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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.).
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Antimaláricos , Cloroquina , Malária Vivax , Primaquina , Adolescente , Adulto , Idoso , Antimaláricos/administração & dosagem , Antimaláricos/efeitos adversos , Antimaláricos/uso terapêutico , Brasil , Criança , Pré-Escolar , Cloroquina/administração & dosagem , Cloroquina/efeitos adversos , Cloroquina/uso terapêutico , Terapia Diretamente Observada , Relação Dose-Resposta a Droga , Esquema de Medicação , Humanos , Malária Vivax/tratamento farmacológico , Malária Vivax/prevenção & controle , Pessoa de Meia-Idade , Primaquina/administração & dosagem , Primaquina/efeitos adversos , Primaquina/uso terapêutico , Recidiva , Prevenção Secundária , Adulto JovemRESUMO
BACKGROUND: Plasmodium falciparum is an apicomplexan parasite responsible for lethal cases of malaria. According to WHO recommendations, P falciparum cases are treated with artemisinin-based combination therapy including dihydroartemisinin-piperaquine. However, the emergence of resistant parasites against dihydroartemisinin-piperaquine was reported in southeast Asia in 2008 and, a few years later, suspected in South America. METHODS: To characterise resistance emergence, a treatment efficacy study was performed on the reported patients infected with P falciparum and treated with dihydroartemisinin-piperaquine in French Guiana (n=6, 2016-18). Contemporary isolates collected in French Guiana were genotyped for P falciparum chloroquine resistance transporter (pfCRT; n=845) and pfpm2 and pfpm3 copy number (n=231), phenotyped using the in vitro piperaquine survival assay (n=86), and analysed through genomic studies (n=50). Additional samples from five Amazonian countries and one outside the region were genotyped (n=1440). FINDINGS: In field isolates, 40 (47%) of 86 (95% CI 35·9-57·1) were resistant to piperaquine in vitro; these phenotypes were more associated with pfCRTC350R (ie, Cys350Arg) and pfpm2 and pfpm3 amplifications (Dunn test, p<0·001). Those markers were also associated with dihydroartemisinin-piperaquine treatment failure (n=3 [50%] of 6). A high prevalence of piperaquine resistance markers was observed in Suriname in 19 (83%) of 35 isolates and in Guyana in 579 (73%) of 791 isolates. The pfCRTC350R mutation emerged before pfpm2 and pfpm3 amplification in a temporal sequence different from southeast Asia, and in the absence of artemisinin partial resistance, suggesting a geographically distinctive epistatic relationship between these genetic markers. INTERPRETATION: The high prevalence of piperaquine resistance markers in parasite populations of the Guianas, and the risk of associated therapeutic failures calls for caution on dihydroartemisinin-piperaquine use in the region. Furthermore, greater attention should be given to potential differences in genotype to phenotype mapping across genetically distinct parasite populations from different continents. FUNDING: Pan American Health Organization and WHO, French Ministry for Research, European Commission, Santé publique France, Agence Nationale de la Recherche, Fundação de Amparo à Pesquisa do Estado do Amazonas, Ministry of Health of Brazil, Oswaldo Cruz Foundation, and National Institutes of Health. TRANSLATIONS: For the French and Portuguese translations of the abstract see Supplementary Materials section.
