Benno Kreuels

A Case of Severe Ebola Virus Infection Complicated by Gram-Negative Septicemia

Ebola virus disease (EVD) developed in a patient who contracted the disease in Sierra Leone and was airlifted to an isolation facility in Hamburg, Germany, for treatment. During the course of the illness, he had numerous complications, including septicemia, respiratory failure, and encephalopathy. Intensive supportive treatment consisting of high-volume fluid resuscitation (approximately 10 liters per day in the first 72 hours), broad-spectrum antibiotic therapy, and ventilatory support resulted in full recovery without the use of experimental therapies. Discharge was delayed owing to the detection of viral RNA in urine (day 30) and sweat (at the last assessment on day 40) by means of polymerase-chain-reaction (PCR) assay, but the last positive culture was identified in plasma on day 14 and in urine on day 26. This case shows the challenges in the management of EVD and suggests that even severe EVD can be treated effectively with routine intensive care.

Spatial Variation of Malaria Incidence in Young Children from a Geographically Homogeneous Area with High Endemicity

BACKGROUND In sub-Saharan Africa, malaria is a leading cause of morbidity and mortality among young children. Detailed knowledge of spatial variation of malaria epidemiology and associated risk factors is important for planning and evaluating malaria-control measures. METHODS The spatial variation of malaria incidences and socioeconomic factors were assessed over 21 months, from January 2003 to September 2005, in 535 children from 9 villages of a small rural area with high Plasmodium falciparum transmission in Ghana. Household positions were mapped by use of a global positioning system, and the spatial effects on malaria rates were assessed by means of ecological analyses and bivariate Poisson regression controlling for possible confounding factors. RESULTS Malaria incidence was surprisingly heterogeneous between villages, and ecological analyses showed strong correlations with village area (R(2) = 0.74; P = .003) and population size (R(2) = 0.68; P = .006). Malaria risk was affected by a number of socioeconomic factors. Poisson regression showed an independent linear rate reduction with increasing distance between childrens households and the fringe of the forest. CONCLUSIONS The exact location of households in villages is an independent and important factor for the variation of malaria incidence in children from high-transmission areas. This fact should be considered in the planning of intervention trials and in spatial targeting of malaria interventions at a local level.

A Randomized Controlled Trial of Extended Intermittent Preventive Antimalarial Treatment in Infants

BACKGROUND Intermittent preventive antimalarial treatment in infants (IPTi) with sulfadoxine-pyrimethamine reduces falciparum malaria and anemia but has not been evaluated in areas with intense perennial malaria transmission. It is unknown whether an additional treatment in the second year of life prolongs protection. METHODS A randomized, double-blinded, placebo-controlled trial with administration of sulfadoxine-pyrimethamine therapy at 3, 9, and 15 months of age was conducted with 1070 children in an area in Ghana where malaria is holoendemic. Participants were monitored for 21 months after recruitment through active follow-up visits and passive case detection. The primary end point was malaria incidence, and additional outcome measures were anemia, outpatient visits, hospital admissions, and mortality. Stratified analyses for 6-month periods after each treatment were performed. RESULTS Protective efficacy against malaria episodes was 20% (95% confidence interval [CI], 11%-29%). The frequency of malaria episodes was reduced after the first 2 sulfadoxine-pyrimethamine applications (protective efficacy, 23% [95% CI, 6%-36%] after the first dose and 17% [95% CI, 1%-30%] after the second dose). After the third treatment at month 15, however, no protection was achieved. Protection against the first or single anemia episode was only significant after the first IPTi dose (protective efficacy, 30%; 95% CI, 5%-49%). The number of anemia episodes increased after the last IPTi dose (protective efficacy, -24%; 95% CI, -50% to -2%). CONCLUSION In an area of intense perennial malaria transmission, sulfadoxine-pyrimethamine-based IPTi conferred considerably lower protection than reported in areas where the disease is moderately or seasonally endemic. Protective efficacy is age-dependent, and extension of IPTi into the second year of life does not provide any benefit.

Differing effects of HbS and HbC traits on uncomplicated falciparum malaria, anemia, and child growth.

The high prevalence of hemoglobin S (HbS) in Africa and hemoglobin C (HbC) in parts of West Africa is caused by the strong protection against severe falciparum malaria during childhood. Much less is known about the effect of HbS and especially HbC on Plasmodium falciparum infection, uncomplicated malaria, and anemia. A total of 1070 children from the Ashanti Region, Ghana, were enrolled at the age of 3 months and visited monthly until 2 years of age. The effects of the beta-globin genotype on the age-dependent incidence of malaria, levels of parasitemia, and hemoglobin as well as physical development were analyzed by population-averaged models. Infants with HbAS were protected from uncomplicated malaria (P < .005) and anemia (P < .001), had lower age-adjusted parasite densities (P < .001), and higher age-adjusted hemoglobin levels compared with children with the HbAA genotype (P = .004). In contrast, HbAC carriers had lower hemoglobin levels (P < .033) and were not protected against malaria or anemia. Notably, infants with HbAS were also significantly protected against stunting compared with carriers of HbAA or HbAC. This indicates differing mechanisms of protection against malaria of HbAS and HbAC and might help to understand why HbC is restricted to distinct areas of West Africa.

