ABSTRACT
BACKGROUND: The RTS,S/AS01E malaria vaccine (RTS,S) was introduced by national immunisation programmes in Ghana, Kenya, and Malawi in 2019 in large-scale pilot schemes. We aimed to address questions about feasibility and impact, and to assess safety signals that had been observed in the phase 3 trial that included an excess of meningitis and cerebral malaria cases in RTS,S recipients, and the possibility of an excess of deaths among girls who received RTS,S than in controls, to inform decisions about wider use. METHODS: In this prospective evaluation, 158 geographical clusters (66 districts in Ghana; 46 sub-counties in Kenya; and 46 groups of immunisation clinic catchment areas in Malawi) were randomly assigned to early or delayed introduction of RTS,S, with three doses to be administered between the ages of 5 months and 9 months and a fourth dose at the age of approximately 2 years. Primary outcomes of the evaluation, planned over 4 years, were mortality from all causes except injury (impact), hospital admission with severe malaria (impact), hospital admission with meningitis or cerebral malaria (safety), deaths in girls compared with boys (safety), and vaccination coverage (feasibility). Mortality was monitored in children aged 1-59 months throughout the pilot areas. Surveillance for meningitis and severe malaria was established in eight sentinel hospitals in Ghana, six in Kenya, and four in Malawi. Vaccine uptake was measured in surveys of children aged 12-23 months about 18 months after vaccine introduction. We estimated that sufficient data would have accrued after 24 months to evaluate each of the safety signals and the impact on severe malaria in a pooled analysis of the data from the three countries. We estimated incidence rate ratios (IRRs) by comparing the ratio of the number of events in children age-eligible to have received at least one dose of the vaccine (for safety outcomes), or age-eligible to have received three doses (for impact outcomes), to that in non-eligible age groups in implementation areas with the equivalent ratio in comparison areas. To establish whether there was evidence of a difference between girls and boys in the vaccine's impact on mortality, the female-to-male mortality ratio in age groups eligible to receive the vaccine (relative to the ratio in non-eligible children) was compared between implementation and comparison areas. Preliminary findings contributed to WHO's recommendation in 2021 for widespread use of RTS,S in areas of moderate-to-high malaria transmission. FINDINGS: By April 30, 2021, 652â673 children had received at least one dose of RTS,S and 494â745 children had received three doses. Coverage of the first dose was 76% in Ghana, 79% in Kenya, and 73% in Malawi, and coverage of the third dose was 66% in Ghana, 62% in Kenya, and 62% in Malawi. 26â285 children aged 1-59 months were admitted to sentinel hospitals and 13â198 deaths were reported through mortality surveillance. Among children eligible to have received at least one dose of RTS,S, there was no evidence of an excess of meningitis or cerebral malaria cases in implementation areas compared with comparison areas (hospital admission with meningitis: IRR 0·63 [95% CI 0·22-1·79]; hospital admission with cerebral malaria: IRR 1·03 [95% CI 0·61-1·74]). The impact of RTS,S introduction on mortality was similar for girls and boys (relative mortality ratio 1·03 [95% CI 0·88-1·21]). Among children eligible for three vaccine doses, RTS,S introduction was associated with a 32% reduction (95% CI 5-51%) in hospital admission with severe malaria, and a 9% reduction (95% CI 0-18%) in all-cause mortality (excluding injury). INTERPRETATION: In the first 2 years of implementation of RTS,S, the three primary doses were effectively deployed through national immunisation programmes. There was no evidence of the safety signals that had been observed in the phase 3 trial, and introduction of the vaccine was associated with substantial reductions in hospital admission with severe malaria. Evaluation continues to assess the impact of four doses of RTS,S. FUNDING: Gavi, the Vaccine Alliance; the Global Fund to Fight AIDS, Tuberculosis and Malaria; and Unitaid.
Subject(s)
Feasibility Studies , Immunization Programs , Malaria Vaccines , Malaria, Cerebral , Humans , Ghana/epidemiology , Malawi/epidemiology , Infant , Female , Kenya/epidemiology , Malaria Vaccines/administration & dosage , Malaria Vaccines/adverse effects , Male , Child, Preschool , Malaria, Cerebral/epidemiology , Malaria, Cerebral/mortality , Prospective Studies , Malaria, Falciparum/prevention & control , Malaria, Falciparum/epidemiology , Meningitis/epidemiology , Meningitis/prevention & controlABSTRACT
Purpose: To assess the frequency and distribution of retinal changes in children suffering from cerebral malaria (CM), study the correlation between fundal changes and severity of disease, visual outcome, and survival of patients. Methods: An observational, cross-sectional study was done on pediatric patients, suffering from CM in a tertiary care center in eastern India. A complete ophthalmological examination was done and findings were tabulated. Their hospital admission records were checked for severity of coma, recovery, and prognosis. Data were analyzed with SPSS software, and P value < 0.05 was considered statistically significant. Results: Total 113 children of age group 0-18 years (mean age 7.88 ± 0.56 years) were enrolled in the study. Seventy-seven children (68.14%) had retinal changes. Most common retinal signs associated with malarial retinopathy were white centered hemorrhage and papilledema (53.09% each), followed by retinal whitening (51.33%) and vessel changes (39.82%). The correlation between the presence of white centered retinal hemorrhages and visual prognosis was found to be statistically significant (P = 0.001). Patients with Grade 4 parasitemia showed maximum retinal signs with a significant correlation between the severity of papilledema and parasite load (P = 0.037). Eighty-six patients (76.11%) survived and 27 patients (23.89%) died. All 27 patients who died showed all four signs of malarial retinopathy. Out of these, patients with retinal whitening suffered from severe coma, and this correlation was found to be statistically significant (P = 0.002). Conclusion: Presence of retinal signs in patients with CM is associated with severe disease (high parasite load), poor visual outcome, and increased mortality.