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Antimaláricos , Artemisininas , Malária Falciparum , Malária , Piperazinas , Quinolinas , Humanos , Plasmodium falciparum , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Resistência a Medicamentos/genética , Artemisininas/farmacologia , Artemisininas/uso terapêutico , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Malária/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Resultado do Tratamento , Estudos Epidemiológicos , Proteínas de Protozoários/genética , Proteínas de Protozoários/uso terapêuticoRESUMO
Several technological approaches have been used to develop vaccines against COVID-19, including those based on inactivated viruses, viral vectors, and mRNA. This study aimed to monitor the maintenance of anti-SARS-CoV-2 antibodies in individuals from Brazil according to the primary vaccination regimen, as follows: BNT162b2 (group 1; 22) and ChAdOx1 (group 2; 18). Everyone received BNT162b2 in the first booster while in the second booster CoronaVac, Ad26.COV2.S, or BNT162b2. Blood samples were collected from 2021 to 2023 to analyze specific RBD (ELISA) and neutralizing antibodies (PRNT50). We observed a progressive increase in anti-RBD and neutralizing antibodies in each subsequent dose, remaining at high titers until the end of follow-up. Group 1 had higher anti-RBD antibody titers than group 2 after beginning the primary regimen, with significant differences after the 2nd and 3rd doses. Group 2 showed a more expressive increase after the first booster with BNT162B2 (heterologous booster). Group 2 also presented high levels of neutralizing antibodies against the Gamma and Delta variants until five months after the second booster. In conclusion, the circulating levels of anti-RBD and neutralizing antibodies against the two variants of SARS-CoV-2 were durable even five months after the 4th dose, suggesting that periodic booster vaccinations (homologous or heterologous) induced long-lasting immunity.
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Tumor necrosis factor (TNF) and interferon-gamma (IFNγ) are important inflammatory mediators in the development of cytokine storm syndrome (CSS). Single nucleotide polymorphisms (SNPs) regulate the expression of these cytokines, making host genetics a key factor in the prognosis of COVID-19. In this study, we investigated the associations of the TNF -308G/A and IFNG +874T/A polymorphisms with COVID-19. We analyzed the frequencies of the two polymorphisms in the control groups (CG: TNF -308G/A, n = 497; IFNG +874T/A, n = 397), a group of patients with COVID-19 (CoV, n = 222) and among the subgroups of patients with nonsevere (n = 150) and severe (n = 72) COVID-19. We found no significant difference between the genotypic and allelic frequencies of TNF -308G/A in the groups analyzed; however, both the frequencies of the high expression genotype (TT) (CoV: 13.51% vs. CG: 6.30%; p = 0.003) and the *T allele (CoV: 33.56% vs. CG: 24. 81%; p = 0.001) of the IFNG +874T/A polymorphism were higher in the COVID-19 group than in the control group, with no differences between the subgroups of patients with nonsevere and severe COVID-19. The *T allele of IFNG +874T/A (rs2430561) is associated with susceptibility to symptomatic COVID-19. These SNPs provided valuables clues about the potential mechanism involved in the susceptibility to developing symptomatic COVID-19.
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COVID-19 , Predisposição Genética para Doença , Genótipo , Interferon gama , SARS-CoV-2 , Feminino , Humanos , Masculino , Alelos , COVID-19/genética , COVID-19/virologia , Síndrome da Liberação de Citocina/genética , Frequência do Gene , Interferon gama/genética , Polimorfismo de Nucleotídeo Único , SARS-CoV-2/patogenicidade , Fator de Necrose Tumoral alfa/genéticaRESUMO
The cGAS-STING pathway appears to contribute to dysregulated inflammation during coronavirus disease 2019 (COVID-19); however, inflammatory factors related to long COVID are still being investigated. In the present study, we evaluated the association of cGAS and STING gene expression levels and plasma IFN-α, TNF-α and IL-6 levels with COVID-19 severity in acute infection and long COVID, based on analysis of blood samples from 148 individuals, 87 with acute COVID-19 and 61 in the post-COVID-19 period. Quantification of gene expression was performed by real-time PCR, and cytokine levels were quantified by ELISA and flow cytometry. In acute COVID-19, cGAS, STING, IFN-α, TNF-α, and IL-6 levels were higher in patients with severe disease than in those with nonsevere manifestations (p < 0.05). Long COVID was associated with elevated cGAS, STING and IFN-α levels (p < 0.05). Activation of the cGAS-STING pathway may contribute to an intense systemic inflammatory state in severe COVID-19 and, after infection resolution, induce an autoinflammatory disease in some tissues, resulting in long COVID.
