***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Background Co-infection with malaria and intestinal parasites such as Ascaris lumbricoides is common . Malaria parasites induce a pro-inflammatory immune response that contributes to the pathogenic sequelae , such as malarial anaemia , that occur in malaria infection . Ascaris is known to create an anti-inflammatory immune environment which could , in theory , counteract the anti-malarial inflammatory immune response , minimizing the severity of malarial anaemia . This study examined whether Ascaris co-infection can minimize the severity of malarial anaemia . Methods Data from a r and omized controlled trial on the effect of antihelminthic treatment in Nigerian preschool-aged ( 6–59 months ) children conducted in 2006–2007 were analysed to examine the effect of malaria and Ascaris co-infection on anaemia severity .  Children were enrolled and tested for malaria , helminths and anaemia at baseline , four , and eight months . Six hundred and ninety subjects were analysed in this study . Generalized linear mixed models were used to assess the relationship between infection status and Ascaris and Plasmodium parasite intensity on severity of anaemia , defined as a haemoglobin less than 11 g/dL. Results Malaria prevalence ranged from 35 - 78 % over the course of this study . Of the malaria-infected children , 55 % were co-infected with Ascaris at baseline , 60 % were co-infected four months later and 48 % were co-infected eight months later , underlining the persistent prevalence of malaria-nematode co-infections in this population . Over the course of the study the percentage of anaemic subjects in the population ranged between 84 % at baseline and 77 % at the eight-month time point . The odds of being anaemic were four to five times higher in children infected with malaria compared to those without malaria . Ascaris infection alone did not increase the odds of being anaemic , indicating that malaria was the main cause of anaemia in this population . There was no significant difference in the severity of anaemia between children singly infected with malaria and co-infected with malaria and Ascaris . Conclusion In this cohort of Nigerian preschool children , malaria infection was the major contributor to anaemia status . Ascaris co-infection neither exacerbated nor ameliorated the severity of malarial anaemia BACKGROUND . Some countries have limited the maximum allowable storage duration for red cells to 5 weeks before transfusion . In the US , red blood cells can be stored for up to 6 weeks , but r and omized trials have not assessed the effects of this final week of storage on clinical outcomes . METHODS . Sixty healthy adult volunteers were r and omized to a  single st and ard , autologous , leukoreduced , packed red cell transfusion after 1 , 2 , 3 , 4 , 5 , or 6 weeks of storage ( n = 10 per group ) . 51-Chromium posttransfusion red cell recovery studies were performed and laboratory parameters measured before and at defined times after transfusion . RESULTS . Extravascular hemolysis after transfusion progressively increased with increasing storage time ( P < 0.001 for linear trend in the AUC of serum indirect bilirubin and iron levels ) . Longer storage duration was associated with decreasing posttransfusion red cell recovery ( P = 0.002 ) , decreasing elevations in hematocrit ( P = 0.02 ) , and increasing serum ferritin ( P < 0.0001 ) . After 6 weeks of refrigerated storage , transfusion was followed by increases in AUC for serum iron ( P < 0.01 ) , transferrin saturation ( P < 0.001 ) , and nontransferrin-bound iron ( P < 0.001 ) as compared with transfusion after 1 to 5 weeks of storage . CONCLUSIONS . After 6 weeks of refrigerated storage , transfusion of autologous red cells to healthy human volunteers increased extravascular hemolysis , saturated serum transferrin , and produced circulating nontransferrin-bound iron . These outcomes , associated with increased risks of harm , provide evidence that the maximal allowable red cell storage duration should be reduced to the minimum sustainable by the blood supply , with 35 days as an attainable goal . REGISTRATION . Clinical Trials.gov NCT02087514 . FUNDING . NIH grant HL115557 and UL1 TR000040 CONTEXT Anemia is a common problem in critically ill patients admitted