Subject(s)
Malaria, Cerebral , Papilledema , Retinal Diseases , Humans , Child , Infant, Newborn , Infant , Child, Preschool , Adolescent , Malaria, Cerebral/complications , Malaria, Cerebral/diagnosis , Malaria, Cerebral/epidemiology , Coma/complications , Cross-Sectional Studies , Retinal Diseases/diagnosisABSTRACT
Children surviving central nervous system (CNS) infections are at high risk of neurological, behavioral, and cognitive sequalae. Early identification, characterization, and treatment of these sequelae may improve child and family health. In Africa, it is unclear if there are demographic or clinical factors that increase the risk of post-hospital loss to follow-up in children with CNS infections. If these factors exist, targeted educational efforts to increase rates of post-hospital retention could be focused on families at highest risk. We performed a case-control study of Malawian children with cerebral malaria, a locally common CNS infection, previously admitted to a specialized research unit in Blantyre, Malawi. Routine survivor post-hospital follow-up was scheduled for 1 month, 6 months, and 12 months. We compared demographic and clinical characteristics between 84 children who missed one or more of these post-hospital visits with 120 children who attended all visits. There were no statistically significant differences in demographic or clinical characteristics between children whose families returned for all follow-up visits and those who did not. Specifically, when comparing these groups, we found no differences in age (P = 00.646), sex (P = 0.789), duration of hospitalization (P = 0.903), distance from home to hospital (P = 0.355), type or severity of neurological sequelae (P = 0.837), guardian literacy (P = 0.057), or number of discharge medications (P = 0.464). No factors assessed in this study were associated with higher risk of loss to follow-up in Malawian child survivors of CNS infections. During hospitalization, educational efforts to increase post-hospital retention should focus on all families.
Subject(s)
Malaria, Cerebral , Child , Humans , Infant , Malaria, Cerebral/complications , Malaria, Cerebral/epidemiology , Follow-Up Studies , Case-Control Studies , Hospitals , Survivors , Malawi/epidemiologyABSTRACT
BACKGROUND: Malaria affects 24 million children globally, resulting in nearly 500,000 child deaths annually in low- and middle-income countries (LMICs). Recent studies have provided evidence that severe malaria infection results in sustained impairment in cognition and behaviour among young children; however, a formal meta-analysis has not been published. The objective was to assess the association between severe malaria infection with cognitive and behavioural outcomes among children living in LMICs. METHODS: Six online bibliographic databases were searched and reviewed in November 2022. Studies included involved children < 18 years of age living in LMICs with active or past severe malaria infection and measured cognitive and/or behaviour outcomes. The quality of studies was assessed. Definitions of severe malaria included cerebral malaria, severe malarial anaemia, and author-defined severe malaria. Results from all studies were qualitatively summarized. For studies with relevant data on attention, learning, memory, language, internalizing behaviour and externalizing behaviour, results were pooled and a meta-analysis was performed. A random-effects model was used across included cohorts, yielding a standardized mean difference between the severe malaria group and control group. RESULTS: Out of 3,803 initial records meeting the search criteria, 24 studies were included in the review, with data from 14 studies eligible for meta-analysis inclusion. Studies across sub-Saharan Africa assessed 11 cohorts of children from pre-school to school age. Of all the studies, composite measures of cognition were the most affected areas of development. Overall, attention, memory, and behavioural problems were domains most commonly found to have lower scores in children with severe malaria. Meta-analysis revealed that children with severe malaria had worse scores compared to children without malaria in attention (standardized mean difference (SMD) -0.68, 95% CI -1.26 to -0.10), memory (SMD -0.52, 95% CI -0.99 to -0.06), and externalizing behavioural problems (SMD 0.45, 95% CI 0.13-0.78). CONCLUSION: Severe malaria is associated with worse neuropsychological outcomes for children living in LMICs, specifically in attention, memory, and externalizing behaviours. More research is needed to identify the long-term implications of these findings. Further interventions are needed to prevent cognitive and behavioural problems after severe malaria infection. TRIAL REGISTRATION: This systematic review was registered under PROSPERO: CRD42020154777.
Subject(s)
Developing Countries , Malaria, Cerebral , Child , Child, Preschool , Humans , Cognition , Malaria, Cerebral/complications , Malaria, Cerebral/epidemiology , Africa South of the SaharaABSTRACT
Hypoglycemia, defined as a blood glucose < 2.2 mmol/L, is associated with death in pediatric cerebral malaria (CM). The optimal duration of glucose monitoring in CM is unknown. We collected data from 1,674 hospitalized Malawian children with CM to evaluate the association between hypoglycemia and death or neurologic disability in survivors. We assessed the optimal duration of routine periodic measurements of blood glucose. Children with hypoglycemia at admission had a 2.87-fold higher odds (95% CI: 1.35-6.09) of death and, if they survived, a 3.21-fold greater odds (95% CI: 1.51-6.86) of sequelae at hospital discharge. If hypoglycemia was detected at 6 hours but not at admission, there was a 7.27-fold higher odds of death (95% CI: 1.85-8.56). The presence of newly developed hypoglycemia after admission was not independently associated with neurological sequelae in CM survivors. Among all new episodes of blood sugar below a treatment threshold of 3.0 mmol/L, 94.7% occurred within 24 hours of admission. In those with blood sugar below 3.0 mmol/L in the first 24 hours, low blood sugar persisted or recurred for up to 42 hours. Hypoglycemia at admission or 6 hours afterward is strongly associated with mortality in CM. Children with CM should have 24 hours of post-admission blood glucose measurements. If a blood glucose less than the treatment threshold of 3.0 mmol/L is not detected, routine assessments may cease. Children who have blood sugar values below the treatment threshold detected within the first 24 hours should continue to have periodic glucose measurements for 48 hours post-admission.
