Effects of early cerebral malaria on cognitive ability in Senegalese children

Specific and cumulative infection burden and mild cognitive impairment and dementia: A population-based study

Infection by pathogenic microbes is widely hypothesized to be a risk factor for the development of neurocognitive disorders and dementia, but evidence remains limited. We analyzed the association of seropositivity to 11 common pathogens and cumulative infection burden with neurocognitive disorder (mild cognitive impairment and dementia) in a population-based cohort of 475 older individuals (mean age = 67.6 y) followed up over 3-5 years for the risk of MCI-dementia. Specific seropositivities showed a preponderance of positive trends of association with MCI-dementia, including for Plasmodium, H. pylori, and RSV (p < 0.05), as well as Chickungunya, HSV-2, CMV and EBV (p > 0.05), while HSV-1 and HHV-6 showed equivocal or no associations, and Dengue and VZV showed negative associations (p < 0.05) with MCI-dementia. High infection burden (5 + cumulated infections) was significantly associated with an increased MCI-dementia risk in comparison with low infection burden (1-3 cumulative infections), adjusted for age, sex, and education. Intriguingly, for a majority (8 of 11) of pathogens, levels of antibody titers were significantly lower in those with MCI-dementia compared to cognitive normal individuals. Based on our observations, we postulate that individuals who are unable to mount strong immunological responses to infection by diverse microorganisms, and therefore more vulnerable to infection by greater numbers of different microbial pathogens or repeated infections to the same pathogen in the course of their lifetime are more likely to develop MCI or dementia. This hypothesis should be tested in more studies.

Poor neurodevelopment, nutritional and physical growth outcomes among children born to mothers with nodding syndrome

INTRODUCTION

Nodding syndrome (NS), a poorly understood severe neurological disorder develops in children. In Uganda, some NS cases have grown into child-bearing adults. Babies born to mothers with NS may be prone to impaired neurodevelopmental outcomes. Cognitive deficits in mothers with NS may further inhibit care offered to their children hence compromising neurocognitive development, physical growth, and behaviour.

OBJECTIVES

The study aimed to determine the neurodevelopmental, behavioural, nutritional, and physical growth outcomes of children whose mothers have nodding syndrome.

METHODS

A comparative cross-sectional study was conducted between May 2021 and April 2022 in Northern Uganda. Children aged 0-5 years of mothers with NS were compared to those of mothers without NS, matched by age, gender and neighbouring residence. Neurodevelopment, behaviour, nutrition, and physical growth were assessed using standardized measures and t-tests employed for group comparisons of outcomes.

RESULTS

Overall,106 children participated. Fifty-three (53) were offspring of mothers with NS and 53 of mothers without NS; having a mean age of 26.9 (2.22) and 27.5(2.12) months respectively. Children whose mothers have NS had significantly lower neurodevelopmental scores than those of NS-unaffected mothers in fine motor (37.5(12.1) vs 44.2(14.3), p = 0.011), receptive language (37.8(10.8) vs 43.9(12.9), p = 0.010), overall cognitive development (74.36(17.8) vs 83.34(19.6), p = 0.015), and attention (0.64(0.20) vs 0.76(0.15), p = 0.001). There were no differences in the behaviour scores. Children of mothers with NS also had significantly lower weight-for-age z scores (WAZ) (p = 0.003) and length/height-for-age z scores (LAZ/HAZ) (p = 0.001); with 19(35.9 %) of them stunted.

CONCLUSION

Children whose mothers have NS have poorer neurodevelopmental, nutritional, and physical growth outcomes. Interventions to improve outcomes in these children are warranted.

8-Year Follow-up of a Maternal Education Trial in a Low-Resource Setting

OBJECTIVES

Nutrition and stimulation interventions promote early childhood development, but little is known about their long-term benefits in low- and middle-income countries. We conducted a follow-up study of a cluster-randomized maternal education trial performed in children aged 6 to 8 months to assess the sustainability of developmental benefits after 8 years.

METHODS

The education intervention lasted 6 months and consisted of nutrition, hygiene, sanitation, and child stimulation aspects. We assessed child processing and cognitive abilities using the Kaufman Assessment Battery for Children Second Edition (KABC-II) and attention and inhibitory control using the Test of Variables of Attention after 8 years. The original trial included 511 mother-child pairs (intervention, n = 263; control, n = 248), whereas in the current study, 361 (71%; intervention, n = 185; control, n = 176) pairs were available for analyses.

RESULTS

The intervention group scored higher than the controls (all P < .001) on all 5 KABC-II subscales and on the KABC-II global score (mean difference: 14; 95% confidence interval, 12-16; P < .001). For all 5 Test of Variables of Attention variables, the intervention group scored higher than the controls on both the visual and auditory tasks (all P < .05). Because the intervention was delivered as a package, a limitation is that we cannot pinpoint the individual contribution of each component (nutrition, hygiene, and stimulation) to the developmental benefits.

CONCLUSIONS

The intervention group consistently scored markedly higher on both neuropsychological tests. Thus, even 8 years after the original maternal education intervention, the developmental benefits that we observed at child age of 1, 2, and 3 years, were sustained.

Is Neurodevelopmental Assessment in Early Childhood Predictive of Performance Assessed Later in Childhood and Adolescence in Sub-Saharan Africa? A Systematic Review of the Literature

BACKGROUND

Most neurodevelopmental tests used to assess child development in sub-Saharan Africa were developed in western or high-income countries, raising the question of their usefulness with African children.

OBJECTIVE

This systematic review identified and synthesized key findings from studies measuring development in children in Sub-Saharan Africa in early childhood and again at school age, to assess neurocognitive associations longitudinally from infancy through middle childhood.

METHODS

The study was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method, selecting articles referenced in the PubMed, PsycInfo, and Embase databases using the following inclusion criteria: published between 2000 and 2022, written in French or English, and presenting results dealing with the objective assessment of child's neurodevelopment. All articles were registered in the Zotero reference manager and analyzed by title, abstract, and full text.

RESULTS

Several of the seven selected studies confirmed that attention and working memory in infancy can predict children's neurocognitive performance, including mathematical ability, at school age. In two of the studies, children with poor mental development at 1 year of age are more likely to present with poorer behavioral development at school age, including learning difficulties in school and risk for grade repetition.

CONCLUSION

Cognitive ability assessed in early childhood is strongly associated with performance at school age in cohorts of African children followed longitudinally. Even with assessments adapted cross-culturally, infants and preschoolers at risk for poor developmental outcomes can be identified to better receive strategic early interventions to enhance their development.

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.

Association of severe malaria with cognitive and behavioural outcomes in low- and middle-income countries: a meta-analysis and systematic review

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.

Neurological Complications of Malaria

PURPOSE OF REVIEW

To discuss the neurological complications and pathophysiology of organ damage following malaria infection.

