***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Malaria is a very important cause of anaemia in tropical countries . Anaemia is assessed either by measurement of the haematocrit or the haemoglobin concentration . For comparisons across studies , it is often necessary to derive one measure from the other . Methods Data on patients with slide-confirmed uncomplicated falciparum malaria were pooled from 85 antimalarial drug trials conducted in 25 different countries , to assess the haemoglobin/haematocrit relationship at different time points in malaria . Using a linear r and om effects model , a conversion equation for haematocrit was derived based on 3,254 measurements from various time points ( ranging from day 0 to day 63 ) from 1,810 patients with simultaneous measurements of both parameters . Haemoglobin was also estimated from haematocrit with the commonly used threefold conversion . Results A good fit was obtained using Haematocrit = 5.62 + 2.60 * Haemoglobin . On average , haematocrit/3 levels were slightly higher than haemoglobin measurements with a mean difference ( ± SD ) of -0.69 ( ± 1.3 ) for children under the age of 5 ( n = 1,440 measurements from 449 patients ) . Conclusion Based on this large data set , an accurate and robust conversion factor both in acute malaria and in convalescence was obtained . The commonly used threefold conversion is also valid Background Recent efforts in malaria control have result ed in great gains in reducing the burden of Plasmodium falciparum , but P. vivax has been more refractory . Its ability to form dormant liver stages confounds control and elimination efforts . To compare the efficacy and safety of primaquine regimens for radical cure , we undertook a r and omized controlled trial in Ethiopia . Methods and findings Patients with normal glucose-6-phosphate dehydrogenase status with symptomatic P. vivax mono-infection were enrolled and r and omly assigned to receive either chloroquine ( CQ ) or artemether-lumefantrine ( AL ) , alone or in combination with 14 d of semi-supervised primaquine ( PQ ) ( 3.5 mg/kg total ) . A total of 398 patients ( n = 104 in the CQ arm , n = 100 in the AL arm , n = 102 in the CQ+PQ arm , and n = 92 in the AL+PQ arm ) were followed for 1 y , and recurrent episodes were treated with the same treatment allocated at enrolment . The primary endpoints were the risk of P. vivax recurrence at day 28 and at day 42 . The risk of recurrent P. vivax infection at day 28 was 4.0 % ( 95 % CI 1.5%–10.4 % ) after CQ treatment and 0 % ( 95 % CI 0%–4.0 % ) after CQ+PQ . The corresponding risks were 12.0 % ( 95 % CI 6.8%–20.6 % ) following AL alone and 2.3 % ( 95 % CI 0.6%–9.0 % ) following AL+PQ . On day 42 , the risk was 18.7 % ( 95 % CI 12.2%–28.0 % ) after CQ , 1.2 % ( 95 % CI 0.2%–8.0 % ) after CQ+PQ , 29.9 % ( 95 % CI 21.6%–40.5 % ) after AL , and 5.9 % ( 95 % CI 2.4%–13.5 % ) after AL+PQ ( overall p < 0.001 ) . In those not prescribed PQ , the risk of recurrence by day 42 appeared greater following AL treatment than CQ treatment ( HR = 1.8 [ 95 % CI 1.0–3.2 ] ; p = 0.059 ) . At the end of follow-up , the incidence rate of P. vivax was 2.2 episodes/person-year for patients treated with CQ compared to 0.4 for patients treated with CQ+PQ ( rate ratio : 5.1 [ 95 % CI 2.9–9.1 ] ; p < 0.001 ) and 2.3 episodes/person-year for AL compared to 0.5 for AL+PQ ( rate ratio : 6.4 [ 95 % CI 3.6–11.3 ] ; p < 0.001 ) . There was no difference in the occurrence of adverse events between treatment arms . The main limitations of the study were the early termination of the trial and the omission of haemoglobin measurement after day 42 , result ing in an inability to estimate the cumulative risk of anaemia . Conclusions Despite evidence of CQ-resistant P. vivax , the risk of recurrence in this study was greater following treatment with AL unless it was combined with a supervised course of PQ . PQ combined with either CQ or AL was well tolerated and reduced recurrence of vivax malaria by 5-fold at 1 y. Trial registration Clinical Trials.gov BACKGROUND Artemisinin-combination therapy ( ACT ) is recommended as first-line treatment of falciparum malaria throughout the world , and fixed-dose combinations are preferred by WHO ; whether a single gametocytocidal dose of primaquine should be added is unknown . We aim ed to compare effectiveness of four fixed-dose ACTs and a loose tablet combination of artesunate and mefloquine , and assess the addition of a single gametocytocidal dose of primaquine . METHODS In an open-label r and omised trial in clinics in Rakhine state , Kachin state , and Shan state in Myanmar ( Burma ) between Dec 30 , 2008 , and March 20 , 2009 , we compared the effectiveness of all four WHO-recommended fixed-dose ACTs ( artesunate-mefloquine , artesunate-amodiaquine , dihydroartemisinin-piperaquine , artemether-lumefantrine ) and loose artesunate-mefloquine in Burmese adults and children . Eligible patients were those who presented to the clinics with acute uncomplicated Plasmodium falciparum malaria or mixed infection , who were older than 6 months , and who weighed more than 5 kg . Treatments were r and omised in equal numbers within blocks of 50 and allocation was in sealed envelopes . All patients were also r and omly assigned to receive either a single dose of primaquine 0·75 mg base/kg or not . Patients were followed up for 63 days . Treatment groups were compared by analysis of variance and multiple logistic regression . The primary outcome was the 63 day recrudescence rate . This study is registered with clinical trials.gov , number NCT00902811 . FINDINGS 155 patients  received artesunate-amodiaquine , 162 artemether-lumefantrine , 169 artesunate-mefloquine , 161 loose artesunate-mefloquine , and 161 dihydroartemisinin-piperaquine . By day 63 of follow-up , 14 patients ( 9·4 % ; 95 % CI 5·7 - 15·3 % ) on artesunate-amodiaquine had recrudescent P falciparum infections , a rate significantly higher than for artemether-lumefantrine ( two patients ; 1·4 % ; 0·3 - 5·3 ; p=0·0013 ) , fixed-dose artesunate-mefloquine ( 0 patients ; 0 - 2·3 ; p<0·0001 ) , loose artesunate-mefloquine ( two patients ; 1·3 % ; 0·3 - 5·3 ; p=0·0018 ) , and dihydroartemisinin-piperaquine ( two patients 1·3 % ; 0·3 - 5·2 % ; p=0·0012 ) . Hazard ratios for re-infection ( 95 % CI ) after artesunate-amodiaquine were 3·2 ( 1·3 - 8·0 ) compared with the two artesunate-mefloquine groups ( p=0·01 ) , 2·6 ( 1·0 - 6 - 0 ) compared with artemether-lumefantrine ( p=0·04 ) , and 2·3 ( 0·9 - 6·0 ) compared with dihydroartemisinin-piperaquine ( p=0·08 ) . Mixed falciparum and vivax infections were common : 129 ( 16 % ) had a mixed infection at presentation and 330 ( 41 % ) patients had one or more episodes of Plasmodium vivax infection during follow-up . The addition of a single dose of primaquine ( 0·75 mg/kg ) reduced P falciparum gametocyte carriage substantially : rate ratio 11·9 ( 95 % CI 7·4 - 20·5 ) . All regimens were well tolerated . Adverse events were reported by 599 patients , most commonly vomiting and dizziness . Other side-effects were less common and were not related to a specific treatment . INTERPRETATION Artesunate-amodiaquine should not be used in Myanmar , because the other ACTs are substantially more effective . Artesunate-mefloquine provided the greatest post-treatment suppression of malaria . Adding a single dose of primaquine would substantially reduce transmission potential . Vivax malaria , not recurrent falciparum malaria , is the main complication after treatment of P falciparum infections in this region . FUNDING Médecins sans Frontières ( Holl and ) and the Wellcome Trust Mahidol University Oxford Tropical Medicine Research Programme ABSTRACT The objective of this study was to conduct a prospect i ve population pharmacokinetic and pharmacodynamic evaluation of lumefantrine during blinded comparisons of artemether-lumefantrine treatment regimens in uncomplicated multidrug-resistant falciparum malaria . Three combination regimens containing an average adult lumefantrine dose of 1,920 mg over 3 days ( four doses ) ( regimen A ) or 2,780 mg over 3 or 5 days ( six doses ) ( regimen B or C , respectively ) were given to 266 Thai patients . Detailed observations were obtained for 51 hospitalized adults , and sparse data were collected for 215 patients of all ages in a community setting . The population absorption half-life of lumefantrine was 4.5 h. The model-based median ( 5th and 95th percentiles ) peak plasma lumefantrine concentrations were 6.2 ( 0.25 and 14.8 ) μg/ml after regimen A , 9.0 ( 1.1 and 19.8 ) μg/ml after regimen B , and 8 ( 1.4 and 17.4 ) μg/ml after regimen C. During acute malaria , there was marked variability in the fraction of drug absorbed by patients ( coefficient of variation , 150 % ) . The fraction increased considerably and variability fell with clinical recovery , largely because food intake was resumed ; taking a normal meal close to drug administration increased oral bioavailability by 108 % ( 90 % confidence interval , 64 to 164 ) ( P , 0.0001 ) . The higher-dose regimens ( B and C ) gave 60 and 100 % higher areas under the concentration-time curves ( AUC ) , respectively , and thus longer duration s for which plasma lumefantrine concentrations exceeded the putative in vivo MIC of 280 μg/ml ( median for regimen B , 252 h ; that for regimen C , 298 h ; that for regimen A , 204 h [ P , 0.0001 ] ) and higher cure  rates . Lumefantrine oral bioavailability is very dependent on food and is consequently poor in acute malaria but improves markedly with recovery . The high cure rates with the two six-dose regimens result ed from increased AUC and increased time at which lumefantrine concentrations were above the in vivo MIC BACKGROUND The burden of Plasmodium vivax infections has been underappreciated , especially in southeast Asia where chloroquine resistant strains have emerged . Our aim was to compare the safety and efficacy of dihydroartemisinin-piperaquine with that of artemether-lumefantrine in patients with uncomplicated malaria caused by multidrug-resistant P falciparum and P vivax . METHODS 774 patients in southern Papua , Indonesia , with slide-confirmed malaria were r and omly assigned to receive either artemether-lumefantrine or dihydroartemisinin-piperaquine and followed up for at least 42 days . The primary endpoint was the overall cumulative risk of parasitological failure at day 42 with a modified intention-to-treat analysis . This trial is registered with Clinical Trials.gov , trial number 00157833 . FINDINGS Of the 754 evaluable patients enrolled , 466 had infections with P falciparum , 175 with P vivax , and 113 with a mixture of both species . The overall risk of failure at day 42 was 43 % ( 95 % CI 38 - 48 ) for artemether-lumefantrine and 19 % ( 14 - 23 ) for dihydroartemisinin-piperaquine ( hazard ratio=3.0 , 95 % CI 2.2 - 4.1 , p<0.0 
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INTERPRETATION Our findings show a high risk of vivax parasitaemia after treatment of falciparum malaria , particularly in areas with short relapse periodicity and after rapidly eliminated treatment .
In co-endemic regions , universal radical cure for all patients with uncomplicated malaria has the potential to substantially reduce recurrent malaria .