Subject(s)
Hypoglycemia , Malaria, Cerebral , Child , Humans , Blood Glucose , Malaria, Cerebral/epidemiology , Malaria, Cerebral/complications , Blood Glucose Self-Monitoring , Hospitalization , Disease ProgressionABSTRACT
BACKGROUND: In malaria-endemic areas, children presenting to hospitals with a decreased level of consciousness remain a diagnostic dilemma. The definition of cerebral malaria in a comatose child demands exclusion of other possible reasons, which requires in-depth investigations that are not easily available. The aim of this study was to investigate the frequency and clinical characteristics of PCR-confirmed malaria in a cohort of children with a decreased level of consciousness, look for potential features that would aid in differentiating children with malaria from those without, and assess the performance of traditional thick film microscopy against the cytb-qPCR-method. METHODS: A total of 345 children aged 30 days-15 years old, presenting to Hospital Pediátrico David Bernardino in Luanda, Angola, with a decreased level of consciousness (Glasgow coma scale score < 15) were prospectively enrolled during 2014-2017. Malaria was defined as a positive cytb-qPCR result on any occasion in hospital. The clinical course and laboratory parameters were compared between children with malaria and those without. The performance of thick film microscopy was analysed against the PCR method. RESULTS: 161 of 345 children (46.7%) had a positive malaria PCR test result. All cases were Plasmodium falciparum species, and 82.6% (133/161) fulfilled the WHO criteria for severe malaria. Overall, children with malaria presented to hospital with a shorter duration of symptoms and less convulsions pre-admission compared to those without malaria. The median GCS score on admission was 8, which did not differ between children with or without malaria. Clinical findings on admission were mostly similar across the whole cohort, but an infection focus outside the central nervous system was more common in malaria-negative children. Moreover, severe anaemia, thrombocytopenia, and high CRP levels occurred more frequently in children with malaria. The case fatality ratio was 28.5% (91/319) and did not differ between parasitaemic children and those without malaria, although parasitaemic children died sooner after hospital admission. When neurological sequelae were also considered, a positive malaria test was associated with a better outcome. The performance of thick film microscopy against PCR yielded a sensitivity of 96.8% and a specificity of 82.7%. CONCLUSIONS: In this cohort of children with a decreased consciousness, the frequent presence of a malarial infection could not be judged from the clinical findings on admission, but the combination of profound aneamia, thrombocytopenia, and a high CRP level increased the odds of a positive malaria test result. Mortality remained high regardless of etiology, but malaria infection associated with fewer neurological deficits at discharge. Thick film microscopy performed well compared to the cytb-qPCR method.
Subject(s)
Anemia , Malaria, Cerebral , Malaria, Falciparum , Thrombocytopenia , Humans , Child , Infant , Malaria, Falciparum/diagnosis , Malaria, Falciparum/epidemiology , Malaria, Falciparum/complications , Prospective Studies , Consciousness , Angola/epidemiology , Malaria, Cerebral/diagnosis , Malaria, Cerebral/epidemiology , Malaria, Cerebral/complications , Anemia/etiology , Polymerase Chain ReactionABSTRACT
BACKGROUND: Cerebral malaria (CM) and severe malarial anemia (SMA) are associated with neurocognitive impairment in childhood but their effects on long-term academic achievement are not known. METHODS: Ugandan children 5 to 12 years old who participated in a previous study evaluating cognitive outcomes after CM (n = 73) or SMA (n = 56), along with community children (CC, n = 100) from the same household or neighborhood, were on average enrolled 67.1 months (range, 19-101 months) after the severe malaria episode or previous study enrollment. Academic achievement in word reading, sentence comprehension, spelling, and math computation was evaluated using the Wide Range Achievement Test, Fourth Edition. Age-adjusted z-scores for academic achievement outcomes were calculated from CC scores. RESULTS: After adjustment for age and time from enrollment, reading scores were lower (mean difference from CC [95% confidence interval]) in children with CM (-0.15 [-0.27 to -0.03], P = .02) or SMA (-0.15 [-0.28 to -0.02], P = .02) than CC. Postdischarge malaria episodes were associated with worse spelling and reading scores in CM and worse spelling scores only in SMA. Pathway analysis showed that incidence of postdischarge uncomplicated malaria contributed significantly to the association of CM or SMA with poorer reading scores. CONCLUSION: Children with CM or SMA have poorer long-term reading skills. Postdischarge malaria episodes contribute significantly to this association. Postdischarge malaria chemoprevention should be assessed as an intervention to improve long-term academic achievement in children with severe malaria.