RECENT FINDINGS

The principal advancement made in malaria research has been a better understanding of the pathogenesis of cerebral malaria (CM), the most dreaded neurological complication generally caused by Plasmodium falciparum infection. However, no definitive treatment has yet been evolved other than the use of antimalarial drugs and supportive care. The development of severe cerebral edema in CM results from two distinct pathophysiologic mechanisms. First, the development of "sticky" red blood cells (RBCs) leads to cytoadherence, where red blood cells (RBCs) get stuck to the endothelial walls and between themselves, resulting in clogging of the brain microvasculature with resultant hypoxemia and cerebral edema. In addition, the P. falciparum-infected erythrocyte membrane protein 1 (PfEMP1) molecules protrude from the raised knob structures on the RBCs walls and are in themselves made of a combination of human and parasite proteins in a tight complex. Antibodies to surfins, rifins, and stevors from the parasite are also located in the RBC membrane. On the human microvascular side, a range of molecules involved in host-parasite interactions, including CD36 and intracellular adhesion molecule 1, is activated during interaction with other molecules such as endothelial protein C receptor and thrombospondin. As a result, an inflammatory response occurs with the dysregulated release of cytokines (TNF, interleukins 1 and 10) which damage the blood-brain barrier (BBB), causing plasma leakage and brain edema. This second mechanism of CNS injury often involves multiple organs in adult patients in endemic areas but remains localized only to the central nervous system (CNS) among African children. Neurological sequelae may follow both P. falciparum and P. vivax infections. The major brain pathology of CM is brain edema with diffuse brain swelling resulting from the combined effects of reduced perfusion and hypoxemia of cerebral neurons due to blockage of the microvasculature by parasitized RBCs as well as the neurotoxic effect of released cytokines from a hyper-acute immune host reaction. A plethora of additional neurological manifestations have been associated with malaria, including posterior reversible encephalopathy syndrome (PRES), reversible cerebral vasoconstriction syndrome (RCVS), malarial retinopathy, post-malarial neurological syndrome (PMNS), acute disseminated encephalomyelitis (ADEM), Guillain-Barré syndrome (GBS), and cerebellar ataxia. Lastly, the impact of the COVID-19 pandemic on worldwide malaria control programs and the possible threat from co-infections is briefly discussed.

Daily Training efficiency during computerized cognitive rehabilitation training (CCRT): an analysis from a randomized trial in Ugandan children with and without severe malaria

Children in Uganda are at risk for significant cognitive sequelae from severe malaria. Computerized cognitive rehabilitation training (CCRT) represents a potential method to improve working memory, behavior, and executive functioning, cognitive domains most at risk following severe malaria. The primary aim of this study was to complete a secondary analysis of data from a concluded CCRT randomized control trial in order to compare the training efficiency of a commonly used CCRT program under conditions of titrated (adaptive) or non-titrated (non-adaptive) training and with children with increasing malaria severity to determine how various factors may affect potential CCRT improvement. A total of 201 school-aged children (66.2% boys) who were either healthy (n = 102) or previously diagnosed with severe or cerebral malaria (n = 99) were randomized into two active treatment arms (titrated and non-titrated learning). Each child received 24 one-hour sessions of training over 8 weeks using Captain's Log® CCRT by BrainTrain, which includes a comprehensive set of CCRT tasks. Children generally benefited from CCRT over the 24 training sessions, but titrated CCRT showed a clear advantage over non-titrated. Severity of illness or factors such as BMI, did not moderate CCRT performance indicators. These findings support our hypothesis that titrated CCRT would result in steeper improvement in learning, but do not support our hypothesis that history of recent significant illness would affect learning proficiency. Findings were evident across all CCRT performance scores, even given that children were from generally rural, low-resource settings and were generally unfamiliar with computers.ABBREVIATIONS:Computerized Cognitive Rehabilitation Training (CCRT); Mental Processing Index (MPI); Home Observation for the Measurement of the Environment (HOME); Socioeconomic Status (SES); least square means (LSM).

Wrong place, wrong time: The long-run effects of in-utero exposure to malaria on educational attainment

This paper investigates the long-term relationship between early life exposure to malaria and human capital accumulation in Brazil. The identification strategy relies on exogenous variation in the risk of malaria outbreaks in different states and seasons of the year to identify in utero exposure according to the timing and location of birth. I find consistent negative treatment effects of in utero exposure to malaria on educational attainment. The effects are stronger for exposure during the first trimester of pregnancy than during other periods of gestation. Effective anti-malaria policies can, thus, be an important factor contributing to reducing the educational inequality by targeting pregnant women, especially those in their first months of gestation.

Adolescent health series: Adolescent neurocognitive development in Western and Sub-Saharan African contexts

The transitional period of adolescence has long been associated with physical, social and behavioural change. During this time, adolescents start to develop their own self-identity, make important life decisions and acquire the necessary skills to successfully transition to adulthood. More recently, advances in brain imaging technology have enabled increased understanding of structural and functional changes in the human brain during this developmental period, and how they relate to social, emotional, motivational and cognitive development. The ability to integrate these developing cognitive processes in increasingly complex social contexts is a key aspect of mature decision-making, which has implications for adolescent health, educational, economic and social outcomes. Insights from the field of developmental cognitive neuroscience could increase our understanding of this influential stage of life and thus inform potential interventions to promote adolescent health, a critical goal for global health research. Many social changes occur during adolescence and the social environment shapes both brain and cognitive development and the decisions adolescents make. Thus, it is important to study adolescent neurocognitive development in socio-cultural context. Yet, despite evidence from Western studies that socio-cultural and economic factors impact on adolescent neurocognitive development, existing studies of adolescent neurocognitive development in sub-Saharan Africa are relatively scarce. We summarise research findings from Western and sub-Saharan African contexts and highlight areas where research is lacking. Longitudinal studies from more diverse global samples will be needed to build a comprehensive model of adolescent development, that characterises both commonalities in developmental trajectories, as well as the way these can meaningfully differ between both individuals and contexts.

Predictors of outcome in childhood Plasmodium falciparum malaria

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

Update on malaria

Despite recent successful efforts to reduce the global malaria burden, this disease remains a significant global health problem. Only in 2018, malaria caused 228 million clinical episodes, 2-4 million of which were severe malaria cases, and 405,000 were fatal. Most of the malaria attributable mortality occurred among children in sub-Saharan Africa. Nowadays, rapid diagnostic tests and artemisinin derivatives are two of the main pillars for the management of malaria. However, considering the current situation, these strategies are not sufficient to maintain a reducing trend in malaria incidence and mortality. New insights into the pathophysiology of malaria have highlighted the importance of the host response to infection. Understanding this response would help to develop new diagnostic and therapeutic tools. Vector and parasite drug resistance are two major challenges for malaria control that require special attention. The most advanced malaria vaccine (RTS,S) is currently being piloted in 3 African countries.

Prevalence of malarial recurrence and hematological alteration following the initial drug regimen: a retrospective study in Western Thailand

Background

The hematological changes following the initial drug regimen has been poorly understood in Thailand. This study was designed to determine the prevalence of malaria parasite recurrence and hematological alteration of patients during the initial drug regimen.

Methods

A retrospective study was conducted at Phop Phra Hospital, Tak Province, located in northwestern Thailand. All data from patients who were diagnosed with Plasmodium spp. infection – including types of Plasmodium spp., clinical characteristics, and hematological parameters – were retrieved and analyzed.

Results

The results demonstrated that during years 2012–2018, 95 out of 971 patients (9.78%) were infected with malaria two or more times. The gender, nationality, symptom of headache, type of Plasmodium spp., and career of each patient were associated with recurrence (P-value< 0.05). Among patients treated with malarial drug, the leukocyte count and red cell distribution width (RDW) were significantly changed when compared to untreated patients with recurrence (P-value< 0.05).

Conclusion

This study indicated the high prevalence of malarial recurrence in Tak Province, Western Thailand, and its relationship to certain characteristics of individuals. Patients who were treated with antimalarial drugs exhibited leukocyte and RDW changes following the initial drug regimen. This data could be useful for prompt detection, treatment, and prevention of malarial recurrence in endemic areas of Thailand.

Acute kidney injury is associated with impaired cognition and chronic kidney disease in a prospective cohort of children with severe malaria

BACKGROUND

Acute kidney injury (AKI) is a recognized complication of pediatric severe malaria, but its long-term consequences are unknown.

METHODS

Ugandan children with cerebral malaria (CM, n = 260) and severe malaria anemia (SMA, n = 219) or community children (CC, n = 173) between 1.5 and 12 years of age were enrolled in a prospective cohort study. Kidney Disease: Improving Global Outcomes (KDIGO) criteria were used to retrospectively define AKI and chronic kidney disease (CKD). Cognitive testing was conducted using the Mullen Scales of Early Learning in children < 5 and Kaufman Assessment Battery for Children (K-ABC) second edition in children ≥ 5 years of age.

