Justus Byarugaba

Cerebral Malaria in Children Is Associated With Long-term Cognitive Impairment

OBJECTIVE. Cerebral malaria affects >785000 African children every year. We previously documented an increased frequency of cognitive impairment in children with cerebral malaria 6 months after their initial malaria episode. This study was conducted to determine the long-term effects of cerebral malaria on the cognitive function of these children. METHODS. Children who were 5 to 12 years of age and presented to Mulago Hospital, Kampala, Uganda, with cerebral malaria (n = 44) or uncomplicated malaria (n = 54), along with healthy, asymptomatic community children (n = 89), were enrolled in a prospective cohort study of cognition. Cognitive testing was performed at enrollment and 2 years later. The primary outcome was presence of a deficit in ≥1 of 3 cognitive areas tested. RESULTS. At 2-year follow-up testing, 26.3% of children with cerebral malaria and 12.5% with uncomplicated malaria had cognitive deficits in ≥1 area, as compared with 7.6% of community children. Deficits in children with cerebral malaria were primarily in the area of attention (cerebral malaria, 18.4%, vs community children, 2.5%). After adjustment for age, gender, nutrition, home environment, and school level, children with cerebral malaria had a 3.67-fold increased risk for a cognitive deficit compared with community children. Cognitive impairment at 2-year follow-up was associated with hyporeflexia on admission and neurologic deficits 3 months after discharge. CONCLUSIONS. Cerebral malaria is associated with long-term cognitive impairments in 1 of 4 child survivors. Future studies should investigate the mechanisms involved so as to develop interventions aimed at prevention and rehabilitation.

Cognitive Impairment After Cerebral Malaria in Children: A Prospective Study

OBJECTIVE. This study was conducted to assess prospectively the frequency of cognitive deficits in children with cerebral malaria. METHODS. Cognitive testing in the areas of working memory, attention, and learning was performed for Ugandan children 5 to 12 years of age with cerebral malaria (n = 44), children with uncomplicated malaria (n = 54), and healthy community children (n = 89) at admission and 3 and 6 months later. RESULTS. Six months after discharge, 21.4% of children with cerebral malaria had cognitive deficits, compared with 5.8% of community children. Deficits were seen in the areas of working memory (11.9% vs 2.3%) and attention (16.7% vs 2.3%). Children with cerebral malaria had a 3.7-fold increased risk of a cognitive deficit, compared with community children, after adjustment for age, gender, nutritional status, school level, and home environment. Among children with cerebral malaria, those with a cognitive deficit had more seizures before admission (mean: 4.1 vs 2.2) and a longer duration of coma (43.6 vs 30.5 hours), compared with those without a deficit. Children with uncomplicated malaria did not have an increased frequency of cognitive deficits. CONCLUSIONS. Cerebral malaria may be a major cause of cognitive impairment in children in sub-Saharan Africa. Cognitive deficits in children with cerebral malaria are more likely for those who have multiple seizures before effective treatment for cerebral malaria.

Comparison of Buccal Midazolam With Rectal Diazepam in the Treatment of Prolonged Seizures in Ugandan Children: A Randomized Clinical Trial

OBJECTIVE. Our goal was to compare the efficacy and safety of buccal midazolam with rectal diazepam in the treatment of prolonged seizures in Ugandan children. METHODS. This was a single-blind, randomized clinical trial in which 330 patients were randomly assigned to receive buccal midazolam or rectal diazepam. The trial was conducted in the pediatric emergency unit of the national referral hospital of Uganda. Consecutive patients who were aged 3 months to 12 years and presented while convulsing or who experienced a seizure that lasted >5 minutes were randomly assigned to receive buccal midazolam plus rectal placebo or rectal diazepam plus buccal placebo. The primary outcome of this study was cessation of visible seizure activity within 10 minutes without recurrence in the subsequent hour. RESULTS. Treatment failures occurred in 71 (43.0%) of 165 patients who received rectal diazepam compared with 50 (30.3%) of 165 patients who received buccal midazolam. Malaria was the most common underlying diagnosis (67.3%), although the risk for failure of treatment for malaria-related seizures was similar: 35.8% for rectal diazepam compared with 31.8% for buccal midazolam. For children without malaria, buccal midazolam was superior (55.9% vs 26.5%). Respiratory depression occurred uncommonly in both of the treatment arms. CONCLUSION. Buccal midazolam was as safe as and more effective than rectal diazepam for the treatment of seizures in Ugandan children, although benefits were limited to children without malaria.

