Blantyre Malaria Project Epilepsy Study (BMPES) of neurological outcomes in retinopathy-positive paediatric cerebral malaria survivors: a prospective cohort study

Inflammation and Elevated Osteopontin in Plasma and CSF in Cerebral Malaria Compared to Plasmodium-Negative Neurological Infections

Cerebral malaria in young African children is associated with high mortality, and persisting neurological deficits often remain in survivors. Sequestered Plasmodium-infected red blood cells lead to cerebrovascular inflammation and subsequent neuroinflammation. Brain inflammation can play a role in the pathogenesis of neurologic sequelae. Therefore, we assessed a select set of proinflammatory analytes (IP10, IL23, MIP3α, GRO, MCP-1, and osteopontin in both the plasma and cerebrospinal fluid(CSF) of Zambian children with cerebral malaria and compared this with children with neurological symptoms that were negative for Plasmodium falciparum (non-cerebral malaria). Several similarities in plasma and CSF levels were found, as were some striking differences. We confirmed that IP10 levels were higher in the plasma of cerebral malaria patients, but this was not found in CSF. Levels of osteopontin were elevated in both the plasma and CSF of CM patients compared to the non-CM patients. These results show again a highly inflammatory environment in both groups but a different profile for CM when compared to non-cerebral malaria. Osteopontin may play an important role in neurological inflammation in CM and the resulting sequelae. Therefore, osteopontin could be a valid target for further biomarker research and potentially for therapeutic interventions in neuroinflammatory infections.

Acetaminophen and Ibuprofen in Pediatric Central Nervous System Malaria: A Randomized Clinical Trial

Importance

A third of children who survive malaria with neurological involvement (central nervous system [CNS] malaria) develop sequelae. A higher maximum temperature (Tmax) and seizures are risk factors for sequelae.

Objective

To compare aggressive antipyretic therapy using scheduled acetaminophen and ibuprofen vs usual care with acetaminophen alone given only for a temperature of 38.5 °C or higher.

Design, Setting, and Participants

This randomized clinical trial was conducted at inpatient pediatric services of 1 tertiary care and 1 district hospital in Zambia and a tertiary care center in Malawi. Included were children aged 2 to 11 years with CNS malaria (excluding those with creatinine >1.2 mg/dL), who were enrolled from 2019 to 2022. Data analysis took place from December 2022 to April 2023.

Intervention

The aggressive antipyretic group received acetaminophen (30 mg/kg load, then 15 mg/kg) plus ibuprofen, 10 mg/kg, every 6 hours, regardless of clinical temperature for 72 hours. The usual care group received 15 mg/kg of acetaminophen as needed every 6 hours for a temperature of 38.5 °C or higher.

Main Outcomes and Measures

The primary outcome variable was Tmax over 72 hours, the total duration of follow-up. Secondary outcomes included seizures and parasite clearance.

Results

Five hundred fifty-three patients were screened, 226 (40.9%) were ineligible, and 57 (10.3%) declined. A total 256 participants (n = 128/group) had a mean (SD) age of 4.3 (2.1) years; 115 (45%) were female, and 141 (55%) were male. The aggressive antipyretic group had a lower Tmax, 38.6 vs 39.2 °C (difference, -0.62 °C; 95% CI, -0.82 to -0.42; P < .001) and lower odds of experiencing multiple or prolonged seizures, 10 (8%) vs 34 children (27%) in the usual care group (odds ratio [OR], 0.26; 95% CI, 0.12 to 0.56). No group difference in parasite clearance time was detected. Severe adverse events occurred in 40 children (15%), 25 (20%) in the usual care group and 15 (12%) in the aggressive antipyretic group, including 13 deaths (10 [8%] and 3 [2%], respectively). Increased creatinine resulted in study drug discontinuation in 8 children (6%) in the usual care group and 13 children (10%) in the aggressive antipyretic group (OR, 1.74; 95% CI, 0.63 to 5.07).

Conclusions and Relevance

This study found that aggressive antipyretic therapy reduced mean Tmax to temperature levels comparable with the Tmax among children without neurological impairments in prior observational studies and improved acute seizure outcomes with no prolongation of parasitemia.

Trial Registration

ClinicalTrials.gov Identifier: NCT03399318.

A Phase I trial of Non-invasive Ventilation and seizure prophylaxis with levetiracetam In Children with Cerebral Malaria Trial (NOVICE-M Trial)

Background

African children with cerebral malaria and seizures caused Plasmodium falciparum are at greater risk of poor outcomes including death and neurological sequelae. The agonal events are severe hypoventilation and respiratory arrest often triggered by seizures. We hypothesised that prophylactic anti-seizure medication (ASM) could avert 'spikes' of intracranial pressure during or following seizures and that adequate ventilation could be supported by biphasic Cuirass Ventilation (BCV) which requires no intubation.

Methods

A Phase I trial conducted in Kilifi, Kenya designed to provide data on safety, feasibility and preliminary data on seizure control using prophylactic ASM (levetiracetam) and BCV as non-invasive ventilatory support in children with cerebral malaria. Children aged 3 months to 12-years hospitalised with P falciparum malaria (positive rapid diagnostic test or a malaria slide), a Blantyre Coma Score ≤2 and a history of acute seizures in this illness are eligible for the trial. In a phased evaluation we will study i) BCV alone for respiratory support (n=10); ii) prophylactic LVT: 40mg/kg loading dose then 30mg/kg every 12 hours given via nasogastric tube for 72 hours (or until fully conscious) plus BCV support (n=10) and; iii) prophylactic LVT: 60mg/kg loading dose then 45mg/kg every 12 hours given via nasogastric tube for 72 hours (or until fully conscious) plus BCV support (n=10). Primary outcome measure: cumulative time with a clinically detected seizures or number of observed seizures over 36 hours. Secondary outcomes will be assessed by feasibility or ability to implement BCV, and recovery from coma within 36 hours. Safety endpoints include: aspiration during admission; death at 28 days and 180 days; and de-novo neurological impairments at 180 days.

Conclusions

This is a Phase I trial largely designed to test the feasibility, tolerability and safety of using non-invasive ventilatory support and LVT prophylaxis in cerebral malaria.

Registration

ISRCTN76942974 (5.02.2019); PACTR202112749708968 (20.12.2021).

Extracellular vesicles derived from plasmodium-infected red blood cells alleviate cerebral malaria in plasmodium berghei ANKA-infected C57BL/6J mice

RTS,S is the first malaria vaccine recommended for implementation among young children at risk. However, vaccine efficacy is modest and short-lived. To mitigate the risk of cerebral malaria (CM) among children under the age of 5, it is imperative to develop new vaccines. EVs are potential vaccine candidates as they obtain the ability of brain-targeted delivery and transfer plasmodium antigens and immunomodulators during infections. This study extracted EVs from BALB/c mice infected with Plasmodium yoelii 17XNL (P.y17XNL). C57BL/6J mice were intravenously immunized with EVs (EV-I.V. + CM group) or subcutaneously vaccinated with the combination of EVs and CpG ODN-1826 (EV + CPG ODN-S.C. + CM group) on days 0 and 20, followed by infection with Plasmodium berghei ANKA (P.bANKA) on day 20 post-second immunization. We monitored Parasitemia and survival rate. The integrity of the Blood-brain barrier (BBB) was examined using Evans blue staining.The levels of cytokines and adhesion molecules were evaluated using Luminex, RT-qPCR, and WB. Brain pathology was evaluated by hematoxylin and eosin and immunohistochemical staining. The serum levels of IgG, IgG1, and IgG2a were analyzed by enzyme-linked immunosorbent assay. Compared with those in the P.bANKA-infected group, parasitemia increased slowly, death was delayed (day 10 post-infection), and the survival rate reached 75 %-83.3 % in the EV-I.V. + ECM and EV + CPG ODN-S.C. + ECM groups. Meanwhile, compared with the EV + CPG ODN-S.C. + ECM group, although parasitemia was almost the same, the survival rate increased in the EV-I.V. + ECM group.Additionally, EVs immunization markedly downregulated inflammatory responses in the spleen and brain and ameliorated brain pathological changes, including BBB disruption and infected red blood cell (iRBC) sequestration. Furthermore, the EVs immunization group exhibited enhanced antibody responses (upregulation of IgG1 and IgG2a production) compared to the normal control group. EV immunization exerted protective effects, improving the integrity of the BBB, downregulating inflammation response of brain tissue, result in reduces the incidence of CM. The protective effects were determined by immunological pathways and brain targets elicited by EVs. Intravenous immunization exhibited better performance than subcutaneous immunization, which perhaps correlated with EVs, which can naturally cross BBB to play a better role in brain protection.

Protocol for a magnetic resonance imaging study of participants in the fever RCT: Does fever control prevent brain injury in malaria?