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COVID-19 , Síndrome de COVID-19 Pós-Aguda , Humanos , Interferon-alfa , Interleucina-6 , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Transdução de Sinais/genética , Fator de Necrose Tumoral alfa/genéticaRESUMO
This study aimed to perform morphological and molecular analyses of parasites isolated from the blood of malaria-infected individuals during an outbreak in the Microregion of Cametá, State of Pará, Brazilian Amazon. A total of 260 positive samples were identified by microscopy as Plasmodium vivax; however, in three samples, forms considered unusual for the species were found and defined as morphological atypia of P. vivax. Single P. vivax infection was confirmed by qPCR in all samples. Among 256 genotyped samples, the VK247 genotype alone was identified in 255 samples, and the VK210 genotype was found in only one. The study showed that this malaria outbreak was caused by the etiological agent P. vivax, and for the first time, morphological atypia was described in isolates circulating in Brazil. Likewise, for the first time, the VK247 genotype was detected predominantly in single infections in an area of the State of Pará, which may suggest a greater circulation of the genotype in the region.
Title: Atypie morphologique et profil moléculaire de Plasmodium vivax : résultats issus d'une épidémie en Amazonie brésilienne. Abstract: Cette étude visait à effectuer des analyses morphologiques et moléculaires de parasites isolés du sang d'individus infectés par le paludisme lors d'une épidémie dans la microrégion de Cametá, État du Pará, Amazonie brésilienne. Au total, 260 échantillons positifs ont été identifiés par microscopie comme Plasmodium vivax mais dans trois échantillons, des formes considérées comme inhabituelles pour l'espèce ont été trouvées et définies comme des atypies morphologiques de P. vivax. Une infection simple à P. vivax a été confirmée par qPCR dans tous les échantillons. Sur 256 échantillons génotypés, le génotype VK247 seul a été identifié dans 255 échantillons, et le génotype VK210 a été trouvé dans un seul échantillon. L'étude a montré que cette épidémie de paludisme était causée par l'agent étiologique P. vivax et, pour la première fois, une atypie morphologique a été décrite dans des isolats circulant au Brésil. De même, pour la première fois, le génotype VK247 a été détecté principalement dans des infections uniques dans une zone de l'État de Pará, ce qui peut suggérer une plus grande circulation du génotype dans la région.
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Malária Vivax , Malária , Humanos , Plasmodium vivax , Brasil/epidemiologia , Proteínas de Protozoários/genética , Malária Vivax/epidemiologiaRESUMO
Aiming to evaluate the role of ten functional polymorphisms in long COVID, involved in major inflammatory, immune response and thrombophilia pathways, a cross-sectional sample composed of 199 long COVID (LC) patients and a cohort composed of 79 COVID-19 patients whose follow-up by over six months did not reveal any evidence of long COVID (NLC) were investigated to detect genetic susceptibility to long COVID. Ten functional polymorphisms located in thrombophilia-related and immune response genes were genotyped by real time PCR. In terms of clinical outcomes, LC patients presented higher prevalence of heart disease as preexistent comorbidity. In general, the proportions of symptoms in acute phase of the disease were higher among LC patients. The genotype AA of the interferon gamma (IFNG) gene was observed in higher frequency among LC patients (60%; p = 0.033). Moreover, the genotype CC of the methylenetetrahydrofolate reductase (MTHFR) gene was also more frequent among LC patients (49%; p = 0.045). Additionally, the frequencies of LC symptoms were higher among carriers of IFNG genotypes AA than among non-AA genotypes (Z = 5.08; p < 0.0001). Two polymorphisms were associated with LC in both inflammatory and thrombophilia pathways, thus reinforcing their role in LC. The higher frequencies of acute phase symptoms among LC and higher frequency of underlying comorbidities might suggest that acute disease severity and the triggering of preexisting condition may play a role in LC development.