Low Levels of RANTES Are Associated with Mortality in Children with Cerebral Malaria

BACKGROUND In children with cerebral malaria (CM), serum chemokine levels and associated morbidity and mortality have not been characterized. METHODS Serum levels of the cytokines interleukin (IL)-1 beta , IL-6, IL-10, interferon (IFN)-gamma, and tumor necrosis factor-alpha and the chemokines macrophage inflammatory protein (MIP)-1 alpha, MIP-1 beta, and regulated upon activation, normal T cell expressed and secreted (RANTES) were measured in Ugandan children with CM, in children with uncomplicated malaria (UM), and in healthy children from the community, as control subjects (CCs). RESULTS Children with CM had lower levels of RANTES and higher levels of all other cytokines and chemokines than CCs (all P<.0001), and they had lower levels of RANTES (P=.004) and higher levels of IL-10 (P=.003), IFN-gamma (P=.007), and IL-1 beta (P=.05) than children with UM. Children with CM who died had lower levels of RANTES (P=.006) and higher of levels of IL-6 (P=.006), IL-10 (P=.01), IFN-gamma (P=.03), and MIP-1 beta (P=.008) than children who survived. After adjustment for other cytokine and chemokine levels, only low levels of RANTES were independently associated with mortality (P=.016). Levels of RANTES correlated with platelet count but were associated with mortality independently of platelet count. CONCLUSIONS The serum cytokine and chemokine profile of children who die of CM is similar to that of individuals who die of sepsis. Levels of RANTES are significantly lower in children with CM, and very low levels of RANTES are associated with mortality, independently of other cytokine and chemokine levels.

Severe neurological sequelae and behaviour problems after cerebral malaria in Ugandan children

BackgroundCerebral malaria is the most severe neurological complication of falciparum malaria and a leading cause of death and neuro-disability in sub-Saharan Africa. This study aimed to describe functional deficits and behaviour problems in children who survived cerebral malaria with severe neurological sequelae and identify patterns of brain injury.FindingsRecords of children attending a specialist child neurology clinic in Uganda with severe neurological sequelae following cerebral malaria between January 2007 and December 2008 were examined to describe deficits in gross motor function, speech, vision and hearing, behaviour problems or epilepsy. Deficits were classified according to the time of development and whether their distribution suggested a focal or generalized injury. Any resolution during the observation period was also documented.Thirty children with probable exposure to cerebral malaria attended the clinic. Referral information was inadequate to exclude other diagnoses in 7 children and these were excluded. In the remaining 23 patients, the commonest severe deficits were spastic motor weakness (14), loss of speech (14), hearing deficit (9), behaviour problems (11), epilepsy (12), blindness (12) and severe cognitive impairment (9). Behaviour problems included hyperactivity, impulsiveness and inattentiveness as in attention deficit hyperactivity disorder (ADHD) and conduct disorders with aggressive, self injurious or destructive behaviour. Two patterns were observed; a) immediate onset deficits present on discharge and b) late onset deficits. Some deficits e.g. blindness, resolved within 6 months while others e.g. speech, showed little improvement over the 6-months follow-up.ConclusionsIn addition to previously described neurological and cognitive sequelae, severe behaviour problems may follow cerebral malaria in children. The observed differences in patterns of sequelae may be due to different pathogenic mechanisms, brain regions affected or extent of injury. Cerebral malaria may be used as a new model to study the pathogenesis of ADHD.

Socioeconomic Predictors of Cognition in Ugandan Children: Implications for Community Interventions

Background Several interventions to improve cognition in at risk children have been suggested. Identification of key variables predicting cognition is necessary to guide these interventions. This study was conducted to identify these variables in Ugandan children and guide such interventions. Methods A cohort of 89 healthy children (45 females) aged 5 to 12 years old were followed over 24 months and had cognitive tests measuring visual spatial processing, memory, attention and spatial learning administered at baseline, 6 months and 24 months. Nutritional status, childs educational level, maternal education, socioeconomic status and quality of the home environment were also measured at baseline. A multivariate, longitudinal model was then used to identify predictors of cognition over the 24 months. Results A higher childs education level was associated with better memory (p = 0.03), attention (p = 0.005) and spatial learning scores over the 24 months (p = 0.05); higher nutrition scores predicted better visual spatial processing (p = 0.002) and spatial learning scores (p = 0.008); and a higher home environment score predicted a better memory score (p = 0.03). Conclusion Cognition in Ugandan children is predicted by childs education, nutritional status and the home environment. Community interventions to improve cognition may be effective if they target multiple socioeconomic variables.

Rectal artemether versus intravenous quinine for the treatment of cerebral malaria in children in Uganda: randomised clinical trial.

Abstract Objective To compare the efficacy and safety of rectal artemether with intravenous quinine in the treatment of cerebral malaria in children. Design Randomised, single blind, clinical trial. Setting Acute care unit at Mulago Hospital, Ugandas national referral and teaching hospital in Kampala. Participants 103 children aged 6 months to 5 years with cerebral malaria. Intervention Patients were randomised to either intravenous quinine or rectal artemether for seven days. Main outcome measures Time to clearance of parasites and fever; time to regaining consciousness, starting oral intake, and sitting unaided; and adverse effects. Results The difference in parasitological and clinical outcomes between rectal artemether and intravenous quinine did not reach significance (parasite clearance time 54.2 (SD 33.6) hours v 55.0 (SD 24.3) hours, P = 0.90; fever clearance time 33.2 (SD 21.9) hours v 24.1(SD 18.9 hours, P = 0.08; time to regaining consciousness 30.1 (SD 24.1) hours v 22.67 (SD 18.5) hours, P = 0.10; time to starting oral intake 37.9 (SD 27.0) hours v 30.3 (SD 21.1) hours, P = 0.14). Mortality was higher in the quinine group than in the artemether group (10/52 v 6/51; relative risk 1.29, 95% confidence interval 0.84 to 2.01). No serious immediate adverse effects occurred. Conclusion Rectal artemether is effective and well tolerated and could be used as treatment for cerebral malaria.

