***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: Abstract The prophylactic and sporontocidal efficacy of st and ard antimalarials was studied among non-immune adult male volunteers challenged by mosquitoes heavily infected with two strains of chloroquine resistant Plasmodium falciparum from Malaya . The Poo . strain from Trengganu broke through in 12 of 15 men receiving chloroquine 300 mg . ( base ) and primaquine 45 mg . ( base ) at weekly intervals , whereas 8 weeks of this treatment protected all 3 men challenged with the Tay . strain from Kota Tinggi , Johore State . The Poo . strain broke through in 5 men given amodiaquine base 300 mg . and DDS 300 mg . weekly . Proguanil 200 mg . ( 2·1–3·2 mg . per kg . body weight ) given daily for 8 weeks after challenge provided complete suppression of the Poo . strain in 4 men ( and probably a fifth ) , and also of the Tay . strain in 4 men , nor did parasitaemia develop after completion of the prophylactic course . Pyrimethamine 25 mg . given weekly failed to protect 2 of 3 men challenged with Poo . , and the Tay . strain also broke through in both men receiving this regimen . A single dose of 45 mg . ( base ) of primaquine was gametocytocidal for both strains and , in one case of Poo . infection studied , rendered gametocytes non-infective to an efficient vector mosquito fed on the patient 24 hours later Background Resistance of malaria parasites to chloroquine ( CQ ) and sulphadoxine-pyrimethamine ( SP ) is increasing in prevalence in Africa . Combination therapy can both improve treatment and provide important public health benefits if it curbs the spread of parasites harbouring resistance genes . Thus , drug combinations must be identified which minimise gametocyte emergence in treated cases , and so prevent selective transmission of parasites resistant to any of the partner drugs . Methods and Findings In a r and omised controlled trial , 497 children with uncomplicated falciparum malaria were treated with CQ and SP ( three doses and one dose respectively ; n = 91 ) , or six doses of artemether in fixed combination with lumefantrine ( co-artemether [ Coartem , Riamet ] ) ( n = 406 ) . Carriage rates of Plasmodium falciparum gametocytes and trophozoites were measured 7 , 14 , and 28 d after treatment . The infectiousness of venous blood from 29 children carrying P. falciparum gametocytes 7 d after treatment was tested by membrane-feeding of Anopheles mosquitoes . Children treated with co-artemether were significantly less likely to carry gametocytes within the 4 weeks following treatment than those receiving CQ/SP ( 30 of 378 [ 7.94 % ] versus 42 of 86 [ 48.8 % ] ; p < 0.0001 ) . Carriers in the co-artemether group harboured gametocytes at significantly lower densities , for shorter periods ( 0.3 d versus 4.2 d ; p < 0.0001 ) and were less infectious to mosquitoes at day 7 ( p < 0.001 ) than carriers who had received CQ/SP . Conclusions Co-artemether is highly effective at preventing post-treatment transmission of P. falciparum . Our results suggest that co-artemether has specific activity against immature sequestered gametocytes , and has the capacity to minimise transmission of drug-resistant parasites Background The combination of artesunate and mefloquine has been reported to be effective against multi-drug resistant Plasmodium falciparum malaria , which has been reported in Nigeria . The objective of this multi-centre study was to evaluate the efficacy , safety and tolerability of the co-packaged formulation of artesunate and mefloquine in the treatment of uncomplicated malaria in two weight groups : those between 15 – 29 kg and ≥ 30 kg respectively . Methods The trial was conducted in rural communities in the north-east , north- central , south-west and south-eastern parts of Nigeria . The WHO protocol for testing antimalarial drugs was followed . Out patients having amongst other criteria , parasite density of ≥1,000 μl were enrolled . The co-packaged drugs were administered for 3 days at a dosage of artesunate , 4 mg/kg