Subject(s)
Academic Success , Anemia , Malaria, Cerebral , Child , Humans , Child, Preschool , Aftercare , Patient Discharge , Malaria, Cerebral/epidemiology , Anemia/complicationsABSTRACT
BACKGROUND: While malaria morbidity and mortality have declined since 2000, viral central nervous system infections appear to be an important, underestimated cause of coma in malaria-endemic Eastern Africa. We aimed to describe the etiology of non-traumatic comas in young children in Benin, as well as their management and early outcomes, and to identify factors associated with death. METHODS: From March to November 2018, we enrolled all HIV-negative children aged between 2 and 6 years, with a Blantyre Coma Score ≤ 2, in this prospective observational study. Children were screened for malaria severity signs and assessed using a systematic diagnostic protocol, including blood cultures, malaria diagnostics, and cerebrospinal fluid analysis using multiplex PCR. To determine factors associated with death, univariate and multivariate analyses were performed. RESULTS: From 3244 admissions, 84 children were included: malaria was diagnosed in 78, eight of whom had a viral or bacterial co-infection. Six children had a non-malarial infection or no identified cause. The mortality rate was 29.8% (25/84), with 20 children dying in the first 24 h. Co-infected children appeared to have a poorer prognosis. Of the 76 children who consulted a healthcare professional before admission, only 5 were prescribed adequate antimalarial oral therapy. Predictors of early death were jaundice or increased bilirubin [odd ratio (OR)= 8.6; 95% confidential interval (CI): 2.03-36.1] and lactate > 5 mmol/L (OR = 5.1; 95% CI: 1.49-17.30). Antibiotic use before admission (OR = 0.1; 95% CI: 0.02-0.85) and vaccination against yellow fever (OR = 0.2, 95% CI: 0.05-0.79) protected against mortality. CONCLUSIONS: Infections were found in all children who died, and cerebral malaria was by far the most common cause of non-traumatic coma. Missed opportunities to receive early effective antimalarial treatment were common. Other central nervous system infections must be considered in their management. Some factors that proved to be protective against early death were unexpected.
Subject(s)
Bacterial Infections , Malaria, Cerebral , Benin/epidemiology , Child , Child, Preschool , Humans , Malaria, Cerebral/complications , Malaria, Cerebral/epidemiology , Odds Ratio , Prospective StudiesABSTRACT
BACKGROUND: Understanding the age patterns of disease is necessary to target interventions to maximise cost-effective impact. New malaria chemoprevention and vaccine initiatives target young children attending routine immunisation services. Here we explore the relationships between age and severity of malaria hospitalisation versus malaria transmission intensity. METHODS: Clinical data from 21 surveillance hospitals in East Africa were reviewed. Malaria admissions aged 1 month to 14 years from discrete administrative areas since 2006 were identified. Each site-time period was matched to a model estimated community-based age-corrected parasite prevalence to provide predictions of prevalence in childhood (PfPR2-10). Admission with all-cause malaria, severe malaria anaemia (SMA), respiratory distress (RD) and cerebral malaria (CM) were analysed as means and predicted probabilities from Bayesian generalised mixed models. RESULTS: 52,684 malaria admissions aged 1 month to 14 years were described at 21 hospitals from 49 site-time locations where PfPR2-10 varied from < 1 to 48.7%. Twelve site-time periods were described as low transmission (PfPR2-10 < 5%), five low-moderate transmission (PfPR2-10 5-9%), 20 moderate transmission (PfPR2-10 10-29%) and 12 high transmission (PfPR2-10 ≥ 30%). The majority of malaria admissions were below 5 years of age (69-85%) and rare among children aged 10-14 years (0.7-5.4%) across all transmission settings. The mean age of all-cause malaria hospitalisation was 49.5 months (95% CI 45.1, 55.4) under low transmission compared with 34.1 months (95% CI 30.4, 38.3) at high transmission, with similar trends for each severe malaria phenotype. CM presented among older children at a mean of 48.7 months compared with 39.0 months and 33.7 months for SMA and RD, respectively. In moderate and high transmission settings, 34% and 42% of the children were aged between 2 and 23 months and so within the age range targeted by chemoprevention or vaccines. CONCLUSIONS: Targeting chemoprevention or vaccination programmes to areas where community-based parasite prevalence is ≥10% is likely to match the age ranges covered by interventions (e.g. intermittent presumptive treatment in infancy to children aged 2-23 months and current vaccine age eligibility and duration of efficacy) and the age ranges of highest disease burden.
Subject(s)
Malaria, Cerebral , Malaria, Falciparum , Adolescent , Africa, Eastern/epidemiology , Bayes Theorem , Child , Child, Preschool , Hospitalization , Humans , Infant , Malaria, Cerebral/epidemiology , Malaria, Falciparum/epidemiology , PhenotypeABSTRACT
Patients with cerebral malaria with polymorphic Cytochrome P450 2C19 (CYP2C19) genotypes who receive concurrent treatment with quinine are at risk of inadequate or toxic therapeutic drug concentrations due to metabolic drug interactions. The study aimed to predict the potential dose regimens of quinine when coadministered with phenobarbital in adult patients with cerebral malaria and complications (e.g., lactic acidosis and acute renal failure) and concurrent with seizures and acute renal failure who carry wild-type and polymorphic CYP2C19. The whole-body physiologically based pharmacokinetic (PBPK) models for quinine, phenobarbital, and quinine-phenobarbital coadministration were constructed based on the previously published information using Simbiology®. Four published articles were used for model validation. A total of 100 virtual patients were simulated based on the 14-day and 3-day courses of treatment. using the drug-drug interaction approach. The predicted results were within 15% of the observed values. Standard phenobarbital dose, when administered with quinine, is suitable for all groups with single or continuous seizures regardless of CYP2C19 genotype, renal failure, and lactic acidosis. Dose adjustment based on area under the curve ratio provided inappropriate quinine concentrations. The recommended dose of quinine when coadministered with phenobarbital based on the PBPK model for all groups is a loading dose of 2000 mg intravenous (i.v.) infusion rate 250 mg/h followed by 1200 mg i.v. rate 150 mg/h. The developed PBPK models are credible for further simulations. Because the predicted quinine doses in all groups were similar regardless of the CYP2C19 genotype, genotyping may not be required.