BACKGROUND

Despite eradication efforts, ~135,000 African children sustained brain injuries as a result of central nervous system (CNS) malaria in 2021. Newer antimalarial medications rapidly clear peripheral parasitemia and improve survival, but mortality remains high with no associated decline in post-malaria neurologic injury. A randomized controlled trial of aggressive antipyretic therapy with acetaminophen and ibuprofen (Fever RCT) for malarial fevers being conducted in Malawi and Zambia began enrollment in 2019. We propose to use neuroimaging in the context of the RCT to further evaluate neuroprotective effects of aggressive antipyretic therapy.

METHODS

This observational magnetic resonance imaging (MRI) ancillary study will obtain neuroimaging and neurodevelopmental and behavioral outcomes in children previously enrolled in the Fever RCT at 1- and 12-months post discharge. Analysis will compare the odds of any brain injury between the aggressive antipyretic therapy and usual care groups based upon MRI structural abnormalities. For children unable to undergo imaging without deep sedation, neurodevelopmental and behavioral outcomes will be used to identify brain injury.

DISCUSSION

Neuroimaging is a well-established, valid proxy for neurological outcomes after brain injury in pediatric CNS malaria. This MRI ancillary study will add value to the Fever RCT by determining if treatment with aggressive antipyretic therapy is neuroprotective in CNS malaria. It may also help elucidate the underlying mechanism(s) of neuroprotection and expand upon FEVER RCT safety assessments.

Cerebral malaria pathogenesis: Dissecting the role of CD4+ and CD8+ T-cells as major effectors in disease pathology

Cerebral malaria (CM) is a severe complication of Plasmodium falciparum (P. falciparum) infection, with complex pathogenesis involving multiple factors, including the host's immunological response. T lymphocytes, specifically CD4+ T helper cells and CD8+ cytotoxic T cells, are crucial in controlling parasite growth and activating cells for parasite clearance via cytokine secretion. Contrary to this, reports also suggest the pathogenic nature of T lymphocytes as they are often involved in disease progression and severity. CD8+ cytotoxic T cells migrate to the host's brain vasculature, disrupting the blood-brain barrier and causing neurological manifestations. CD4+ T helper cells on the other hand play a variety of functions as they differentiate into different subtypes which may function as pro-inflammatory or anti-inflammatory. The excessive pro-inflammatory response in CM can lead to multi-organ failure, necessitating a check mechanism to maintain immune homeostasis. This is achieved by regulatory T cells and their characteristic cytokines, which counterbalance the pro-inflammatory immune response. Maintaining a critical balance between pro and anti-inflammatory responses is crucial for determining disease outcomes in CM. A slight change in this balance may contribute to a disease severity owing to an extreme inflammatory response or unrestricted parasite growth, a potential target for designing immunotherapeutic treatment approaches. The review briefly discusses the pathogenesis of CM and various mechanisms responsible for the disruption of the blood-brain barrier. It also highlights the role of different T cell subsets during infection and emphasizes the importance of balance between pro and anti-inflammatory T cells that ultimately decides the outcome of the disease.

Malaria: A focused review for the emergency medicine clinician

INTRODUCTION

Malaria is a potentially fatal parasitic disease transmitted by the Anopheles mosquito. A resurgence in locally acquired infections has been reported in the U.S.

OBJECTIVE

This narrative review provides a focused overview of malaria for the emergency clinician, including the epidemiology, presentation, diagnosis, and management of the disease.

DISCUSSION

Malaria is caused by Plasmodium and is transmitted by the Anopheles mosquito. Disease severity can range from mild to severe. Malaria should be considered in any returning traveler from an endemic region, as well as those with unexplained cyclical, paroxysms of symptoms or unexplained fever. Patients most commonly present with fever and rigors but may also experience cough, myalgias, abdominal pain, fatigue, vomiting, and diarrhea. Hepatomegaly, splenomegaly, pallor, and jaundice are findings associated with malaria. Although less common, severe malaria is precipitated by microvascular obstruction with complications of anemia, acidosis, hypoglycemia, multiorgan failure, and cerebral malaria. Peripheral blood smears remain the gold standard for diagnosis, but rapid diagnostic tests are available. Treatment includes specialist consultation and antimalarial drugs tailored depending on chloroquine resistance, geographic region of travel, and patient comorbidities. Supportive care may be required, and patients with severe malaria will require resuscitation. Most patients will require admission for treatment and further monitoring.

CONCLUSION

Emergency medicine clinicians should be aware of the presentation, diagnosis, evaluation, and management of malaria to ensure optimal outcomes.

Adult Cerebral Malaria: Acute and Subacute Imaging Findings, Long-term Clinical Consequences

Cerebral malaria is an important cause of mortality and neurodisability in endemic regions. We show magnetic resonance imaging (MRI) features suggestive of cytotoxic and vasogenic cerebral edema followed by microhemorrhages in 2 adult UK cases, comparing them with an Indian cohort. Long-term follow-up images correlate ongoing changes with residual functional impairment.

Post hospital admission blood lactate measurements are associated with mortality but not neurologic morbidity in children with cerebral malaria

BACKGROUND

In children with cerebral malaria (CM) admission blood lactate has previously guided intravenous fluid therapy and been validated as a prognostic biomarker associated with death. The usefulness of post-admission measurements of blood lactate in children with CM is less clear. The strength of association between blood lactate and neurological sequelae in CM survivors, as well as the optimal duration of post-admission measurements of blood lactate to identify children at higher risk of adverse outcomes is unknown.

METHODS

A retrospective cohort study of 1674 Malawian children with CM hospitalized from 2000 to 2018 who had blood lactate measurements every 6 h for the first 24 h after admission was performed. The strength of association between admission lactate or values measured at any time point in the first 24 h post-admission and outcomes (mortality and neurological morbidity in survivors) was estimated. The duration of time after admission that lactate remained a valid prognostic biomarker was assessed.

RESULTS

When lactate is analysed as a continuous variable, children with CM who have higher values at admission have a 1.05-fold higher odds (95% CI 0.99-1.11) of death compared to those with lower lactate values. Children with higher blood lactate at 6 h have 1.16-fold higher odds (95% CI 1.09-1.23) of death, compared to those with lower values. If lactate levels are dichotomized into hyperlactataemic (lactate > 5.0 mmol/L) or not, the strength of association between admission lactate and mortality increases (OR = 2.49, 95% CI 1.47-4.22). Blood lactate levels obtained after 18 h post-admission are not associated with outcomes. Similarly, the change in lactate concentrations through time during the first 24 h of hospital admission is not associated with outcomes. Blood lactate during hospitalization is not associated with adverse neurologic outcomes in CM survivors.

CONCLUSIONS

In children with CM, blood lactate is associated with death but not neurologic morbidity in survivors. To comprehensively estimate prognosis, blood lactate in children with CM should be assessed at admission and for 18 h afterwards.

An imported malaria case with repeated episodes of neurological syndromes resulting from different Plasmodium species

BACKGROUND

Imported cerebral malaria (CM) cases in non-endemic areas are often misdiagnosed, which delays treatment. Post-malaria neurological syndrome (PMNS) after recovery from severe malaria can also complicate diagnosis.

CASE

We report an imported malaria case from West Africa with two sequential episodes with neurological syndromes within about a month. The first episode was diagnosed as CM with microscopy-positive Plasmodium falciparum infection. The second episode, occurring a month after the recovery from the first CM episode, was consistent with PMNS, since malaria parasites were not detected by microscopy in peripheral blood smears. However, this diagnosis was complicated by the detection of Plasmodium vivax in peripheral blood by PCR, suggesting a potential cause of the second episode by P. vivax.

CONCLUSION

This study suggests that PMNS often occurs after severe falciparum malaria. Concurrent P. vivax infection with pathogenic biomass being predominantly extravascular further complicates accurate diagnosis.

Severe malaria-related disability in African children: a scoping review

PURPOSE

Disability is a consequence of severe malaria for a significant proportion of African children. This scoping review aims to describe the impact of severe malaria on African children according to current literature using an international biopsychical classification and framework of disability and functioning.

MATERIALS AND METHODS

MEDLINE, EMBASE, Global Health, and CINHAL databases were searched for original research conducted on African children aged 0-18 using terms related to severe malaria and components of disability. Independent and dependent variables were extracted and classified using the World Health Organization's International Classification of Functioning, Disability, and Health-Children and Youth version (ICF-CY) using standardized coding methods.

RESULTS

Seventy-two percent of the measured variables in the 34 included studies were coded as "body functions," (i.e., impairments), such as mental, neuromusculoskeletal, movement, and sensory functions, and 23.3% of variables were coded as "activities and participation" (i.e., activity limitations/participation restrictions), such as difficulties with general tasks and demands, communication, mobility, interpersonal interactions, and relationships. "Environment" variables such as family support, health access, education, or societal attitudes were not found in the included studies.

CONCLUSIONS

Existing peer-reviewed quantitative research of severe malaria-related disability is focused on neurological sequelae, with less research about activity limitations and participation restrictions.