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COVID-19 , Trombofilia , Humanos , Síndrome de COVID-19 Pós-Aguda , Frequência do Gene , Marcadores Genéticos , Estudos Transversais , COVID-19/genética , Genótipo , Predisposição Genética para Doença , Trombofilia/genética , Polimorfismo de Nucleotídeo Único , Estudos de Casos e ControlesRESUMO
The first case of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in Brazil was diagnosed on February 26, 2020. Due to the important epidemiological impact of COVID-19, the present study aimed to analyze the specificity of IgG antibody responses to the S1, S2 and N proteins of SARS-CoV-2 in different COVID-19 clinical profiles. This study enrolled 136 individuals who were diagnosed with or without COVID-19 based on clinical findings and laboratory results and classified as asymptomatic or as having mild, moderate or severe disease. Data collection was performed through a semistructured questionnaire to obtain demographic information and main clinical manifestations. IgG antibody responses to the S1 and S2 subunits of the spike (S) protein and the nucleocapsid (N) protein were evaluated using an enzyme-linked immunosorbent assay (ELISA) according to the manufacturer's instructions. The results showed that among the participants, 87.5% (119/136) exhibited IgG responses to the S1 subunit and 88.25% (120/136) to N. Conversely, only 14.44% of the subjects (21/136) displayed S2 subunit responses. When analyzing the IgG antibody response while considering the different proteins of the virus, patients with severe disease had significantly higher antibody responses to N and S1 than asymptomatic individuals (p ≤ 0.0001), whereas most of the participants had low antibody titers against the S2 subunit. In addition, individuals with long COVID-19 showed a greater IgG response profile than those with symptomatology of a short duration. Based on the results of this study, it is concluded that levels of IgG antibodies may be related to the clinical evolution of COVID-19, with high levels of IgG antibodies against S1 and N in severe cases and in individuals with long COVID-19.
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COVID-19 , Humanos , Anticorpos Antivirais , Formação de Anticorpos , Imunoglobulina G , Proteínas do Nucleocapsídeo , Síndrome de COVID-19 Pós-Aguda , SARS-CoV-2 , Glicoproteína da Espícula de CoronavírusRESUMO
Interleukin-6 has been recognized as a major role player in COVID-19 severity, being an important regulator of the cytokine storm. Hence, the evaluation of the influence of polymorphisms in key genes of the IL-6 pathway, namely IL6, IL6R, and IL6ST, may provide valuable prognostic/predictive markers for COVID-19. The present cross-sectional study genotyped three SNPs (rs1800795, rs2228145, and rs7730934) at IL6. IL6R and IL6ST genes, respectively, in 227 COVID-19 patients (132 hospitalized and 95 non-hospitalized). Genotype frequencies were compared between these groups. As a control group, published data on gene and genotype frequencies were gathered from published studies before the pandemic started. Our major results point to an association of the IL6 C allele with COVID-19 severity. Moreover, IL-6 plasmatic levels were higher among IL6 CC genotype carriers. Additionally, the frequency of symptoms was higher at IL6 CC and IL6R CC genotypes. In conclusion, the data suggest an important role of IL6 C allele and IL6R CC genotype on COVID-19 severity, in agreement with indirect evidence from the literature about the association of these genotypes with mortality rates, pneumonia, and heightening of protein plasmatic levels pro-inflammatory driven effects.
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COVID-19 , Interleucina-6 , Humanos , Interleucina-6/genética , Estudos Transversais , Receptores de Interleucina-6/genética , COVID-19/genética , Genótipo , Polimorfismo de Nucleotídeo Único , Predisposição Genética para Doença , Receptor gp130 de Citocina/genéticaRESUMO
Introduction: Mannose-binding lectin (MBL) promotes opsonization, favoring phagocytosis and activation of the complement system in response to different microorganisms, and may influence the synthesis of inflammatory cytokines. This study investigated the association of MBL2 gene polymorphisms with the plasma levels of MBL and inflammatory cytokines in COVID-19. Methods: Blood samples from 385 individuals (208 with acute COVID-19 and 117 post-COVID-19) were subjected to real-time PCR genotyping. Plasma measurements of MBL and cytokines were performed by enzyme-linked immunosorbent assay and flow cytometry, respectively. Results: The frequencies of the polymorphic MBL2 genotype (OO) and allele (O) were higher in patients with severe COVID-19 (p< 0.05). The polymorphic genotypes (AO and OO) were associated with lower MBL levels (p< 0.05). IL-6 and TNF-α were higher in patients with low MBL and severe COVID-19 (p< 0.05). No association of polymorphisms, MBL levels, or cytokine levels with long COVID was observed. Discussion: The results suggest that, besides MBL2 polymorphisms promoting a reduction in MBL levels and therefore in its function, they may also contribute to the development of a more intense inflammatory process responsible for the severity of COVID-19.