Subject(s)
Anticonvulsants/administration & dosage , Antimalarials/administration & dosage , Malaria, Cerebral/drug therapy , Phenobarbital/administration & dosage , Quinine/administration & dosage , Seizures/drug therapy , Acidosis, Lactic/epidemiology , Acidosis, Lactic/pathology , Acute Kidney Injury/epidemiology , Acute Kidney Injury/pathology , Adolescent , Adult , Anticonvulsants/therapeutic use , Antimalarials/therapeutic use , Area Under Curve , Computer Simulation , Cytochrome P-450 CYP2C19/genetics , Dose-Response Relationship, Drug , Drug Interactions , Drug Therapy, Combination , Female , Genotype , Humans , Malaria, Cerebral/complications , Malaria, Cerebral/epidemiology , Male , Middle Aged , Models, Biological , Phenobarbital/therapeutic use , Quinine/therapeutic use , Seizures/etiology , Young AdultABSTRACT
Cerebral malaria (CM) may cause death or long-term neurological damage in children, and several host genetic risk factors have been reported. Malaria-specific immunoglobulin (Ig) G3 antibodies are crucial to human immune response against malaria. The hinge region of IgG3 exhibits length polymorphism (with long [L], medium [M], and short [S] alleles), which may influence its functionality. We studied IgG3 hinge region length polymorphisms in 136 Ghanaian children with malaria. Using logistic regression models, we found that children with the recessive MM allotype encoding medium IgG3 hinge region length had an increased risk of CM (adjusted odds ratio, 6.67 [95% confidence interval,1.30-34.32]; P=.004) . This has implications for future epidemiological studies on CM.
Subject(s)
Antibodies, Protozoan , Immunoglobulin G , Malaria, Cerebral , Malaria, Falciparum , Antibodies, Protozoan/genetics , Child , Ghana/epidemiology , Humans , Immunoglobulin G/genetics , Malaria, Cerebral/epidemiology , Malaria, Cerebral/genetics , Malaria, Falciparum/epidemiology , Malaria, Falciparum/genetics , Plasmodium falciparumABSTRACT
The relationship between community prevalence of Plasmodium falciparum and the burden of severe, life-threatening disease remains poorly defined. To examine the three most common severe malaria phenotypes from catchment populations across East Africa, we assembled a dataset of 6506 hospital admissions for malaria in children aged 3 months to 9 years from 2006 to 2020. Admissions were paired with data from community parasite infection surveys. A Bayesian procedure was used to calibrate uncertainties in exposure (parasite prevalence) and outcomes (severe malaria phenotypes). Each 25% increase in prevalence conferred a doubling of severe malaria admission rates. Severe malaria remains a burden predominantly among young children (3 to 59 months) across a wide range of community prevalence typical of East Africa. This study offers a quantitative framework for linking malaria parasite prevalence and severe disease outcomes in children.
Subject(s)
Malaria, Falciparum/epidemiology , Plasmodium falciparum , Africa, Eastern/epidemiology , Age Factors , Bayes Theorem , Child , Child, Preschool , Epidemiological Monitoring , Hospitalization , Humans , Incidence , Infant , Malaria, Cerebral/epidemiology , Malaria, Falciparum/prevention & control , Malaria, Falciparum/transmission , Models, Statistical , Prevalence , Risk Factors , Severity of Illness IndexABSTRACT
Artesunate therapy for severe malaria syndromes has been associated with post-treatment hemolysis and anemia. We defined post-malaria anemia as any decrease in hematocrit between the index hospitalization for severe malaria and 1 month after. We determined the incidence and severity of post-malaria anemia in Malawian children surviving cerebral malaria (CM) by analyzing hospital and follow-up data from a long-standing study of CM pathogenesis. Children enrolled before 2014 and treated with quinine (N = 258) were compared with those admitted in 2014 and after, and treated with artesunate (N = 235). The last hematocrit value obtained during hospitalization was compared with the 1-month post-hospitalization hematocrit value. The overall rate of a post-hospitalization decrease in hematocrit in children surviving CM was 5.3% (11 of 235 or 4.7% for quinine, 15 of 258 or 5.8% for artesunate; odds ratio, 3.23 [0.88, 18.38]); no patients with a decrease in hematocrit were symptomatic, and none required transfusion after hospitalization. Of the 26 children who had a decrease in hematocrit 1 month after hospitalization, 23.1% had evidence of a new malaria infection. When children treated with quinine and artesunate were combined, a higher hematocrit level on admission, lower quantitative histidine-rich protein level, and splenomegaly were associated independently with post-malaria anemia. In African survivors of CM, post-malaria anemia is rare, mild, and unassociated with the anti-malarial treatment received.