Age-specific malaria vulnerability and transmission reservoir among children

Purpose

The pediatric population, especially under-five children, is highly susceptible to malaria and accounts for 76 % of global malaria deaths according to the World Malaria Report 2022. The purpose of this manuscript is to discuss the various factors involved in the susceptibility of the pediatric population to Malaria and the importance of this age group for malaria elimination.

Methodology

Data on pediatric malaria epidemiology that includes prevalence, risk factors, immune factors, socioeconomic factors, control methods, etc. were extracted from published literature using PubMed and Google Scholar. This data was further correlated with malaria incidence data from the World Health Organization (WHO) and the National Center for Vector Borne Diseases Control (NCVBDC).

Results

The younger age group is vulnerable to severe malaria due to an immature immune system. The risk of infection and clinical disease increases after the waning of maternal immunity. In the initial years of life, the developing brain is more susceptible to malaria infection and its after-effects. The pediatric population may act as a malaria transmission reservoir due to parasite density and asymptomatic infections. WHO recommended RTS,S/AS01 has limitations and may not be applicable in all settings to propel malaria elimination.

Conclusion

The diagnosis of malaria is based on clinical suspicion and confirmed with microscopy and/or rapid diagnostic testing. The school-age pediatric population serves as a transmission reservoir in the form of asymptomatic malaria since they have acquired some immunity due to exposure in early childhood. Targeting the hidden reservoir in the pediatric population and protecting this vulnerable group will be essential for malaria elimination from the countries targeting elimination.

Protocol for a Magnetic Resonance Imaging (MRI) Study of Participants in the Fever Randomized Controlled Trial: Does fever control prevent brain injury in malaria?

Background

Despite eradication efforts, ~135,000 African children sustained brain injuries as a result of central nervous system (CNS) malaria in 2021. Newer antimalarial medications rapidly clear peripheral parasitemia and improve survival, but mortality remains high with no associated decline in post-malaria neurologic injury. A randomized controlled trial of aggressive antipyretic therapy with acetaminophen and ibuprofen (Fever RCT) for malarial fevers being conducted in Malawi and Zambia began enrollment in 2019. We propose to use neuroimaging in the context of the RCT to further evaluate neuroprotective effects of aggressive antipyretic therapy.

Methods

This observational magnetic resonance imaging (MRI) ancillary study will obtain neuroimaging and neurodevelopmental and behavioral outcomes in children previously enrolled in the Fever RCT at 1- and 12-months post discharge. Analysis will compare the odds of any brain injury between the aggressive antipyretic therapy and usual care groups based upon MRI structural abnormalities. For children unable to undergo imaging without deep sedation, neurodevelopmental and behavioral outcomes will be used to identify brain injury.

Discussion

Neuroimaging is a well-established, valid proxy for neurological outcomes after brain injury in pediatric CNS malaria. This MRI ancillary study will add value to the Fever RCT by determining if treatment with aggressive antipyretic therapy is neuroprotective in CNS malaria. It may also help elucidate the underlying mechanism(s) of neuroprotection and expand upon FEVER RCT safety assessments.

Loss to Hospital Follow-Up in Pediatric Cerebral Malaria Survivors: A Case-Control Study

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.

Malarial retinopathy in a preschool child: A case report with long-term paediatric and ophthamological follow-up

AIM

To report a paediatric case of retinopathy-positive cerebral malaria, emphasizing the clinical significance of long-term neurological and ophthalmological follow-up (5,5 years).

CASE REPORT

After a recent journey in Ghana, a 17-month-old African female child was admitted at the Paediatric Emergency Room with fever and vomiting. Blood smear confirmed a Plasmodium Falciparum parasitaemia. Iv quinine was promptly administered, but after a few hours, the child developed generalized seizures, requiring benzodiazepine therapy and assisted ventilation for severe desaturation. Brain imaging (CT and MRI), lumbar puncture and several electroencephalograms showed data compatible with cerebral involvement of malaria. Schepens ophthalmoscopy and Ret-Cam pictures acquisition revealed macular haemorrhages in the left eye with central whitening and bilateral capillary abnormalities, typical signs of malarial retinopathy. Antimalarial therapy and iv Levetiracetam allowed neurological improvement. Eleven days after the admission, the child was discharged, showing no neurological symptoms and with an improved EEG signal, a normalized fundus oculi and brain imaging. Neurological and ophthalmological long-term follow-up were conducted: EEG controls didn't reveal abnormalities and the complete ophthalmological assessment showed a regular visual acuity and fundus oculi, as well as a normal SD-OCT and electrophysiologic testing.

CONCLUSION

Cerebral malaria is a severe complication, characterized by a high fatality rate and challenging diagnosis. A helpful instrument for diagnostic and prognostic evaluation is the ophthalmological detection of malarial retinopathy and its monitoring over time. In our patient the long term visual follow-up didn't reveal any adverse outcome.

Cerebrospinal fluid tumor necrosis factor-alpha (TNF-α) levels in children with cerebral malaria

This prospective cross-sectional study evaluated the diagnostic and prognostic role of cerebrospinal fluid (CSF) tumor necrosis factor-alpha (TNF-α) in children with cerebral malaria (CM) and its role in the differentiation of CM from non-cerebral severe malaria. CSF TNF-α was measured using a human TNF-α enzyme-linked immunosorbent assay kit of 39 cases of CM and 19 cases of non-cerebral severe malaria. CSF TNF-α levels were significantly higher in CM (p < 0.001). Based on the receiver operating characteristics curve, a cutoff value of CSF TNF-α was 5.7 pg/ml for diagnosis of CM with sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 87.2%, 94.7%, 97.1% and 78.3% respectively. The cutoff value of CSF TNF-α was 13.7 pg/ml for predicting adverse outcomes in CM with sensitivity, specificity, PPV and NPV of 100%, 96.8%, 88.9% and 100%, respectively. However, the cutoff value of CSF TNF-α was 4.96 pg/ml for predicting adverse outcomes in non-cerebral severe malaria with a sensitivity, specificity, PPV and NPV of 100%, 94.1%, 88.9% and 100% respectively. So, CSF TNF-α is an excellent biomarker and can be used as a diagnostic and prognostic tool. More studies are needed to establish CSF TNF-α as a predictor of neurological sequelae.

Mechanistic insights into the interaction between the host gut microbiome and malaria

Malaria is a devastating infectious disease and significant global health burden caused by the bite of a Plasmodium-infected female Anopheles mosquito. Gut microbiota was recently discovered as a risk factor of severe malaria. This review entails the recent advances on the impact of gut microbiota composition on malaria severity and consequence of malaria infection on gut microbiota in mammalian hosts. Additionally, this review provides mechanistic insight into interactions that might occur between gut microbiota and host immunity which in turn can modulate malaria severity. Finally, approaches to modulate gut microbiota composition are discussed. We anticipate this review will facilitate novel hypotheses to move the malaria-gut microbiome field forward.

Admission Clinical and EEG Features Associated With Mortality and Long-term Neurologic and Cognitive Outcomes in Pediatric Cerebral Malaria

BACKGROUND AND OBJECTIVES

For children with cerebral malaria, mortality is high, and in survivors, long-term neurologic and cognitive dysfunctions are common. While specific clinical factors are associated with death or long-term neurocognitive morbidity in cerebral malaria, the association of EEG features with these outcomes, particularly neurocognitive outcomes, is less well characterized.

METHODS

In this prospective cohort study of 149 children age 6 months to 12 years who survived cerebral malaria in Kampala, Uganda, we evaluated whether depth of coma, number of clinical seizures, or EEG features during hospitalization were associated with mortality during hospitalization, short-term and long-term neurologic deficits, or long-term cognitive outcomes (overall cognition, attention, memory) over the 2-year follow-up.

RESULTS

Higher Blantyre or Glasgow Coma Scores (BCS and GCS, respectively), higher background voltage, and presence of normal reactivity on EEG were each associated with lower mortality. Among clinical and EEG features, the presence of >4 seizures on admission had the best combination of negative and positive predictive values for neurologic deficits in follow-up. In multivariable modeling of cognitive outcomes, the number of seizures and specific EEG features showed independent association with better outcomes. In children younger than 5 years throughout the study, seizure number and presence of vertex sharp waves were independently associated with better posthospitalization cognitive performance, faster dominant frequency with better attention, and higher average background voltage and faster dominant background frequency with better associative memory. In children younger than 5 years at CM episode but 5 years or older at cognitive testing, seizure number, background dominant frequency, and the presence of vertex sharp waves were each associated with changes in cognition, seizure number and variability with attention, and seizure number with working memory.

DISCUSSION

In children with cerebral malaria, seizure number is strongly associated with the risk of long-term neurologic deficits, while seizure number and specific EEG features (average background voltage, dominant rhythm frequency, presence of vertex sharp waves, presence of variability) are independently associated with cognitive outcomes. Future studies should evaluate the predictive value of these findings.

