Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Robert O. Opoka is active.

Publication


Featured researches published by Robert O. Opoka.


The New England Journal of Medicine | 2011

Mortality after Fluid Bolus in African Children with Severe Infection

Kathryn Maitland; Sarah Kiguli; Robert O. Opoka; Charles Engoru; Peter Olupot-Olupot; Samuel Akech; Richard Nyeko; George Mtove; Hugh Reyburn; Trudie Lang; Bernadette Brent; Jennifer Evans; James K. Tibenderana; Jane Crawley; Elizabeth C. Russell; Michael Levin; Abdel Babiker; Diana M. Gibb

BACKGROUND The role of fluid resuscitation in the treatment of children with shock and life-threatening infections who live in resource-limited settings is not established. METHODS We randomly assigned children with severe febrile illness and impaired perfusion to receive boluses of 20 to 40 ml of 5% albumin solution (albumin-bolus group) or 0.9% saline solution (saline-bolus group) per kilogram of body weight or no bolus (control group) at the time of admission to a hospital in Uganda, Kenya, or Tanzania (stratum A); children with severe hypotension were randomly assigned to one of the bolus groups only (stratum B). All children received appropriate antimicrobial treatment, intravenous maintenance fluids, and supportive care, according to guidelines. Children with malnutrition or gastroenteritis were excluded. The primary end point was 48-hour mortality; secondary end points included pulmonary edema, increased intracranial pressure, and mortality or neurologic sequelae at 4 weeks. RESULTS The data and safety monitoring committee recommended halting recruitment after 3141 of the projected 3600 children in stratum A were enrolled. Malaria status (57% overall) and clinical severity were similar across groups. The 48-hour mortality was 10.6% (111 of 1050 children), 10.5% (110 of 1047 children), and 7.3% (76 of 1044 children) in the albumin-bolus, saline-bolus, and control groups, respectively (relative risk for saline bolus vs. control, 1.44; 95% confidence interval [CI], 1.09 to 1.90; P=0.01; relative risk for albumin bolus vs. saline bolus, 1.01; 95% CI, 0.78 to 1.29; P=0.96; and relative risk for any bolus vs. control, 1.45; 95% CI, 1.13 to 1.86; P=0.003). The 4-week mortality was 12.2%, 12.0%, and 8.7% in the three groups, respectively (P=0.004 for the comparison of bolus with control). Neurologic sequelae occurred in 2.2%, 1.9%, and 2.0% of the children in the respective groups (P=0.92), and pulmonary edema or increased intracranial pressure occurred in 2.6%, 2.2%, and 1.7% (P=0.17), respectively. In stratum B, 69% of the children (9 of 13) in the albumin-bolus group and 56% (9 of 16) in the saline-bolus group died (P=0.45). The results were consistent across centers and across subgroups according to the severity of shock and status with respect to malaria, coma, sepsis, acidosis, and severe anemia. CONCLUSIONS Fluid boluses significantly increased 48-hour mortality in critically ill children with impaired perfusion in these resource-limited settings in Africa. (Funded by the Medical Research Council, United Kingdom; FEAST Current Controlled Trials number, ISRCTN69856593.).


Pediatrics | 2008

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

Chandy C. John; Paul Bangirana; Justus Byarugaba; Robert O. Opoka; Richard Idro; Anne M. Jurek; Baolin Wu; Michael J. Boivin

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.


Pediatrics | 2007

Cognitive Impairment After Cerebral Malaria in Children: A Prospective Study

Michael J. Boivin; Paul Bangirana; Justus Byarugaba; Robert O. Opoka; Richard Idro; Anne M. Jurek; Chandy C. John

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.


Expert Review of Anti-infective Therapy | 2010

Adjunctive therapy for cerebral malaria and other severe forms of Plasmodium falciparum malaria

Chandy C. John; Elizabeth Kutamba; Keith Mugarura; Robert O. Opoka

Severe malaria due to Plasmodium falciparum causes more than 800,000 deaths every year. Primary therapy with quinine or artesunate is generally effective in controlling P. falciparum parasitemia, but mortality from cerebral malaria and other forms of severe malaria remains unacceptably high. Long-term cognitive impairment is also common in children with cerebral malaria. Of the numerous adjunctive therapies for cerebral malaria and severe malaria studied over the past five decades, only one (albumin) was associated with a reduction in mortality. In this article, we review past and ongoing studies of adjunctive therapy, and examine the evidence of efficacy for newer therapies, including inhibitors of cytoadherence (e.g., levamisole), immune modulators (e.g., rosiglitazone), agents that increase nitric oxide levels (e.g., arginine) and neuroprotective agents (e.g., erythropoietin).