Subject(s)
Anemia/epidemiology , Anemia/etiology , Malaria, Cerebral/epidemiology , Malaria, Falciparum/epidemiology , Adolescent , Anemia/parasitology , Antimalarials/therapeutic use , Child , Child, Preschool , Cohort Studies , Female , Hospitalization , Humans , Infant , Malaria, Cerebral/complications , Malaria, Cerebral/drug therapy , Malaria, Cerebral/mortality , Malaria, Falciparum/complications , Malaria, Falciparum/drug therapy , Malaria, Falciparum/mortality , Malawi/epidemiology , MaleABSTRACT
BACKGROUND: Few recent descriptions of severe childhood malaria have been published from high-transmission regions. In the current study, the clinical epidemiology of severe malaria in Mbale, Eastern Uganda, is described, where the entomological inoculation rate exceeds 100 infective bites per year. METHODS: A prospective descriptive study was conducted to determine the prevalence, clinical spectrum and outcome of severe Plasmodium falciparum malaria at Mbale Regional Referral Hospital in Eastern Uganda. All children aged 2 months-12 years who presented on Mondays to Fridays between 8.00 am and 5.00 pm from 5th May 2011 until 30th April 2012 were screened for parasitaemia. Clinical and laboratory data were then collected from all P. falciparum positive children with features of WHO-defined severe malaria by use of a standardized proforma. RESULTS: A total of 10 208 children were screened of which 6582 (64%) had a positive blood film. Of these children, 662 (10%) had clinical features of severe malaria and were consented for the current study. Respiratory distress was the most common severity feature (554; 83.7%), while 365/585 (62.4%) had hyperparasitaemia, 177/662 (26.7%) had clinical jaundice, 169 (25.5%) had severe anaemia, 134/660 (20.2%) had hyperlactataemia (lactate ≥ 5 mmol/L), 93 (14.0%) had passed dark red or black urine, 52 (7.9%) had impaired consciousness and 49/662 (7.4%) had hypoxaemia (oxygen saturations < 90%). In-hospital mortality was 63/662 (9.5%) overall but was higher in children with either cerebral malaria (33.3%) or severe anaemia (19.5%). Factors that were independently associated with mortality on multivariate analysis included severe anaemia [odds ratio (OR) 5.36; 2.16-1.32; P = 0.0002], hyperlactataemia (OR 3.66; 1.72-7.80; P = 0.001), hypoxaemia (OR) 3.64 (95% CI 1.39-9.52; P = 0.008), and hepatomegaly (OR 2.29; 1.29-4.06; P = 0.004). No independent association was found between mortality and either coma or hyperparasitaemia. CONCLUSIONS: Severe childhood malaria remains common in Eastern Uganda where it continues to be associated with high mortality. An unusually high proportion of children with severe malaria had jaundice or gave a history of having recently passed dark red or black urine, an issue worthy of further investigation.
Subject(s)
Anemia/epidemiology , Malaria, Cerebral/epidemiology , Malaria, Falciparum/epidemiology , Parasitemia/epidemiology , Anemia/complications , Anemia/mortality , Anemia/parasitology , Child , Child, Preschool , Female , Hospitals , Humans , Infant , Malaria, Cerebral/complications , Malaria, Cerebral/mortality , Malaria, Cerebral/parasitology , Malaria, Falciparum/complications , Malaria, Falciparum/mortality , Malaria, Falciparum/parasitology , Male , Parasitemia/complications , Parasitemia/mortality , Parasitemia/parasitology , Prevalence , Prospective Studies , Uganda/epidemiologyABSTRACT
OBJECTIVES: Evaluate the relationship between endothelial activation, malaria complications, and long-term cognitive outcomes in severe malaria survivors. DESIGN: Prospectively cohort study of children with cerebral malaria, severe malarial anemia, or community children. SETTING: Mulago National Referral Hospital in Kampala, Uganda. SUBJECTS: Children 18 months to 12 years old with severe malaria (cerebral malaria, n = 253 or severe malarial anemia, n = 211) or community children (n = 206) were followed for 24 months. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Children underwent neurocognitive evaluation at enrollment (community children) or a week following hospital discharge (severe malaria) and 6, 12, and 24 months follow-up. Endothelial activation was assessed at admission on plasma samples (von Willebrand factor, angiopoietin-1 and angiopoietin-2, soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, soluble E-Selectin, and P-Selectin). False discovery rate was used to adjust for multiple comparisons. Severe malaria was associated with widespread endothelial activation compared with community children (p < 0.0001 for all markers). Acute kidney injury was independently associated with changes in von Willebrand factor, soluble intercellular adhesion molecule-1, soluble E-Selectin, P-Selectin, and angiopoietin-2 (p < 0.0001 for all). A log10 increase in angiopoietin-2 was associated with lower cognitive z scores across age groups (children < 5, ß -0.42, 95% CI, -0.69 to -0.15, p = 0.002; children ≥ 5, ß -0.39, 95% CI, -0.67 to -0.11, p = 0.007) independent of disease severity (coma, number of seizures, acute kidney injury) and sociodemographic factors. Angiopoietin-2 was associated with hemolysis (lactate dehydrogenase, total bilirubin) and inflammation (tumor necrosis factor-α, interleukin-10). In children with cerebral malaria who had a lumbar puncture performed, angiopoietin-2 was associated with blood-brain barrier dysfunction, and markers of neuroinflammation and injury in the cerebrospinal fluid (tumor necrosis factor-α, kynurenic acid, tau). CONCLUSIONS: These data support angiopoietin-2 as a measure of disease severity and a risk factor for long-term cognitive injury in children with severe malaria.