Elevated brain derived neurotrophic factor in plasma and interleukin-6 levels in cerebrospinal fluid in meningitis compared to cerebral malaria

Neurological infections, such as Cerebral malaria (CM) and meningitis are associated with high mortality and in survivors, particularly young children, persistent neurologic deficits often remain. As brain inflammation plays a role in the development of these neurological sequelae, multiplex assays were used to assess a select set of immune mediators in both plasma and cerebrospinal fluid (CSF) from Zambian children with neurological infections. Both CM and meningitis patients showed high levels of markers for vascular inflammation, such as soluble ICAM-1 and angiopoietins. Although high levels of angiopoietin 1 and angiopoietin 2 were found in the meningitis group, their levels in the CSF were low and did not differ. As expected, there were high levels of cytokines and notably a significantly elevated IL-6 level in the CSF of the meningitis group. Interestingly, although elevated levels BDNF were found, BDNF levels were significantly higher in plasma of the meningitis group but similar in the CSF. The striking differences in plasma BDNF and IL-6 levels in the CSF point to markedly different neuro-pathological processes. Therefore, further investigations in the role of both IL-6 and BDNF in the neurological outcomes are needed.

Retinal imaging technologies in cerebral malaria: a systematic review

BACKGROUND

Cerebral malaria (CM) continues to present a major health challenge, particularly in sub-Saharan Africa. CM is associated with a characteristic malarial retinopathy (MR) with diagnostic and prognostic significance. Advances in retinal imaging have allowed researchers to better characterize the changes seen in MR and to make inferences about the pathophysiology of the disease. The study aimed to explore the role of retinal imaging in diagnosis and prognostication in CM; establish insights into pathophysiology of CM from retinal imaging; establish future research directions.

METHODS

The literature was systematically reviewed using the African Index Medicus, MEDLINE, Scopus and Web of Science databases. A total of 35 full texts were included in the final analysis. The descriptive nature of the included studies and heterogeneity precluded meta-analysis.

RESULTS

Available research clearly shows retinal imaging is useful both as a clinical tool for the assessment of CM and as a scientific instrument to aid the understanding of the condition. Modalities which can be performed at the bedside, such as fundus photography and optical coherence tomography, are best positioned to take advantage of artificial intelligence-assisted image analysis, unlocking the clinical potential of retinal imaging for real-time diagnosis in low-resource environments where extensively trained clinicians may be few in number, and for guiding adjunctive therapies as they develop.

CONCLUSIONS

Further research into retinal imaging technologies in CM is justified. In particular, co-ordinated interdisciplinary work shows promise in unpicking the pathophysiology of a complex disease.

Mechanism of Immune Evasion in Mosquito-Borne Diseases

In recent decades, mosquito-borne illnesses have emerged as a major health burden in many tropical regions. These diseases, such as malaria, dengue fever, chikungunya, yellow fever, Zika virus infection, Rift Valley fever, Japanese encephalitis, and West Nile virus infection, are transmitted through the bite of infected mosquitoes. These pathogens have been shown to interfere with the host's immune system through adaptive and innate immune mechanisms, as well as the human circulatory system. Crucial immune checkpoints such as antigen presentation, T cell activation, differentiation, and proinflammatory response play a vital role in the host cell's response to pathogenic infection. Furthermore, these immune evasions have the potential to stimulate the human immune system, resulting in other associated non-communicable diseases. This review aims to advance our understanding of mosquito-borne diseases and the immune evasion mechanisms by associated pathogens. Moreover, it highlights the adverse outcomes of mosquito-borne disease.

Predicting Acute and Post-Recovery Outcomes in Cerebral Malaria and Other Comas by Optical Coherence Tomography (OCT in CM) - A protocol for an observational cohort study of Malawian children

Cerebral malaria (CM) remains a significant global health challenge with high morbidity and mortality. Malarial retinopathy has been shown to be diagnostically and prognostically significant in the assessment of CM. The major mechanism of death in paediatric CM is brain swelling. Long term morbidity is typically characterised by neurological and neurodevelopmental sequelae. Optical coherence tomography can be used to quantify papilloedema and macular ischaemia, identified as hyperreflectivity. Here we describe a protocol to test the hypotheses that quantification of optic nerve head swelling using optical coherence tomography can identify severe brain swelling in CM, and that quantification of hyperreflectivity in the macula predicts neurodevelopmental outcomes post-recovery. Additionally, our protocol includes the development of a novel, low-cost, handheld optical coherence tomography machine and artificial intelligence tools to assist in image analysis.

Pathogenesis of Cerebral Malaria: New Trends and Insights for Developing Adjunctive Therapies

No specific or adjunctive therapies exist to treat cerebral malaria (CM) as of date. CM is a neuropathological manifestation of the malaria infection in humans, caused by the hemoparasitic pathogen Plasmodium falciparum. Driven through a multitude of virulence factors, varied immune responses, variations in brain swelling with regard to the age of patients, parasite biomass, and parasite-typing, the essential pathogenetic mechanisms underlying clinical CM have remained elusive. However, a recent series of studies based on molecular, immunologic, and advanced neuroradiologic and machine-learning approaches have unraveled new trends and insights to better understand and focus on the key determinants of CM in humans. This could possibly be the beginning of the design of new and effective adjunctive therapies that may not be common or applicable to the entire malarious world, but that could, rather, be specific to the variations in the determinants of CM.

Identifying effective diagnostic biomarkers for childhood cerebral malaria in Africa integrating coexpression analysis with machine learning algorithm

BACKGROUND

Cerebral malaria (CM) is a manifestation of malaria caused by plasmodium infection. It has a high mortality rate and severe neurological sequelae, existing a significant research gap and requiring further study at the molecular level.

METHODS

We downloaded the GSE117613 dataset from the Gene Expression Omnibus (GEO) database to determine the differentially expressed genes (DEGs) between the CM group and the control group. Weighted gene coexpression network analysis (WGCNA) was applied to select the module and hub genes most relevant to CM. The common genes of the key module and DEGs were selected to perform further analysis. The least absolute shrinkage and selection operator (LASSO) logistic regression and support vector machine recursive feature elimination (SVM-RFE) were applied to screen and verify the diagnostic markers of CM. Eventually, the hub genes were validated in the external dataset. Gene set enrichment analysis (GSEA) was applied to investigate the possible roles of the hub genes.

RESULTS

The GO and KEGG results showed that DEGs were enriched in some neutrophil-mediated pathways and associated with some lumen structures. Combining LASSO and the SVM-RFE algorithms, LEF1 and IRAK3 were identified as potential hub genes in CM. Through the GSEA enrichment results, we found that LEF1 and IRAK3 participated in maintaining the integrity of the blood-brain barrier (BBB), which contributed to improving the prognosis of CM.

CONCLUSIONS

This study may help illustrate the pathophysiology of CM at the molecular level. LEF1 and IRAK3 can be used as diagnostic biomarkers, providing new insight into the diagnosis and prognosis prediction in pediatric CM.

Theta-Alpha Variability on Admission EEG Is Associated With Outcome in Pediatric Cerebral Malaria

PURPOSE

Pediatric cerebral malaria has high rates of mortality and neurologic morbidity. Although several biomarkers, including EEG, are associated with survival or morbidity, many are resource intensive or require skilled interpretation for clinical use. Automation of quantitative interpretation of EEG may be preferable in resource-limited settings, where trained interpreters are rare. As currently used quantitative EEG factors do not adequately describe the spectrum of variability seen in studies from children with cerebral malaria, the authors developed and validated a new quantitative EEG variable, theta-alpha variability (TAV).

METHODS

The authors developed TAV, a new quantitative variable, as a composite of multiple automated EEG outputs. EEG records from 194 children (6 months to 14 years old) with cerebral malaria were analyzed. Independent EEG interpreters performed standard quantitative and qualitative analyses, with the addition of the newly created variable. The associations of TAV with other quantitative EEG factors, a qualitative assessment of variability, and outcomes were assessed.

RESULTS

Theta-alpha variability was not highly correlated with alpha, theta, or delta power and was not associated with qualitative measures of variability. Children whose EEGs had higher values of TAV had a lower risk of death (odds ratio = 0.934, 95% confidence interval = 0.902-0.966) or neurologic sequelae (odds ratio = 0.960, 95% confidence interval = 0.932-0.990) compared with those with lower values. Receiver operating characteristic analysis in predicting death at a TAV threshold of 0.244 yielded a sensitivity of 74% and specificity of 70% for an area under the receiver operating characteristic curve of 0.755.

CONCLUSIONS

Theta-alpha variability is independently associated with outcome in pediatric cerebral malaria and can predict death with high sensitivity and specificity. Automated determination of this newly created EEG factor holds promise as a potential method to increase the clinical utility of EEG in resource-limited settings by allowing interventions to be targeted to those at higher risk of death or disability.