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COVID-19 , Lectina de Ligação a Manose , Humanos , Fator de Necrose Tumoral alfa/genética , Interleucina-6/genética , Citocinas/genética , Síndrome de COVID-19 Pós-Aguda , COVID-19/genética , Polimorfismo Genético , Lectina de Ligação a Manose/genéticaRESUMO
BACKGROUND: Ensuring the quality of malaria medicines is crucial in working toward malaria control and eventual elimination. Unlike other validated tests that can assess all critical quality attributes, which is the standard for determining the quality of medicines, basic tests are significantly less expensive, faster, and require less skilled labour; yet, these tests provide reproducible data and information on several critical quality attributes, such as identity, purity, content, and disintegration. Visual and physical inspection also provides valuable information about the manufacturing and the labelling of medicines, and in many cases this inspection is sufficient to detect counterfeit medicines. The Promoting the Quality of Medicines (PQM) programme has provided technical assistance to Amazon Malaria Initiative (AMI) countries to implement the use of basic tests as a key screening mechanism to assess the quality of malaria medicines available to patients in decentralized regions. METHODS: Trained personnel from the National Malaria Control Programmes (NMCPs), often in collaboration with country's Official Medicine Control Laboratory (OMCL), developed country- specific protocols that encompassed sampling methods, sample analysis, and data reporting. Sampling sites were selected based on malaria burden, accessibility, and geographical location. Convenience sampling was performed and countries were recommended to store the sampled medicines under conditions that did not compromise their quality. Basic analytical tests, such as disintegration and thin layer chromatography (TLC), were performed utilizing a portable mini-laboratory. RESULTS: Results were originally presented at regional meetings in a non-standardized format that lacked relevant medicines information. However, since 2008 information has been submitted utilizing a template specifically developed by PQM for that purpose. From 2005 to 2010, the quality of 1,663 malaria medicines from seven AMI countries was evaluated, mostly collected from the public sector, 1,445/1,663 (86.9%). Results indicate that 193/1,663 (11.6%) were found not to meet quality specifications. Most failures were reported during visual and physical inspection, 142/1663 (8.5%), and most of these were due to expired medicines, 118/142 (83.1%). Samples failing TLC accounted for 27/1,663 (1.6%) and those failing disintegration accounted for 24/1,663 (1.4%). Medicines quality failures decreased significantly during the last two years. CONCLUSIONS: Basic tests revealed that the quality of medicines in the public sector improved over the years, since the implementation of this type of quality monitoring programme in 2005. However, the lack of consistent confirmatory tests in the quality control (QC) laboratory, utilizing methods that can also evaluate additional quality attributes, could still mask quality issues. In the future, AMI countries should improve coordination with their health authorities and their QC lab consistently, to provide a more complete picture of malaria medicines quality and support the implementation of corrective actions. Facilities in the private and informal sectors also should be included when these sectors constitute an important source of medicines used by malaria patients.
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Antimaláricos/farmacologia , Antimaláricos/normas , Técnicas de Química Analítica , Preparações Farmacêuticas/química , Preparações Farmacêuticas/normas , Antimaláricos/química , Humanos , Malária/tratamento farmacológico , Controle de Qualidade , América do SulRESUMO
Antimalarial Research in the AmazonMany patients who receive treatment for vivax malaria in the Americas present with recurrent infection within six months after completing treatment. This raises an important question: Does higher-dose primaquine work better than the treatment currently used in the Americas to prevent recurrences? This Clinical Trial Case Study describes the behind-the-scenes story of a randomized trial to evaluate antimalarial treatment efficacy in the Brazilian Amazon.