Subject(s)
Acute Kidney Injury/etiology , Angiopoietin-2/biosynthesis , Cognitive Dysfunction/etiology , Endothelium/metabolism , Malaria, Cerebral/complications , Acute Kidney Injury/physiopathology , Age Factors , Anemia, Sickle Cell/epidemiology , Child , Child, Preschool , Cognitive Dysfunction/physiopathology , Comorbidity , Female , Hemolysis/physiology , Humans , Immunoassay , Infant , Inflammation Mediators/metabolism , Malaria, Cerebral/epidemiology , Malaria, Cerebral/physiopathology , Male , Risk Factors , Severity of Illness Index , Socioeconomic Factors , Survivors , Uganda/epidemiologyABSTRACT
BACKGROUND: Cerebral malaria is the most severe form of infection with Plasmodium falciparum characterized by a highly inflammatory response. This systematic review aimed to investigate the association between TNF-α levels and cerebral malaria. METHODS: This review followed the Preferred Reporting of Systematic Review and Meta-analyses (PRISMA) guidelines. The search was performed at PubMed, LILACS, Scopus, Web of Science, The Cochrane Library, OpenGrey and Google Scholar. We have included studies of P. falciparum-infected humans with or without cerebral malaria and TNF-α dosage level. All studies were evaluated using a risk of bias tool and the GRADE approach. RESULTS: Our results have identified 2338 studies, and 8 articles were eligible according to this systematic review inclusion criteria. Among the eight articles, five have evaluated TNF- α plasma dosage, while two have evaluated at the blood and one at the brain (post-Morten). Among them, only five studies showed higher TNF-α levels in the cerebral malaria group compared to the severe malaria group. Methodological problems were identified regarding sample size, randomization and blindness, but no risk of bias was detected. CONCLUSION: Although the results suggested that that TNF-α level is associated with cerebral malaria, the evidence is inconsistent and imprecise. More observational studies evaluating the average TNF-alpha are needed.
Subject(s)
Malaria, Cerebral/epidemiology , Malaria, Falciparum/epidemiology , Tumor Necrosis Factor-alpha/blood , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Malaria, Cerebral/blood , Malaria, Falciparum/blood , Male , Middle Aged , Plasmodium falciparum , Young AdultABSTRACT
Zoonotic and vector-borne parasites are important preventable risk factors for epilepsy. Three parasitic infections - cerebral malaria, Taenia solium cysticercosis and onchocerciasis - have an established association with epilepsy. Parasitoses are widely prevalent in low-income and middle-income countries, which are home to 80% of the people with epilepsy in the world. Once a parasitic infection has taken hold in the brain, therapeutic measures do not seem to influence the development of epilepsy in the long term. Consequently, strategies to control, eliminate and eradicate parasites represent the most feasible way to reduce the epilepsy burden at present. The elucidation of immune mechanisms underpinning the parasitic infections, some of which are parasite-specific, opens up new therapeutic possibilities. In this Review, we explore the pathophysiological basis of the link between parasitic infections and epilepsy, and we consider preventive and therapeutic approaches to reduce the burden of epilepsy attributable to parasitic disorders. We conclude that a concerted approach involving medical, veterinary, parasitological and ecological experts, backed by robust political support and sustainable funding, is the key to reducing this burden.
Subject(s)
Developing Countries/economics , Epilepsy/economics , Parasitic Diseases/economics , Poverty/economics , Vector Borne Diseases/economics , Zoonoses/economics , Animals , Cysticercosis/economics , Cysticercosis/epidemiology , Epilepsy/epidemiology , Humans , Malaria, Cerebral/economics , Malaria, Cerebral/epidemiology , Neurocysticercosis/economics , Neurocysticercosis/epidemiology , Onchocerciasis/economics , Onchocerciasis/epidemiology , Parasites , Parasitic Diseases/epidemiology , Poverty/trends , Vector Borne Diseases/epidemiology , Zoonoses/epidemiologyABSTRACT
Despite the implementation of effective conjugate vaccines against the three main bacterial pathogens that cause meningitis, Streptococcus pneumoniae, Haemophilus influenzae type b (Hib), and Neisseria meningitidis serogroup A, the burden of meningitis in West Africa remains high. The relative importance of other bacterial, viral, and parasitic pathogens in central nervous system infections is poorly characterized. Cerebrospinal fluid (CSF) specimens were collected from children younger than 5 years with suspected meningitis, presenting at pediatric teaching hospitals across West Africa in five countries including Senegal, Ghana, Togo, Nigeria, and Niger. Cerebrospinal fluid specimens were initially tested using bacteriologic culture and a triplex real-time polymerase chain reaction (PCR) assay for N. meningitidis, S. pneumoniae, and H. influenzae used in routine meningitis surveillance. A custom TaqMan Array Card (TAC) assay was later used to detect 35 pathogens including 15 bacteria, 17 viruses, one fungus, and two protozoans. Among 711 CSF specimens tested, the pathogen positivity rates were 2% and 20% by the triplex real-time PCR (three pathogens) and TAC (35 pathogens), respectively. TAC detected 10 bacterial pathogens, eight viral pathogens, and Plasmodium. Overall, Escherichia coli was the most prevalent (4.8%), followed by S. pneumoniae (3.5%) and Plasmodium (3.5%). Multiple pathogens were detected in 4.4% of the specimens. Children with human immunodeficiency virus (HIV) and Plasmodium detected in CSF had high mortality. Among 220 neonates, 17% had at least one pathogen detected, dominated by gram-negative bacteria. The meningitis TAC enhanced the detection of pathogens in children with meningitis and may be useful for case-based meningitis surveillance.