Malaria infection and the risk of epilepsy: a meta-analysis

Epilepsy, a chronic disease of the central nervous system, is highly prevalent in malaria-endemic regions. Therefore, several studies have evaluated the associations between malaria infection and epilepsy development. A meta-analysis of observational studies published from inception to 10 May 2022 has been conducted to synthesize and pool the existing data on this topic. The relevant publications were systematically searched in PubMed/Medline, Scopus, Embase and Web of Science database collections. A random-effects meta-analysis model (REM) was utilized to generate the pooled odds ratio (OR) at 95% confidence intervals (CIs). The between-studies heterogeneity was assessed with I2, as well as several subgroups, meta-regression and sensitivity analysis were performed to identify the source of heterogeneity. Overall, 17 eligible studies containing 6285 cases and 13 909 healthy controls were included. The REM showed a significant positive association between malaria infection and epilepsy development (OR 2.36; 95% CI 1.44–3.88). In subgroup analyses, significant positive associations were observed in studies that: epilepsy was the outcome in the follow-up of patients with cerebral malaria (OR 7.10; 95% CI 3.50–14.38); used blood smear to diagnose malaria (OR 4.80; 95% CI 2.36–9.77); included only children (OR 3.92; 95% CI 1.81–8.50); published before 2010 (OR 6.39; 95% CI 4.25–9.62). Our findings indicated that patients with malaria, especially those with cerebral malaria, are at a high risk of epilepsy development; however, further well-designed and controlled studies are needed to verify the strength of the association.

Plasma Amino Acid Concentrations in Children With Severe Malaria Are Associated With Mortality and Worse Long-term Kidney and Cognitive Outcomes

BACKGROUND

Global changes in amino acid levels have been described in severe malaria (SM), but the relationship between amino acids and long-term outcomes in SM has not been evaluated.

METHODS

We measured enrollment plasma concentrations of 20 amino acids using high-performance liquid chromatography in 500 Ugandan children aged 18 months to 12 years, including 122 community children and 378 children with SM. The Kidney Disease: Improving Global Outcomes criteria were used to define acute kidney injury (AKI) at enrollment and chronic kidney disease (CKD) at 1-year follow-up. Cognition was assessed over 2 years of follow-up.

RESULTS

Compared to laboratory-defined, age-specific reference ranges, there were deficiencies in sulfur-containing amino acids (methionine, cysteine) in both community children and children with SM. Among children with SM, global changes in amino acid concentrations were observed in the context of metabolic complications including acidosis and AKI. Increases in threonine, leucine, and valine were associated with in-hospital mortality, while increases in methionine, tyrosine, lysine, and phenylalanine were associated with postdischarge mortality and CKD. Increases in glycine and asparagine were associated with worse attention in children <5 years of age.

CONCLUSIONS

Among children with SM, unique amino acid profiles are associated with mortality, CKD, and worse attention.

Cerebral Malaria and Neuronal Implications of Plasmodium Falciparum Infection: From Mechanisms to Advanced Models

Reorganization of host red blood cells by the malaria parasite Plasmodium falciparum enables their sequestration via attachment to the microvasculature. This artificially increases the dwelling time of the infected red blood cells within inner organs such as the brain, which can lead to cerebral malaria. Cerebral malaria is the deadliest complication patients infected with P. falciparum can experience and still remains a major public health concern despite effective antimalarial therapies. Here, the current understanding of the effect of P. falciparum cytoadherence and their secreted proteins on structural features of the human blood-brain barrier and their involvement in the pathogenesis of cerebral malaria are highlighted. Advanced 2D and 3D in vitro models are further assessed to study this devastating interaction between parasite and host. A better understanding of the molecular mechanisms leading to neuronal and cognitive deficits in cerebral malaria will be pivotal in devising new strategies to treat and prevent blood-brain barrier dysfunction and subsequent neurological damage in patients with cerebral malaria.

Genetics of cerebral malaria: pathogenesis, biomarkers and emerging therapeutic interventions

Background

Cerebral malaria (CM) is a preeminent cause of severe disease and premature deaths in Sub-Saharan Africa, where an estimated 90% of cases occur. The key features of CM are a deep, unarousable coma that persists for longer than 1 h in patients with peripheral Plasmodium falciparum and no other explanation for encephalopathy. Significant research efforts on CM in the last few decades have focused on unravelling the molecular underpinnings of the disease pathogenesis and the identification of potential targets for therapeutic or pharmacologic intervention. These efforts have been greatly aided by the generation and study of mouse models of CM, which have provided great insights into key events of CM pathogenesis, revealed an interesting interplay of host versus parasite factors that determine the progression of malaria to severe disease and exposed possible targets for therapeutic intervention in severe disease.

Main Body

This paper reviews our current understanding of the pathogenic and immunologic factors involved in CM. We present the current view of the roles of certain gene products e.g., the var gene, ABCA-1, ICAM-1, TNF-alpha, CD-36, PfEMP-1 and G6PD, in CM pathogenesis. We also present alterations in the blood–brain barrier as a consequence of disease proliferation as well as complicated host and parasite interactions, including the T-cell immune reaction, reduced deformation of erythrocytes and cytoadherence. We further looked at recent advances in cerebral malaria treatment interventions by emphasizing on biomarkers, new diagnostic tools and emerging therapeutic options.

Conclusion

Finally, we discuss how the current understanding of some of these pathogenic and immunologic factors could inform the development of novel therapeutic interventions to fight CM.

Risk factors for acute kidney injury at presentation among children with CNS malaria: a case control study

BACKGROUND

Recent research has established that acute kidney injury (AKI) is a common problem in severe paediatric malaria. Limited access to kidney diagnostic studies in the low resources settings where malaria is common has constrained research on this important problem.

METHODS

Enrolment data from an ongoing clinical trial of antipyretics in children with central nervous system (CNS) malaria, CNS malaria being malaria with seizures or coma, was used to identify risk factors for AKI at presentation. Children 2-11 years old with CNS malaria underwent screening and enrollment assessments which included demographic and anthropomorphic data, clinical details regarding the acute illness, and laboratory studies including creatinine (Cr), quantitative parasite count (qPC), quantitative histidine rich protein 2 (HRP2), lactate, and bilirubin levels. Children with a screening Cr > 106 µmol/l were excluded from the study due to the potential nephrotoxic effects of the study drug. To identify risk factors for AKI at the time of admission, children who were enrolled in the study were categorized as having AKI using estimates of their baseline (i.e. before this acute illness) kidney function and creatinine at enrollment applying the Kidney Disease: Improving Global Outcome (KDIGO) 2012 guidelines. Logistic regressions and a multivariate model were used to identify clinical and demographic risk factors for AKI at presentation among those children enrolled in the study.

RESULTS

465 children were screened, 377 were age-appropriate with CNS malaria, 22 (5.8%) were excluded due to Cr > 106 µmol/l, and 209 were enrolled. Among the 209, AKI using KDIGO criteria was observed in 134 (64.1%). One child required dialysis during recovery. Risk factors for AKI in both the logistic regression and multivariate models included: hyperpyrexia (OR 3.36; 95% CI 1.39-8.12) and age with older children being less likely to have AKI (OR 0.72; 95% CI 0.62-0.84).

CONCLUSION

AKI is extremely common among children presenting with CNS malaria. Hyperpyrexia with associated dehydration may contribute to the AKI or may simply be a marker for a more inflammatory systemic response that is also affecting the kidney. Appropriate fluid management in children with CNS malaria and AKI may be challenging since generous hydration to support kidney recovery could worsen malaria-induced cerebral oedema in this critically ill population. Trial registration https://clinicaltrials.gov/ct2/show/NCT03399318.

Aggressive antipyretics in central nervous system malaria: Study protocol of a randomized-controlled trial assessing antipyretic efficacy and parasite clearance effects (Malaria FEVER study)

BACKGROUND

Malaria remains a major public health challenge in Africa where annually, ~250,000 children with malaria experience a neurologic injury with subsequent neuro-disability. Evidence indicates that a higher temperature during the acute illness is a risk factor for post-infectious neurologic sequelae. As such, aggressive antipyretic therapy may be warranted among children with complicated malaria at substantial risk of brain injury. Previous clinical trials conducted primarily in children with uncomplicated malaria and using only a single antipyretic medication have shown limited benefits in terms of fever reduction; however, no studies to date have examined malaria fever management using dual therapies. In this clinical trial of aggressive antipyretic therapy, children hospitalized with central nervous system (CNS) malaria will be randomized to usual care (acetaminophen every 6 hours for a temperature ≥ 38.5°C) vs. prophylactic acetaminophen and ibuprofen every 6 hours for 72 hours.