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Antimaláricos , Malária Vivax , Primaquina , Humanos , Antimaláricos/uso terapêutico , Brasil/epidemiologia , Malária Vivax/tratamento farmacológico , Malária Vivax/epidemiologia , Malária Vivax/prevenção & controle , Primaquina/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
The duration and severity of COVID-19 are related to age, comorbidities, and cytokine synthesis. This study evaluated the impact of these factors on patients with clinical presentations of COVID-19 in a Brazilian cohort. A total of 317 patients diagnosed with COVID-19 were included; cases were distributed according to clinical status as severe (n=91), moderate (n=56) and mild (n=170). Of these patients, 92 had acute COVID-19 at sample collection, 90 had already recovered from COVID-19 without sequelae, and 135 had sequelae (long COVID syndrome). In the acute COVID-19 group, patients with the severe form had higher IL-6 levels (p=0.0260). In the post-COVID-19 group, there was no significant difference in cytokine levels between groups with different clinical conditions. In the acute COVID-19 group, younger patients had higher levels of TNF-α, and patients without comorbidities had higher levels of TNF-α, IL-4 and IL-2 (p<0.05). In contrast, patients over age 60 with comorbidities had higher levels of IL-6. In the post-COVID-19 group, subjects with long COVID-19 had higher levels of IL-17 and IL-2 (p<0.05), and subjects without sequelae had higher levels of IL-10, IL-6 and IL- 4 (p<0.05). Our results suggest that advanced age, comorbidities and elevated serum IL-6 levels are associated with severe COVID-19 and are good markers to differentiate severe from mild cases. Furthermore, high serum levels of IL-17 and IL-2 and low levels of IL-4 and IL-10 appear to constitute a cytokine profile of long COVID-19, and these markers are potential targets for COVID-19 treatment and prevention strategies.
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Tratamento Farmacológico da COVID-19 , COVID-19 , Biomarcadores , COVID-19/complicações , Citocinas , Humanos , Interleucina-10 , Interleucina-17 , Interleucina-2 , Interleucina-4 , Interleucina-6 , Pessoa de Meia-Idade , SARS-CoV-2 , Fator de Necrose Tumoral alfa , Síndrome de COVID-19 Pós-AgudaRESUMO
Histidine-rich proteins 2 and 3 gene (pfhrp2 and pfhrp3) deletions affect the efficacy of rapid diagnostic tests (RDTs) based on the histidine-rich protein 2 (HRP2), compromising the correct identification of the Plasmodium falciparum species. Therefore, molecular surveillance is necessary for the investigation of the actual prevalence of this phenomenon and the extent of the disappearance of these genes in these areas and other South American countries, thus guiding national malaria control programs on the appropriate use of RDTs. This study aimed to evaluate the pfhrp2 and pfhrp3 gene deletion in P. falciparum in endemic areas of the Brazilian Amazon. Aliquots of DNA from the biorepository of the Laboratory of Basic Research in Malaria, Evandro Chagas Institute, with a positive diagnosis for P. falciparum infection as determined by microscopy and molecular assays, were included. Monoinfection was confirmed by nested-polymerase chain reaction assay, and DNA quality was assessed by amplification of the merozoite surface protein-2 gene (msp2). The pfhrp2 and pfhrp3 genes were amplified using primers for the region between exons 1 and 2 and for all extension of exon 2. Aliquots of DNA from 192 P. falciparum isolates were included in the study, with 68.7% (132/192) from the municipality of Cruzeiro do Sul (Acre) and 31.3% (60/192) from Manaus (Amazonas). Of this total, 82.8% (159/192) of the samples were considered of good quality. In the state of Acre, 71.7% (71/99) showed pfhrp2 gene deletion and 94.9% (94/99) showed pfhrp3 gene deletion, while in the state of Amazonas, 100.0% (60/60) of the samples showed pfhrp2 gene deletion and 98.3% (59/60) showed pfhrp3 gene deletion. Moreover, 79.8% (127/159) of isolates displayed gene deletion. Our findings confirm the presence of a parasite population with high frequencies of pfhrp2 and pfhrp3 gene deletions in the Brazilian Amazon region. This suggests reconsidering the use of HRP2-based RDTs in the Acre and Amazonas states and calls attention to the importance of molecular surveillance and mapping of pfhrp2/pfhrp3 deletions in this area and in other locations in the Amazon region to guarantee appropriate patient care, control and ultimately contribute to achieving P. falciparum malaria elimination.