RESULTS

The prevalence of AKI was 35.1%, ranging from 25.1% in SMA to 43.5% in CM. In-hospital mortality was 11.9% in AKI compared to 4.2% in children without AKI (p = 0.001), and post-discharge mortality was 4.7% in AKI compared to 1.3% in children without AKI (p = 0.030) corresponding to an all-cause adjusted hazard ratio of 2.30 (95% CI 1.21, 4.35). AKI was a risk factor for short- and long-term neurocognitive impairment. At 1 week post-discharge, the frequency of neurocognitive impairment was 37.3% in AKI compared to 13.5% in children without AKI (adjusted odds ratio (aOR) 2.31 [95% CI 1.32, 4.04]); at 1-year follow-up, it was 13.3% in AKI compared to 3.4% in children without AKI (aOR 2.48 [95% CI 1.01, 6.10]), and at 2-year follow-up, it was 13.0% in AKI compared to 3.4% in children without AKI (aOR 3.03 [95% CI 1.22, 7.58]). AKI was a risk factor for CKD at 1-year follow-up: 7.6% of children with severe malaria-associated AKI had CKD at follow-up compared to 2.8% of children without AKI (p = 0.038) corresponding to an OR of 2.81 (95% CI 1.02, 7.73). The presenting etiology of AKI was consistent with prerenal azotemia, and lactate dehydrogenase as a marker of intravascular hemolysis was an independent risk factor for AKI in CM and SMA (p < 0.0001). In CM, AKI was associated with the presence and severity of retinopathy (p < 0.05) and increased cerebrospinal fluid albumin suggestive of blood-brain barrier disruption.

CONCLUSIONS

AKI is a risk factor for long-term neurocognitive impairment and CKD in pediatric severe malaria.

Malaria impact on cognitive function of children in a peri-urban community in the Brazilian Amazon

Background

In Latin America, where Plasmodium vivax malaria is more prevalent, it is known that this species plays an important role in the sustainability of transmission, and can have an impact on morbidity in terms of anaemia, nutritional status, and cognitive development in children.

Methods

The present study aimed to assess the impact of malaria infection on cognition of children in a peri-urban community in the Brazilian Amazon with moderate endemicity by applying Home Inventory and WPPSI-IV. A non-concurrent cohort study was designed and the cognitive, haematological, and nutritional profiles of the children were assessed. Children with documented malaria history were identified from official reported data.

Results

A total of 219 children aged between 2 and 7 years were enrolled. Although 205 (95%) children had normal birth weight, 177 (81%) were malnourished, and 35 (16%) had anaemia. Among the 100 (46%) children who experienced at least one episode of malaria, 89 (89%) children demonstrated low level of cognitive development. The findings showed that Plasmodium vivax malaria was an independent risk factor for low cognitive development.

Conclusions

In addition to the known economic impact of malaria in the Amazon region, the study highlights the deleterious effects P. vivax malaria has on the socio-cultural development of the population.

Neuropsychological benefits of computerized cognitive rehabilitation training in Ugandan children surviving severe malaria: A randomized controlled trial

BACKGROUND

Computerized cognitive rehabilitation training (CCRT) may be beneficial for alleviating persisting neurocognitive deficits in Ugandan severe malaria survivors. We completed a randomized controlled trial of CCRT for both severe malaria and non-malaria cohorts of children.

METHODS

150 school-age severe malaria and 150 non-malaria children were randomized to three treatment arms: 24 sessions of Captain's Log CCRT for attention, working memory and nonverbal reasoning, in which training on each of 9 tasks difficulty increased with proficiency; a limited CCRT arm that did not titrate to proficiency but randomly cycled across the simplest to moderate level of training; and a passive control arm. Before and after 2 months of CCRT intervention and one year following, children were tested with the Kaufman Assessment Battery for Children, 2nd edition (KABC-II), computerized CogState cognitive tests, the Behavior Rating Inventory for Executive Function (BRIEF), and the Achenbach Child Behavior Checklist (CBCL).

RESULTS

Malaria children assigned to the limited-CCRT intervention arm were significantly better than passive controls on KABC-II Mental Processing Index (P = 0.04), Sequential Processing (working memory) (P = 0.02) and the Conceptual Thinking subtest (planning/reasoning) (P = 0.02). At one year post-training, the limited CCRT malaria children had more rapid CogState card detection (attention) (P = 0.02), and improved BRIEF Global Executive Index (P = 0.01) as compared to passive controls. Non-malaria children receiving CCRT significantly benefited only on KABC-II Conceptual Thinking (both full- and limited-CCRT; P < 0.01), CogState Groton maze chase and learning (P < 0.01), and CogState card identification (P = 0.05, full CCRT only). Improvements in KABC-II Conceptual Thinking planning subtest for the non-malaria children persisted to one-year follow-up only for the full-CCRT intervention arm.

CONCLUSION

For severe malaria survivors, limited CCRT improved attention and memory outcomes more than full CCRT, perhaps because of the greater repetition and practice on relevant training tasks in the absence of the performance titration for full CCRT. There were fewer significant cognitive and behavior benefits for the non-malaria children, with the exception of the planning/reasoning subtest of Conceptual Thinking, with stronger full- compared to limited-CCRT improvements persisting to one-year follow-up.

Effects of schooling on aspects of attention in rural Burkina Faso, West Africa

Background

We aimed to study the effects of schooling on aspects of attention using the Test of Variables of Attention (TOVA) among children in rural Burkina Faso.

Methods

We re-enrolled children of a previously community-based cluster randomized exclusive breastfeeding trial in rural Burkina Faso. A total of 534 children (280 boys and 254 girls) aged 6 to 8 years were assessed using the TOVA. We examined the effect size difference using Cohen’s d, ANOVA and conducted regression analyses.

Results

Forty nine percent of the children were in school. Children not in school performed poorly with a small effect size difference for ‘Response Time’, ‘Errors of omission’, and ‘Errors of commission’ compared to children in school. The effect size difference was moderate for ‘Response Time Variability’, and ‘D prime score’.

Conclusion

Schooling affects different aspects of attention in rural Burkina Faso. In settings where literacy and schooling rate is low, public sensitizations of the benefits of schooling need to be reinforced and advice on sending children to school need to be provided continuously.

Concurrent exposure to heavy metals and cognition in school-age children in Congo-Kinshasa: A complex overdue research agenda

The impact of concurrent exposure to neurotoxic metals is a significant threat to brain function, mostly in contexts of multiple exposures as seen in the developing world. Ninety-five children (46 boys and 49 girls, 6 to 11-year old) from Congo-Kinshasa were assessed for cognition using the Kaufman Assessment Battery for Children (2nd edition) and exposure to Cr, Cu, Zn, Co, Mn, As, Cd, Se, Hg, Fe, and Pb by inductively coupled plasma mass spectrometry (ICPMS) in serum and urine collections. Concentrations of elements were all above normal ranges except for Cd, Se and Hg. General linear mixed effects models were used to predict neurocognitive outcomes with variable selection methods including backward elimination, elastic net, or subsets identified based on subject matter expertise. After adjusting for sex, age, and SES, urinary Co > 5 μg/l was associated with poor simultaneous processing (memory) (p = 0.0237). Higher excretion but normal concentration of Cd in serum was associated with better memory (p = 0.03), planning (p = 0.05), and overall performance scores (p < 0.01); thus appeared to be neuroprotective. However, higher excretion of Zn had negative influence on the overall performance scores (p = 0.02). Predictive neurotoxicology is a challenging task in contexts of multiple and concurrent exposures. Urinary Co > 5 μg/l is a risk factor for poor neurodevelopmental outcomes in such contexts. The impact of heavy metals on cognition is dependent on concentrations of and interactions between toxic and essential elements.