METHODS

In this double-blinded, placebo controlled, two-armed clinical trial, we will enroll 284 participants from three settings at Queen Elizabeth Central Hospital in Blantyre, Malawi; at the University Teaching Hospitals Children's Hospital in Lusaka, Zambia and at Chipata Central Hospital, Chipata, Zambia. Parents or guardians must provide written informed consent. Eligible participants are 2-11 years with evidence of P. falciparum malaria infection by peripheral blood smear or rapid diagnostic test with CNS symptoms associated with malaria. Eligible children will receive treatment allocation randomization either to standard of care for fever management or to prophylactic, scheduled treatment every 6 hours for 72 hours with dual antipyretic therapies using acetaminophen and ibuprofen. Assignment to treatment groups will be with 1:1 allocation using blocked randomization. The primary outcome will be maximum temperature in the 72 hours after enrolment. Secondary outcomes include parasite clearance as determined by quantitative Histidine Rich Protein II and seizures through 72 hours after enrolment.

DISCUSSION

This clinical trial seeks to challenge the practice paradigm of limited fever treatment based upon hyperpyrexia by evaluating the fever-reduction efficacy of more aggressive antipyretic using two antipyretics and prophylactic administration and will elucidate the impact of antipyretics on parasite clearance and acute symptomatic seizures. If aggressive antipyretic therapy is shown to safely reduce the maximum temperature, a clinical trial evaluating the neuroprotective effects of temperature reduction in CNS malaria is warranted.

The Next Frontier in Neurocritical Care in Resource-Constrained Settings

Neurocritical care (NCC) is an emerging field within critical care medicine, reflecting the widespread prevalence of neurologic injury in critically ill patients. Morbidity and mortality from neurocritical illness (NCI) have been reduced substantially in resource-rich settings (RRS), owing to the development of advanced technologies, neuro-specific units, and subspecialized medical training. Despite shouldering much of the burden of NCI worldwide, resource-limited settings (RLS) face immense hurdles when implementing guidelines generated in RRS. This review summarizes the current epidemiology, management, and outcomes of the most common NCIs in RLS and offers commentary on future directions in NCC practiced in RLS.

A mixed-methods study on evaluating an updated, francophone version of ETAT+ training in Madagascar

Background

Madagascar needs major efforts to achieve the UN Sustainable Development Goals, despite the considerable reduction of child mortality during past years. In this context, implementation of emergency triage assessment and treatment (ETAT) plays an important role. In recent years, ETAT training activities rarely took place in Madagascar. To strengthen ETAT in Madagascar, a pilot training course was conducted in December 2019 at the University Hospital Mahajanga.

Objectives

This study aims to evaluate if the ETAT+ pilot training content matches clinical needs in Madagascar and whether participants achieved their learning objectives.

Methods

In this cross-sectional mixed-methods study, a 41-item questionnaire was used at the end of the ETAT+ training to evaluate their learning experience from the 12 participants (paediatricians, physicians, nurses and midwives). Six weeks after the training, guided interviews were conducted among five participants to describe how training content could be transferred into clinical practice in five health facilities.

Results

Results suggest that this pilot project designed to contribute to the re-establishment of ETAT in Madagascar meets participants’ needs and is adapted to clinical realities in terms of transmitted knowledge, skills and competencies. However, results also show that considerable multi-disciplinary efforts are needed to advance ETAT+ implementation in Madagascar.

Conclusion

Implementation processes of ETAT training programmes need re-evaluation to assure their validity to contribute to quality of care improvements efficiently. Further operational research is required to evaluate sustainable, innovative implementation strategies adapted to contexts in Madagascar.

Contributions of the study

This study aims to evaluate an updated Malagasy version of the Emergency Triage Assessment and Treatment Plus (ETAT+). The training met the participants’ needs and was adapted to the clinical realities in Madagascar relating to transmitted knowledge, skills and competencies.

Cerebral malaria induced by plasmodium falciparum: clinical features, pathogenesis, diagnosis, and treatment

Cerebral malaria (CM) caused by Plasmodium falciparum is a fatal neurological complication of malaria, resulting in coma and death, and even survivors may suffer long-term neurological sequelae. In sub-Saharan Africa, CM occurs mainly in children under five years of age. Although intravenous artesunate is considered the preferred treatment for CM, the clinical efficacy is still far from satisfactory. The neurological damage induced by CM is irreversible and lethal, and it is therefore of great significance to unravel the exact etiology of CM, which may be beneficial for the effective management of this severe disease. Here, we review the clinical characteristics, pathogenesis, diagnosis, and clinical therapy of CM, with the aim of providing insights into the development of novel tools for improved CM treatments.

Identifying biomarkers for epilepsy after cerebral malaria in Zambian children: rationale and design of a prospective observational study

INTRODUCTION

Malaria affecting the central nervous system (CM) is a major contributor to paediatric epilepsy in resource-poor settings, with 10%-16% of survivors developing epilepsy within 2 years of infection. Despite high risk for post-malaria epilepsy (PME), biomarkers indicating which CM survivors will develop epilepsy are absent. Such biomarkers are essential to identify those at highest risk who might benefit most from close surveillance and/or preventive treatments. Electroencephalography (EEG) contains signals (specifically gamma frequency activity), which are correlated with higher risk of PME and provide a biomarker for the development of epilepsy. We propose to study the sensitivity of quantitative and qualitative EEG metrics in predicting PME, and the potential increased sensitivity of this measure with additional clinical metrics. Our goal is to develop a predictive PME index composed of EEG and clinical history metrics that are highly feasible to obtain in low-resourced regions.

METHODS AND ANALYSES

This prospective observational study being conducted in Eastern Zambia will recruit 250 children aged 6 months to 11 years presenting with acute CM and follow them for two years. Children with pre-existing epilepsy diagnoses will be excluded. Outcome measures will include qualitative and quantitative analysis of routine EEG recordings, as well as clinical metrics in the acute and subacute period, including histidine-rich protein 2 levels of parasite burden, depth and length of coma, presence and severity of acute seizures, presence of hypoglycaemia, maximum temperature and 1-month post-CM neurodevelopmental assessment scores. We will test the performance of these EEG and clinical metrics in predicting development of epilepsy through multivariate logistic regression analyses.

ETHICS AND DISSEMINATION

This study has been approved by the Boston Children's Hospital Institutional Review Board, University of Zambia Biomedical Research Ethics Committee, and National Health Research Authority of Zambia. Results will be disseminated locally in Zambia followed by publication in international, open access, peer-reviewed journals when feasible.

Mechanisms of Transcranial Doppler Ultrasound phenotypes in paediatric cerebral malaria remain elusive

Background

Cerebral malaria (CM) results in significant paediatric death and neurodisability in sub-Saharan Africa. Several different alterations to typical Transcranial Doppler Ultrasound (TCD) flow velocities and waveforms in CM have been described, but mechanistic contributors to these abnormalities are unknown. If identified, targeted, TCD-guided adjunctive therapy in CM may improve outcomes.

Methods

This was a prospective, observational study of children 6 months to 12 years with CM in Blantyre, Malawi recruited between January 2018 and June 2021. Medical history, physical examination, laboratory analysis, electroencephalogram, and magnetic resonance imaging were undertaken on presentation. Admission TCD results determined phenotypic grouping following a priori definitions. Evaluation of the relationship between haemodynamic, metabolic, or intracranial perturbations that lead to these observed phenotypes in other diseases was undertaken. Neurological outcomes at hospital discharge were evaluated using the Paediatric Cerebral Performance Categorization (PCPC) score.

Results

One hundred seventy-four patients were enrolled. Seven (4%) had a normal TCD examination, 57 (33%) met criteria for hyperaemia, 50 (29%) for low flow, 14 (8%) for microvascular obstruction, 11 (6%) for vasospasm, and 35 (20%) for isolated posterior circulation high flow. A lower cardiac index (CI) and higher systemic vascular resistive index (SVRI) were present in those with low flow than other groups (p < 0.003), though these values are normal for age (CI 4.4 [3.7,5] l/min/m2, SVRI 1552 [1197,1961] dscm-5m2). Other parameters were largely not significantly different between phenotypes. Overall, 118 children (68%) had a good neurological outcome. Twenty-three (13%) died, and 33 (19%) had neurological deficits. Outcomes were best for participants with hyperaemia and isolated posterior high flow (PCPC 1–2 in 77 and 89% respectively). Participants with low flow had the least likelihood of a good outcome (PCPC 1–2 in 42%) (p < 0.001). Cerebral autoregulation was significantly better in children with good outcome (transient hyperemic response ratio (THRR) 1.12 [1.04,1.2]) compared to a poor outcome (THRR 1.05 [0.98,1.02], p = 0.05).

Conclusions

Common pathophysiological mechanisms leading to TCD phenotypes in non-malarial illness are not causative in children with CM. Alternative mechanistic contributors, including mechanical factors of the cerebrovasculature and biologically active regulators of vascular tone should be explored.