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Plasmodium falciparum/genética , Proteínas/genética , Proteínas de Protozoários , Antígenos de Protozoários/genética , Brasil/epidemiologia , Testes Diagnósticos de Rotina , Deleção de Genes , Humanos , Malária Falciparum , Proteínas de Protozoários/genéticaRESUMO
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.
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Artemisininas/farmacologia , Resistência a Medicamentos/genética , Malária Falciparum/parasitologia , Mutação/genética , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Genótipo , Humanos , Fenótipo , Plasmodium falciparum/efeitos dos fármacosRESUMO
Conventional molecular methods, such as nested polymerase chain reaction (PCR), are very sensitive for detection of malaria parasites, but require advanced laboratory equipment and trained personnel. Real-time loop-mediated isothermal amplification (RealAmp), a loop-mediated isothermal amplification-based molecular tool (LAMP), facilitates rapid target amplification at a single temperature setting, reducing the need for sophisticated equipment. We evaluated the performance of a field-adapted RealAmp assay for malaria diagnosis in Cruzeiro do Sul, Acre State, Brazil, a remote area in Brazil with limited laboratory capabilities. We enrolled 1,000 patients with fever (axillary temperature ≥ 37.5 C) or history of fever in last 24 h presenting for malaria diagnosis from February through June 2015. DNA was extracted from dried blood spots using a boil and spin method (heat treatment) at the sample processing site, and also using commercial kits at a Brazilian national reference laboratory. RealAmp was performed for Plasmodium genus, P. falciparum, and P. vivax identification. In addition, Giemsa-stained blood smears were prepared and examined by two independent well-trained study microscopists. A combination of Real-time PCR and nested PCR was used as reference test. The sensitivity and specificity of RealAmp in the field site laboratory were 94.1% (95% confidence interval [CI]: 90.1-96.8) and 83.9% (95% CI: 81.1-86.4), respectively. The sensitivity and specificity of local microscopy were 87.7% (95% CI: 82.6-91.7) and 98.9% (95% CI: 97.8-99.4), respectively, while study microscopy showed sensitivity of 96.4% (95% CI: 93.0-98.4) and specificity of 98.2% (95% CI: 97.0-99.0). None of the three tests detected 20 P. falciparum and P. vivax mixed infections identified by the reference test. Our findings highlight that it is possible to implement simple molecular tests in facilities with limited resources such as Cruzeiro do Sul in Brazil. RealAmp sensitivity was similar to that of microscopy performed by skilled professionals; both RealAmp and study microscopy performed poorly in detection of mixed infection. Attempts to develop and evaluate simpler molecular tools should continue, especially for the detection of malaria infection in remote areas.
Assuntos
Malária Falciparum , Malária Vivax , Técnicas de Amplificação de Ácido Nucleico/métodos , Plasmodium falciparum/genética , Plasmodium vivax/genética , Brasil , Feminino , Humanos , Malária Falciparum/sangue , Malária Falciparum/diagnóstico , Malária Falciparum/genética , Malária Vivax/sangue , Malária Vivax/diagnóstico , Malária Vivax/genética , Masculino , Sensibilidade e EspecificidadeRESUMO
We evaluated the therapeutic efficacy of artemether-lumefantrine (AL) fixed-dose combination to treat uncomplicated Plasmodium falciparum malaria in Cruzeiro do Sul, Acre State, in the Amazon region of Brazil. Between December 2015 and May 2016, we enrolled 79 patients, 5-79 years old with fever or history of fever in the previous 48 hours and P. falciparum monoinfection confirmed by microscopy. Attempts were made to provide direct observation or phone reminders for all six doses of AL, and patients were followed-up for 28 days. AL was well tolerated, with no adverse events causing treatment interruption. All but one of the 74 patients who completed the 28-day follow-up had an adequate clinical and parasitologic response = 98.6% (95% CI: 93.2-100%). We could not amplify the one isolate of the case with recurrent infection to differentiate between recrudescence and reinfection. Five (6.3%) patients demonstrated persistent asexual parasitemia on Day 3, but none met definition for early treatment failure. We found no mutations in selected kelch13 gene domains, known to be associated with artemisinin resistance in P. falciparum isolates from Day 0. These results strongly support the continued use of AL as a first-line therapy for uncomplicated P. falciparum malaria in Acre. Routine monitoring of in vivo drug efficacy coupled with molecular surveillance of drug resistance markers remains critical.