Association between stunting and neuro-psychological outcomes among children in Burkina Faso, West Africa

BACKGROUND

In Burkina Faso, stunting affects children and is a public health problem. We studied the association between stunting and child's neuro-psychological outcomes at 6-8 years of age in rural Burkina Faso using the Kaufman Assessment Battery for Children, 2nd edition (KABC-II), the Children's Category Test 1 (CCT-1) and the Test of Variable of Attention (TOVA).

METHODS

We re-enrolled children of a previously community-based Exclusive breastfeeding trial in Burkina Faso. We assessed a total of 532 children aged 6-8 years using KABC-II for memory (Atlantis and Number Recall subtests), spatial abilities (Conceptual Thinking, Face Recognition and Triangle subtests), reasoning (Block Counting subtest), general cognition and CCT-1 for cognitive flexibility. A total 513 children were assessed using the TOVA to measure attention and inhibition. We calculated the Cohen's d to examine the effect size and conducted a linear regression to examine the association.

RESULTS

The proportion of stunting was 15.6% (83/532). Stunted children performed significantly poorer for memory (Atlantis and Number Recall), spatial abilities (Conceptual Thinking, Face Recognition and Triangle), general cognition and attention with a small effect size compared to non-stunted children. Children who were exposed scored significantly higher errors for cognitive flexibility and inhibition with a small effect size compared to unexposed children. At standardized and unstandardized multivariable regression analysis, stunted children performed significantly poorer for Atlantis (p = 0.001), Number Recall (p = 0.02), Conceptual Thinking (p = 0.01), Triangle (p = 0.001), general cognition (p ≤ 0.0001) and attention (p = 0.04) compared to non-stunted children. Children who were exposed scored significantly higher errors for cognitive flexibility (p = 0.02) and for inhibition (p = 0.02) compared to unexposed children. We adjusted all the results for age, schooling, sex, playing, father education, mother employment and promotion of previous exclusive breastfeeding.

CONCLUSION

Stunting is associated with poorer neuro-psychological outcomes among children in rural Burkina Faso. Initiatives related to prevention need to be established and advice on nutrition need to be provided.

Endothelial Activation: The Ang/Tie Axis in Sepsis

Sepsis, a dysregulated host response to infection that causes life-threatening organ dysfunction, is a highly heterogeneous syndrome with no specific treatment. Although sepsis can be caused by a wide variety of pathogenic organisms, endothelial dysfunction leading to vascular leak is a common mechanism of injury that contributes to the morbidity and mortality associated with the syndrome. Perturbations to the angiopoietin (Ang)/Tie2 axis cause endothelial cell activation and contribute to the pathogenesis of sepsis. In this review, we summarize how the Ang/Tie2 pathway is implicated in sepsis and describe its prognostic as well as therapeutic utility in life-threatening infections.

Early and middle childhood developmental, cognitive, and psychiatric outcomes of Malawian children affected by retinopathy positive cerebral malaria

The objective is to determine the short -and long-term developmental, cognitive, and psychiatric effects of retinopathy positive cerebral malaria (CM-R) among young children in a prospective study assessing them around the onset of disease and again 2 years at preschool and again at school age. In total, 109 children were recruited from the Queen Elizabeth Central Hospital in Blantyre, Malawi, (N = 49) with CM-R and non-malaria controls  (N = 60). Children were assessed for overall motor, language, and social skills using the Malawi Developmental Assessment Tool (MDAT) at preschool age. At school age, the same children were then given the Kaufman Assessment Battery for Children, second edition (KABC-II), which assessed global cognitive performancememory, and learning; as well as the Test of Variables of Attention (TOVA), which assessed attention. The Achenbach Child Development Checklist (CBCL) was administered at both time points to assess emotional and behavioral patterns. Controls scored significantly better on all KABC-II global domains as well as on the mental processing index than their CM-R group counterparts, but showed no performance differences in the TOVA and CBCL assessments at school age, or in the MDAT and CBCL assessments at preschool age. The MDAT total score was significantly correlated with the KABC-II sequential processing, learning, and mental processing index among CM-R survivors but not among controls. Persisting neurocognitive effects of CM can be captured with the KABC-II at school age. The MDAT at preschool age is correlated with the KABC-II among CM-R survivors and can be used to capture early emerging developmental deficits due to CM-R.

Inhaled nitric oxide and cognition in pediatric severe malaria: A randomized double-blind placebo controlled trial

BACKGROUND

Severe malaria is a leading cause of acquired neurodisability in Africa and is associated with reduced nitric oxide (NO) bioavailability. A neuroprotective role for inhaled NO has been reported in animal studies, and administration of inhaled NO in preterm neonates with respiratory distress syndrome is associated with a 47% reduced risk of cognitive impairment at two years of age.

METHODS

A randomized double-blind placebo-controlled trial of inhaled NO versus placebo as an adjunctive therapy for severe malaria was conducted in Uganda between 2011 and 2013. Children received study gas for a maximum 72 hours (inhaled NO, 80 parts per million; room air placebo). Neurocognitive testing was performed on children<5 years at 6 month follow-up. The neurocognitive outcomes assessed were overall cognition (a composite of fine motor, visual reception, receptive language, and expressive language), attention, associative memory, and the global executive composite. Main outcomes were attention, associative memory, and overall cognitive ability.

RESULTS

Sixty-one children receiving iNO and 59 children receiving placebo were evaluated. Forty-two children (35.0%) were impaired in at least one neurocognitive domain. By intention-to-treat analysis, there were no differences in unadjusted or unadjusted age-adjusted z-scores for overall cognition (β (95% CI): 0.26 (-0.19, 0.72), p = 0.260), attention (0.18 (-0.14, 0.51), p = 0.267), or memory (0.14 (-0.02, 0.30), p = 0.094) between groups by linear regression. Children receiving inhaled NO had a 64% reduced relative risk of fine motor impairment than children receiving placebo (relative risk, 95% CI: 0.36, 0.14-0.96) by log binomial regression following adjustment for anticonvulsant use.

CONCLUSIONS

Severe malaria is associated with high rates of neurocognitive impairment. Treatment with inhaled NO was associated with reduced risk of fine motor impairment. These results need to be prospectively validated in a larger study powered to assess cognitive outcomes in order to evaluate whether strategies to increase bioavailable NO are neuroprotective in children with severe malaria.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01255215.

Adjunctive therapy for severe malaria: a review and critical appraisal

BACKGROUND

Despite recent efforts and successes in reducing the malaria burden globally, this infection still accounts for an estimated 212 million clinical cases, 2 million severe malaria cases, and approximately 429,000 deaths annually. Even with the routine use of effective anti-malarial drugs, the case fatality rate for severe malaria remains unacceptably high, with cerebral malaria being one of the most life-threatening complications. Up to one-third of cerebral malaria survivors are left with long-term cognitive and neurological deficits. From a population point of view, the decrease of malaria transmission may jeopardize the development of naturally acquired immunity against the infection, leading to fewer total cases, but potentially an increase in severe cases. The pathophysiology of severe and cerebral malaria is not completely understood, but both parasite and host determinants contribute to its onset and outcomes. Adjunctive therapy, based on modulating the host response to infection, could help to improve the outcomes achieved with specific anti-malarial therapy.

RESULTS AND CONCLUSIONS

In the last decades, several interventions targeting different pathways have been tested. However, none of these strategies have demonstrated clear beneficial effects, and some have shown deleterious outcomes. This review aims to summarize evidence from clinical trials testing different adjunctive therapy for severe and cerebral malaria in humans. It also highlights some preclinical studies which have evaluated novel strategies and other candidate therapeutics that may be evaluated in future clinical trials.