body wt/day and mefloquine , 25 mg/kg/body wt total ) on days 0 , 1 and 2 . Patients were followed up for 28 days with the assessment of the parasitological parameters on days 1 , 2 , 3 , 7 , and 28 . Results Four hundred and forty-six ( 446 ) patients were enrolled and 431 completed the study . Cure rates in both treatment groups was > 90 % at day 28 . The mean parasite clearance times in treatment groups I and II were 40.1 and 42.4 hours respectively . The combination of artesunate and mefloquine  showed good gametocidal activity , ( gametocyte clearance time of 42.0 & 45.6 hours in treatment groups I and II respectively ) . There were no serious adverse events . Other adverse events observed were headache , dizziness , vomiting and abdominal discomfort . There was no significant derangement in the haematological and biochemical parameters . Conclusion This co-packaged formulation of artesunate + mefloquine ( Artequin ™ ) is highly efficacious , safe and well-tolerated . It is recommended for the treatment of uncomplicated P. falciparum malaria in Nigeria ABSTRACT The activities of primaquine in combination with quinine or artesunate against asexual- and sexual-stage parasites were assessed in 176 adult Thai patients with uncomplicated Plasmodium falciparum malaria . Patients were r and omized to one of the six following 7-day oral treatment regimens : ( i ) quinine alone , ( ii ) quinine with tetracycline , ( iii ) quinine with primaquine at 15 mg/day , ( iv ) quinine with primaquine at 30 mg/day , ( v ) artesunate alone , or ( vi ) artesunate with primaquine .  Clinical recovery occurred in all patients . There were no significant differences in fever clearance times , rates of P. falciparum reappearance , or recurrent vivax malaria between the six treatment groups . Patients treated with artesunate alone or in combination with primaquine had significantly shorter parasite clearance times ( mean ± st and ard deviation = 65± 18 versus 79 ± 21 h ) and lower gametocyte carriage rates ( 40 versus 62.7 % ) than those treated with quinine ( P ≤ 0.007 ) . Primaquine did not affect the therapeutic response ( P > 0.2 ) . Gametocytemia was detected in 98 patients ( 56 % [ 22 % before treatment and 34 % after treatment ] ) . Artesunate reduced the appearance of gametocytemia ( relative risk [ 95 % confidence interval ] = 0.34 [ 0.17 to 0.70 ] ) , whereas combinations containing primaquine result ed in shorter gametocyte clearance times ( medians of 66 versus 271 h for quinine groups and 73 versus 137 h for artesunate groups ; P≤ 0.038 ) . These results suggest that artesunate predominantly inhibits gametocyte development whereas primaquine accelerates gametocyte clearance in P. falciparum malaria Background Artesunate and amodiaquine ( AS&AQ ) is at present the world 's second most widely used artemisinin-based combination therapy ( ACT ) . It was necessary to evaluate the efficacy of ACT , recently adopted by the World Health Organization ( WHO ) and deployed over 80 countries , in order to make an evidence -based drug policy . Methods An individual patient data ( IPD ) analysis was conducted on efficacy outcomes in 26 clinical studies in sub-Saharan Africa using the WHO protocol with similar primary and secondary endpoints . Results A total of 11,700 patients ( 75 % under 5 years old ) , from 33 different sites in 16 countries were followed for 28 days . Loss to follow-up was 4.9 % ( 575/11,700 ) . AS&AQ was given to 5,897 patients . Of these , 82 % ( 4,826/5,897 ) were included in r and omized comparative trials with polymerase chain reaction ( PCR ) genotyping results and compared to 5,413 patients ( half receiving an ACT).AS&AQ and other ACT comparators result ed in rapid clearance of fever and parasitaemia , superior to non-ACT . Using survival analysis on a modified intent-to-treat population , the Day 28 PCR-adjusted efficacy of AS&AQ was greater than 90 % ( the WHO cut-off ) in 11/16 countries . In r and omized comparative trials ( n = 22 ) , the crude efficacy of AS&AQ was 75.9 % ( 