data analysis of the 2014 Malaria Indicator Survey dataset

BACKGROUND

In the midst of success with malaria reduction in Uganda, there are areas that still have high prevalence of malaria parasitaemia. This project aimed at investigating factors associated with this prevalence and its relationship with anaemia.

METHODS

This is a secondary data analysis of the 2014 Malaria Indicator Survey dataset of children under 5 years. All had a blood sample taken by finger or heel prick for determination of malaria parasitaemia and estimation of haemoglobin level for anaemia status. The main outcome was the presence of malaria parasitaemia by microscopy and independent variables included: age, gender, residence (urban vs rural), use of a long-lasting, insecticidal-treated net, indoor residual spraying (IRS) of household in the past 6 months, mother's highest education level, mother heard malaria prevention message in the past 6 months, and household wealth status.

RESULTS

The analysis included 4930 children and of these, 938 (19.04%: 95% CI 16.63-21.71) tested positive for malaria parasites. Malaria parasite prevalence significantly increased from 11.08 (95% CI 9.12-13.40) among children with no anaemia to 50.99% (95% CI 39.13-62.74) with severe anaemia (Chi-square p-value = 0.001). Additionally, prevalence significantly rose from the youngest age group (under 6 months) by 1.62 times (95% CI 1.04-2.52, p = 0.033) among the age group of 7-12 months and to four times (95% CI 2.57-6.45, p = 0.001) among those who were between 49 and 59 months. The following were associated with reduced parasitaemia: IRS use (AOR 0.23 [0.08-0.61], p = 0.004), educated mothers (primary AOR 0.75 [0.59-0.96], p = 0.023 to tertiary AOR 0.11 [0.02-0.53], 0.006), mother heard malaria message (AOR 0.78 [0.62-0.99], p = 0.037), and wealthier households (richest AOR 0.17 [0.08-0.36], p = 0.001).

CONCLUSIONS

Increasing malaria parasite prevalence among children under 5 years is still related to increasing age and severity of anaemia even in the context of decreasing malaria prevalence. Designing interventions that include the use of IRS and behaviour change communication tailored to include older children, especially in areas with high malaria prevalence, could be of added value. All this should be done in an environment that improves the socio-economic status and equity of such populations.

CD4 T-cell expression of IFN-γ and IL-17 in pediatric malarial anemia

In Plasmodium falciparum holoendemic transmission regions of western Kenya, life-threatening pediatric malaria manifests primarily as severe malarial anemia (SMA, Hb≤6.0 g/dL with any density parasitemia). To determine the role that CD4+ T-cell-driven inflammatory responses have in the pathogenesis of SMA, peripheral CD4+ T-cell populations and their intracellular production of pro-inflammatory cytokines (IFN-γ and IL-17) were characterized in children aged 12–36 months of age stratified into two groups: non-severe malarial anemia (non-SMA, Hb≥6.0 g/dL, n = 50) and SMA (n = 39). In addition, circulating IFN-γ and IL-17 were measured as part of a Cytokine 25-plex Antibody Bead Kit, Human (BioSource™ International). Children with SMA had higher overall proportions of circulating lymphocytes (P = 0.003) and elevated proportions of lymphocytes expressing IFN-γ (P = 0.014) and comparable IL-17 (P = 0.101). In addition, SMA was characterized by decreased memory-like T-cells (CD4+CD45RA-) expressing IL-17 (P = 0.009) and lower mean fluorescence intensity in memory-like CD4+ T-cells for both IFN-γ (P = 0.063) and IL-17 (P = 0.006). Circulating concentrations of IFN-γ were higher in children with SMA (P = 0.009), while IL-17 levels were comparable between the groups (P = 0.164). Furthermore, circulating levels of IFN-γ were negatively correlated with IL-17 levels in both groups of children (SMA: r = -0.610, P = 0.007; and non-SMA: r = -0.516, P = 0.001), while production of both cytokines by lymphocytes were positively correlated (SMA: r = 0.349, P = 0.037; and non-SMA: r = 0.475, P = 0.001). In addition, this correlation was only maintained by the memory-like CD4+ T cells (r = 0.365, P = 0.002) but not the naïve-like CD4+ T cells. However, circulating levels of IFN-γ were only associated with naïve-like CD4+ T cells producing IFN-γ (r = 0.547, P = 0.028), while circulating levels of IL-17 were not associated with any of the cell populations. Taken together, these results suggest that enhanced severity of malarial anemia is associated with higher overall levels of circulating lymphocytes, enhanced intracellular production of IFN-γ by peripheral lymphocytes and high circulating IFN-γ levels. In addition, the observed inverse relationship between the circulating levels of IFN-γ and IL-17 together with the reduction in the levels of memory-like CD4+ T cells expressing IL-17 in children with SMA may suggest possible relocation of these cells in the deeper tissues for their pathological effect.