Implications of Combined Exposure to Household Air Pollution and HIV on Neurocognition in Children

Air pollution exposure and HIV infection can each cause neurocognitive insult in children. The purpose of this study was to test whether children with combined high air pollution exposure and perinatal HIV infection have even greater risk of neurocognitive impairment. This was a cross-sectional study of HIV-uninfected unexposed (HUU) and HIV-infected children and their caregivers in Nairobi, Kenya. We used a detailed neuropsychological battery to evaluate neurocognitive functioning in several domains. We measured caregiver 24-h personal CO exposure as a proxy for child CO exposure and child urinary 1-hydroxypyrene (1-OHP), a biomarker for exposure to polycyclic aromatic hydrocarbons (PAHs). Median 24-h caregiver CO exposure was 6.1 and 3.7 ppm for 45 HIV-infected (mean age 6.6 years) and 49 HUU (mean age 6.7 years), respectively; 48.5% of HIV-infected and 38.6% of HUU had caregiver 24-h CO levels exceeding the WHO recommended level. Median 1-OHP exposure was 0.6 and 0.7 µmol/mol creatinine among HIV-infected and HUU children, respectively. HIV-infected children with high urinary 1-OHP (exceeding 0.68 µmol/mol creatinine) had significantly lower global cognition (p = 0.04), delayed memory (p = 0.01), and attention scores (p = 0.003). Among HUU children, urinary 1-OHP and caregiver 24-h caregiver CO were not significantly associated with neurocognitive function. Our findings suggest that combined chronic exposure to air pollutants and perinatal HIV infection may be associated with poorer neurocognitive outcomes. High prevalence of air pollution exposure highlights the need to reduce these exposures.

[Formula: see text]Selecting measures for the neurodevelopmental assessment of children in low- and middle-income countries

Diseases affecting millions of children in low- and middle-income countries (LMICs), such as malnutrition, micronutrient deficiency, malaria, and HIV, can lead to adverse neurodevelopmental outcomes. Thus, a key health outcome in children is neurodevelopmental status. In this paper, the neurodevelopmental screening and testing measures most commonly utilized in LMICs are reviewed, and a matrix is presented to help researchers and clinicians determine which measures may be most useful for various LMIC inquiries. The matrix is based on an Internet literature review of 114 publications for the period January 1998 to February 2016, reporting the psychometric properties of instruments tested in LMIC children. The measures are classified as screening tests or more detailed tests that include both comprehensive batteries of general development and tests of specific domains. For completeness, two experts have reviewed this paper, as well as the authors. An overview of the tests used to date is presented, including the benefits and drawbacks of each test, in order to provide researchers and developmental clinicians with a way to decide which tests may be best suited to their developmental assessment goals. Remarkable progress has been made in neurodevelopmental testing in children in LMICs over the past two decades but there remains a need for additional research in this area to develop new tests, better evaluate and adapt current tests, and assess test validity and reliability across cultures.

Cerebrospinal fluid kynurenine and kynurenic acid concentrations are associated with coma duration and long-term neurocognitive impairment in Ugandan children with cerebral malaria

Background

One-fourth of children with cerebral malaria (CM) retain cognitive sequelae up to 2 years after acute disease. The kynurenine pathway of the brain, forming neuroactive metabolites, e.g. the NMDA-receptor antagonist kynurenic acid (KYNA), has been implicated in long-term cognitive dysfunction in other CNS infections. In the present study, the association between the kynurenine pathway and neurologic/cognitive complications in children with CM was investigated.

Methods

Cerebrospinal fluid (CSF) concentrations of KYNA and its precursor kynurenine in 69 Ugandan children admitted for CM to Mulago Hospital, Kampala, Uganda, between 2008 and 2013 were assessed. CSF kynurenine and KYNA were compared to CSF cytokine levels, acute and long-term neurologic complications, and long-term cognitive impairments. CSF kynurenine and KYNA from eight Swedish children without neurological or infectious disease admitted to Astrid Lindgren’s Children’s Hospital were quantified and used for comparison.

Results

Children with CM had significantly higher CSF concentration of kynurenine and KYNA than Swedish children (P < 0.0001 for both), and CSF kynurenine and KYNA were positively correlated. In children with CM, CSF kynurenine and KYNA concentrations were associated with coma duration in children of all ages (P = 0.003 and 0.04, respectively), and CSF kynurenine concentrations were associated with worse overall cognition (P = 0.056) and attention (P = 0.003) at 12-month follow-up in children ≥5 years old.

Conclusions

CSF KYNA and kynurenine are elevated in children with CM, indicating an inhibition of glutamatergic and cholinergic signaling. This inhibition may lead acutely to prolonged coma and long-term to impairment of attention and cognition.

Maternal alcohol consumption during pregnancy and child's cognitive performance at 6-8 years of age in rural Burkina Faso: an observational study

Background

In Burkina Faso, it is not uncommon for mothers to drink alcohol, even during pregnancy. We aimed to study the association between maternal alcohol consumption during pregnancy and the child’s cognitive performance using the Kaufman Assessment Battery for Children, 2nd edition (KABC-II) and the Children’s Category Test Level 1 (CCT-1) in rural Burkina Faso.

Methods

We conducted a follow-up study of a community cluster-randomised Exclusive breastfeeding trial, and re-enrolled the children in rural Burkina Faso. A total of 518 children (268 boys and 250 girls) aged 6–8 years were assessed using the KABC-II and the CCT-1. We examined the effect size difference using Cohen’s d and conducted a linear regression analysis to examine the association.

Results

Self-reported alcohol consumption during pregnancy was 18.5% (96/518). Children whose mothers reported alcohol consumption during pregnancy performed significantly poorly for memory and spatial abilities tests from small effect size difference for ‘Atlantis’ (0.27) and ‘Triangle’ (0.29) to moderate effect size difference for ‘Number recall’ (0.72) compared to children whose mothers did not consume alcohol during pregnancy; the exposed children scored significantly higher errors with a small effect size (0.37) at problem solving (CCT-1) test compared to unexposed children.

At unstandardized and standardized multivariable analysis, children whose mothers reported alcohol consumption during pregnancy performed significantly poorer for memory-‘Atlantis’ (p = 0.03) and ‘Number recall’ (p = 0.0001), and spatial ability tests-‘Triangle’ (p = 0.03); they scored significantly higher errors at problem solving CCT-1 test (p = 0.002); all the results were adjusted for age, sex, schooling, stunting, father’s education, mother’s employment and the promotion of exclusive breastfeeding. No statistical association was found for visual abilities-‘Conceptual Thinking’, ‘Face recognition’, ‘Story completion’, and reasoning tests-‘Rover’, ‘Block counting’, and ‘Pattern Reasoning’.

Conclusion

Maternal alcohol consumption during pregnancy is associated with poorer cognitive performance for memory, spatial ability, and problem solving tests in the offspring in rural Burkina Faso. Futures studies needs to assess in more detail the maternal alcohol consumption patterns in Burkina Faso and possible preventive strategies.

Safety and tolerability of adjunctive rosiglitazone treatment for children with uncomplicated malaria

BACKGROUND

Despite the widespread use and availability of rapidly acting anti-malarials, the fatality rate of severe malaria in sub-Saharan Africa remains high. Adjunctive therapies that target the host response to malaria infection may further decrease mortality over that of anti-malarial agents alone. Peroxisome proliferator-activated receptor-gamma agonists (e.g. rosiglitazone) have been shown to act on several pathways implicated in the pathogenesis of severe malaria and may improve clinical outcome as an adjunctive intervention.

METHODS

In this study, the safety and tolerability of adjunctive rosiglitazone in paediatric uncomplicated malaria infection was evaluated in Mozambique, as a prelude to its evaluation in a randomized controlled trial in paediatric severe malaria. The study was a prospective, randomized, double-blind, placebo-controlled, phase IIa trial of rosiglitazone (0.045 mg/kg/dose) twice daily for 4 days versus placebo as adjunctive treatment in addition to Mozambican standard of care (artemisinin combination therapy Coartem^®) in children with uncomplicated malaria. The primary outcomes were tolerability and safety, including clinical, haematological, biochemical, and electrocardiographic evaluations.