JAMA | 2015

Effect of Transfusion of Red Blood Cells With Longer vs Shorter Storage Duration on Elevated Blood Lactate Levels in Children With Severe Anemia: The TOTAL Randomized Clinical Trial

Aggrey Dhabangi; Brenda Ainomugisha; Henry Ddungu; Dorothy Kyeyune; Ezra Musisi; Robert O. Opoka; Christopher P. Stowell; Walter H. Dzik

IMPORTANCE Although millions of transfusions are given annually worldwide, the effect of red blood cell (RBC) unit storage duration on oxygen delivery is uncertain. OBJECTIVE To determine if longer-storage RBC units are not inferior to shorter-storage RBC units for tissue oxygenation as measured by reduction in blood lactate levels and improvement in cerebral tissue oxygen saturation among children with severe anemia. DESIGN, SETTING, AND PARTICIPANTS Randomized noninferiority trial of 290 children (aged 6-60 months), most with malaria or sickle cell disease, presenting February 2013 through May 2015 to a university-affiliated national referral hospital in Kampala, Uganda, with a hemoglobin level of 5 g/dL or lower and a lactate level of 5 mmol/L or higher. INTERVENTIONS Patients were randomly assigned to receive RBC units stored 25 to 35 days (longer-storage group; n = 145) vs 1 to 10 days (shorter-storage group; n = 145). All units were leukoreduced prior to storage. All patients received 10 mL/kg of RBCs during hours 0 through 2 and, if indicated per protocol, an additional 10 mL/kg during hours 4 through 6. MAIN OUTCOMES AND MEASURES The primary outcome was the proportion of patients with a lactate level of 3 mmol/L or lower at 8 hours using a margin of noninferiority equal to an absolute difference of 25%. Secondary measures included noninvasive cerebral tissue oxygen saturation during the first transfusion, clinical and laboratory changes up to 24 hours, and survival and health at 30 days after transfusion. Adverse events were monitored up to 24 hours. RESULTS In the total population of 290 children, the mean (SD) presenting hemoglobin level was 3.7 g/dL (1.3) and mean lactate level was 9.3 mmol/L (3.4). Median (interquartile range) RBC unit storage was 8 days (7-9) for shorter storage vs 32 days (30-34) for longer storage without overlap. The proportion achieving the primary end point was 0.61 (95% CI, 0.52 to 0.69) in the longer-storage group vs 0.58 (95% CI, 0.49 to 0.66) in the shorter-storage group (between-group difference, 0.03 [95% CI, -0.07 to ∞], P < .001), meeting the prespecified margin of noninferiority. Mean lactate levels were not statistically different between the 2 groups at 0, 2, 4, 6, 8, or 24 hours. Kaplan-Meier analysis and global nonlinear regression revealed no statistical difference in lactate reduction between the 2 groups. Clinical assessment, cerebral oxygen saturation, electrolyte abnormalities, adverse events, survival, and 30-day recovery were also not significantly different between the groups. CONCLUSIONS AND RELEVANCE Among children with lactic acidosis due to severe anemia, transfusion of longer-storage compared with shorter-storage RBC units did not result in inferior reduction of elevated blood lactate levels. These findings have relevance regarding the efficacy of stored RBC transfusion for patients with critical tissue hypoxia and lactic acidosis due to anemia. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01586923.


Neuropsychology (journal) | 2010

A Pilot Study of the Neuropsychological Benefits of Computerized Cognitive Rehabilitation in Ugandan Children With HIV

Michael J. Boivin; Rachelle A. Busman; Sujal M. Parikh; Paul Bangirana; Connie Page; Robert O. Opoka; Bruno Giordani

OBJECTIVE Because antiretroviral treatment (ART) fails to improve neurocognitive impairment in children with HIV, we completed a pilot study evaluating the feasibility and cognitive benefit of computerized cognitive rehabilitation therapy (CCRT) in Ugandan children with HIV. METHOD Sixty Ugandan children with HIV (23 on ART) were randomly assigned to 10 sessions of Captains Log CCRT (Sandford, 2007) training configured for attention and memory skills or no intervention. Kaufman Assessment Battery for Children (2nd ed., KABC-2; Kaufman & Kaufman, 2004) performance at baseline indicated pervasive neurocognitive impairment. Cognitive ability was assessed before and after training using the Cogstate computerized neuropsychological test (Darby, Maruff, Collie, & McStephen, 2002). Viral load along with CD4 and CD8 absolute and activation levels also were measured posttest. RESULTS CCRT was well received with a 95% adherence rate to scheduled training sessions. CCRT intervention children showed greater improvement on a Cogstate card detection task of simple attention (p = .02), and speed of correct moves on a Groton Maze Learning Task (p < .001). These analyses were completed using an analysis of covariance model that adjusted Cogstate performance for the childs age, standardized weight for age, gender, socioeconomic status, school grade level, and baseline KABC-2 performance. ART treatment was not related to Cogstate performance or improvement as a result of CCRT. CD4 and CD8 activation levels were correlated with Cogstate improvement specifically for the CCRT group. CONCLUSIONS CCRT was feasible with our study population and improved maze learning and attention on a detection task. This supports previous findings by our group with cerebral malaria survivors (Bangirana, Giordani, et al., 2009).


Journal of Developmental and Behavioral Pediatrics | 2009

Immediate neuropsychological and behavioral benefits of computerized cognitive rehabilitation in Ugandan pediatric cerebral malaria survivors.