Evidencing the Role of Erythrocytic Apoptosis in Malarial Anemia

In the last decade it has become clear that, similarly to nucleated cells, enucleated red blood cells (RBCs) are susceptible to programmed apoptotic cell death. Erythrocytic apoptosis seems to play a role in physiological clearance of aged RBCs, but it may also be implicated in anemia of different etiological sources including drug therapy and infectious diseases. In malaria, severe anemia is a common complication leading to death of children and pregnant women living in malaria-endemic regions of Africa. The pathogenesis of malarial anemia is multifactorial and involves both ineffective production of RBCs by the bone marrow and premature elimination of non-parasitized RBCs, phenomena potentially associated with apoptosis. In the present overview, we discuss evidences associating erythrocytic apoptosis with the pathogenesis of severe malarial anemia, as well as with regulation of parasite clearance in malaria. Efforts to understand the role of erythrocytic apoptosis in malarial anemia can help to identify potential targets for therapeutic intervention based on apoptotic pathways and consequently, mitigate the harmful impact of malaria in global public health.

Joint modeling of Anaemia and Malaria in children under five in Nigeria

Malaria and anaemia which jointly account for high proportion of morbidity and mortality among young children in developing countries have been individually studied using binary regression model. We adopt geoadditive latent variable model for binary/ordinal indicators to analyze the influence of variables of different types on the morbidity among young children in Nigeria. Latent variable models allow for the analysis of multidimensional response variables that reveal the indicator's underlying relationship that are caused by the latent variables. We extend the structural model to a semi-parametric geoadditive model in order to quantify the joint spatial structure of morbidity from malaria and anaemia. Findings revealed substantial geographical variations and the generated maps can guide policy makers and donors on how to prudently utilize the scarce resources for designing more cost-effective interventions.

Oral iron supplements for children in malaria-endemic areas

BACKGROUND

Iron-deficiency anaemia is common during childhood. Iron administration has been claimed to increase the risk of malaria.

OBJECTIVES

To evaluate the effects and safety of iron supplementation, with or without folic acid, in children living in areas with hyperendemic or holoendemic malaria transmission.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library, MEDLINE (up to August 2015) and LILACS (up to February 2015). We also checked the metaRegister of Controlled Trials (mRCT) and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) up to February 2015. We contacted the primary investigators of all included trials, ongoing trials, and those awaiting assessment to ask for unpublished data and further trials. We scanned references of included trials, pertinent reviews, and previous meta-analyses for additional references.

SELECTION CRITERIA

We included individually randomized controlled trials (RCTs) and cluster RCTs conducted in hyperendemic and holoendemic malaria regions or that reported on any malaria-related outcomes that included children younger than 18 years of age. We included trials that compared orally administered iron, iron with folic acid, and iron with antimalarial treatment versus placebo or no treatment. We included trials of iron supplementation or fortification interventions if they provided at least 80% of the Recommended Dietary Allowance (RDA) for prevention of anaemia by age. Antihelminthics could be administered to either group, and micronutrients had to be administered equally to both groups.

DATA COLLECTION AND ANALYSIS

The primary outcomes were clinical malaria, severe malaria, and death from any cause. We assessed the risk of bias in included trials with domain-based evaluation and assessed the quality of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. We performed a fixed-effect meta-analysis for all outcomes and random-effects meta-analysis for hematological outcomes, and adjusted analyses for cluster RCTs. We based the subgroup analyses for anaemia at baseline, age, and malaria prevention or management services on trial-level data.

MAIN RESULTS

Thirty-five trials (31,955 children) met the inclusion criteria. Overall, iron does not cause an excess of clinical malaria (risk ratio (RR) 0.93, 95% confidence intervals (CI) 0.87 to 1.00; 14 trials, 7168 children, high quality evidence). Iron probably does not cause an excess of clinical malaria in both populations where anaemia is common and those in which anaemia is uncommon. In areas where there are prevention and management services for malaria, iron (with or without folic acid) may reduce clinical malaria (RR 0.91, 95% CI 0.84 to 0.97; seven trials, 5586 participants, low quality evidence), while in areas where such services are unavailable, iron (with or without folic acid) may increase the incidence of malaria, although the lower CIs indicate no difference (RR 1.16, 95% CI 1.02 to 1.31; nine trials, 19,086 participants, low quality evidence). Iron supplementation does not cause an excess of severe malaria (RR 0.90, 95% CI 0.81 to 0.98; 6 trials, 3421 children, high quality evidence). We did not observe any differences for deaths (control event rate 1%, low quality evidence). Iron and antimalarial treatment reduced clinical malaria (RR 0.54, 95% CI 0.43 to 0.67; three trials, 728 children, high quality evidence). Overall, iron resulted in fewer anaemic children at follow up, and the end average change in haemoglobin from base line was higher with iron.