RESULTS

Thirty children were enrolled: 20 were assigned to rosiglitazone and 10 to placebo. Rosiglitazone treatment did not induce hypoglycaemia nor significantly alter clinical, biochemical, haematological, or electrocardiographic parameters.

CONCLUSIONS

Adjunctive rosiglitazone was safe and well-tolerated in children with uncomplicated malaria, permitting the extension of its evaluation as adjunctive therapy for severe malaria. The trial is registered with Clinicaltrials.gov, NCT02694874.

Long-term Behavioral Problems in Children With Severe Malaria

BACKGROUND

Severe malaria in children is associated with long-term neurocognitive impairment, but it is unclear whether it is associated with long-term behavioral problems.

METHODS

Children <5 years old with cerebral malaria (CM) or severe malarial anemia (SMA) treated at Mulago Hospital, Kampala, Uganda were assessed for behavioral outcomes at 0, 6, 12, and 24 months using the Child Behavior Checklist. Sample sizes at 0, 12, and 24 months were 122, 100, and 80 in the CM group, 130, 98, and 81 in the SMA group, and 149, 123, and 90 in healthy community control (CC) children, respectively. Age adjusted z-scores for behavioral outcomes were computed using scores for the CC group. Study groups were compared using regression models adjusted for age, nutritional status, preschool education, and socioeconomic status.

RESULTS

At 12 months, children with SMA had higher z-scores than CC children for internalizing (mean difference, 0.49; SE, 0.14; P = .001), externalizing (mean difference, 0.49; SE, 0.15; P = .001), and total problems (mean difference, 0.51; SE, 0.15; P < .001). Children with CM had higher adjusted z-scores than CC children for externalizing problems (mean difference, 0.39; SE, 0.15; P = .009) but not internalizing or total problems. At 24 months, children with CM or SMA both had increased internalizing and externalizing behavioral problems compared with CC children (P ≤ .05 for all).

CONCLUSIONS

CM and SMA are associated with long-term internalizing and externalizing behavioral problems in children. They may contribute substantially to mental health morbidity in children <5 years old in malaria endemic areas.

Diagnostic Accuracy, Sensitivity, and Specificity of Executive Function Tests in Moderate Traumatic Brain Injury in Ghana

The sociocultural differences between Western and sub-Saharan African countries make it imperative to standardize neuropsychological tests in the latter. However, Western-normed tests are frequently administered in sub-Saharan Africa because of challenges hampering standardization efforts. Yet a salient topical issue in the cross-cultural neuropsychology literature relates to the utility of Western-normed neuropsychological tests in minority groups, non-Caucasians, and by extension Ghanaians. Consequently, this study investigates the diagnostic accuracy, sensitivity, and specificity of executive function (EF) tests (The Stroop Test, Trail Making Test, and Controlled Oral Word Association Test), and a Revised Quick Cognitive Screening Test (RQCST) in a sample of 50 patients diagnosed with moderate traumatic brain injury and 50 healthy controls in Ghana. The EF test scores showed good diagnostic accuracy, with area under the curve (AUC) values of the Trail Making Test scores ranging from .746 to .902. With respect to the Stroop Test scores, the AUC values ranged from .793 to .898, while Controlled Oral Word Association Test had AUC value of .787. The RQCST scores discriminated between the groups, with AUC values ranging from .674 to .912. The AUC values of composite EF score and a neuropsychological score created from EF and RQCST scores were .936 and. 942, respectively. Additionally, the Stroop Test, Trail Making Test, EF composite score, and RQCST scores showed good to excellent sensitivities and specificities. In general, this study has shown that commonly used EF tests in Western countries have diagnostic accuracy, sensitivity, and specificity when administered in Ghanaian samples. The findings and implications of the study are discussed.

Pathophysiological Mechanisms in Gaseous Therapies for Severe Malaria

Over 200 million people worldwide suffer from malaria every year, a disease that causes 584,000 deaths annually. In recent years, significant improvements have been achieved on the treatment of severe malaria, with intravenous artesunate proving superior to quinine. However, mortality remains high, at 8% in children and 15% in adults in clinical trials, and even worse in the case of cerebral malaria (18% and 30%, respectively). Moreover, some individuals who do not succumb to severe malaria present long-term cognitive deficits. These observations indicate that strategies focused only on parasite killing fail to prevent neurological complications and deaths associated with severe malaria, possibly because clinical complications are associated in part with a cerebrovascular dysfunction. Consequently, different adjunctive therapies aimed at modulating malaria pathophysiological processes are currently being tested. However, none of these therapies has shown unequivocal evidence in improving patient clinical status. Recently, key studies have shown that gaseous therapies based mainly on nitric oxide (NO), carbon monoxide (CO), and hyperbaric (pressurized) oxygen (HBO) alter vascular endothelium dysfunction and modulate the host immune response to infection. Considering gaseous administration as a promising adjunctive treatment against severe malaria cases, we review here the pathophysiological mechanisms and the immunological aspects of such therapies.

Long-term impact of childhood malaria infection on school performance among school children in a malaria endemic area along the Thai-Myanmar border

BACKGROUND

Children represent a high-risk group for malaria worldwide. Among people in Thailand who have malaria during childhood, some may have multiple malaria attacks during their lifetime. Malaria may affect neurological cognition in children, resulting in short-term impairment of memory and language functions. However, little is known regarding the long-term effects of malaria infection on cognitive function. This study examines the long-term impact of malaria infection on school performance among school children living in a malaria-endemic area along the Thai-Myanmar border.

METHODS

A retrospective cohort study was conducted among school children aged 6-17 years in a primary-secondary school of a sub-district of Ratchaburi Province, Thailand. History of childhood malaria infection was obtained from the medical records of the sole malaria clinic in the area. School performance was assessed by using scores for the subjects Thai Language and Mathematics in 2014. Other variables, such as demographic characteristics, perinatal history, nutritional status, and emotional intelligence, were also documented.

RESULTS

A total of 457 students were included, 135 (30 %) of whom had a history of uncomplicated malaria infection. About half of the malaria-infected children had suffered infection before the age of four years. The mean scores for both Mathematics and Thai Language decreased in relation to the increasing number of malaria attacks. Most students had their last malaria episode more than two years previously. The mean scores were not associated with duration since the last malaria attack. The association between malaria infection and school performance was not significant after adjusting for potential confounders, including gender, school absenteeism over a semester term, and emotional intelligence.

CONCLUSIONS

This study characterizes the long-term consequences of uncomplicated malaria disease during childhood. School performance was not associated with a history of malaria infection, considering that most students had their last malaria infection more than two years previously. These findings indicate that the impact of uncomplicated malaria infection on school performance may not be prolonged.

Vascular dysfunction as a target for adjuvant therapy in cerebral malaria

Cerebral malaria (CM) is a life-threatening complication of Plasmodium falciparum malaria that continues to be a major global health problem. Brain vascular dysfunction is a main factor underlying the pathogenesis of CM and can be a target for the development of adjuvant therapies for the disease. Vascular occlusion by parasitised red blood cells and vasoconstriction/vascular dysfunction results in impaired cerebral blood flow, ischaemia, hypoxia, acidosis and death. In this review, we discuss the mechanisms of vascular dysfunction in CM and the roles of low nitric oxide bioavailability, high levels of endothelin-1 and dysfunction of the angiopoietin-Tie2 axis. We also discuss the usefulness and relevance of the murine experimental model of CM by Plasmodium berghei ANKA to identify mechanisms of disease and to screen potential therapeutic interventions.

Risk factors affecting child cognitive development: a summary of nutrition, environment, and maternal-child interaction indicators for sub-Saharan Africa

An estimated 200 million children worldwide fail to meet their development potential due to poverty, poor health and unstimulating environments. Missing developmental milestones has lasting effects on adult human capital. Africa has a large burden of risk factors for poor child development. The objective of this paper is to identify scope for improvement at the country level in three domains--nutrition, environment, and mother-child interactions. We used nationally representative data from large-scale surveys, data repositories and country reports from 2000 to 2014. Overall, there was heterogeneity in performance across domains, suggesting that each country faces distinct challenges in addressing risk factors for poor child development. Data were lacking for many indicators, especially in the mother-child interaction domain. There is a clear need to improve routine collection of high-quality, country-level indicators relevant to child development to assess risk and track progress.

Designing and evaluating Brain Powered Games for cognitive training and rehabilitation in at-risk African children

BACKGROUND

Valid, reliable, accessible, and cost-effective computer-training approaches can be important components in scaling up educational support across resource-poor settings, such as sub-Saharan Africa. The goal of the current study was to develop a computer-based training platform, the Michigan State University Games for Entertainment and Learning laboratory's Brain Powered Games (BPG) package that would be suitable for use with at-risk children within a rural Ugandan context and then complete an initial field trial of that package.

METHODS

After game development was completed with the use of local stimuli and sounds to match the context of the games as closely as possible to the rural Ugandan setting, an initial field study was completed with 33 children (mean age = 8.55 ± 2.29 years, range 6-12 years of age) with HIV in rural Uganda. The Test of Variables of Attention (TOVA), CogState computer battery, and the Non-Verbal Index from the Kaufman Assessment Battery for Children, 2nd edition (KABC-II) were chosen as the outcome measures for pre- and post-intervention testing. The children received approximately 45 min of BPG training several days per week for 2 months (24 sessions).

RESULTS

Although some improvements in test scores were evident prior to BPG training, following training, children demonstrated clinically significant changes (significant repeated-measures outcomes with moderate to large effect sizes) on specific TOVA and CogState measures reflecting processing speed, attention, visual-motor coordination, maze learning, and problem solving.

CONCLUSIONS

Results provide preliminary support for the acceptability, feasibility, and neurocognitive benefit of BPG and its utility as a model platform for computerized cognitive training in cross-cultural low-resource settings.

Executive function and attention-deficit/hyperactivity disorder in Ugandan children with perinatal HIV exposure

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is among the most commonly diagnosed mental disorders in childhood and is associated with substantial deficits in executive functioning and lost academic and occupational attainment. This study evaluates symptoms of ADHD and their association with neurocognitive deficits in a cohort of rural Ugandan children who were born to HIV-infected mothers.

METHODS

We assessed ADHD symptoms and executive function (including memory and attention) in a non-clinical sample of children born to HIV-infected mothers in rural eastern Uganda. Analyses included assessments of the psychometric properties, factor structure, and convergent and discriminant validity of the ADHD measure (ADHD-Rating Scale-IV); and executive function deficits in children meeting symptom criteria for ADHD.

RESULTS

232 children [54% female; mean age 7.8 years (s.d. 2.0)] were assessed for ADHD and executive function deficits. The ADHD measure showed good internal consistency (α = 0.85.) Confirmatory factor analysis showed an acceptable fit for the diagnostic and statistical manual of mental disorders (DSM-5) two-factor model. Subjects meeting DSM-5 symptom criteria for ADHD had worse parent-rated executive function on six out of seven subscales.

CONCLUSIONS

Our results demonstrate structural validity of the ADHD measure with this population, strong associations between ADHD symptom severity and poorer executive function, and higher levels of executive function problems in perinatally HIV-exposed Ugandan children with ADHD. These findings suggest that ADHD may be an important neurocognitive disorder associated with executive function problems among children in sub-Saharan African settings where perinatal HIV exposure is common.

Impacts of Climate Change on Inequities in Child Health

This paper addresses an often overlooked aspect of climate change impacts on child health: the amplification of existing child health inequities by climate change. Although the effects of climate change on child health will likely be negative, the distribution of these impacts across populations will be uneven. The burden of climate change-related ill-health will fall heavily on the world's poorest and socially-disadvantaged children, who already have poor survival rates and low life expectancies due to issues including poverty, endemic disease, undernutrition, inadequate living conditions and socio-economic disadvantage. Climate change will exacerbate these existing inequities to disproportionately affect disadvantaged children. We discuss heat stress, extreme weather events, vector-borne diseases and undernutrition as exemplars of the complex interactions between climate change and inequities in child health.

Cerebral malaria retinopathy predictors of persisting neurocognitive outcomes in Malawian children

BACKGROUND

Neuropsychological sequelae from pediatric cerebral malaria (CM) have been well-documented. Although malaria-specific retinopathy during acute illness has become a defining criterion for CM, its relationship to neurocognitive sequelae has not been documented. This relationship is important if malaria-specific retinopathy reflects the possible brain neuropathogenesis leading to long-term neurocognitive deficits.

METHODS

From 2008 to 2012, 49 Malawian children 4.5-12 years of age surviving retinopathy-positive CM (CM-R) were tested 1-6 yrs after illness with the Kaufman Assessment Battery for Children, 2 edition, the tests of variables of attention and the Achenbach Child Behavior Checklist. In an observational study of a cohort of cerebral malaria survivors, these neurocognitive and behavioral outcomes were statistically related to types and severity of retinopathy measures, while controlling for age, sex, body mass index, socioeconomic status and time interval between illness and testing.

RESULTS

Worse scores for hemorrhages, papilledema, optic disk hyperemia, retinal whitening of macula and foveal annulus were associated with poorer Kaufman Assessment Battery for Children, 2 edition mental processing index and global scale scores. Disk hyperemia was also predictive of tests of variables of attention D prime overall attention performance (inattention) and commission errors (impulsivity). Few associations were found between retinopathy scores and Achenbach Child Behavior Checklist (emotional and behavioral) outcomes.

CONCLUSIONS

We are the first to report the relationship between severity of malaria-specific retinopathy during acute illness in CM survivors and persisting neurocognitive problems. These findings support earlier studies documenting that severity of retinopathy during acute illness is medically prognostic in CM survivors. We extend these findings to include long-term neurocognitive outcomes.

Contrasting pediatric and adult cerebral malaria: the role of the endothelial barrier

Malaria affects millions of people around the world and a small subset of those infected develop cerebral malaria. The clinical presentation of cerebral malaria differs between children and adults, and it has been suggested that age-related changes in the endothelial response may account for some of these differences. During cerebral malaria, parasites sequester within the brain microvasculature but do not penetrate into the brain parenchyma and yet, the infection causes severe neurological symptoms. Endothelial dysfunction is thought to play an important role in mediating these adverse clinical outcomes. During infection, the endothelium becomes activated and more permeable, which leads to increased inflammation, hemorrhages, and edema in the surrounding tissue. We hypothesize that post-natal developmental changes, occurring in both endothelial response and the neurovascular unit, account for the differences observed in the clinical presentations of cerebral malaria in children compared with adults.

The association between cognition and academic performance in Ugandan children surviving malaria with neurological involvement

Background

The contribution of different cognitive abilities to academic performance in children surviving cerebral insult can guide the choice of interventions to improve cognitive and academic outcomes. This study's objective was to identify which cognitive abilities are associated with academic performance in children after malaria with neurological involvement.

Methods

62 Ugandan children with a history of malaria with neurological involvement were assessed for cognitive ability (working memory, reasoning, learning, visual spatial skills, attention) and academic performance (reading, spelling, arithmetic) three months after the illness. Linear regressions were fit for each academic score with the five cognitive outcomes entered as predictors. Adjusters in the analysis were age, sex, education, nutrition, and home environment. Exploratory factor analysis (EFA) and structural equation models (SEM) were used to determine the nature of the association between cognition and academic performance. Predictive residual sum of squares was used to determine which combination of cognitive scores was needed to predict academic performance.

Results

In regressions of a single academic score on all five cognitive outcomes and adjusters, only Working Memory was associated with Reading (coefficient estimate = 0.36, 95% confidence interval = 0.10 to 0.63, p<0.01) and Spelling (0.46, 0.13 to 0.78, p<0.01), Visual Spatial Skills was associated with Arithmetic (0.15, 0.03 to 0.26, p<0.05), and Learning was associated with Reading (0.06, 0.00 to 0.11, p<0.05). One latent cognitive factor was identified using EFA. The SEM found a strong association between this latent cognitive ability and each academic performance measure (P<0.0001). Working memory, visual spatial ability and learning were the best predictors of academic performance.