to intensive care units ( ICUs ) , but the consequences of anemia on morbidity and mortality in the critically ill is poorly defined . OBJECTIVES To prospect ively define the incidence of anemia and use of red blood cell ( RBC ) transfusions in critically ill patients and to explore the potential benefits and risks associated with transfusion in the ICU . DESIGN Prospect i ve observational study conducted November 1999 , with 2 components : a blood sampling study and an anemia and blood transfusion study . SETTING AND PATIENTS The blood sampling  study included 1136 patients from 145 western European ICUs , and the anemia and blood transfusion study included 3534 patients from 146 western European ICUs . Patients were followed up for 28 days or until hospital discharge , interinstitutional transfer , or death . MAIN OUTCOME MEASURES Frequency of blood drawing and associated volume of blood drawn , collected over a 24-hour period ; hemoglobin levels , transfusion rate , organ dysfunction ( assessed using the Sequential Organ Failure Assessment score ) , and mortality , collected throughout a 2-week period . RESULTS The mean ( SD ) volume per blood draw was 10.3 ( 6.6 ) mL , with an average total volume of 41.1 ( 39.7 ) mL during the 24-hour period . There was a positive correlation between organ dysfunction and the number of blood draws ( r = 0.34 ; P<.001 ) and total volume drawn ( r = 0.28 ; P<.001 ) . The mean hemoglobin concentration at ICU admission was 11.3 ( 2.3 ) g/dL , with 29 % ( 963/3295 ) having a concentration of less than 10 g/dL. The transfusion rate during the ICU period was 37.0 % ( 1307/3534 ) . Older patients and those with a longer ICU length of stay were more commonly transfused . Both ICU and overall mortality rates were significantly higher in patients who had vs had not received a transfusion ( ICU rates : 18.5 % vs 10.1 % , respectively ; chi(2 ) = 50.1 ; P<.001 ; overall rates : 29.0 % vs 14.9 % , respectively ; chi(2 ) = 88.1 ; P<.001 ) . For similar degrees of organ dysfunction , patients who had a transfusion had a higher mortality rate . For matched patients in the propensity analysis , the 28-day mortality was 22.7 % among patients with transfusions and 17.1 % among those without ( P = .02 ) ; the Kaplan-Meier log-rank test confirmed this difference . CONCLUSIONS This multicenter observational study reveals the common occurrence of anemia and the large use of blood transfusion in critically ill patients . Additionally , this epidemiologic study provides evidence of an association between transfusions and diminished organ function as well as between transfusions and mortality BACKGROUND Prolonged storage of red blood cells ( RBCs ) is a potential risk factor for postoperative infections . The objective of this study was to examine the effect of age of RBCs transfused on development of postoperative infection . STUDY DESIGN AND METHODS In this prospect i ve , double-blind r and omized trial , 199 patients undergoing elective noncardiac surgery and requiring RBC transfusion were assigned to receive nonleukoreduced RBCs stored for not more than 14 days ( " fresh blood " group , n = 101 ) or for more than 14 days ( " old blood " group , n = 98 ) . The primary outcome was occurrence of infection within 28 days after surgery ; secondary outcomes were postoperative acute kidney injury ( AKI ) , in-hospital and 90-day mortality , admission to intensive care unit , and hospital length of stay ( LOS ) . As older blood was not always available , an " as-treated " ( AT ) analysis was also performed according to actual age of the RBCs transfused . RESULTS The median [ interquartile range ] storage time of RBCs was 6 [ 5 - 10 ] and 15 [ 11 - 20 ] days in fresh blood and in old blood groups , respectively . The occurrence of postoperative infection did not differ between groups ( fresh blood 22 % vs. old blood 25 % ; relative risk [ RR ] , 1.17 ; confidence interval [ CI ] , 0.71 - 1.93 ) , although wound infections occurred more frequently in old blood ( 15 % vs. 5 % ; RR , 3.09 ; CI , 1.17- 8.18 ) . Patients receiving older units had a higher rate of AKI ( 24 % vs. 6 % ; p < 0.001 ) and , according to AT analysis , longer LOS ( mean difference , 3.6 days ; CI , 0.6 - 7.5 ) . CONCLUSION Prolonged RBC storage time did not increase the risk of postoperative