AUTHORS' CONCLUSIONS

Iron treatment does not increase the risk of clinical malaria when regular malaria prevention or management services are provided. Where resources are limited, iron can be administered without screening for anaemia or for iron deficiency, as long as malaria prevention or management services are provided efficiently.

Influence of Plasmodium gametocyte carriage on the prevalence of fever, splenomegaly and cardiovascular parameters in children less than 15 years in the Mount Cameroon area: cross sectional study

Background

Cardiovascular parameters can be impaired by repeated infections with P. falciparum. This study aimed at investigating the influence of gametocyte carriage on; the prevalence of fever and splenomegaly, blood pressure, heart rate and haematological indices in children <15 years, in the Mount Cameroon area.

Methods

A cross-sectional study was carried out, from February to July 2013. A child with axillary body temperature ≥37.5 °C was considered febrile and splenomegaly was investigated by palpation. Systolic and diastolic blood pressures as well as heart rate were assessed by non-invasive methods. Malaria parasites were detected and density assessed from Giemsa-stained thin and thick blood films. An auto haematology analyser was used to obtain complete blood count values such as haemoglobin (Hb), haematocrit (Hct), red blood cell (RBC) and white blood cell (WBC) counts, mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), and mean corpuscular haemoglobin (MCH). Univariate analyses were used to examine influence of gametocyte carriage on fever and splenomegaly while, multiple linear regression models were used to evaluate influence of independent variables on the dependent variables.

Results

Of a total of 454 children examined, malaria parasitaemia, fever, splenomegaly and gametocyte carriage were detected in 36.6, 21.6, 14.3 and 7.3 % of them respectively. Children who were asexual parasite and gametocyte positive (ASP + Gam Pos) had significantly highest (P = 0.03, P = 0.002) prevalence of fever and splenomegaly (39.4 %, 33.3 %) respectively than their aparasitaemic (AP) and asexual parasite positive (ASP Pos) equivalents (19.0 %, 10.9 % and 22.8 %, 16.9 % respectively). The presence of asexual malaria parasitaemia significantly influenced the MCV (P = 0.03), MCH (P = 0.03) and heart beats /min (0.03) while gametocytaemia significantly influenced the Hb (P < 0.001), Hct (P < 0.001), RBC (P < 0.001) and systolic blood pressure (P < 0.05).

Conclusion

Gametocyte carriage significantly influenced the prevalence of fever, splenomegaly and some cardiovascular indices. In effect, children concurrently having asexual parasitaemia and gametocytes had significantly lower, Hct, Hb levels, RBC and platelet counts and systolic blood pressure.

Malarial anaemia and anaemia severity in apparently healthy primary school children in urban and rural settings in the Mount Cameroon area: cross sectional survey

BACKGROUND

This study examines the relative importance of living in an urban versus rural setting and malaria in contributing to the public health problem of malarial anaemia (MA) and anaemia respectively in apparently healthy primary school children.

METHODS

A cross-sectional study was conducted among 727 school children aged between four and 15 years living in an urban (302) and rural (425) settings in the Mount Cameroon area. Blood sample collected from each child was used for the preparation of blood films for detection of malaria parasites and assessment of malaria parasite density as well as full blood count determination using an automated haematology analyzer. Based on haemoglobin (Hb) measurements, children with malaria parasitaemia were stratified into MA (Hb<11 g/dL); mild MA (Hb of 8-10.9 g/dL); moderate MA (Hb of 6.1-7.9 g/dL) and severe MA (Hb≤6 g/dL). Evaluation of potential determinants of MA and anaemia was performed by multinomial logistic-regression analysis and odds ratios used to evaluate risk factors.