95 % CI 74.6–77.1 ) and the PCR-adjusted efficacy was 93.9 % ( 95 % CI 93.2–94.5 ) . The risk ( weighted by site ) of failure PCR-adjusted of AS&AQ was significantly inferior to non-ACT , superior to dihydroartemisinin-piperaquine ( DP , in one Ug and an site ) , and not different from AS+SP or AL ( artemether-lumefantrine ) . The risk of gametocyte appearance and the carriage rate of AS&AQ was only greater in one Ug and an site compared to AL and DP , and lower compared to non-ACT ( p = 0.001 , for all comparisons ) . Anaemia recovery was not different than comparator groups , except in one site in Rw and a where the patients in the DP group had a slower recovery . Conclusion AS&AQ compares well to other treatments and meets the WHO efficacy criteria for use against falciparum malaria in many , but not all , the sub-Saharan African countries where it was studied . Efficacy varies between and within countries . An IPD analysis can inform general and local treatment policies . Ongoing monitoring evaluation is required Background The gametocyte sex ratio of Plasmodium falciparum , defined as the proportion of gametocytes that are male , may influence transmission but little is known of the effects of mefloquine or artesunate-mefloquine on gametocyte sex ratio and on the sex ratio of first appearing gametocytes . Methods 350 children with uncomplicated P. falciparum malaria were enrolled in prospect i ve treatment trial of mefloquine or artesunate-mefloquine between 2007 and 2008 .  Gametocytaemia was quantified , and gametocytes were sexed by morphological appearance , before and following treatment . The area under curve of gametocyte density versus time ( AUCgm ) was calculated by linear trapezoidal method . Results 91 % and 96 % of all gametocytes appeared by day 7 and day 14 , respectively following treatment . The overall rate of gametocytaemia with both treatments was 31 % , and was significantly higher in mefloquine than in artesunate-mefloquine treated children if no gametocyte was present a day after treatment began ( 25.3 % v 12.8 % , P = 0.01 ) . Gametocyte clearance was significantly faster with artesunate-mefloquine ( 1.8 ± 0.22 [ sem ] v 5.6 ± 0.95 d ; P = 0.001 ) . AUCgm was significantly lower in the artesunate mefloquine group ( P = 0.008 ) . The pre-treatment sex ratio was male-biased , but post-treatment sex ratio or the sex ratio of first appearing gametocytes , was significantly lower and female-biased two or three days after beginning of treatment in children given artesunate-mefloquine . Conclusion Addition of artesunate to mefloquine significantly modified the emergence , clearance , and densities of gametocytes and has short-lived , but significant , sex ratio modifying effects in children from this endemic area Background Artemisinin-based combination therapy ( ACT ) is being widely promoted as a strategy to counteract the increase in Plasmodium falciparum antimalarial drug resistance . Methods A r and omized , double-blind , placebo-controlled , clinical trial of the efficacy , effect on gametocytes and safety of the addition of artesunate/placebo ( 4 mg/kg/day × 3 d ) to amodiaquine ( 10 mg/kg/day × 3 d ) was conducted in Choco department , a low intensity transmission area in northwest Colombia . Results From 2,137 screened subjects , 85 entered the study : 43 in the amodiaquine plus placebo and 42 in the amodiaquine plus artesunate groups . Potentially eligible cases failed to qualify mostly because they were not available for follow-up visits ( 73 % ) . Based on a per protocol analysis , the therapeutic response to both treatments was high : amodiaquine/placebo 35/36 , 97.2 % ( 95 % CI 85.5–99.9 ) , and amodiaquine/artesunate 32/32 , 100 % ( 89.1–100 ) after PCR genotyping . The Kaplan-Meier 
    Output:
    
In non-comparative longitudinal studies , the use of a single-dose of primaquine was shown to deter the transmission of malaria briefly .
Conclusion Evidence on the transmission blocking effect of artemisinin derivatives and primaquine is conclusive .