Genetic diversity of Plasmodium falciparum infections in mild and severe malaria of children from Kampala, Uganda

Diversity in parasite virulence is one of the factors that contribute to the clinical outcome of malaria infections. The association between the severity of Plasmodium falciparum malaria and the number of distinct parasite populations infecting the host (multiplicity of infection) or polymorphism within any of the specific antigen genes was investigated. The study included 164 children presenting with mild and severe malaria from central Uganda where malaria is meso-endemic. The polymorphic regions of the circumsporozoite protein (csp), merozoite surface proteins 1 and 2 (msp1 and msp2), and glutamate-rich protein (glurp) were genotyped by polymerase chain reaction methods and fragment analysis by gel electrophoresis. In a subset of samples fragment analysis was also performed by fluorescent PCR genotyping followed by capillary electrophoresis. The multiplicity of infection (MOI), determined as the highest number of alleles detected within any of the four genetic loci, was significantly higher in severe than in mild malaria cases (mean 3.7 and 3.0, respectively, P = 0.002). No particular genotype or allelic family of msp1 or msp2 was associated with severity of malaria, and nor did the genotyping method reveal any significant difference in MOI when only assessed by msp2 genotyping. Severity of malaria was not linked to the predominance of any particular msp1 or msp2 allelic types, independent of methods used for genotyping. Monitoring the dynamics of multiple clone infections in relation to disease outcome, host immune status and genetic factors will provide more insight into parasite virulence mechanisms.

Mannitol as adjunct therapy for childhood cerebral malaria in Uganda: A randomized clinical trial

BackgroundSeveral reports have suggested that raised intracranial pressure (ICP) is a major contributor to death among children with cerebral malaria. Mannitol, an osmotic diuretic, effectively lowers ICP and is used to treat post-traumatic raised ICP. It is not clear whether intravenous mannitol given to children with cerebral malaria improves clinical outcome. The objective of this study was to determine the effect of mannitol as adjunct therapy on the clinical outcome of children with cerebral malaria.MethodsThis randomized double-blind placebo controlled clinical trial was carried out at the Emergency Paediatric ward of Mulago Hospital, Ugandas national referral and teaching hospital. One hundred and fifty six children aged 6 to 60 months with cerebral malaria were randomized to either one dose of mannitol 1 g/kg or placebo, in addition to intravenous quinine. Main outcome measures included coma recovery time; time to sit unsupported, begin oral intake; duration of hospitalization; death and adverse effects.ResultsTime to regain consciousness (p = 0.11), sit unsupported (p = 0.81), time to start oral intake (p = 0.13) and total coma duration (p = 0.07) were similar in both groups. There was no significant difference in the mortality between the placebo (13/80 or 16.3%) and mannitol (10/76 or 13.2%) groups: RR = 1.2 (CI 0.5–2.7). No adverse effects were observed after administration of mannitol.ConclusionMannitol had no significant impact on clinical outcome of cerebral malaria. It is difficult to recommend intravenous mannitol as adjunct therapy for childhood cerebral malaria.Clinical registration numberClinicalTrials.gov ID: NCT00113854

var gene transcription dynamics in Plasmodium falciparum patient isolates

A major feature of Plasmodium falciparum parasitized red blood cells (pRBC) is their capacity to sequester in the microcirculation. The binding is mediated by PfEMP1 (P. falciparum erythrocyte membrane protein 1), a variable protein encoded by the var gene family. P. falciparum avoids the host antibody response generated against previously used variants by switching the expression of PfEMP1, which may affect the disease outcome. We have here studied var gene transcription over time within the life cycle of the parasite by semi-quantitative PCR and sequencing by employing three sets of degenerate primers to the 5-prime end of the var genes (corresponding to the DBL1alpha-domain). To accurately determine transcript levels, subsequent in-depth analysis was made by amplifying the 10 most frequently expressed var sequences identified in each developmental stage by quantitative PCR (Q-PCR). The maximum peak in var gene transcription seems to vary in time among parasites. In five out of seven parasites, var gene transcription was found to be higher or equal at 22-26h post-invasion compared to 4-10h post-invasion. Our data indicate that the intra-isolate var gene transcription dominance order may change between different developmental stages. The transcription of var genes in field isolates is more complex than in laboratory strains and often changes after in vitro adaption of the parasite. By using semi-quantitative PCR employing degenerate primers combined with quantitative-PCR using specific primers it is possible to monitor var gene transcription in detail during the life cycle of the parasite. The work presented here suggests that trophozoite pRBC is likely to be the optimal source of RNA for predicting the translated var gene species.