RESULTS

Out of the 727 children examined, 72 (9.9%) had MA. The prevalence of MA and anaemia were significantly higher (χ2 = 36.5, P <0.001; χ2 = 16.19, P <0.001 respectively) in children in the urban (17.9%; 26.8% respectively) than in the rural area (4.2%; 14.8% respectively). Majority of the MA cases were mild (88.9%), with moderate (5.6%) and severe MA (5.6%) occurring in the urban area only. The age group ≤6 years was significantly (P <0.05) associated with both MA and anaemia. In addition, low parasite density was associated with MA while malaria parasite negative and microcytosis were associated with anaemia.

CONCLUSIONS

Malarial anaemia and anaemia display heterogeneity and complexity that differ with the type of settlement. The presence of severe MA and the contributions of the age group ≤6 years, low parasite density and microcytosis to the public health problem of MA and anaemia are noteworthy.

Effects of malaria parasite density on blood cell parameters

Changes in blood cell parameters are already a well-known feature of malarial infections. To add to this information, the objective of this study was to investigate the varying effects that different levels of parasite density have on blood cell parameters. Patients diagnosed with malaria at Phobphra Hospital, Tak Province, Thailand between January 1st 2009 and January 1st 2012 were recruited as subjects for data collection. Blood cell parameters of 2,024 malaria-infected patients were evaluated and statistically analyzed. Neutrophil and platelet counts were significantly higher, however, RBC count was significantly lower in patients with P. falciparum infection compared to those with P. vivax infection (p<0.0001). Leukocyte counts were also significantly higher in patients with high parasitemia compared to those with low and moderate parasitemia. In terms of differential leukocyte count, neutrophil count was significantly higher in patients with high parasitemia compared to those with low and moderate parasitemia (p<0.0001). On the other hand, both lymphocyte and monocyte counts were significantly lower in patients with high parasitemia (p<0.0001). RBC count and Hb concentration, as well as platelet count were also significantly reduced (p<0.05) and (p<0.0001), respectively. To summarize, patients infected with different malaria parasites exhibited important distinctive hematological parameters, with neutrophil and eosinophil counts being the two hematological parameters most affected. In addition, patients infected with different malarial densities also exhibited important changes in leukocyte count, platelet count and hemoglobin concentration during the infection. These findings offer the opportunity to recognize and diagnose malaria related anemia, help support the treatment thereof, as well as relieve symptoms of severe malaria in endemic regions.

[Comparison of the effectiveness of artemether and quinine for treatment of severe malaria in children, Bangui, Central African Republic]

The management of severe malaria is a major challenge in the health care services in sub-Saharan Africa. This study aimed to assess the efficacy and safety of artemether and quinine in severe malaria at Complexe pédiatrique of Bangui, Central African Republic. A total of 212 children among 1125 hospital admissions (18.8%), and aged 6 to 59 months were randomly treated with artemether and quinine. Anemia (58.5%) and seizures (33.5%) were the major syndromes observed. On the third day of follow up, a regression of clinical signs and parasite clearance were observed in 98.1% of children treated with artemether and 97.1% of children treated with quinine. The death rate was 2.3% due to anemic and neurological forms. These findings show that the artemether and quinine have similar efficacy. Hence, associated with adequate intensive health care, the use of these antimalarial drugs can significantly reduce mortality from severe malaria in the Central African Republic.

Prevalence and risk factors of anaemia among children aged between 6 months and 14 years in Kenya

Background

Anaemia is one of the significant public health problems among children in the world. Understanding risk factors of anaemia provides more insight to the nature and types of policies that can be put up to fight anaemia. We estimated the prevalence and risk factors of anaemia in a population-based, cross-sectional survey.

Methodology

Blood samples from 11,711 children aged between 6 months and 14 years were collected using a single-use, spring-loaded, sterile lancet to make a finger prick. Anaemia was measured based on haemoglobin concentration level. The generalized linear model framework was used to analyse the data, in which the response variable was either a child was anemic or not anemic.

Results

The overall prevalence of anaemia among the children in Kenya was estimated to be 28.8%. The risk of anaemia was found to decrease with age progressively with increase in each year of age; children below 1 year were at highest risk of anaemia. The risk of anaemia was significantly higher in male than female children. Mothers with secondary and above education had a protective effect on the risk of anaemia on their children. Malaria diagnosis status of a child was positively associated with risk anaemia.

Conclusion

Controlling co-morbidity of malaria and improving maternal knowledge are potential options for reducing the burden of anaemia.