infection . However , old blood transfusion increased wound infections rate and incidence of AKI Although red blood cell transfusion is a potentially lifesaving intervention in severely anemic and acutely bleeding patients , some observational studies have suggested that prolonged red cell storage before transfusion is associated with harm . INFORM is a large , pragmatic , r and omized controlled trial comparing the effect of the shorter storage with longer storage red blood cell transfusions on inhospital mortality in hospitalized patients who require a blood transfusion . The trial is being conducted in centers in Australia , Canada , Israel , and the United States and is expected to enroll 31497 patients . If the results of INFORM indicate that shorter storage red blood cell transfusion is associated with superior outcomes compared with st and ard issue red blood cell transfusion , consideration may be given to shortening blood storage times . If , in contrast , the INFORM trial provides no evidence of harm from longer storage red blood cells , clinicians and patients may be reassured that current blood inventory management strategies are appropriate Summary . In a prospect i ve study , 237 patients undergoing a primary coronary bypass operation were r and omized to receive 2 units of fresh whole blood ( study group ) or stored ( 2–5 d ) blood ( control group ) at the end of the extracorporeal circulation BACKGROUND Whether the duration of storage of blood has an impact on patient outcomes remains controversial . The objective was to determine feasibility of a comparative effectiveness trial to evaluate duration of storage of blood  before transfusion on in-hospital mortality . STUDY DESIGN AND METHODS A single-center r and omized controlled trial was performed at an acute care hospital in Canada between June and December 2010 , involving consecutive hospitalized patients needing blood transfusion . Patients ( n=910 ) were r and omly assigned in a 1:2 ratio to receive freshest available versus st and ard-issue ( oldest available ) blood . Four feasibility criteria were measured : proportion of eligible patients r and omized , contrast in age of blood between treatment groups , real-time data acquisition , and trial impact on blood outdating . In-hospital mortality was also reported . RESULTS A total of 1075 of 1129 patients ( 95.2 % ) were eligible and 910 of 1075 ( 84.7 % ) were r and omized : 309 received freshest available blood ( 1157 units ) , and 601 received st and ard-age blood ( 2369 units ) . Contrast in mean age of the oldest blood transfused between groups was 14.6 days : 12.0 ( st and ard deviation [ SD ] , 6.8 ) days in the fresh arm and 26.6 ( SD , 7.8 ) days in the st and ard arm . Weekly recruitment and event reporting were achieved for all patients . The blood out date rate was 0.10 % . In-hospital mortality was 10.5 % : 35 deaths ( 11.3 % ) in the fresh arm and 61 deaths ( 10.1 % ) in the st and ard arm ( odds ratio , 1.13 ; 95 % confidence interval [ CI ] , 0.73 , 1.76 ) . CONCLUSION It is feasible to conduct a large comparative effectiveness trial comparing the effect of freshest available versus st and ard-issue blood on in-hospital mortality . The wide CI around the estimate for in-hospital mortality supports the need for a large trial We investigated the safety and efficacy of using a single unit of packed red blood cells until its expiration date ( 35 days ) to meet the transfusion needs of infants weighting < 1.5 kg . Unit concentration of potassium and infants ' hematocrit value , K+ level , pH , and base excess were measured before and after transfusion . Compared with control infants , study infants had similar transfusion needs , but received blood from significantly fewer donors . The age of the blood received by study infants was significantly older and had a higher plasma K+ level . However , the change in infants ' serum K+ levels before and after a transfusion was not significantly different in the two groups , and no adverse effects from transfusion of older blood were observed . We conclude that a protocol that allows use of an assigned unit of packed red blood cells preserved with citrate- 
    Output:
    
There appears to be no evidence of an effect on mortality that is related to length of storage of transfused RBCs .