Unique human immune signature of Ebola virus disease in Guinea

Despite the magnitude of the Ebola virus disease (EVD) outbreak in West Africa, there is still a fundamental lack of knowledge about the pathophysiology of EVD. In particular, very little is known about human immune responses to Ebola virus. Here we evaluate the physiology of the human T cell immune response in EVD patients at the time of admission to the Ebola Treatment Center in Guinea, and longitudinally until discharge or death. Through the use of multiparametric flow cytometry established by the European Mobile Laboratory in the field, we identify an immune signature that is unique in EVD fatalities. Fatal EVD was characterized by a high percentage of CD4+ and CD8+ T cells expressing the inhibitory molecules CTLA-4 and PD-1, which correlated with elevated inflammatory markers and high virus load. Conversely, surviving individuals showed significantly lower expression of CTLA-4 and PD-1 as well as lower inflammation, despite comparable overall T cell activation. Concomitant with virus clearance, survivors mounted a robust Ebola-virus-specific T cell response. Our findings suggest that dysregulation of the T cell response is a key component of EVD pathophysiology.

A randomized trial on effectiveness of artemether-lumefantrine versus artesunate plus amodiaquine for unsupervised treatment of uncomplicated Plasmodium falciparum malaria in Ghanaian children

BackgroundNumerous trials have demonstrated high efficacy and safety of artemisinin-based combination therapy (ACT) under supervised treatment. In contrast, effectiveness studies comparing different types of ACT applied unsupervised are scarce. The aim of this study was to compare effectiveness, tolerability and acceptance of artesunate plus amodiaquine (ASAQ) against that of artemether-lumefantrine (AL) in Ghanaian children with uncomplicated Plasmodium falciparum malaria.MethodsA randomized open-label trial was conducted at two district hospitals in the Ashanti region, Ghana, an area of intense malaria transmission. A total of 246 children under five years of age were randomly assigned to either ASAQ (Arsucam®) or AL (Coartem®). Study participants received their first weight-adjusted dose under supervision. After the parent/guardian was advised of times and mode of administration the respective three-day treatment course was completed unobserved at home. Follow-up visits were performed on days 3, 7, 14 and 28 to evaluate clinical and parasitological outcomes, adverse events, and haematological recovery. Length polymorphisms of variable regions of msp1 and msp2 were determined to differentiate recrudescences from reinfections. Acceptance levels of both treatment regimens were assessed by means of standardized interviews.ResultsAdequate clinical and parasitological responses after AL and ASAQ treatment were similar (88.3% and 91.7%, respectively). Interestingly, more late clinical failures until day 28 occurred in AL-treated children than in those who received ASAQ (17.5% and 7.3%, respectively; Hazard Ratio 2.41, 95% CI 1.00–5.79, p < 0.05).Haematological recovery and drug tolerability were not found to be significantly different in both study arms. The acceptance of treatment with ASAQ was higher than that with AL (rank-scores 10.6 and 10.3, respectively; p < 0.05).ConclusionUnobserved AL and ASAQ treatment showed high adequate clinical and parasitological responses, though AL was inferior in preventing late clinical failures.

The causal effect of malaria on stunting: a Mendelian randomization and matching approach

BACKGROUND Previous studies on the association of malaria and stunted growth delivered inconsistent results. These conflicting results may be due to different levels of confounding and to considerable difficulties in elucidating a causal relationship. Randomized experiments are impractical and previous observational studies have not fully controlled for potential confounding including nutritional deficiencies, breastfeeding habits, other infectious diseases and socioeconomic status. METHODS This study aims to estimate the causal effect between malaria episodes and stunted growth by applying a combination of Mendelian randomization, using the sickle cell trait, and matching. We demonstrate the method on a cohort of children in the Ashanti Region, Ghana. RESULTS We found that the risk of stunting increases by 0.32 (P-value: 0.004, 95% CI: 0.09, 1.0) for every malaria episode. The risk estimate based on Mendelian randomization substantially differs from the multiple regression estimate of 0.02 (P-value: 0.02, 95% CI: 0.003, 0.03). In addition, based on the sensitivity analysis, our results were reasonably insensitive to unmeasured confounders. CONCLUSIONS The method applied in this study indicates a causal relationship between malaria and stunting in young children in an area of high endemicity and demonstrates the usefulness of the sickle cell trait as an instrument for the analysis of conditions that might be causally related to malaria.

Adjusting for Heterogeneity of Malaria Transmission in Longitudinal Studies

(See the article by Bejon et al, on pages 9–18.) Although the heterogeneity of malaria transmission has been known for many years, it has only recently become recognized as having importance in the analysis of longitudinal studies [1]. Assumptions of homogenous transmission (ie, that every participant in a given study is exposed to the same number of infectious bites) can lead to incorrect conclusions (eg, that placental malaria is a risk factor for childhood malaria or that parasitemia is protective against clinical malaria) [2–3]. In both these cases, associations have been confused with a causal pathway, and the outcomes have been confounded by the heterogeneity of risk in malaria transmission. Persons living in an area of higher transmission are more likely to develop malaria again than are persons living outside that locality. In turn, after repeated attacks, these persons will develop immunity against clinical disease and become asymptomatic carriers of infection. Infection itself is not the cause of the observed association, but rather exposure to repeated infections in the area of residence. In this issue of the Journal, 2 original articles have examined the effects of heterogeneity in malaria transmission in great depth, using cohort studies to determine how best to consider variation in risk when analyzing studies. One, an observational cohort [4], and the other, a cohort in a vaccine study [5], use measurements of antibodies as their outcome measures.

Patient selection based on treatment duration and liver biochemistry increases success rates after treatment withdrawal in autoimmune hepatitis

BACKGROUND & AIMS In autoimmune hepatitis (AIH), relapse rates as high as 90% have been reported after treatment withdrawal. We therefore investigated, whether longer duration of treatment and proper patient selection could increase the long-term success rates after treatment withdrawal. METHODS Following our previously published experience, treatment withdrawal was considered when biochemical remission was maintained under immunosuppressive monotherapy for at least 2 years. Remission was defined as repeatedly normal serum aminotransferase levels as well as normal IgG levels. RESULTS Out of 288 patients with well-defined AIH, 28 patients were included. Median duration of treatment was 48.5 months (range 35-179) and a sustained remission was observed for 45 months (range 24-111). All patients were in remission on immunosuppressive monotherapy for a minimum of 2 years before treatment was withdrawn. Using this strict approach, 15 patients (54%) remained in long-term remission after a median of 28 months follow-up (range 17-57) and 13 patients (46%) required reinstitution of treatment. Higher ALT and IgG levels - although within the normal range in all patients--were associated with the time to relapse. All patients who remained in remission had ALT levels less than half the ULN and IgG levels not higher than 12 g/L at the time of treatment withdrawal. CONCLUSIONS Proper patient selection including a sustained complete biochemical remission on immunosuppressive monotherapy for a minimum of 2 years can markedly improve the success rates of treatment withdrawal. The interpretation of aminotransferase and IgG levels within the normal range could aid in predicting the risk of relapse.

Therapeutic and prophylactic effect of intermittent preventive anti-malarial treatment in infants (IPTi) from Ghana and Gabon

BackgroundIntermittent preventive treatment in infants (IPTi) with sulphadoxine-pyrimethamine (SP) reduces the incidence of malaria episodes in young children. The exact mechanism by which the protective effect is mediated needs to be defined. This study aimed to investigate therapeutic, prophylactic, and possible exceeding effects of SP-based IPTi in two clinical trials.MethodsProtective efficacies from two IPTi trials performed in Kumasi, Ghana, and Lambaréné, Gabon, were assessed for overlapping time series of 61 days. For six-months periods after each of three IPTi doses a multivariate Poisson regression model with the respective cohort as co-variate was generated and effect modification of protective efficacy with time strata was evaluated by log-likelihood tests.ResultsProtective efficacies were not significantly different between the two study cohorts. Study-cohort corrected protective efficacy was highest for the first 61 days after each IPTi application and decreased continuously. For the first 61 days after IPTi-1, IPTi-2, and IPTi-3 the protective efficacy was 71%, 44%, and 43%, respectively. A reduction of the malaria incidence rate was detectable for the first 60, 30 and 40 days after IPTi-1, IPTi-2 and IPTi-3 drug application, respectively. After IPTi-3 a higher risk for malaria could be seen after day 60. This effect was mainly based on the overwhelming influence of the Kumasi cohort.ConclusionThe results suggest that SP-based IPTi mainly works through a therapeutic and prophylactic effect over 30 to 60 days after drug application and that a sustained effect beyond post-treatment prophylaxis might be very low.Trial registrationData analysis from clinical trials NCT ID # 00206739 (Kumasi Trial) and NCT ID # 00167843 (Lambaréné Trial), http://www.clinicaltrials.gov.