Assuntos
Combinação Arteméter e Lumefantrina/uso terapêutico , Malária Falciparum/tratamento farmacológico , Plasmodium gallinaceum/efeitos dos fármacos , Adolescente , Adulto , Idoso , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Malária Falciparum/epidemiologia , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: The objective of this prospective study was to verify the effectiveness of a multidisciplinary surveillance program that was implemented in a teaching hospital in southern Brazil, to prevent and control the spread of multidrug-resistant organisms. METHODS: The program implemented involved establishment of prevention guidelines, hand-hygiene promotion, isolation of patients colonized or infected by such organisms, enforced contact precautions, and terminal cleaning and disinfection of isolation rooms. A microbiology service, previously provided by an external laboratory, was established in the hospital. Detection of bacteria-resistant genes and molecular typing were performed also. RESULTS: Statistically significant differences were observed between the pre- and post-intervention periods (P = .00198). Control measures were effective in blocking the dissemination of a previously endemic clone of Acinetobacter baumannii. Changes were observed in the dissemination pattern, from a monoclonal to a polyclonal mode. The incidence of vancomycin-resistant Enterococcus during the surveillance period was low. Only 2 isolates of BLAKPC-positive Klebsiella pneumoniae (distinct profiles), and 5 isolates of BLASPM-positive Pseudomonas aeruginosa (a single cluster), were detected. CONCLUSIONS: These results indicate that the surveillance program implemented was effective in preventing the spread of multidrug-resistant organisms in the hospital.
Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla , Monitoramento Epidemiológico , Bactérias/genética , Bactérias/isolamento & purificação , Técnicas de Tipagem Bacteriana , Hospitais de Ensino , Humanos , Controle de Infecções , Testes de Sensibilidade Microbiana , FilogeniaRESUMO
A low body mass index (BMI) and serum albumin are associated with increased risk of mortality in patients with chronic kidney disease (CKD). The purpose of this study was to evaluate BMI and serum albumin as predictors of all-cause and cardiovascular (CV) mortality in hemodialysed (HD) patients. We describe the results of a five-year retrospective observational study with 187 HD patients (54.9 +/- 15.6 years old, 54% men, and 46% suffering from diabetes) from RenalCor Clinic in Rio de Janeiro, Brazil. The influence of serum albumin levels and BMI (determined every three months) over all-cause mortality was examined using a Cox model, while the influence of the same factors over CV mortality among all-cause mortality was modeled through a logistic regression. During the five years, 26.7% of the patients died, 62% of which due to CV disease (CVD). Analysis by the Cox model showed that low serum albumin and low BMI were significant predictors of mortality. Patients with higher BMI had a lower hazard of death for all-cause mortality (hazard ratio [HR] = 0.92; P ( )= 0.035) and a 1 g/l increase in serum albumin was associated with significantly lower hazard of death (hazard ratio = 0.9679; P < 0.001). The highest BMI value (>30 kg/m(2)) was significantly associated with an increase of odds of CV mortality (odds ratio = 1.22, P = 0.03). We confirm here in a Brazilian cohort of hemodialysis patients that both low BMI (<19 kg/m(2)) and hypoalbuminemia are strong predictors of death.