Robert O Opoka

Makerere University · Department of Paediatrics and Child Health

This study assesses artemisinin partial resistance, Pfkelch13 variations, and malaria recrudescence in Ugandan children with complicated malaria.

Background Children with severe malarial anemia (SMA) typically have low in-hospital mortality but have a high risk of post-discharge readmission or death. We hypothesized that the dysregulation of hematopoiesis, vascular growth factors, and endothelial function that occurs in SMA might affect risk of readmission or death. Methods Plasma was obtai...

Co-infection by intestinal helminths and Plasmodium spp. may be common in endemic communities. Several studies have identified a relationship between helminth infection, Plasmodium spp. infection and malaria severity. However, the relationship is not well defined, and results are inconclusive. We analyzed 202 stool samples from a cohort of children...

Background Pneumonia remains the leading cause of mortality among children under 5 years. Poor nutritional status increases pneumonia mortality. Nutritional status assessed by anthropometry alone does not provide information on which body composition element predicts survival. Body composition proxy measures including arm-fat-area (AFA), arm-muscle...

Objectives Continuous, noninvasive tools to monitor peripheral perfusion, such as perfusion index (PI), can detect hemodynamic abnormalities and assist in the management of critically ill children hospitalized with severe malaria. In this study of hospitalized children with severe malaria, we aimed to assess whether PI correlates with clinical mark...

Introduction: Few studies have described post-discharge morbidity of children with specific manifestations of severe malaria (SM) beyond severe malarial anemia or cerebral malaria. Methods: Children 6 months to 4 years of age admitted at Jinja and Mulago hospitals in Uganda, with one or more of the five most common manifestations of SM, cerebral ma...

Background Recently, there has been an unexplained increase in the incidence of blackwater fever (BWF) in Eastern Uganda. In this study, we evaluate the association between immune complexes, glucose-6-phosphate dehydrogenase (G6PD) deficiency, and the occurrence and recurrence of BWF in children with severe malaria (SM). Methods Between 2014 and 2...

Background Sub-Saharan Africa bears the highest burden of sickle cell disease (SCD) globally with Nigeria, Democratic Republic of Congo, Tanzania, Uganda being the most affected countries. Uganda reports approximately 20,000 SCD births annually, constituting 6.67% of reported global SCD births. Despite this, there is a paucity of comprehensive data...

Background Current prognostic tools do not reliably and objectively identify children with pneumonia at risk of a severe or life-threatening episode. Heparin-binding protein (HBP) is a host immune protein that is released in response to infection. We hypothesized that measuring HBP concentrations at hospital admission could help risk-stratify child...

Objective: Academic achievement in school-age children is crucial for advancing learning goals. Children with sickle cell anaemia (SCA) in Sub-Saharan Africa may be at risk of disease-associated school difficulties. Limited data exist on the academic achievement of children with SCA in the region. This study aimed to assess academic achievement of...

Introduction: People with sickle cell anemia (SCA) may require frequent blood transfusions to treat acute and chronic complications. Hydroxyurea is a life-saving treatment for SCA that could also decrease the need for blood transfusions. Inadequate medication access and challenges in dose optimization limit the widespread use of hydroxyurea in Afr...

Background Severe pneumonia in African children results in poor long-term outcomes (deaths/readmissions) with undernutrition as a key risk factor. We hypothesised additional energy/protein-rich Ready-to-Use Therapeutic Foods (RUTF) would meet additional nutritional requirements and improve outcomes. Methods COAST-Nutrition was an open-label Phase...

Introduction The neurocognitive functions in Ugandan children aged 1–12 years with sickle cell anemia (SCA) were compared to their non-SCA siblings to identify risk factors for disease-associated impairment. Methods This cross-sectional study of the neurocognitive functions in children with SCA ( N = 242) and non-SCA siblings ( N = 127) used age-...

After starting hydroxyurea treatment, Ugandan children with sickle cell anemia had 60% less severe or invasive infections, including malaria, bacteremia, respiratory tract infections and gastroenteritis, than before starting hydroxyurea treatment (incidence rate ratio =0.40 [95% confidence interval], 0.29-0.54, P<0.001).

Background Severe anaemia is associated with high in-hospital mortality among young children. In malaria-endemic areas, surviving children also have an increased risk of mortality or readmission after hospital discharge. We conducted a systematic review and individual patient data meta-analysis to determine the efficacy of monthly post-discharge ma...

Background Malaria is an important cause of mortality in African children. Identification of biomarkers to identify children at risk of mortality has the potential to improve outcomes. Methods We evaluated 11 biomarkers of host response in 592 children with severe malaria. The primary outcome was biomarker performance for predicting mortality. Bio...

Introduction Children with sickle cell anemia (SCA) experience severe illness and risk of malnutrition in sub-Saharan Africa. Treatment with hydroxyurea (HU) decreases SCA complications. In high-income regions, hydroxyurea also improves pediatric growth and overall quality of life. We assessed the effects of hydroxyurea on growth and body compositi...

Background. Few large prospective studies have evaluated burden and outcomes of malaria in children with sickle cell anaemia (SCA) in malaria endemic countries. We evaluated the incidence, complications and outcome of malaria in three cohorts of Ugandan children with SCA in three areas with differing malaria transmission. Methods. Cohort 1 were SCA...

Introduction: Cerebrovascular injury can lead to neurocognitive impairment in children with sickle cell anemia (SCA). The prospective impact of hydroxyurea therapy on neurocognitive function has not been previously reported in a large sample of children with SCA in sub-Saharan Africa. We assessed the impact of hydroxyurea therapy at the trial's18-m...

Background: Children are the primary recipients of blood transfusions in sub-Saharan Africa where the demand for safe blood far exceeds the supply. Without disease-modifying therapy, sickle cell anemia (SCA) causes excess morbidity, mortality, and healthcare resource utilization, specifically requiring a high reliance on blood transfusions. Hydroxy...

Persistent neurodisability is a known complication in paediatric survivors of cerebral malaria and severe malarial anaemia. Tau, ubiquitin C-terminal hydrolase-L1, neurofilament-light chain, and glial fibrillary acidic protein have proven utility as biomarkers that predict adverse neurologic outcomes in adult and paediatric disorders. In paediatric...

Background: The relationship of apolipoprotein-E4 (APOE4) to mortality and cognition after severe malaria in children is unknown. Methods: APOE genotyping was performed in children with cerebral malaria (CM, n = 261), severe malarial anemia (SMA, n = 224) and community children (CC, n = 213). Cognition was assessed over 2-year follow-up. Result...

Objectives: To compare neurocognitive function between children with sickle cell anemia (SCA) and their non-SCA siblings and determine risk factors for poor neurocognition in Uganda. Study Design: This cross-sectional study assessed children with SCA and their non-SCA siblings for neurocognitive and executive function at a childrens SCA clinic in K...

Severe anemia is an important contributor to mortality in children with severe malaria. Anemia in malaria is a multi-factorial complication, since dyserythropoiesis, hemolysis and phagocytic clearance of uninfected red blood cells (RBCs) can contribute to this syndrome. High levels of oxidative stress and immune dysregulation have been proposed to...

Cerebrovascular injury frequently occurs in children with sickle cell anaemia (SCA). Limited access to magnetic resonance imaging and angiography (MRI‐MRA) in sub‐Saharan Africa impedes detection of clinically unapparent cerebrovascular injury. Blood‐based brain biomarkers of cerebral infarcts have been identified in non‐SCA adults. Using plasma sa...

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

Background and objective: The disease burden of sickle cell anemia (SCA) in sub-Saharan African (SSA) countries is substantial, with many children dying without an established diagnosis or proper treatment. The global burden of SCA is increasing each year, making therapeutic intervention a high priority. Hydroxyurea is the only disease-modifying t...

Introduction: Children who are HIV-exposed but uninfected (CHEU) are at risk of linear growth faltering and neurodevelopmental delay. Circulating biomarkers associated with these adverse outcomes may elucidate pathways of injury. Objective: To identify biomarkers associated with growth faltering and neurodevelopmental delay in CHEU. Methods: W...

Introduction Cerebral malaria is one of the most severe manifestations of malaria and is a leading cause of acquired neurodisability in African children. Recent studies suggest acute kidney injury (AKI) is a risk factor for brain injury in cerebral malaria. The present study evaluates potential mechanisms of brain injury in cerebral malaria by eval...

Background: An estimated 300,000 babies are born with sickle cell anaemia (SCA) annually. Affected children have chronic ill health and suffer premature death. Febrile illnesses such as malaria commonly precipitate acute crises in children with SCA. Thus, chemoprophylaxis for malaria is an important preventive strategy, but current regimes are eit...

Respiratory distress (RD) in pediatric malaria portends a grave prognosis. Lactic acidosis is a biomarker of severe disease. We investigated whether lactate, measured at admission using a handheld device among children hospitalized with malaria and RD, was predictive of subsequent mortality. We performed a pooled analysis of Ugandan children under...

Data from small clinical trials in the USA and India suggest zinc supplementation reduces infection in adolescents and adults with sickle cell anemia (SCA), but no studies of zinc supplementation for infection prevention have been conducted in young children with SCA living in Africa, who have higher infection rates. We conducted a randomized doubl...

Children recovering from severe malarial anaemia (SMA) remain at high risk of readmission and death after discharge from hospital. However, a recent trial found that post-discharge malaria chemoprevention (PDMC) with dihydroartemisinin-piperaquine reduces this risk. We developed a mathematical model describing the daily incidence of uncomplicated a...

Diagnostic biomarkers for childhood pneumonia could guide management and improve antibiotic stewardship in low-resource settings where chest x-ray (CXR) is not always available. In this cross-sectional study, we measured chitinase 3-like protein 1 (CHI3L1), surfactant protein D (SP-D), lipocalin-2 (LCN2), and tissue inhibitor of metalloproteinases-...

Sex and gender are well-established determinants of health in adult and adolescent populations in low resource settings. There are limited data on sex as a determinant of host response to disease and clinical outcome in febrile children in sub-Saharan Africa, where the risk of infection-related mortality is greatest. We examined sex differences and...

Background Medical schools in Sub-Saharan Africa have adopted competency based medical education (CBME) to improve the quality of graduates trained. In 2015, Makerere University College of Health Sciences (MaKCHS) implemented CBME for the Bachelor of Medicine and Bachelor of Surgery (MBChB) programme in order to produce doctors with the required at...

Background Malaria in pregnancy has been associated with worse cognitive outcomes in children, but its association with behavioral outcomes and the effectiveness of malaria chemoprevention on child neurodevelopment are not well characterized. Methods To determine if more effective malaria chemoprevention in mothers and their children results in be...

Background Practice-based learning is crucial in forming appropriate strategies for improving learning among the medical students that support the country’s understaffed health sector. Unsatisfactory learning consequently results in poor performance of students and poor quality of health care workforce in the long run. Exploring the perceptions abo...

Background Children hospitalised with severe anaemia in malaria-endemic areas are at a high risk of dying or being readmitted within six months of discharge. A trial in Kenya and Uganda showed that three months of postdischarge malaria chemoprevention (PDMC) with monthly dihydroartemisinin-piperaquine (DP) substantially reduced this risk. The World...

Background: Global changes in amino acid levels have been described in severe malaria (SM) but the relationship between amino acids and long-term outcomes in SM have not been evaluated. Methods: We measured enrollment plasma concentrations of twenty amino acids using high-performance liquid chromatography in 500 Ugandan children aged 18 months t...

Severe malaria (SM) increases the risk of invasive bacterial infection, and there is evidence to suggest increased gastrointestinal permeability. Studies have shown sequestration of infected erythrocytes in intestinal microvasculature, and in vivo studies of rectal mucosa have demonstrated disruption of microvascular blood flow. However, the extent...

Background Severe malaria is associated with multiple organ dysfunction syndrome (MODS), which may involve the gastrointestinal tract. Methods In a prospective cohort study in Uganda, we measured markers of intestinal injury (intestinal fatty-acid binding protein, I-FABP, and zonula occludens-1, ZO-1), and microbial translocation (lipopolysacchari...

Severe malaria caused by Plasmodium falciparum is difficult to diagnose accurately in children in high-transmission settings. Using data from 2649 pediatric and adult patients enrolled in four studies of severe illness in three countries (Bangladesh, Kenya, and Uganda), we fitted Bayesian latent class models using two diagnostic markers: the platel...

Background Despite the global burden of pneumonia, reliable triage tools to identify children in low-resource settings at risk of severe and fatal respiratory tract infection are lacking. This study assessed the ability of circulating host markers of immune and endothelial activation quantified at presentation, relative to currently used clinical m...

Background: Acute kidney injury (AKI) and blackwater fever (BWF) are related but distinct renal complications of acute febrile illness in East Africa. The pathogenesis and prognostic significance of BWF and AKI are not well understood. Methods: A prospective observational cohort study was conducted to evaluate the association between BWF and AKI...

Background: Sickle cell anaemia (SCA) has historically been associated with high levels of childhood mortality in Africa. Although malaria has a major contribution to this mortality, to date, the clinical pathology of malaria among children with SCA has been poorly described. We aimed to explore the relationship between SCA and Plasmodium falcipar...

Background: Murine experimental cerebral malaria studies suggest both protective and deleterious central nervous system effects from alterations in the interleukin-33 (IL-33)/ST2 pathway. Methods: We assessed whether soluble ST2 (sST2) was associated with neuronal injury or cognitive impairment in a cohort of Ugandan children with cerebral malar...

Background: Current malaria diagnostic tests do not reliably identify children at risk of severe and fatal infection. Host immune and endothelial activation contribute to malaria pathogenesis. Soluble urokinase-type plasminogen activator receptor (suPAR) is a marker of these pathways. We hypothesized that measuring suPAR at presentation could risk...

Background: We hypothesized that oxidative stress in Ugandan children with severe malaria is associated with mortality. Methods: We evaluated biomarkers of oxidative stress in children with cerebral malaria (CM, n=77) or severe malarial anemia (SMA, n=79), who were enrolled in a randomized clinical trial of immediate vs. delayed iron therapy, comp...

Urine neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of acute kidney injury that has been adapted to a urine dipstick test. However, there is limited data on its use in low-and-middle-income countries where diagnosis of acute kidney injury remains a challenge. To study this, we prospectively enrolled 250 children with sickle cell...

Access to therapeutic oxygen in low-resource settings remains a significant global problem. Solar powered oxygen (SPO2) delivery is a reliable and cost-effective solution. We followed implementation research methodology to gather data on engineering parameters (remote monitoring), nurse training (before and after knowledge questionnaire), patients...

Background Medical schools in Sub-Saharan Africa have adopted competency based medical education (CBME) to improve the quality of graduates trained. In 2015, Makerere University College of Health Sciences (MaKCHS) implemented CBME for the Bachelor of Medicine and Bachelor of Surgery (MBChB) programme in order to produce doctors with the required at...

Acute kidney injury (AKI) is a life-threatening complication. Malaria and sepsis are leading causes of AKI in low-and-middle-income countries, but its etiology and pathogenesis are poorly understood. A prospective observational cohort study was conducted to evaluate pathways of immune and endothelial activation in children hospitalized with an acut...

Abstarct Objective Children with sickle cell anaemia (SCA) are highly susceptible to cerebrovascular injury. We performed brain magnetic resonance imaging and angiography (MRI-MRA) in Ugandan children with SCA to identify structural cerebrovascular abnormalities and examine their relationship to standardized clinical assessments. Methods A sub-sa...