Medical cannabis and cannabidiol: A new harvest for Malawi

In February 2020 parliament passed the Cannabis Regulation Bill (2020) which regulates the cultivation and production of industrial hemp and medical cannabis. The country will only fully benefit from this development if the medical and scientific community can take the lead in enabling the country to exploit the plant's potential to help address some of our economic and public health challenges. This special communication provides some basic information on cannabis and discusses its history and medical uses. Cannabidiol (CBD) has emerged as one of the most important cannabis-derived phytochemicals and has formed the basis for the growth of the medical cannabis industry. The scientific data on the mechanisms of the effects of CBD on the human neuroendocrine-immune network is reviewed and the first effective cannabis-based FDA-approved treatment for epilepsy discussed. Some clinical research that is being done on the antipsychotic and neuroprotective properties of CBD is also reviewed. A case is made for the potential of CBD as a neuroprotective adjunctive therapy for the prevention of neuropsychological sequelae associated with complicated malaria. The safety profile of CBD is reviewed and finally, the potential importance of the re-medicalization of cannabis-based therapies for the broader field of phytomedicine is pointed out.

"I do lack peace, and I've run out of answers": primary caregivers' perspectives on social and behaviour problems in cerebral malaria survivors in Blantyre, Malawi

Background

Despite recent advances in treatment and prevention, the prevalence of cerebral malaria (CM) remains high globally, especially in children under 5 years old. As treatment improves, more children will survive episodes of CM with lasting neurodisabilities, such as social and behavioural issues. Behaviour problems in children who survive CM are poorly characterized, and the impact of caring for a child with post-CM behaviour issues has not been well-explored. Caregivers’ perceptions of and experiences with their child’s post-CM behaviour problems are reported here.

Methods

Semi-structured interviews were conducted with 29 primary caregivers of children who survived CM with reported behaviour issues in Blantyre, Malawi. Interviews were conducted in Chicheŵa, audio-recorded, transcribed, and translated into English. Data were coded manually, utilizing inductive and deductive approaches. Identified codes were thematically analysed.

Results

Post-CM behaviours reported include externalizing, aggressive behaviours and learning difficulties. Variable timescales for behaviour change onset were noted, and most caregivers reported some evolution of their child’s behaviour over time. Caregivers experienced a variety of emotions connected to their child’s behaviour and to reactions of family and community members. Caregivers who experienced discrimination were more likely to describe negative emotions tied to their child’s behaviour changes, compared to caregivers who experienced support.

Conclusions

Caregiver perceptions of behaviour changes in post-CM survivors are variable, and caregiver experience is strongly impacted by family and community member responses. Future educational, rehabilitation, and support-based programmes should focus on the specific types of behaviour problems identified and the difficulties faced by caregivers and their communities.

Plasmodium vivax cerebral malaria with pancytopenia in the peruvian amazon: case report

Plasmodium vivax causes 81% of all malaria cases and is the most common species in the Peruvian Amazon. We present the case of a male patient with cerebral malaria caused by Plasmodium vivax, who had general malaise and fever, and then presented seizures more than twice a day with loss of consciousness and motor functional limitation. Plasmodium vivax trophozoites were detected by thick blood smear, besides, we also observed low counts of all three blood cell types. Treatment began with artesunate and clindamycin for five days, then one unit of packed red blood cells was transfused; treatment continued with primaquine for seven days. The patient showed clinical improvement with neurological sequelae in one lower limb.

Acute Kidney Injury Interacts With Coma, Acidosis, and Impaired Perfusion to Significantly Increase Risk of Death in Children With Severe Malaria

BACKGROUND

Mortality in severe malaria remains high in children treated with intravenous artesunate. Acute kidney injury (AKI) is a common complication of severe malaria, but the interactions between AKI and other complications on the risk of mortality in severe malaria are not well characterized.

METHODS

Between 2014 and 2017, 600 children aged 6-48 months to 4 years hospitalized with severe malaria were enrolled in a prospective clinical cohort study evaluating clinical predictors of mortality in children with severe malaria.

RESULTS

The mean age of children in this cohort was 2.1 years (standard deviation, 0.9 years) and 338 children (56.3%) were male. Mortality was 7.3%, and 52.3% of deaths occurred within 12 hours of admission. Coma, acidosis, impaired perfusion, AKI, elevated blood urea nitrogen (BUN), and hyperkalemia were associated with increased mortality (all P < .001). AKI interacted with each risk factor to increase mortality (P < .001 for interaction). Children with clinical indications for dialysis (14.4% of all children) had an increased risk of death compared with those with no indications for dialysis (odds ratio, 6.56; 95% confidence interval, 3.41-12.59).

CONCLUSIONS

AKI interacts with coma, acidosis, or impaired perfusion to significantly increase the risk of death in severe malaria. Among children with AKI, those who have hyperkalemia or elevated BUN have a higher risk of death. A better understanding of the causes of these complications of severe malaria, and development and implementation of measures to prevent and treat them, such as dialysis, are needed to reduce mortality in severe malaria.

Epileptogenesis in Common Parasitic Infections

Purpose of the review

Neurocysticercosis (NCC) has been well recognized as a leading cause of epilepsy. More recently, studies of other parasitic diseases such as cerebral malaria (CM) and onchocerciasis are yielding novel insights into the pathogenesis of parasite-associated epilepsy. We compare the clinical and electrophysiological findings in epilepsy associated with these highly prevalent parasites and discuss the mechanisms involved in epileptogenesis.

Recent Findings

Electrophysiological and imaging biomarkers continue to emerge, and individuals who are at-risk of developing parasite-associated epilepsies are being identified with greater reliability. While both Taenia solium and Plasmodium falciparum directly affect the brain parenchyma, Onchocerca volvulus is not known to invade the central nervous system. Thus, the causal association between O. volvulus and epilepsy remains controversial.

Summary

Both NCC and CM have a well-defined acute phase when the parasites directly or indirectly invade the brain parenchyma and lead to local inflammatory changes. This is followed by a chronic phase marked by recurrent seizures. However, these stages of epileptogenic process have not been identified in the case of O. volvulus.

Delayed presentation to hospital care is associated with sequelae but not mortality in children with cerebral malaria in Malawi

Background

Cerebral malaria is still a major cause of death in children in sub-Saharan Africa. Among survivors, debilitating neurological sequelae can leave children with permanent cognitive impairments and societal stigma, resulting in taxing repercussions for their families. This study investigated the effect of delay in presentation to medical care on outcome in children with cerebral malaria in Malawi.

Methods

This retrospective study included participants enrolled in a longstanding study of cerebral malaria between 2001 and 2021 and considered coma duration prior to arrival at hospital (with or without anti-malarial treatment), HIV status, blood lactate levels at admission and age as factors that could affect clinical outcome. Outcomes were categorized as full recovery, sequelae at the time of discharge, or death. A multinomial regression was fit and run controlling for coma duration, HIV status, lactate levels and age, to determine the association between each explanatory variable and outcome.

Results

A total of 1663 children with cerebral malaria, aged 6 months to 14 years were included. Longer coma duration (in hours) was associated with greater odds of developing sequelae (OR = 1.023, 95% CI 1.007–1.039, p = 0.006) but not death (OR = 1.00, 95% CI 0.986–1.015, p = 0.961). Younger age (in months) was also correlated with higher rates of sequelae, (OR = 0.990, 95% CI 0.983–0.997, p = 0.004) but not with increased mortality (OR = 0.998, 95% CI 0.993–1.003, p = 0.335). Blood lactate levels on admission were correlated with mortality (OR = 1.125, 95% CI 1.090–1.161, p < 0.001) but not associated with increased rates of sequelae (OR = 1.016, 95% CI 0.973–1.060, p = 0.475). Positive HIV status and treatment with an anti-malarial (artemisinin or non-artemisinin-based) prior to arrival at the hospital were not significantly associated with either adverse outcome.

Conclusions

In Malawian children with cerebral malaria, higher rates of sequelae were significantly associated with extended coma duration prior to admission and younger age. Mortality rates were correlated with increased lactate levels on admission. The differential effects of variables on clinical outcomes suggest that there may be different pathogenic pathways leading to sequelae and death. Actions taken by parents and health care professionals are critical in defining when patients arrive at hospital and determining their ultimate outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04080-2.

Malaria Related Neurocognitive Deficits and Behavioral Alterations

Typical of tropical and subtropical regions, malaria is caused by protozoa of the genus Plasmodium and is, still today, despite all efforts and advances in controlling the disease, a major issue of public health. Its clinical course can present either as the classic episodes of fever, sweating, chills and headache or as nonspecific symptoms of acute febrile syndromes and may evolve to severe forms. Survivors of cerebral malaria, the most severe and lethal complication of the disease, might develop neurological, cognitive and behavioral sequelae. This overview discusses the neurocognitive deficits and behavioral alterations resulting from human naturally acquired infections and murine experimental models of malaria. We highlighted recent reports of cognitive and behavioral sequelae of non-severe malaria, the most prevalent clinical form of the disease worldwide. These sequelae have gained more attention in recent years and therapies for them are required and demand advances in the understanding of neuropathogenesis. Recent studies using experimental murine models point to immunomodulation as a potential approach to prevent or revert neurocognitive sequelae of malaria.