Malarial anemia: digestive vacuole of Plasmodium falciparum mediates complement deposition on bystander cells to provoke hemophagocytosis

The digestive vacuole (DV) of Plasmodium falciparum, which is released into the bloodstream upon rupture of each parasitized red blood cell (RBC), was recently discovered to activate the alternative complement pathway. In the present work, we show that C3- and C5-convertases assembling on the parasitic organelle are able to provoke deposition of activated C3 and C5b-9 on non-infected bystander erythrocytes. Direct contact of DVs with cells is mandatory for the effect, and bystander complement deposition occurs focally, possibly at the sites of contact. Complement opsonization promotes protracted erythrophagocytosis by human macrophages, an effect that is magnified when ring-stage infected RBCs with reduced CD55 and CD59, or paroxysmal nocturnal hemoglobinuria (PNH)-RBCs lacking these complement inhibitors are employed as targets. Bystander attack can also directly induce lysis of PNH-RBCs. Direct evidence for complement activation and bystander attack mediated by DVs was obtained through immunohistochemical analyses of brain paraffin sections from autopsies of patients who had died of cerebral malaria. C3d and the assembled C5b-9 complex could be detected in all sections, colocalizing with and often extending locally beyond massive accumulations of DVs that were identified under polarized light. This is the first demonstration that a complement-activating particle can mediate opsonization of bystander cells to promote their antibody-independent phagocytosis. The phenomenon may act in concert with other pathomechanisms to promote the development of anemia in patients with severe malaria.

Can an integrated approach reduce child vulnerability to anaemia? Evidence from three African countries

Addressing the complex, multi-factorial causes of childhood anaemia is best done through integrated packages of interventions. We hypothesized that due to reduced child vulnerability, a "buffering" of risk associated with known causes of anaemia would be observed among children living in areas benefiting from a community-based health and nutrition program intervention. Cross-sectional data on the nutrition and health status of children 24-59 mo (N=2405) were obtained in 2000 and 2004 from program evaluation surveys in Ghana, Malawi and Tanzania. Linear regression models estimated the association between haemoglobin and immediate, underlying and basic causes of child anaemia and variation in this association between years. Lower haemoglobin levels were observed in children assessed in 2000 compared to 2004 (difference -3.30 g/L), children from Tanzania (-9.15 g/L) and Malawi (-2.96 g/L) compared to Ghana, and the youngest (24-35 mo) compared to oldest age group (48-59 mo; -5.43 g/L). Children who were stunted, malaria positive and recently ill also had lower haemoglobin, independent of age, sex and other underlying and basic causes of anaemia. Despite ongoing morbidity, risk of lower haemoglobin decreased for children with malaria and recent illness, suggesting decreased vulnerability to their anaemia-producing effects. Stunting remained an independent and unbuffered risk factor. Reducing chronic undernutrition is required in order to further reduce child vulnerability and ensure maximum impact of anaemia control programs. Buffering the impact of child morbidity on haemoglobin levels, including malaria, may be achieved in certain settings.

Fascinating interaction between host and pathogen

Clinical manifestations of disease depend upon host's immune response that is induced by pathogen and modified by the host's innate and adaptive immunity. Immunocompetent children of similar age and nutrition evoke different responses to the same pathogen varying from benign to potentially fatal condition. This results in diverse clinical presentations of a disease, that is different from the standard expected pattern and thus, poses a diagnostic challenge. Even, subsequent progression of a disease is also variable. It is the balance between immune stimulation, immune suppression and immune tolerance that decides the outcome. In case of balanced response, child recovers completely without any damage. However at times, cure is at the expense of permanent sequalae while in case of unfavourable immune response, survival may not be certain inspite of successful therapy. Symptoms and physical signs of primary disease often overlap with those caused by host's immune response. In such a situation, it is difficult to decide whether therapy of primary disease has failed due to drug resistance or whether persistence or deterioration is the result of immune response. Occasionally pathogen can transform into "superantigen" that may lead to "cytokine storm". Resulting immune-mediated complications may endanger life and at best, treated symptomatically. Immune suppressive drugs such as steroids, chemotherapeutic agents, IVIG or specific antibodies may not be able to suppress undesirable immune response. It is not just the immune suppression that is required but ideally immune modulation. Immune modulation refers to enhancing protective responses while avoiding destructive ones. At present, science falls short of anticipating harmful immune responses and lacks specific immune intervention.Laboratory test results are also dependent on host response and hence need cautious interpretation based on clinical profile in consideration with multiple variables. In final analysis, fight between host and pathogen is a complex one and often unpredictable. It is hoped that most children evoke favourable response but pediatrician has to be watchful even in the most benign disease.

