ABSTRACT Background: Some studies have suggested the importance of vitamin D [25(OH)D] in malaria clinical practice. The prevalence of 25(OH)D deficiency in the Amazon population is not well known, and there are few studies in patients with malaria. This study aimed to evaluate 25(OH)D serum levels in patients with malaria and determine their relationships with epidemiological, clinical, laboratory, and parasitemia data. Methods: An analytical cross-sectional study of 123 patients with malaria and 122 individuals without malaria was performed in Itaituba, Pará, Brazil, from January 2018 to October 2019, by evaluating sociodemographic, clinical-epidemiological, parasitological, and laboratory data and adopting a 5% significance level. Parametric tests (Student's t-test), non-parametric tests (Mann-Whitney U), and Spearman’s correlation ([rs], for non-parametric variables) were used according to the nature of the distribution of the variables. For the qualitative variables, Pearson's chi-square test, Fisher's exact test, and the G test were used. Spearman's correlation was used to compare the results of the 25(OH)D levels and blood counts performed among patients and the control group. Results: Malaria patients residing in a mining area had 25(OH)D serum levels that were significantly lower than those in the control group residing in the mining area, though both were within normal levels. Red blood cell counts had an inverse correlation with parasitemia (Plasmodium falciparum), and platelet levels had an inverse correlation with parasitemia (Plasmodium vivax). 25(OH)D deficiency was evidenced in Itaituba, in the state of Pará, which is an endemic area of malaria in the Amazon region.

Abstract INTRODUCTION Mutations in the propeller domain of the Plasmodium falciparum kelch13 (k13) gene are associated with artemisinin resistance. METHODS: We developed a PCR protocol to sequence the pfk13 gene and determined its sequence in a batch of 50 samples collected from 2003 to 2016 in Brazil. RESULTS: We identified 1 K189T substitution located outside the propeller domain of the PfK13 protein in 36% of samples. CONCLUSIONS: Although the sample size is relatively small, these results suggest that P. falciparum artemisinin-resistant mutants do not exist in Brazil, thereby supporting the continuation of current treatment programs based on artemisinin-based combination therapy.

Malaria remains a major public health problem in Brazil where Plasmodium vivax is the predominant species, responsible for 82% of registered cases in 2013. Though benign, P. vivax infection may sometimes evolve with complications and a fatal outcome. Here, we report a severe case of P. vivax malaria in a 35-year-old Brazilian man from a malaria endemic area, who presented with reversible myocarditis.

OBJETIVOS: avaliar a resposta de anticorpos IgG anti-P. vivax (IgG anti-PV) e suas subclasses citofílicas (IgG1 e IgG3) e não citofílicas (IgG2), em 34 crianças com malária por P. vivax, de 0 a 15 anos de idade. MÉTODOS: os níveis de anticorpos IgG foram mensurados pela técnica de imunofluorescência indireta, durante a fase aguda e de controle de cura. Os pacientes foram distribuídos em dois grupos, de priminfectados e pacientes com história de malária anterior. Os níveis de anticorpos no dia do início do tratamento (ou dia zero) e no último dia de tratamento (ou D7) foram comparados (teste t de Student) e correlacionados com a parasitemia assexuada nos dois grupos (Correlação de Spearman). RESULTADOS E CONCLUÕES : foi observado aumento inicial significativo dos títulos de IgG anti-PV no início e no final do tratamento. As médias geométricas dos títulos de subclasses de IgG anti-PV encontradas nos pacientes com história prévia de malária foram IgG1 (806,35) > IgG3 (28,28) > IgG2 (20). Nos pacientes priminfectados as respostas obtidas foram IgG1 (709,21) > IgG3 (39,3) > IgG2 (10,7). Não ocorreu associação entre parasitemia assexuada e títulos de IgG anti-PV no primeiro dia de tratamento. Houve predominância de anticorpos citofílicos (IgG1> IgG3) sobre os não citofílicos.

OBJECTIVE: To assess the IgG antibody response against P. vivax (IgG anti-PV), and cytophilic (IgG1 and IgG3) and noncytophilic (IgG2) IgG subclasses in 34 children aged 0 to 15 years old infected with P. vivax malaria. METHODS: IgG levels were determined by indirect fluorescent antibody technique during the acute and therapeutic control phase. Patients were distributed into 2 groups according to the presence or absence of a previous malaria episode. IgG anti-PV levels were measured on the first and last day of treatment, and compared by Student's t test. Antibody levels were correlated with asexual parasitemia (Spearman's correlation test). RESULTS AND CONCLUSIONS : Increased IgG levels were observed on the first and on the last day of treatment. The geometric means for IgG subclass titers found in patients with previous history of malaria were: IgG1 (806.35) > IgG3 (28.28) > IgG2 (20). In patients infected for the first time, the responses obtained were: IgG1 (709.21) > IgG3 (39.3) > IgG2 (10.7). There was no association between asexual parasitemia and antibody levels on the first day of treatment. Cytophilic antibodies (IgG1, IgG3) predominated over noncytophilic antibodies (IgG2).