Using EEG in Resource-Limited Areas: Comparing Qualitative and Quantitative Interpretation Methods in Cerebral Malaria

BACKGROUND

Our goal was to compare the strength of association and predictive ability of qualitative and quantitative electroencephalographic (EEG) factors with the outcomes of death and neurological disability in pediatric cerebral malaria (CM).

METHODS

We enrolled children with a clinical diagnosis of CM admitted to Queen Elizabeth Central Hospital (Blantyre, Malawi) between 2012 and 2017. A routine-length EEG was performed within four hours of admission. EEG data were independently interpreted using qualitative and quantitative methods by trained pediatric neurophysiologists. EEG interpreters were unaware of patient discharge outcome.

RESULTS

EEG tracings from 194 patients were reviewed. Multivariate modeling revealed several qualitative and quantitative EEG variables that were independently associated with outcomes. Quantitative methods modeled on mortality had better goodness of fit than qualitative ones. When modeled on neurological morbidity in survivors, goodness of fit was better for qualitative methods. When the probabilities of an adverse outcome were calculated using multivariate regression coefficients, only the model of quantitative EEG variables regressed on the neurological sequelae outcome showed clear separation between outcome groups.

CONCLUSIONS

Multiple qualitative and quantitative EEG factors are associated with outcomes in pediatric CM. It may be possible to use quantitative EEG factors to create automated methods of study interpretation that have similar predictive abilities for outcomes as human-based interpreters, a rare resource in many malaria-endemic areas. Our results provide a proof-of-concept starting point for the development of quantitative EEG interpretation and prediction methodologies useful in resource-limited settings.

Assay of Static Adhesion of Plasmodium falciparum-Infected Erythrocytes to Cells, Including Inhibition of the Adhesion

A feature of the virulent malaria parasite, Plasmodium falciparum, is the sequestration of infected erythrocytes (IEs) to host endothelium. The IEs sequester in the microvasculature by adhesion to host cells resulting in the obstruction of blood flow and often harmful consequences in the host. IEs bind to receptors on host cells with the P. falciparum erythrocyte membrane protein 1 (PfEMP1) that is expressed on the surface of the IEs. The study of parasite cytoadhesion is essential to decipher these ligands, including types of PfEMP1 required for cytoadhesion, the receptors the IEs bind, and how they may be related to the type of malaria disease. An assay for IE adhesion to host cells, including the inhibition of cytoadhesion is described here. The assay involves the purification of IEs with knobs and binding of the IEs to a monolayer of host cells under static conditions. Compounds including proteins, antibodies or drugs can be tested for cytoadhesion inhibitory activity in the assay.

[Ocular changes as a diagnostic tool for malaria]

BACKGROUND

According to the WHO Malaria Report 2019 a total of 229 million people fall ill with malaria each year and two thirds of deaths involve children under 5 years of age.

AIM

To review the fundus changes in the context of malaria and the importance of ophthalmoscopy in the diagnosis.

MATERIAL AND METHODS

Summary of changes in cerebral malaria visible on fundus examination, possible underlying pathomechanisms and the value of ophthalmoscopy in practice.

RESULTS

Retinal findings in malaria include white or gray staining of the retina (retinal whitening), color change of retinal vessels (orange or white staining), hemorrhages often with a white center, such as Roth's spot and papilledema.

DISCUSSION

The retinal changes in malaria are specific and may help to differentiate malaria from other causes of coma and fever. Smartphone-based fundus photography and artificial intelligence could support malaria diagnostics particularly in resource-poor regions.

Evidence of Brain Alterations in Noncerebral Falciparum Malaria

BACKGROUND

Cerebral malaria in adults is associated with brain hypoxic changes on magnetic resonance (MR) images and has a high fatality rate. Findings of neuroimaging studies suggest that brain involvement also occurs in patients with uncomplicated malaria (UM) or severe noncerebral malaria (SNCM) without coma, but such features were never rigorously characterized.

METHODS

Twenty patients with UM and 21 with SNCM underwent MR imaging on admission and 44-72 hours later, as well as plasma analysis. Apparent diffusion coefficient (ADC) maps were generated, with values from 5 healthy individuals serving as controls.

RESULTS

Patients with SNCM had a wide spectrum of cerebral ADC values, including both decreased and increased values compared with controls. Patients with low ADC values, indicating cytotoxic edema, showed hypoxic patterns similar to cerebral malaria despite the absence of deep coma. Conversely, high ADC values, indicative of mild vasogenic edema, were observed in both patients with SNCM and patients with UM. Brain involvement was confirmed by elevated circulating levels of S100B. Creatinine was negatively correlated with ADC in SNCM, suggesting an association between acute kidney injury and cytotoxic brain changes.

CONCLUSIONS

Brain involvement is common in adults with SNCM and a subgroup of hospitalized patients with UM, which warrants closer neurological follow-up. Increased creatinine in SNCM may render the brain more susceptible to cytotoxic edema.

Cerebrospinal Fluid Pterins, Pterin-Dependent Neurotransmitters, and Mortality in Pediatric Cerebral Malaria

BACKGROUND

Cerebral malaria (CM) pathogenesis remains incompletely understood. Having shown low systemic levels of tetrahydrobiopterin (BH4), an enzymatic cofactor for neurotransmitter synthesis, we hypothesized that BH4 and BH4-dependent neurotransmitters would likewise be low in cerebrospinal fluid (CSF) in CM.

METHODS

We prospectively enrolled Tanzanian children with CM and children with nonmalaria central nervous system conditions (NMCs). We measured CSF levels of BH4, neopterin, and BH4-dependent neurotransmitter metabolites, 3-O-methyldopa, homovanillic acid, and 5-hydroxyindoleacetate, and we derived age-adjusted z-scores using published reference ranges.

RESULTS

Cerebrospinal fluid BH4 was elevated in CM (n = 49) compared with NMC (n = 51) (z-score 0.75 vs -0.08; P < .001). Neopterin was increased in CM (z-score 4.05 vs 0.09; P < .001), and a cutoff at the upper limit of normal (60 nmol/L) was 100% sensitive for CM. Neurotransmitter metabolite levels were overall preserved. A higher CSF BH4/BH2 ratio was associated with increased odds of survival (odds ratio, 2.94; 95% confidence interval, 1.03-8.33; P = .043).

CONCLUSION

Despite low systemic BH4, CSF BH4 was elevated and associated with increased odds of survival in CM. Coma in malaria is not explained by deficiency of BH4-dependent neurotransmitters. Elevated CSF neopterin was 100% sensitive for CM diagnosis and warrants further assessment of its clinical utility for ruling out CM in malaria-endemic areas.

Severe stridor and profound weakness after cerebral malaria

Cerebral malaria (CM) is defined by WHO as coma (Blantyre Coma Score 2 or less) in a patient with Plasmodium falciparum parasitaemia and no alternative cause of coma identified. Mortality is approximately 15%-30% in African children and up to one-third of survivors have neurological sequelae. We present a patient with severe stridor and prolonged profound weakness during an intensive care admission with CM. These complications initially presented a diagnostic dilemma in our limited resourced setting. The stridor failed to improve with empiric steroids and a subsequent opportunistic ENT consult diagnosed vocal cord paresis. The weakness was so profound that the patient was unable to lift his head during the acute illness. The child received intensive physiotherapy, and at 1-month follow-up, the stridor and weakness had resolved.

Identification of Plasmodium falciparum-specific protein PIESP2 as a novel virulence factor related to cerebral malaria

Cerebral malaria (CM) is the most severe complication caused by Plasmodium falciparum infection. The pathophysiological changes caused by parasite virulence factors and the human immune response to parasites contribute to CM. To date, very few parasite virulence proteins have been found to participate in CM. Here, we employed comparative genomics analysis and identified parasite-infected erythrocyte specific protein 2 (PIESP2) to be a CM-related protein. We conducted further experimental investigations and found that PIESP2 is an immunogenic protein. PIESP2 expression begins at the early trophozoite stage and progressively increases with parasite development. Although PIESP2 proteins mainly reside within infected red blood cells (IRBCs), some of them are present on the IRBC surface at the pigmented stage. Moreover, blockage of PIESP2 by antiserum apparently inhibited the adhesion of IRBCs to brain microvascular endothelial cells (BMECs). Western blot analysis detected the binding of PIESP2 to BMECs. Transcriptional analysis revealed that the binding of PIESP2 to BMECs can increase the expression of genes involved in the inflammatory response but decrease the expression of genes related to the anchoring junction. Overall, PIESP2 might be associated with CM by mediating the sequestration of IRBCs, inducing the inflammation response, and impairing the integrity of blood-brain barrier.