The blood supply in Sub-Saharan Africa: needs, challenges, and solutions

Sub-Saharan Africa (SSA) is burdened with a growing population and poor health care resources. Transfusion medicine is uniquely affected for SSA as a result of a combination of factors which put tremendous pressure on the blood supply. In this review, we consider these factors including: malaria, sickle cell anemia, transfusion medicine infrastructure, and past transfusion medicine policies including those which are tied to foreign aid, such as a VNRD-only practice. We also consider how SSA can overcome some of these hurdles to achieve a safe and adequate blood supply for its people through the advent of new vaccines, medications, infrastructure development, policy changes, and education.

A Study on Course of Infection and Haematological Changes in falciparum-Infected in Comparison with Artemisinin(s)-Treated Mice

To find out the efficacy and effect of artemisinin derivatives on haematological indices, C57BL/6J mice were challenged with Plasmodium falciparum and treated with therapeutic doses of AS, AE, and AL. Course of infection was studied in the infected and treated groups up to day 42. Peak level of parasitaemia (38%) was observed on day 11 in infected group. Haematological indices indicated significant (P < 0.05) decrease in RBC, WBC, haemoglobin, packed cell volume, mean cell volume, and platelet counts in infected mice. But all the parameters were restored to normal values, and significant (P < 0.05) changes were observed in all drug-treated groups. Insignificant changes were observed for MCHC (P > 0.05) in all drug-treated groups. Percent of peak parasitaemia was much reduced in AL- (3.2% on day 3) treated group in comparison with AE- (2.4% on day 4) and AS- (4% on day 2) treated groups. Parasites were completely cleared on day 6 in AS group, day 5 in AE group, and day 4 in AL group. Hence, our results strongly support that combination therapy has high efficacy rates than monotherapy. No adverse effects were observed on haematological parameters when animals were treated with therapeutic dosages.

Determinants of anemia in postpartum HIV-negative women in Dar es Salaam, Tanzania

OBJECTIVE

The determinants of anemia during both pregnancy and postpartum recovery remain incompletely understood in sub-Saharan African women.

SUBJECTS/METHODS

In a prospective cohort study among pregnant women, we assessed dietary, biochemical, anthropometric, infectious and sociodemographic factors at baseline. In multivariate Cox proportional hazards models, we examined predictors of incident anemia (hemoglobin <11 g/dl) and iron deficiency anemia (anemia plus mean corpuscular volume <80fL), and recovery from anemia and iron deficiency anemia through 18 months postpartum at antenatal clinics in Dar es Salaam, Tanzania between 2001 and 2005. A total of 2364 non-anemic pregnant women and 4884 anemic women were enrolled between 12 and 27 weeks of gestation.

RESULTS

In total, 292 women developed anemia during the postpartum period and 165 developed iron deficiency anemia, whereas 2982 recovered from baseline anemia and 2044 from iron deficiency anemia. Risk factors for postpartum anemia were delivery complications (RR 1.6, 95% confidence interval (CI) 1.13, 2.22) and low postpartum CD4 cell count (RR 1.73, 95% CI 0.96, 3.17). Iron/folate supplementation during pregnancy had a protective relationship with the incidence of iron deficiency anemia. Absence of delivery complications, education status and iron/folate supplementation were positively associated with time to recovery from iron deficiency.

CONCLUSION

Maternal nutritional status during pregnancy, prenatal iron/folate supplementation, perinatal care, and prevention and management of infections, such as malaria, are modifiable risk factors for the occurrence of, and recovery from, anemia.

Simultaneous determination of phagocytosis of Plasmodium falciparum-parasitized and non-parasitized red blood cells by flow cytometry

Background

Severe falciparum malaria anaemia (SMA) is a frequent cause of mortality in children and pregnant women. The most important determinant of SMA appears to be the loss of non-parasitized red blood cells (np-RBCs) in excess of loss of parasitized (p-) RBCs at schizogony. Based on data from acute SMA where excretion of haemoglobin in urine and increased plasma haemoglobin represented respectively less than 1% and 0.5% of total Hb loss, phagocytosis appears to be the predominant mechanism of removal of np- and p-RBC.

Estimates indicate that np-RBCs are cleared in approximately 10-fold excess compared to p-RBCs. An even larger removal of np-RBCs has been described in vivax malaria anaemia. Estimates were based on two single studies both performed on neurosyphilitic patients who underwent malaria therapy. As the share of np-RBC removal is likely to vary between wide limits, it is important to assess the contribution of both np- and p-RBC populations to overall RBC loss, and disclose the mechanism of such variability. As available methods do not discriminate between the removal of np- vs p-RBCs, the purpose of this study was to set up a system allowing the simultaneous determination of phagocytosis of p- and np-RBC in the same sample.