Paul Bangirana; Bruno Giordani; Chandy C. John; Connie Page; Robert O. Opoka; Michael J. Boivin

Objective: Our earlier studies on Ugandan children surviving cerebral malaria showed cognitive deficits mainly in attention and memory. We now present the first study in sub-Saharan Africa to investigate the feasibility and potential benefits of computerized cognitive rehabilitation training on neuropsychological and behavioral functioning of children surviving cerebral malaria. Methods: A randomized trial in which 65 children admitted 45 months earlier with cerebral malaria were recruited at Mulago Hospital, Kampala, Uganda. For 8 weeks, 32 of the children received weekly training sessions using Captains Log cognitive training software and the other 33 were assigned to a nontreatment condition. Pre- and postintervention assessments were completed using CogState, a computerized neuropsychological battery, measuring visuomotor processing speed, working memory, learning, attention and psychomotor speed and the Child Behavior Checklist measuring internalizing problems, externalizing problems, and total problems. Results: Preintervention scores were similar between both groups. Treatment effects were observed on visuospatial processing speed [group effect (standard error) 0.14 (0.03); p < .001], on a working memory and learning task [0.08 (0.02); p < .001], psychomotor speed [0.14 (0.07); p = .04], and on internalizing problems [−3.80 (1.56); p = .02] after controlling for age, sex, school grade, quality of the home environment, and weight for age z scores. Similar treatment effects were observed when no adjustments for the above covariates were made. Conclusions: Computerized cognitive training long after the cerebral malaria episode has immediate benefit on some neuropsychological and behavioral functions in African children. The long-term benefit of this intervention needs to be investigated.


PLOS ONE | 2009

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

Paul Bangirana; Chandy C. John; Richard Idro; Robert O. Opoka; Justus Byarugaba; Anne M. Jurek; Michael J. Boivin

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.


American Journal of Tropical Medicine and Hygiene | 2010

TLR9 Polymorphisms Are Associated with Altered IFN-γ Levels in Children with Cerebral Malaria

Nadia A. Sam-Agudu; Jennifer A. Greene; Robert O. Opoka; James W. Kazura; Michael J. Boivin; Peter A. Zimmerman; Melissa A. Riedesel; Tracy L. Bergemann; Lisa A. Schimmenti; Chandy C. John

Toll-like receptor (TLR) polymorphisms have been associated with disease severity in malaria infection, but mechanisms for this association have not been characterized. The TLR2, 4, and 9 single nucleotide polymorphism (SNP) frequencies and serum interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) levels were assessed in Ugandan children with cerebral malaria (CM, N = 65) and uncomplicated malaria (UM, N = 52). The TLR9 C allele at -1237 and G allele at 1174 were strongly linked, and among children with CM, those with the C allele at -1237 or the G allele at 1174 had higher levels of IFN-gamma than those without these alleles (P = 0.03 and 0.008, respectively). The TLR9 SNPs were not associated with altered IFN-gamma levels in children with UM or altered TNF-alpha levels in either group. We present the first human data that TLR SNPs are associated with altered cytokine production in parasitic infection.


The Journal of Pediatrics | 2013

A year-long caregiver training program improves cognition in preschool Ugandan children with human immunodeficiency virus.

Michael J. Boivin; Paul Bangirana; Noeline Nakasujja; Connie Page; Cilly Shohet; Deborah Givon; Judith Bass; Robert O. Opoka; Pnina S. Klein

OBJECTIVE To evaluate mediational intervention for sensitizing caregivers (MISC). MISC biweekly caregiver training significantly enhanced child development compared with biweekly training on health and nutrition (active control) and to evaluate whether MISC training improved the emotional well-being of the caregivers compared with controls. STUDY DESIGN Sixty of 120 rural Ugandan preschool child/caregiver dyads with HIV were assigned by randomized clusters to biweekly MISC training, alternating between home and clinic for 1 year. Control dyads received a health and nutrition curriculum. Children were evaluated at baseline, 6 months, and 1 year with the Mullen Early Learning Scales and the Color-Object Association Test for memory. Caldwell Home Observation for Measurement of the Environment and videotaped child/caregiver MISC interactions also were evaluated. Caregivers were evaluated for depression and anxiety with the Hopkins Symptoms Checklist. RESULTS Between-group repeated-measures ANCOVA comparisons were made with age, sex, CD4 levels, viral load, material socioeconomic status, physical development, and highly active anti-retroviral therapy treatment status as covariates. The children given MISC had significantly greater gains compared with controls on the Mullen Visual Reception scale (visual-spatial memory) and on Color-Object Association Test memory. MISC caregivers significantly improved on Caldwell Home Observation for Measurement of the Environment scale and total frequency of MISC videotaped interactions. MISC caregivers also were less depressed. Mortality was less for children given MISC compared with controls during the training year. CONCLUSIONS MISC was effective in teaching Ugandan caregivers to enhance their childrens cognitive development through practical and sustainable techniques applied during daily interactions in the home.

Collaboration


Dive into the Robert O. Opoka's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge