Automated red blood cell exchange as an adjunctive treatment for severe Plasmodium falciparum malaria at the Vienna General Hospital in Austria: a retrospective cohort study

Use of Therapeutic Apheresis methods in ICU

Apheresis is a modern medical approach in which plasma or cellular components are separated from the whole blood. Apheresis can be either diagnostic or therapeutic. Diagnostic apheresis is typically applied in hematology and cancer research. Therapeutic Apheresis (TA) includes a broad spectrum of extracorporeal treatments applied in various medical specialties, including Intensive Care Unit (ICU). Considering the complexity of the pathophysiologic characteristics of various clinical entities and in particular sepsis, apheresis methods are becoming increasingly applicable. Therapeutic Plasma Exchange (TPE) is the most common used method in ICU. It is considered as first line therapy for Thrombotic Thrombocytopenic Purpura (TTP) and Guillain Barre Syndrome, while the current data for sepsis are scarce. Over the last decades, technologic evolution has led to increasing application of new and more selective methods based on adsorptive techniques. In this review we will describe the current data of characteristics of different techniques, safety and clinical impact of apheresis methods used in ICUs.

Plasmodium knowlesi (Pk) Malaria: A Review & Proposal of Therapeutically Rational Exchange (T-REX) of Pk-Resistant Red Blood Cells

Plasmodium knowlesi (Pk) causes zoonotic malaria and is known as the "fifth human malaria parasite". Pk malaria is an emerging threat because infections are increasing and can be fatal. While most infections are in Southeast Asia (SEA), especially Malaysia, travelers frequently visit this region and can present with Pk malaria around the world. So, clinicians need to know (1) patients who present with fever after recent travel to SEA might be infected with Pk and (2) Pk is often misdiagnosed as P. malariae (which typically causes less severe malaria). Here we review the history, pathophysiology, clinical features, diagnosis, and treatment of Pk malaria. Severe disease is most common in adults. Signs and symptoms can include fever, abdominal pain, jaundice, acute kidney injury, acute respiratory distress syndrome, hyponatremia, hyperparasitemia, and thrombocytopenia. Dengue is one of the diseases to be considered in the differential. Regarding pathophysiologic mechanisms, when Pk parasites invade mature red blood cells (RBCs, i.e., normocytes) and reticulocytes, changes in the red blood cell (RBC) surface can result in life-threatening cytoadherence, sequestration, and reduced RBC deformability. Since molecular mechanisms involving the erythrocytic stage are responsible for onset of severe disease and lethal outcomes, it is biologically plausible that manual exchange transfusion (ET) or automated RBC exchange (RBCX) could be highly beneficial by replacing "sticky" parasitized RBCs with uninfected, deformable, healthy donor RBCs. Here we suggest use of special Pk-resistant donor RBCs to optimize adjunctive manual ET/RBCX for malaria. "Therapeutically-rational exchange transfusion" (T-REX) is proposed in which Pk-resistant RBCs are transfused (instead of disease-promoting RBCs). Because expression of the Duffy antigen on the surface of human RBCs is essential for parasite invasion, T-REX of Duffy-negative RBCs-also known as Fy(a-b-) RBCs-could replace the majority of the patient's circulating normocytes with Pk invasion-resistant RBCs (in a single procedure lasting about 2 h). When sequestered or non-sequestered iRBCs rupture-in a 24 h Pk asexual life cycle-the released merozoites cannot invade Fy(a-b-) RBCs. When Fy(a-b-) RBC units are scarce (e.g., in Malaysia), clinicians can consider the risks and benefits of transfusing plausibly Pk-resistant RBCs, such as glucose-6-phosphate dehydrogenase deficient (G6PDd) RBCs and Southeast Asian ovalocytes (SAO). Patients typically require a very short recovery time (<1 h) after the procedure. Fy(a-b-) RBCs should have a normal lifespan, while SAO and G6PDd RBCs may have mildly reduced half-lives. Because SAO and G6PDd RBCs come from screened blood donors who are healthy and not anemic, these RBCs have a low-risk for hemolysis and do not need to be removed after the patient recovers from malaria. T-REX could be especially useful if (1) antimalarial medications are not readily available, (2) patients are likely to progress to severe disease, or (3) drug-resistant strains emerge. In conclusion, T-REX is a proposed optimization of manual ET/RBCX that has not yet been utilized but can be considered by physicians to treat Pk malaria patients.

Efficacy of Red Blood Cell Exchange as Adjunctive Treatment for Hypoxemia and Survival Rate of Patients With Severe Coronavirus-2 Disease: An Open-Labeled Phase 2 Randomized Clinical Trial

Background

Severe acute respiratory syndrome (SARS) coronavirus-2 may infect red blood cells (RBCs) and impact oxygenation. We aimed to evaluate the efficacy of RBC exchange as an adjunctive treatment for hypoxemia and the survival rate of patients with severe coronavirus disease 2019 (COVID-19).

Methods

In a randomized clinical trial, we divided sixty patients with severe COVID-19 into two groups. The intervention group received the standard treatment of severe COVID-19 with RBC exchange three to four times in 2 days. The control group only received the standard treatment. Our primary outcomes were improving hypoxemia in 7 days, recovery or discharge, and death in 28 days. We conducted Chi-square test, independent samples t-test, and Fisher’s exact test to analyze the results. The ethical committee of Aja University of Medical Sciences approved the study (IR.AJAUMS.REC.1399.054), and the Iranian clinical trial registration organization registered it (IRCT20160316027081N2).

Results

Twenty-nine men and thirty-one women with a mean age of 67.5 years entered the study. The frequency of hypertension and diabetes mellitus was 86.7 and 68.3%, respectively. The most common symptoms of severe COVID-19 were dyspnea (91.6%), cough (75%), and fever (66.6%). Our results showed that hypoxemia improved in 21 of the 30 patients (70%) in the intervention group and 10 of the 30 patients (33.3%) in the control group (P < 0.004). The recovery and discharge rates were 19 of 30 patients (63.3%) in the intervention group and 2 of 30 patients (6.7%) in the control group (P < 0.001).

Conclusion

The RBC exchange improved the oxygenation and survival rate in patients with severe COVID-19.

Red blood cell exchange for SARS-CoV-2: A Gemini of therapeutic opportunities

As of now, therapeutic strategies for the novel coronavirus (SARS-CoV-2) are limited and much focus has been placed on social distancing techniques to “flatten the curve”. Initial treatment efforts including ventilation and hydroxychloroquine garnered significant controversy and today, SARS-CoV-2 outbreaks are still occurring throughout the world. Needless to say, new therapeutic strategies are needed to combat this unprecedented pandemic. Nature Reviews Immunology recently published an article hypothesizing the pathogenesis of TAM (Tyro3, Axl, and Mer) receptor signaling in COVID-19. In it they expressed that hypercoagulation and immune hyper-reaction could occur secondary to decreased Protein S (PROS1). And hypoxia has been recently discovered to significantly decrease expression of PROS1. Regarding the cause of hypoxia in COVID-19; NIH funded research utilizing state-of-the-art topologies has recently demonstrated significant metabolomic, proteomic, and lipidomic structural aberrations in hemoglobin (Hb) secondary to infection with SARS-CoV-2. In this setting, Hb may be incapacitated and unable to respond to environmental variations, compromising RBCs and oxygen delivery to tissues. The use of red blood cell exchange would target hypoxia at its source; representing a Gemini of therapeutic opportunities.

Recommendations for Therapeutic Apheresis by the Section "Preparative and Therapeutic Hemapheresis" of the German Society for Transfusion Medicine and Immunohematology

The section "Preparative and Therapeutic Hemapheresis" of the German Society for Transfusion Medicine and Immunohematology (DGTI) has reviewed the actual literature and updated techniques and indications for evidence-based use of therapeutic apheresis in human disease. The recommendations are mostly in line with the "Guidelines on the Use of Therapeutic Apheresis in Clinical Practice" published by the Writing Committee of the American Society for Apheresis (ASFA) and have been conducted by experts from the DACH (Germany, Austria, Switzerland) region.

Red Blood Cells: Exchange, Transfuse, or Deplete

Erythrocytapheresis, red blood cell (RBC) depletion, and RBC exchange transfusions are apheresis techniques used to rapidly lower the circulating RBC mass or to exchange the patient erythrocyte mass with donor RBC. Automated RBC exchange is performed using an apheresis device, while manual RBC exchange is based on sequential phlebotomies and isovolemic replacement. Compared to simple RBC transfusions, RBC exchange offers several advantages, e.g., a lower risk for iron accumulation and efficient control of pathological erythrocyte populations. Disadvantages are the higher costs of the procedure, the increased use of donor RBC, and the requirement of apheresis devices and trained hospital staff. The most frequent indication for RBC exchange is sickle cell disease (SCD). RBC exchange transfusions are standard treatment in SCD patients with a history of or a risk for acute stroke and are clinical options for other acute complications of SCD. The most common indication for RBC depletion is the removal of donor RBC from the bone marrow grafts in major ABO-incompatible allogeneic hematopoietic stem cell transplantation to avoid immediate hemolysis. Rare indications for RBC exchange are severe infections with intraerythrocytic pathogens such as malaria or babesiosis and severe erythrocytosis or hereditary hemochromatosis where the aim is to rapidly decrease RBC populations or the iron content. However, only few high-quality studies are available looking at the efficacy of RBC exchange in the different disease entities, and treatment is often based on low levels of evidence and should therefore be decided in close collaboration with a transfusion medicine specialist.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Safety and effectiveness of apheresis in the treatment of infectious diseases: A systematic review

OBJECTIVES

Apheresis has been used as adjunctive treatment of severe falciparum malaria, loiasis and babesiosis. This systematic review aimed to investigate the safety and efficacy of apheresis in the treatment of these conditions.

METHODS

MEDLINE, PUBMED, EMBASE and CINAHL databases were searched to identify studies published between January 1969 and March 2018 involving patients treated using apheresis for severe falciparum malaria, loiasis or babesiosis. Data extracted included details about the apheresis intervention, populations, study methods and outcomes relating to efficacy and safety.

RESULTS

A total of 67 publications met the inclusion criteria and were included in the data synthesis, 36 for malaria (70 cases), 17 for babesiosis (22 cases) and 14 for loiasis (34 cases). Publications were case reports, case series, and cohort studies; there were no randomised controlled trials identified. Potential publication bias was considered to be high.

CONCLUSIONS

Systematic review of the literature suggests that apheresis may be a useful adjunct in the treatment of patients hospitalised for babesiosis, and prior to chemotherapy in loiasis with microfilarial count >8000 parasites/mL. Data does not support the use of apheresis in patients with severe falciparum malaria.

Red blood cell exchange in treatment of severe cerebral P. falciparum malaria: A case report

INTRODUCTION

Red blood cells exchange transfusion has been demonstrated to be helpful in treatment of sever P. falciparum malaria. However, no large scale randomized controlled trials have been completed to date and the CDC does not recommend RBC exchange transfusions as standard of care. We present a case of severe cerebral malaria in a patient with extremely high parasitemia and severe altered mental status who improved rapidly with automated RBC exchange.

REPORT

Seventy-two year old female presented with 1 day history of weakness, altered mental status, malaise, and cyclic sweats after returning from a trip to Sierra Leone. Thick and Thin Smears demonstrated P. falciparum rings present and Quantitative malaria screen demonstrated 53.33% parasitemia. Patient was started on quinidine and doxycycline but continued to deteriorate. Automated RBC exchange transfusion was performed within 24 hours of admission and resulted in rapid improvement in symptomology. Repeat thick and thin smears revealed undetectable parasite load.

CONCLUSION

Automated RBC exchange may improve outcomes in severe P. falciparum malaria when presenting parasite loads are very high.

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.

Severe Plasmodium falciparum malaria in the intensive care unit: A 6-year experience in Milano, Italy

BACKGROUND

Severe imported Plasmodium falciparum malaria is a potentially life-threatening disease with a reported mortality rate of 5-10% when patients are admitted to the Intensive Care Unit.

METHODS

To retrospectively review the clinical aspects, the value of severity predictive scores and the management of patients with severe P. falciparum malaria admitted to an ICU in Milano, Italy between January 2010 and December 2015.

RESULTS

Twelve patients were included: seven were male and five female with a median age of 43 years. All were initially treated with intravenous quinine. Median parasitaemia upon admission was 14,5% (range 1-20%). At the time of ICU admission, 3 patients (25%) had 5 or more World Health Organization criteria for severe malaria while another 6 of them developed one or more of the latter during their stay in ICU. Five required mechanical ventilation because of respiratory failure due to ARDS. Four patients required renal replacement therapy. Three patients underwent blood exchange transfusion. All patients survived.

CONCLUSIONS

Our retrospective evaluation of adults patients admitted to the ICU with severe imported P. falciparum malaria demonstrated a favourable outcome. Severity predictive scores currently in use probably overestimate the risk of malaria mortality in patients treated in health care systems of high income countries.

Landscape structure affects distribution of potential disease vectors (Diptera: Culicidae)

Background

Vector-pathogen dynamics are controlled by fluctuations of potential vector communities, such as the Culicidae. Assessment of mosquito community diversity and, in particular, identification of environmental parameters shaping these communities is therefore of key importance for the design of adequate surveillance approaches. In this study, we assess effects of climatic parameters and habitat structure on mosquito communities in eastern Austria to deliver these highly relevant baseline data.

Methods

Female mosquitoes were sampled twice a month from April to October 2014 and 2015 at 35 permanent and 23 non-permanent trapping sites using carbon dioxide-baited traps. Differences in spatial and seasonal abundance patterns of Culicidae taxa were identified using likelihood ratio tests; possible effects of environmental parameters on seasonal and spatial mosquito distribution were analysed using multivariate statistical methods. We assessed community responses to environmental parameters based on 14-day-average values that affect ontogenesis.

Results

Altogether 29,734 female mosquitoes were collected, and 21 of 42 native as well as two of four non-native mosquito species were reconfirmed in eastern Austria. Statistical analyses revealed significant differences in mosquito abundance between sampling years and provinces. Incidence and abundance patterns were found to be linked to 14-day mean sunshine duration, humidity, water–level maxima and the amount of precipitation. However, land cover classes were found to be the most important factor, effectively assigning both indigenous and non-native mosquito species to various communities, which responded differentially to environmental variables.

Conclusions

These findings thus underline the significance of non-climatic variables for future mosquito prediction models and the necessity to consider these in mosquito surveillance programmes.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-017-2140-6) contains supplementary material, which is available to authorized users.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Severe malaria in Europe: an 8-year multi-centre observational study

Background

Malaria remains one of the most serious infections for travellers to tropical countries. Due to the lack of harmonized guidelines a large variety of treatment regimens is used in Europe to treat severe malaria.

Methods

The European Network for Tropical Medicine and Travel Health (TropNet) conducted an 8-year, multicentre, observational study to analyse epidemiology, treatment practices and outcomes of severe malaria in its member sites across Europe. Physicians at participating TropNet centres were asked to report pseudonymized retrospective data from all patients treated at their centre for microscopically confirmed severe Plasmodium falciparum malaria according to the 2006 WHO criteria.

Results

From 2006 to 2014 a total of 185 patients with severe malaria treated in 12 European countries were included. Three patients died, resulting in a 28-day survival rate of 98.4%. The majority of infections were acquired in West Africa (109/185, 59%). The proportion of patients treated with intravenous artesunate increased from 27% in 2006 to 60% in 2013. Altogether, 56 different combinations of intravenous and oral drugs were used across 28 study centres. The risk of acute renal failure (36 vs 17% p = 0.04) or cerebral malaria (54 vs 20%, p = 0.001) was significantly higher in patients ≥60 years than in younger patients. Respiratory distress with the need for mechanical ventilation was significantly associated with the risk of death in the study population (13 vs 0%, p = 0.001). Post-artemisinin delayed haemolysis was reported in 19/70 (27%) patients treated with intravenous artesunate.