Conclusion

Academic performance is strongly associated with the latent variable labelled “cognitive ability” which captures most of the variation in the individual specific cognitive outcome measures. Working memory, visual spatial skills, and learning together stood out as the best combination to predict academic performance.

Association between early childhood exposure to malaria and children's pre-school development: evidence from the Zambia early childhood development project

BACKGROUND

Despite major progress made over the past 10 years, malaria remains one of the primary causes of ill health in developing countries in general, and in sub-Saharan Africa in particular. Whilst a large literature has documented the frequency and severity of malaria infections for children under-five years, relatively little evidence is available regarding the impact of early childhood malaria exposure on subsequent child development.

METHODS

The objective of the study was to assess the associations between early childhood exposure to malaria and pre-school development. Child assessment data for 1,410 children in 70 clusters collected through the 2010 Zambian Early Childhood Development Project was linked with malaria parasite prevalence data from the 2006 Zambia Malaria Indicator Survey. Linear and logistic models were used to estimate the effect of early childhood exposure to malaria on anthropometric outcomes as well as on a range of cognitive and behavioural development measures.

RESULTS

No statistically significant associations were found between parasite exposure and children's height and weight. Exposure to the malaria parasite was, however, associated with lower ability to cope with cognitive tasks administered by interviewers (z-score difference -1.11, 95% CI -2.43-0.20), as well as decreased overall socio-emotional development as assessed by parents (z-score difference -1.55, 95% CI -3.13-0.02). No associations were found between malaria exposure and receptive vocabulary or fine-motor skills.

CONCLUSIONS

The results presented in this paper suggest potentially large developmental consequences of early childhood exposure to malaria. Continued efforts to lower the burden of malaria will not only reduce under-five mortality, but may also have positive returns in terms of the long-term well-being of exposed cohorts.

Statistical Approaches to Assess the Effects of Disease on Neurocognitive Function Over Time

INTRODUCTION

Assessment of the effects of disease on neurocognitive outcomes in children over time presents several challenges. These challenges are particularly pronounced when conducting studies in low-income countries, where standardization and validation is required for tests developed originally in high-income countries. We present a statistical methodology to assess multiple neurocognitive outcomes over time. We address the standardization and adjustment for age in neurocognitive testing, present a statistical methodology for development of a global neurocognitive score, and assess changes in individual and global neurocognitive scores over time in a cohort of children with cerebral malaria.

METHODS

Ugandan children with cerebral malaria (CM, N = 44), uncomplicated malaria (UM, N = 54) and community controls (N = 89) were assessed by cognitive tests of working memory, executive attention and tactile learning at 0, 3, 6 and 24 months after recruitment. Tests were previously developed and validated for the local area. Test scores were adjusted for age, and a global score was developed based on the controls that combined the assessments of impairment in each neurocognitive domain. Global normalized Z-scores were computed for each of the three study groups. Model-based tests compare the Z-scores between groups.

RESULTS

We found that continuous Z-scores gave more powerful conclusions than previous analyses of the dataset. For example, at all four time points, children with CM had significantly lower global Z-scores than controls and children with UM. Our methods also provide more detailed descriptions of longitudinal trends. For example, the Z-scores of children with CM improved from initial testing to 3 months, but remained at approximately the same level below those of controls or children with UM from 3 to 24 months. Our methods for combining scores are more powerful than tests of individual cognitive domains, as testing of the individual domains revealed differences at only some but not all time points.

Pediatric cerebral malaria: a scourge of Africa

Cerebral malaria, defined as an otherwise unexplained coma in a patient with Plasmodium falciparum parasitemia, affects up to 1 million people per year, the vast majority of them being children living in sub-Saharan Africa. Despite optimal treatment, this condition kills 15% of those affected and leaves 30% of survivors with neurologic sequelae. The clinical diagnosis is hampered by its poor specificity, but the presence or absence of a malarial retinopathy in cerebral malaria has proven to be important in the differentiation of underlying coma etiology. Both antimalarials and intense supportive care are necessary for optimal treatment. As of yet, clinical trials of adjunctive therapies have not improved the high rates of mortality and morbidity. Survivors are at high risk of neurologic sequelae including epilepsy, neurodisabilities and cognitive–behavioral problems. The neuroanatomic and functional bases of these sequelae are being elucidated. Although adjunctive therapy trials continue, the best hope for African children may lie in disease prevention. Strategies include bednets, chemoprophylaxis and vaccine development.

Global perspective on early diagnosis and intervention for children with developmental delays and disabilities

Low- and middle-income countries are experiencing a significant reduction in mortality of children under 5 years of age. This reduction is bringing in its wake large numbers of surviving children with developmental delays and disabilities. Very little attention has been paid to these children, most of whom receive minimal or no support. Thus, there is an urgent need to recognize that improving the quality of life of the survivors must complement mortality reduction in healthcare practice and programs. The incorporation of early evaluation and intervention programs into routine pediatric care is likely to have the most impact on the quality of life of these children. We therefore call for leadership from practitioners, governments, and international organizations to prioritize regular childhood developmental surveillance for possible delays and disabilities, and to pursue early referral for intervention.

Altered regulation of Akt signaling with murine cerebral malaria, effects on long-term neuro-cognitive function, restoration with lithium treatment

Neurological and cognitive impairment persist in more than 20% of cerebral malaria (CM) patients long after successful anti-parasitic treatment. We recently reported that long term memory and motor coordination deficits are also present in our experimental cerebral malaria model (ECM). We also documented, in a murine model, a lack of obvious pathology or inflammation after parasite elimination, suggesting that the long-term negative neurological outcomes result from potentially reversible biochemical and physiological changes in brains of ECM mice, subsequent to acute ischemic and inflammatory processes. Here, we demonstrate for the first time that acute ECM results in significantly reduced activation of protein kinase B (PKB or Akt) leading to decreased Akt phosphorylation and inhibition of the glycogen kinase synthase (GSK3β) in the brains of mice infected with Plasmodium berghei ANKA (PbA) compared to uninfected controls and to mice infected with the non-neurotrophic P. berghei NK65 (PbN). Though Akt activation improved to control levels after chloroquine treatment in PbA-infected mice, the addition of lithium chloride, a compound which inhibits GSK3β activity and stimulates Akt activation, induced a modest, but significant activation of Akt in the brains of infected mice when compared to uninfected controls treated with chloroquine with and without lithium. In addition, lithium significantly reversed the long-term spatial and visual memory impairment as well as the motor coordination deficits which persisted after successful anti-parasitic treatment. GSK3β inhibition was significantly increased after chloroquine treatment, both in lithium and non-lithium treated PbA-infected mice. These data indicate that acute ECM is associated with abnormalities in cell survival pathways that result in neuronal damage. Regulation of Akt/GSK3β with lithium reduces neuronal degeneration and may have neuroprotective effects in ECM. Aberrant regulation of Akt/GSK3β signaling likely underlies long-term neurological sequelae observed in ECM and may yield adjunctive therapeutic targets for the management of CM.

Cerebral malaria: we have come a long way

Despite decades of research, cerebral malaria remains one of the most serious complications of Plasmodium infection and is a significant burden in Sub-Saharan Africa, where, despite effective antiparasitic treatment, survivors develop long-term neurological sequelae. Although much remains to be discovered about the pathogenesis of cerebral malaria, The American Journal of Pathology has been seminal in presenting original research from both human and experimental models. These studies have afforded significant insight into the mechanism of cerebral damage in this devastating disease. The present review highlights information gleaned from these studies, especially in terms of their contributions to the understanding of cerebral malaria.