Methods and Results

Phagocytosis of p- and np-RBCs was quantified in the same sample using double-labelled target cells and the human phagocytic cell-line THP-1, pre-activated by TNF and IFNγ to enhance their phagocytic activity. Target RBCs were double-labelled with fluorescent carboxyfluorescein-succinimidyl ester (CF-SE) and the DNA label ethidium bromide (EB). EB, a DNA label, allowed to discriminate p-RBCs that contain parasitic DNA from the np-RBCs devoid of DNA. FACS analysis of THP-1 cells fed with double-labelled RBCs showed that p- and np-RBCs were phagocytosed in different proportions in relation to parasitaemia.

Conclusions

The assay allowed the analysis of phagocytosis rapidly and with low subjective error, and the differentiation between phagocytosed p- and np-RBCs in the same sample. The presented method may help to analyse the factors or conditions that modulate the share of np-RBC removal in vitro and in vivo and lead to a better understanding of the pathogenesis of SMA.

Malaria: a haematological disease

Plasmodium falciparum malaria remains a major cause of mortality throughout the tropical world. Haematological abnormalities are considered a hallmark of malaria, bearing an impact on final outcome and representing indices of prognostic and follow-up value. These include severe anaemia, coagulation disturbances, leukocyte numerical or functional changes and spleen involvement. Anaemia involves red blood cell lysis due to parasite invasion, as well as mechanisms of intravascular haemolysis and decreased erythropoiesis. Exchange or blood transfusion is mainly recommended in the management of these patients. Haemorrhagic complications in severe malaria are relatively rare despite prominent thrombocytopenia and dysfunction in the coagulation pathway. Numerical, as well as functional changes in the white blood cell are less dramatic than other blood cell series, but still, remain a significant index of disease progression and ultimate prognosis. Finally, the role of the spleen in severe malaria is multifactorial. Care and vigilance should be taken against splenic rupture which is fatal and can occur despite appropriate antimalarial prophylaxis and treatment.

Plasmodium falciparum--malaria in pregnant African immigrants often goes unrecognized

We report four cases of asymptomatic Plasmodium falciparum malaria in pregnant African women. They had immigrated to Finland 3 to 13 months earlier. The disease was revealed only by anemia. The diagnosis relied on blood smear which showed a parasitemia <0.2% in three cases. Medical personnel should be informed about the possibility of afebrile forms of malaria in pregnant women even months after immigration. Very low levels of parasitemia may call for a more sensitive diagnostic approach such as polymerase chain reaction.

Chemical biology of glycosylphosphatidylinositol anchors

Glycosylphosphatidylinositols (GPIs) are complex glycolipids that are covalently linked to the C-terminus of proteins as a posttranslational modification. They anchor the attached protein to the cell membrane and are essential for normal functioning of eukaryotic cells. GPI-anchored proteins are structurally and functionally diverse. Many GPIs have been structurally characterized but comprehension of their biological functions, beyond the simple physical anchoring, remains largely speculative. Work on functional elucidation at a molecular level is still limited. This Review focuses on the roles of GPI unraveled by using synthetic molecules and summarizes the structural diversity of GPIs, as well as their biological and chemical syntheses.

Association of ABO blood group and P. falciparum malaria related outcomes: a cross-sectional study in Ethiopia

Studies elucidate conflicting results about the relationships between ABO blood groups and Plasmodium infection outcomes in humans. This study examined association between ABO blood group and Plasmodium falciparum (P. falciparum) malaria related outcomes among 1065 malaria suspected febrile patients who attended Dore Baafano Health Center, southern Ethiopia, between December, 2010 and February, 2011. Blood specimens were collected and examined for malaria using Giemsa-staining, while stool specimens were examined for helminth infections using Kato-Katz method. Haemoglobin level and blood group were determined using hemocue machine and antisera hemagglutination test, respectively. Clinical data were also collected for the patients. Among the study participants, the proportion of O, A, B and AB blood groups were 40.1%, 30.1%, 29.0% and 14.3%, respectively, and P. falciparum malaria cases in the corresponding blood groups were 14.8%, 14.0%, 13.4% and 15.7%. The odds of non-severe P. falciparum malaria were not significantly different between individuals of blood group A versus O or B versus O or AB versus O. Mean haemoglobin concentration was significantly lower in P. falciparum infected blood type A individuals compared to P. falciparum infected blood type O (β=-1.25, 95% CI=-2.31 to -0.19) or non-A (β=-1.27, 95% CI=-2.23 to -0.32) individuals. The odds of P. falciparum malaria related anaemia was about three times higher in individuals with blood type A compared to those with blood type O (adjusted OR=2.82, 95% CI=1.05-7.56) or non-A individuals (adjusted OR=2.84, 95% CI=1.15-7.01). However, mean P. falciparum density did not significantly differ among patients according to their blood groups. In conclusion, individuals with blood group A had higher risk of anaemia compared to those with O and non-A phenotypes among P. falciparum malaria patients. However, there is a need to investigate the mechanism.

