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Abstract Background Studies in South-East Asia have suggested that early diagnosis and treatment with artesunate (AS) and mefloquine (MQ) combination therapy may reduce the transmission of Plasmodium falciparum malaria and the progression of MQ resistance. Methods The effectiveness of a fixed-dose combination of AS and MQ (ASMQ) in reducing malaria transmission was tested in isolated communities of the Juruá valley in the Amazon region. Priority municipalities within the Brazilian Legal Amazon area were selected according to pre-specified criteria. Routine national malaria control programmatic procedures were followed. Existing health structures were reinforced and health care workers were trained to treat with ASMQ all confirmed falciparum malaria cases that match inclusion criteria. A local pharmacovigilance structure was implemented. Incidence of malaria and hospitalizations were recorded two years before, during, and after the fixed-dose ASMQ intervention. In total, between July 2006 and December 2008, 23,845 patients received ASMQ. Two statistical modelling approaches were applied to monthly time series of P. falciparum malaria incidence rates, P. falciparum/Plasmodium vivax infection ratio, and malaria hospital admissions rates. All the time series ranged from January 2004 to December 2008, whilst the intervention period span from July 2006 to December 2008. Results The ASMQ intervention had a highly significant impact on the mean level of each time series, adjusted for trend and season, of 0.34 (95%CI 0.20 – 0.58) for the P. falciparum malaria incidence rates, 0.67 (95%CI 0.50 – 0.89) for the P. falciparum/P. vivax infection ratio, and 0.53 (95%CI 0.41 – 0.69) for the hospital admission rates. There was also a significant change in the seasonal (or monthly) pattern of the time series before and after intervention, with the elimination of the malaria seasonal peak in the rainy months of the years following the introduction of ASMQ. No serious adverse events relating to the use of fixed-dose ASMQ were reported. Conclusions In the remote region of the Juruá valley, the early detection of malaria by health care workers and treatment with fixed-dose ASMQ was feasible and efficacious, and significantly reduced the incidence and morbidity of P. falciparum malaria.

Introduction: The present study is a systematic review of the literature on the efficacy and safety of the treatment of uncomplicated Plasmodium falciparum infections with artesunate-mefloquine (ASMQ) compared to other artemisinin-based combination therapies (ACTs), designed to assist decision makers in Brazil. Methods: Twenty-four randomized controlled trials (RCTs) were selected in four electronic databases and in complementary sources. Meta-analyses were performed to evaluate the efficacy expressed by relative risks (RR) obtained from treatment failure confirmed by the PCR. Results: Due primarily to the presence of measurement bias in the selected studies, the quality of the evidence was considered predominantly moderate. Statistically significant associations were not observed when ASMQ was compared to artemether-lumefentrine and dihydroartemisinin-piperaquine. The results of studies performed in areas with a history of use of ASMQ, regardless of the intensity of transmission, were not statistically different from those presented in the meta-analyses. For comparisons with artesunate-amodiaquine and artesunate+sulfadoxine-pyrimethamine, the results were favourable to ASMQ. No deaths were attributed to ASMQ, severe adverse events were rare and some studies indicate a higher frequency of mild adverse events. Conclusions: The use of ASMQ it is recommended to Brazil as first line treatment of uncomplicated P. falciparum infections. [ABSTRACT FROM AUTHOR]

Background: In most of the Americas, the recommended treatment to prevent relapse of Plasmodium vivax malaria is primaquine at a total dose of 3.5 mg per kilogram of body weight, despite evidence of only moderate efficacy.Methods: In this trial conducted in Brazil, we evaluated three primaquine regimens to prevent relapse of P. vivax malaria in children at least 5 years of age and in adults with microscopy-confirmed P. vivax monoinfection. All the patients received directly observed chloroquine for 3 days (total dose, 25 mg per kilogram). Group 1 received a total primaquine dose of 3.5 mg per kilogram (0.5 mg per kilogram per day) over 7 days with unobserved administration; group 2 received the same regimen as group 1 but with observed administration; and group 3 received a total primaquine dose of 7.0 mg per kilogram over 14 days (also 0.5 mg per kilogram per day) with observed administration. We monitored the patients for 168 days.Results: We enrolled 63 patients in group 1, 96 in group 2, and 95 in group 3. The median age of the patients was 22.4 years (range, 5.4 to 79.8). By day 28, three P. vivax recurrences were observed: 2 in group 1 and 1 in group 2. By day 168, a total of 70 recurrences had occurred: 24 in group 1, 34 in group 2, and 12 in group 3. No serious adverse events were noted. On day 168, the percentage of patients without recurrence was 58% (95% confidence interval [CI], 44 to 70) in group 1, 59% (95% CI, 47 to 69) in group 2, and 86% (95% CI, 76 to 92) in group 3. Survival analysis showed a difference in the day 168 recurrence-free percentage of 27 percentage points (97.5% CI, 10 to 44; P<0.001) between group 1 and group 3 and a difference of 27 percentage points (97.5% CI, 12 to 42; P<0.001) between group 2 and group 3.Conclusions: The administration of primaquine at a total dose of 7.0 mg per kilogram had higher efficacy in preventing relapse of P. vivax malaria than a total dose of 3.5 mg per kilogram through day 168. (Supported by the U.S. Agency for International Development; ClinicalTrials.gov number, NCT03610399.). [ABSTRACT FROM AUTHOR]

Brazilian garimpeiros are a highly hard-to-reach and mobile population, with little access to basic hygiene and health services, and have been crossing the border to work irregularly in gold mines in French Guiana since the 1990s. This study aimed to characterize this population and identify their main health problems. A cross-sectional study was carried out in the municipality of Oiapoque-AP, with two surveys: before (2018) and after (2019) the implementation of Malakit. Individuals were recruited from resting places and given a questionnaire regarding demographic variables, history and knowledge of malaria, and health issues in the mines. Simultaneously, a clinical evaluation was performed. The garimpeiros were mainly men from Maranhão, Pará, and Amapá, with a low educational level and who had worked on average for 10 years in the mining sites. The study population mentioned numerous health problems: malaria, followed by leishmaniasis, flu, body aches, headaches, and digestive problems. Other diseases mentioned were skin diseases, bat bites, hepatitis, and HIV infection. This vulnerable population is constantly subjected to heavy routines and exposed to different diseases and infections that can spread across borders. Knowledge of this is essential for developing public health policies that can be integrated into specific epidemiological situations.