Background Recognition of the burden of sickle cell anaemia (SCA) in sub-Saharan African (SSA) countries is increasing, with few therapies available for clinical management. Hydroxyurea is the only disease-modifying therapy that has proven feasible and clinically efficacious in low-income countries in SSA; however, the health economic implications...

Background Mortality in severe malaria remains high in children treated with intravenous artesunate. Acute kidney injury (AKI) is a common complication of severe malaria, but the interactions between AKI and other complications on the risk of mortality in severe malaria are not well characterized. Methods Between 2014 and 2017, 600 children aged 6...

Background: Children with sickle cell anemia (SCA) are at increased risk of acute kidney injury (AKI) that may lead to death or chronic kidney disease. This study evaluated AKI prevalence and risk factors in children with SCA hospitalized with a vaso-occlusive crisis (VOC) in a low-resource setting. Further, we evaluated whether modifications to t...

In a prospective cohort study of 77 children with severe pneumonia from two hospitals in Uganda, we assessed soluble T cell immunoglobulin and mucin-domain containing protein 3 (sTIM-3) levels at hospital admission and their association with pneumonia severity and subsequent mortality. sTIM-3 levels were positively correlated with the Respiratory I...

Background The TRACT trial established the timing of transfusion in children with uncomplicated anaemia (haemoglobin 4–6 g/dL) and the optimal volume (20 vs 30 mL/kg whole blood or 10 vs 15 mL/kg red cell concentrates) for transfusion in children admitted to hospital with severe anaemia (haemoglobin <6 g/dL) on day 28 mortality (primary endpoint)....

Sickle cell anemia (SCA) is common in sub‐Saharan Africa where approximately 1% of births are affected. Severe anemia is a common cause for hospital admission within the region yet few studies have investigated the contribution made by SCA. The Transfusion and Treatment of severe anemia in African Children Trial (ISRCTN84086586) investigated variou...

Pneumonia is the leading infectious cause of death in children, with especially high mortality in low- and middle-income countries. Interleukin-18 binding protein (IL-18BP) is a natural antagonist of the pro-inflammatory cytokine interleukin-18 and is elevated in numerous autoimmune conditions and infectious diseases. We conducted a prospective coh...

Background Globally, 85% of acute kidney injury (AKI) cases occur in low-and-middle-income countries. There is limited information on persistent kidney disease (acute kidney disease [AKD]) following severe malaria-associated AKI. Methods Between March 28, 2014, and April 18, 2017, 598 children with severe malaria and 118 community children were en...

Pediatric critical care has continued to advance since our last article, “ Pediatric Critical Care in Resource-Limited Settings—Overview and Lessons Learned” was written just 3 years ago. In that article, we reviewed the history, current state, and gaps in level of care between low- and middle-income countries (LMICs) and high-income countries (HIC...

Background Children discharged from hospital after recovery from severe malarial anaemia (SMA) are at high risk of readmission and death in subsequent months. Clinical trial results show that three months of post-discharge malaria chemoprevention (PMC) with dihydroartemisinin-piperaquine reduces this risk. Methods We developed a compartmental math...

Cerebral malaria (CM), coma caused by Plasmodium falciparum-infected red blood cells (iRBCs), is the deadliest complication of malaria. The mechanisms that lead to CM development are incompletely understood. Here we report on the identification of activation and inhibition pathways leading to mouse CM with supporting evidence from the analysis of h...

Importance Cerebral malaria (CM) and severe malarial anemia (SMA) are associated with persistent neurocognitive impairment (NCI) among children in Africa. Identifying blood biomarkers of acute brain injury that are associated with future NCI could allow early interventions to prevent or reduce NCI in survivors of severe malaria. Objective To inves...

Background:Severe malaria (SM) remains a major global health problem causing ~275,000 pediatric deaths annually, worldwide. Continuous, non-invasive monitoring of peripheral perfusion can help detect abnormalities in systemic circulation, a common problem in critically ill patients, and can improve outcomes in children hospitalized with SM. Perfusi...