Implications of malaria on iron deficiency control strategies

The populations in greatest need of iron supplementation are also those at greatest risk of malaria: pregnant women and young children. Iron supplementation has been shown to increase malaria risk in these groups in numerous studies, although this effect is likely diminished by factors such as host immunity, host iron status, and effective malaria surveillance and control. Conversely, the risk of anemia is increased by malaria infections and preventive measures against malaria decrease anemia prevalence in susceptible populations without iron supplementation. Studies have shown that subjects with malaria experience diminished absorption of orally administered iron, so that as a consequence, iron supplementation may have generally reduced efficacy in malarious populations. A possible mechanistic link between malaria, poor absorption of iron, and anemia is provided by recent research on hepcidin, the human iron control hormone. Our improved understanding of iron metabolism may contribute to the control of malaria and the treatment of anemia. Malaria surveillance and control are necessary components of programs to control iron deficiency and may enhance the efficacy of iron supplementation.

α-Thalassemia impairs the cytoadherence of Plasmodium falciparum-infected erythrocytes

BACKGROUND

α-Thalassemia results from decreased production of α-globin chains that make up part of hemoglobin tetramers (Hb; α(2)β(2)) and affects up to 50% of individuals in some regions of sub-Saharan Africa. Heterozygous (-α/αα) and homozygous (-α/-α) genotypes are associated with reduced risk of severe Plasmodium falciparum malaria, but the mechanism of this protection remains obscure. We hypothesized that α-thalassemia impairs the adherence of parasitized red blood cells (RBCs) to microvascular endothelial cells (MVECs) and monocytes--two interactions that are centrally involved in the pathogenesis of severe disease.

METHODS AND FINDINGS

We obtained P. falciparum isolates directly from Malian children with malaria and used them to infect αα/αα (normal), -α/αα and -α/-α RBCs. We also used laboratory-adapted P. falciparum clones to infect -/-α RBCs obtained from patients with HbH disease. Following a single cycle of parasite invasion and maturation to the trophozoite stage, we tested the ability of parasitized RBCs to bind MVECs and monocytes. Compared to parasitized αα/αα RBCs, we found that parasitized -α/αα, -α/-α and -/-α RBCs showed, respectively, 22%, 43% and 63% reductions in binding to MVECs and 13%, 33% and 63% reductions in binding to monocytes. α-Thalassemia was associated with abnormal display of P. falciparum erythrocyte membrane protein 1 (PfEMP1), the parasite's main cytoadherence ligand and virulence factor, on the surface of parasitized RBCs.

CONCLUSIONS

Parasitized α-thalassemic RBCs show PfEMP1 display abnormalities that are reminiscent of those on the surface of parasitized sickle HbS and HbC RBCs. Our data suggest a model of malaria protection in which α-thalassemia ameliorates the pro-inflammatory effects of cytoadherence. Our findings also raise the possibility that other unstable hemoglobins such as HbE and unpaired α-globin chains (in the case of β-thalassemia) protect against life-threatening malaria by a similar mechanism.

The anaemia of Plasmodium vivax malaria

Plasmodium vivax threatens nearly half the world's population and is a significant impediment to achievement of the millennium development goals. It is an important, but incompletely understood, cause of anaemia. This review synthesizes current evidence on the epidemiology, pathogenesis, treatment and consequences of vivax-associated anaemia. Young children are at high risk of clinically significant and potentially severe vivax-associated anaemia, particularly in countries where transmission is intense and relapses are frequent. Despite reaching lower densities than Plasmodium falciparum, Plasmodium vivax causes similar absolute reduction in red blood cell mass because it results in proportionately greater removal of uninfected red blood cells. Severe vivax anaemia is associated with substantial indirect mortality and morbidity through impaired resilience to co-morbidities, obstetric complications and requirement for blood transfusion. Anaemia can be averted by early and effective anti-malarial treatment.