Conclusion

The majority of patients with severe malaria in this study were tourists or migrants acquiring the infection in West Africa. Intravenous artesunate is increasingly used for treatment of severe malaria in many European treatment centres and can be given safely to European patients with severe malaria. Patients treated with intravenous artesunate should be followed up to detect and manage late haemolytic events.

Study of Twenty One Cases of Red Cell Exchange in a Tertiary Care Hospital in Southern India

INTRODUCTION

Red Cell Exchange (RCE) is removal of a patient's red blood cells while replacing with donor red blood cells either manually or using automated systems. RCE is beneficial in patients with Sickle Cell Disease (SCD) either during sickling crisis or prior to major surgical procedures to bring down the sickling percentage as high sickling percentage during prolonged anaesthesia may lead to vaso-occlusive crisis. It is also employed in patients infested with malaria and babesiosis where parasitic index remain high despite medical management. RCE is also tried as an adjuvant therapy in certain poisons like nitrobenzene and carbon monoxide when first line management fails.

AIM

To study the effectiveness, clinical outcome, challenges and complications of RCE in various clinical scenario and to understand how this procedure can be effectively utilized in the management of patients in Indian scenario.

MATERIALS AND METHODS

This retro prospective study was conducted in tertiary care center in southern India which analyzed 21 RCE procedures performed on patients with different clinical conditions. Of the 21 RCE performed, 18 procedures were performed on patients with case of sickle cell disease, Two procedures were performed on patients infested with severe falciparum malaria and one procedure was performed on a patient with nitrobenzene poisoning. All procedures were performed using Spectra Optia(®) Apheresis System - Terumo BCT.

RESULTS

All the 18 patients who underwent the RCE for sickle cell anaemia were admitted for hemi-arthroplasty for avascular necrosis of the head of femur. The average initial HbS levels were between 73-85% and post RCE it was brought down to 22-29% and was achieved in a single sitting in all the cases. Among the two patients infested with severe falciparum malaria, RCE helped in reducing the infestation rate. In case of nitrobenzene poisoning, RCE helped in improvement of oxygen saturation and patient showed significant improvement.

CONCLUSION

RCE is an safe and clinically effective therapeutic modality with very minimal to nil side effects. RCE is possibly underutilized therapy in developing world like India due to various reasons like inadequate awareness/ technical expertise, lack of equipments and facilities to identify the clinical conditions per se etc.

The role of red blood cell exchange for severe imported malaria in the artesunate era: a retrospective cohort study in a referral centre

Background

Intravenous artesunate has replaced quinine as the first-line therapy for severe imported malaria, given its anti-malarial superiority shown in clinical trials conducted in endemic countries. Evidence for red blood cell (RBC) exchange in patients with severe malaria treated with artesunate is lacking. This retrospective cohort study describes the experience at Hospital Clinic of Barcelona with the use of artesunate for severe malaria and the joint use of RBC exchange in selected cases.

Methods

Patients treated for severe malaria at Hospital Clinic of Barcelona between August 2013 and January 2015 were included in this retrospective study. Severe malaria was defined according to WHO criteria. Data were extracted from electronic hospital records. A log-linear mixed model approach was used to estimate parasite clearance times.

Results

Within the study period, 42 patients were diagnosed of malaria at this centre, of which 38 had Plasmodium falciparum (90.5 %). Sixteen patients (42 %) had severe malaria cases and were treated with intravenous artesunate. Four patients underwent RBC exchange within a period of 15 h after the first dose of artesunate (range 9–21 h). The procedure lasted a median of 2 h (IQR 1.8–2 h), using a median of 12 (IQR 11–14) units of packed RBCs to replace a median of 3794 ml (IQR 2977–4343). The technique was well-tolerated without haemodynamic complications. There were no deaths. The regression model showed an estimated time to 95 % decay of 21.6 h (95 % CI 17.3–28.8). When assessing effect modification by RBC exchange, there was no difference in the parasite elimination rate (p = 0.286).

Discussion and conclusion

In this study RBC exchange failed to show benefits in terms of parasite clearance probably due to the small number of patients analysed. The evidence for exchange transfusion remains limited.

Haemolysis associated with the treatment of malaria with artemisinin derivatives: a systematic review of current evidence

BACKGROUND

Artemisinin derivatives are the mainstay of antimalarial treatment, both for uncomplicated malaria and for severe disease. Artemisinins are known for their rapid onset of action, good tolerability, and safety. However, besides the sporadic but worrying reports of delayed parasite clearance after treatment with artemisinins, there have been an increasing number of reports of acute haemolytic anaemia following their use and the safety of this class of antimalarials is being questioned.

METHODS

In this systematic review, all reports of patients experiencing haemolysis following the use of artemisinins for the treatment of malaria were identified and collated into an electronic database. Summary statistics were calculated to characterize the epidemiology and clinical features of this safety concern related to artemisinin derivatives.

RESULTS

A total of 37 patients were identified suffering from haemolysis following the treatment of severe malaria with artemisinin derivatives. Thirty-one cases had received intravenous artesunate, while the remaining cases were attributed to other parenteral or oral regimens of artemisinin derivatives. The majority of patients were returning travellers (n=30), and six clinical cases had been reported in paediatric patients. The median onset of haemolysis was 15 (interquartile range (IQR) 13-15) days after the initiation of treatment for the 'delayed-onset' pattern and 17 (IQR 13-22) days for the 'persistent' haemolysis pattern. The median reduction in haemoglobin due to haemolysis was 6 g/dl (IQR 4-8 g/dl). The estimated proportion of patients suffering from severe malaria experiencing haemolysis after treatment with artemisinin derivatives was 13% (95% confidence interval 9-18%), and 73% of these (i.e., 9% of the total population) required blood transfusions. No fatal outcome has been reported in the literature to date.

CONCLUSIONS

Haemolysis is commonly associated with the class of artemisinin drugs when used for the treatment of severe malaria. Potential causes of this safety issue are discussed. Although no deaths attributed to haemolysis have been reported so far, this safety issue may lead to life-threatening anaemia and is particularly worrying for regions where safe blood products are not readily available.

Exchange transfusion for severe malaria: evidence base and literature review

BACKGROUND

Exchange transfusion (ET) has biologic plausibility as an adjunct to antimalarial drugs in treating severe malaria and has been used for decades despite limited evidence of its efficacy in improving survival. We examined the efficacy of ET as an adjunct treatment for severe malaria using US surveillance data and reviewed the literature to update recommendations.

METHODS

Patients with severe malaria reported to the US national malaria surveillance system during 1985-2010 were matched, and survival outcomes were compared between patients receiving and not receiving ET. The literature review used search terms "severe malaria" and "exchange transfusion." Case reports and series, observational and case-control studies, and meta-analysis were included.

RESULTS

One hundred one patients receiving ET were matched to 314 patients not receiving ET. There was no statistically significant association between ET and survival outcome (odds ratio, 0.84; 95% confidence interval, .44-1.60). We found 87 articles, mostly case reports or series, showing successful use of ET, likely reporting bias. There were 12 comparative studies, most of which were retrospective cohort studies, underpowered with no significant differences in survival. A previously published meta-analysis of 8 comparative studies found no significant survival differences. Adverse events were rarely reported but included acute respiratory distress syndrome, ventricular fibrillation, and hypotension.

CONCLUSIONS

Despite rapid parasite clearance times resulting from ET, there is no evidence for efficacy of ET as adjunctive therapy in severe malaria. Adjunct ET cannot be recommended. When rapidly acting antimalarials, specifically artemisinins, become more widely available, the biologic plausibility argument for ET will become less relevant.

Management of severe malaria in the intensive care unit

Severe malaria is a medical emergency requiring early intervention to prevent death. This article highlights key aspects of the management of severe malaria syndromes in the intensive care unit, with a focus on individual case management of imported malaria. Key differences in the presentation, management, and outcomes of severe malaria by endemicity and by age group are emphasized. In all groups with severe malaria, intravenous artesunate is the antimalarial agent of choice. This article discusses specific antimalarial therapies, optimal supportive management strategies, differences from strategies for bacterial sepsis, and trials of adjunctive therapy for severe malaria in humans.

Adjunctive management of malaria

PURPOSE OF REVIEW

Artesunate treatment reduces mortality in severe malaria when compared with quinine. Nevertheless, severe malaria is associated with mortality rates between 1.4 and 9.5% after hospitalization. This review puts into context the recent developments in understanding the pathophysiology of malaria and how these may be reflected in renewed attempts at improving adjunct therapies. Identifying new adjunct approaches has been particularly difficult for severe malaria because most interventions have either caused harm or failed to confer benefit.

RECENT FINDINGS

Imaging and postmortem findings in children with severe and cerebral malaria have given impetus to study new interventions that could be added to antimalarial treatment. Some pilot studies have (re)tested different approaches to improve complications of cerebral malaria such as the use of N-acetyl cysteine or mannitol. Fluids administration, blood transfusions and red cell exchanges in severe malaria are controversial and important areas that are also reviewed with new evidence. Other interventions such as measures to increase nitric oxide, manage acute renal failure or optimize artesunate dosing are discussed.

SUMMARY

Outcomes with adjunct therapies for severe malaria have been poor, but as insights into pathophysiological processes are deepened it may be possible eventually to reduce mortality further.

Current evidence and future of automated erythrocyte exchange in the treatment of severe malaria

Despite the administration of antimalarial treatment, severe malaria still has a high mortality rate. Since overall survival is associated with total parasite biomass, whole blood exchange (e.g. blood exchange transfusions) has been proposed as a potential method to rapidly reduce peripheral parasitaemia. Automated red blood cell exchange has been advocated as a physical method to remove parasites. Compared to exchange transfusion, automated red blood exchange may avoid the risk of volume alterations and haemodynamic distress. Since 1984, there have been 37 published cases in which automated red blood cell exchange was used as an adjunctive treatment in severe malaria caused by Plasmodium falciparum. This short review summarizes current evidence and discusses problems, challenges and goals for future studies and research in order to assess the clinical benefit of automated erythrocyte exchange in severe malaria cases.

Management of imported malaria in Europe

In this position paper, the European Society for Clinical Microbiology and Infectious Diseases, Study Group on Clinical Parasitology, summarizes main issues regarding the management of imported malaria cases. Malaria is a rare diagnosis in Europe, but it is a medical emergency. A travel history is the key to suspecting malaria and is mandatory in patients with fever. There are no specific clinical signs or symptoms of malaria although fever is seen in almost all non-immune patients. Migrants from malaria endemic areas may have few symptoms.Malaria diagnostics should be performed immediately on suspicion of malaria and the gold- standard is microscopy of Giemsa-stained thick and thin blood films. A Rapid Diagnostic Test (RDT) may be used as an initial screening tool, but does not replace urgent microscopy which should be done in parallel. Delays in microscopy, however, should not lead to delayed initiation of appropriate treatment. Patients diagnosed with malaria should usually be hospitalized. If outpatient management is preferred, as is the practice in some European centres, patients must usually be followed closely (at least daily) until clinical and parasitological cure. Treatment of uncomplicated Plasmodium falciparum malaria is either with oral artemisinin combination therapy (ACT) or with the combination atovaquone/proguanil. Two forms of ACT are available in Europe: artemether/lumefantrine and dihydroartemisinin/piperaquine. ACT is also effective against Plasmodium vivax, Plasmodium ovale, Plasmodium malariae and Plasmodium knowlesi, but these species can be treated with chloroquine. Treatment of persistent liver forms in P. vivax and P. ovale with primaquine is indicated after excluding glucose 6 phosphate dehydrogenase deficiency. There are modified schedules and drug options for the treatment of malaria in special patient groups, such as children and pregnant women. The potential for drug interactions and the role of food in the absorption of anti-malarials are important considerations in the choice of treatment.Complicated malaria is treated with intravenous artesunate resulting in a much more rapid decrease in parasite density compared to quinine. Patients treated with intravenous artesunate should be closely monitored for haemolysis for four weeks after treatment. There is a concern in some countries about the lack of artesunate produced according to Good Manufacturing Practice (GMP).