Subject(s)
Escherichia coli Infections/epidemiology , Malaria, Cerebral/epidemiology , Meningitis, Pneumococcal/epidemiology , Meningitis/epidemiology , Meningitis/microbiology , Africa, Western/epidemiology , Child, Preschool , Culture Techniques , Cytomegalovirus Infections/cerebrospinal fluid , Cytomegalovirus Infections/diagnosis , Cytomegalovirus Infections/epidemiology , Escherichia coli Infections/cerebrospinal fluid , Escherichia coli Infections/diagnosis , Female , Ghana/epidemiology , HIV Infections/cerebrospinal fluid , HIV Infections/diagnosis , HIV Infections/epidemiology , Haemophilus Vaccines/therapeutic use , Humans , Infant , Infant, Newborn , Klebsiella Infections/cerebrospinal fluid , Klebsiella Infections/diagnosis , Klebsiella Infections/epidemiology , Malaria, Cerebral/cerebrospinal fluid , Malaria, Cerebral/diagnosis , Male , Meningitis/cerebrospinal fluid , Meningitis/diagnosis , Meningitis, Haemophilus/cerebrospinal fluid , Meningitis, Haemophilus/epidemiology , Meningitis, Haemophilus/prevention & control , Meningitis, Meningococcal/cerebrospinal fluid , Meningitis, Meningococcal/epidemiology , Meningitis, Meningococcal/prevention & control , Meningitis, Pneumococcal/cerebrospinal fluid , Meningitis, Pneumococcal/prevention & control , Meningococcal Vaccines/therapeutic use , Molecular Diagnostic Techniques , Mortality , Multiplex Polymerase Chain Reaction , Niger/epidemiology , Nigeria/epidemiology , Pneumococcal Vaccines/therapeutic use , Real-Time Polymerase Chain Reaction , Roseolovirus Infections/cerebrospinal fluid , Roseolovirus Infections/diagnosis , Roseolovirus Infections/epidemiology , Senegal/epidemiology , Staphylococcal Infections/cerebrospinal fluid , Staphylococcal Infections/diagnosis , Staphylococcal Infections/epidemiology , Togo/epidemiologyABSTRACT
Sleeping sickness and malaria are parasitic diseases with overlapping geographical distributions in sub-Saharan Africa. We hypothesized that the immune response elicited by an infection with Trypanosoma brucei, the etiological agent of sleeping sickness, would inhibit a subsequent infection by Plasmodium, the malaria parasite, decreasing the severity of its associated pathology. To investigate this, we established a new co-infection model in which mice were initially infected with T. brucei, followed by administration of P. berghei sporozoites. We observed that a primary infection by T. brucei significantly attenuates a subsequent infection by the malaria parasite, protecting mice from experimental cerebral malaria and prolonging host survival. We further observed that an ongoing T. brucei infection leads to an accumulation of lymphocyte-derived IFN-γ in the liver, limiting the establishment of a subsequent hepatic infection by P. berghei sporozoites. Thus, we identified a novel host-mediated interaction between two parasitic infections, which may be epidemiologically relevant in regions of Trypanosoma/Plasmodium co-endemicity.
Subject(s)
Antiviral Agents/pharmacology , Coinfection/drug therapy , Liver/drug effects , Malaria, Cerebral/prevention & control , Plasmodium berghei/physiology , Trypanosoma brucei brucei/isolation & purification , Trypanosomiasis, African/complications , Animals , Coinfection/epidemiology , Coinfection/parasitology , Interferon-gamma/pharmacology , Liver/immunology , Liver/parasitology , Malaria, Cerebral/epidemiology , Malaria, Cerebral/immunology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Trypanosomiasis, African/parasitologyABSTRACT
BACKGROUND: Many parts of Africa have witnessed reductions in Plasmodium falciparum transmission over the last 15 years. Since immunity to malaria is acquired more rapidly at higher transmission, the slower acquisition of immunity at lower transmission may partially offset the benefits of reductions in transmission. We examined the clinical spectrum of disease and predictors of mortality after sustained changes in transmission intensity, using data collected from 1989 to 2016. METHODS: We conducted a temporal observational analysis of 18,000 children, aged 14 days to 14 years old, who were admitted to Kilifi County Hospital, Kenya, from 1989 to 2016 with malaria. We describe the trends over time of the clinical and laboratory criteria for severe malaria and associated risk of mortality. RESULTS: During the time periods 1989-2003, 2004-2008, and 2009-2016, Kilifi County Hospital admitted averages of 657, 310, and 174 cases of severe malaria per year including averages of 48, 14, and 12 malaria-associated deaths per year, respectively. The median ages in years of children admitted with cerebral malaria, severe anaemia, and malaria-associated mortality were 3.0 (95% confidence interval (CI) 2.2-3.9), 1.1 (95% CI 0.9-1.4), and 1.1 (95% CI 0.3-2.2) in the year 1989, rising to 4.9 (95% CI 3.9-5.9), 3.8 (95% CI 2.5-7.1), and 5 (95% CI 3.3-6.3) in the year 2016. The ratio of children with cerebral malaria to severe anaemia rose from 1:2 before 2004 to 3:2 after 2009. Hyperparasitaemia was a risk factor for death after 2009 but not in earlier time periods. CONCLUSION: Despite the evidence of slower acquisition of immunity, continued reductions in the numbers of cases of severe malaria resulted in lower overall mortality. Our temporal data are limited to a single site, albeit potentially applicable to a secular trend present in many parts of Africa.