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1.
Curr Top Membr ; 94: 107-132, 2024.
Article in English | MEDLINE | ID: mdl-39370204

ABSTRACT

Malaria is a life-threatening disease caused by parasites from the genus Plasmodium. Five species can cause malaria in humans, with Plasmodium vivax being the most common in many countries and Plasmodium falciparum having the highest lethality, which can lead to cerebral malaria. Extracellular vesicles (EVs) are in focus in malaria research to better understand pathogenesis, diagnosis, therapy, and prognosis. Malaria-causing parasites use EVs to transfer their molecules to host cells, a mechanism that significantly contributes to parasite survival and successful infection. EVs have thus emerged as an essential component of the immunopathological cascade of malaria, playing a pivotal role in disease progression and severity. This chapter discusses the epidemiology and pathogenesis of malaria and the role of EVs as new diagnostic and therapeutic tools, emphasizing their potential clinical significance.


Subject(s)
Extracellular Vesicles , Malaria , Extracellular Vesicles/metabolism , Humans , Malaria/diagnosis , Malaria/metabolism , Malaria/drug therapy , Animals
2.
Mem Inst Oswaldo Cruz ; 119: e240116, 2024.
Article in English | MEDLINE | ID: mdl-39383404

ABSTRACT

BACKGROUND: Anopheles darlingi is the most efficient vector of malaria parasites in the Neotropics. Nevertheless, the specificities of its larval habitats are still poorly known. OBJECTIVES: Characterize permanent larval habitats, and population dynamics of An. darlingi and other potential vectors in relation to climate, physicochemical variables, insect fauna and malaria cases. METHODS: A 14-month longitudinal study was conducted in Porto Velho, Rondônia, western Brazilian Amazon. Monthly, 21 permanent water bodies were sampled. Immature anophelines and associated fauna were collected, physicochemical characteristics, and climate variables were recorded and analyzed. FINDINGS: Five types of habitats were identified: lagoon, stream, stream combined with lagoon, stream combined with dam, and fishpond. A total of 60,927 anophelines were collected. The most abundant species in all habitats were Anopheles braziliensis and An. darlingi. The highest density was found in the lagoon, while streams had the highest species richness. Abundance was higher during the transition period wet-dry season. There was a lag of respectively four and five months between the peak of rainfall and the Madeira River level and the highest abundance of An. darlingi larvae, which were positively correlated with habitats partially shaded, pH close to neutrality, increase dissolved oxygen and sulphates. MAIN CONCLUSIONS: The present study provides data on key factors defining permanent larval habitats for the surveillance of An. darlingi and other potential vectors as well as a log-linear Negative Binomial model based on immature mosquito abundance and climate variables to predict the increase in the number of malaria cases.


Subject(s)
Anopheles , Ecosystem , Larva , Malaria , Mosquito Vectors , Population Density , Seasons , Animals , Anopheles/classification , Anopheles/growth & development , Anopheles/physiology , Brazil , Mosquito Vectors/physiology , Mosquito Vectors/classification , Mosquito Vectors/growth & development , Malaria/transmission , Longitudinal Studies , Population Dynamics
3.
Malar J ; 23(1): 299, 2024 Oct 07.
Article in English | MEDLINE | ID: mdl-39375756

ABSTRACT

BACKGROUND: Battling malaria's morbidity and mortality rates demands innovative methods related to malaria diagnosis. Thick blood smears (TBS) are the gold standard for diagnosing malaria, but their coloration quality is dependent on supplies and adherence to standard protocols. Machine learning has been proposed to automate diagnosis, but the impact of smear coloration on parasite detection has not yet been fully explored. METHODS: To develop Coloration Analysis in Malaria (CAM), an image database containing 600 images was created. The database was randomly divided into training (70%), validation (15%), and test (15%) sets. Nineteen feature vectors were studied based on variances, correlation coefficients, and histograms (specific variables from histograms, full histograms, and principal components from the histograms). The Machine Learning Matlab Toolbox was used to select the best candidate feature vectors and machine learning classifiers. The candidate classifiers were then tuned for validation and tested to ultimately select the best one. RESULTS: This work introduces CAM, a machine learning system designed for automatic TBS image quality analysis. The results demonstrated that the cubic SVM classifier outperformed others in classifying coloration quality in TBS, achieving a true negative rate of 95% and a true positive rate of 97%. CONCLUSIONS: An image-based approach was developed to automatically evaluate the coloration quality of TBS. This finding highlights the potential of image-based analysis to assess TBS coloration quality. CAM is intended to function as a supportive tool for analyzing the coloration quality of thick blood smears.


Subject(s)
Image Processing, Computer-Assisted , Machine Learning , Image Processing, Computer-Assisted/methods , Humans , Malaria , Color
4.
Diagn. tratamento ; 29(3): 118-126, jul-set. 2024. tab, quad
Article in Portuguese | LILACS | ID: biblio-1561640

ABSTRACT

Contexto e objetivo: A transmissão de doenças por mosquitos afeta a população e a economia de todo o mundo. Há um número considerável de doenças que podem ser transmitidas por mosquitos, com destaque para a malária e a dengue, endêmica em regiões tropicais. Evidentemente, medidas preventivas são imprescindíveis para a redução da transmissão. Avaliar as evidências de efetividade das telas de proteção com e sem inseticida para prevenção de doenças transmitidas por mosquitos. Métodos: Trata-se de sinopse baseada em evidências. Procedeu-se à busca por estudos que associavam o uso de telas de proteção contra mosquitos à redução do contágio de doenças transmitidas por mosquitos em três bases de dados: PubMed (1966-2024), Portal BVS (1982-2024) e Epistemonikos (2024) e também no metabuscador de evidências TRIP DATABASE (2024). O desfecho de análise envolveu a efetividade das telas de proteção na redução de doenças transmitidas por mosquitos. Resultados: Foram encontradas 307 citações. Seis estudos (1 revisão sistemática e 5 ensaios clínicos) foram incluídos. Discussão: A maioria dos estudos envolveu a colocação de telas de proteção com inseticida, havendo evidência de alta certeza para redução de mortalidade por malária e redução na entrada de mosquitos nas habitações, mesmo com redes sem inseticida. Conclusões: Embora não haja robustez na evidência da efetividade das telas de proteção sem inseticidas contra mosquitos transmissores de doenças, o que demanda a necessidade de realização de novos estudos prospectivos, parece lícita e benéfica a utilização de telas de proteção em regiões endêmicas para doenças transmitidas por esses vetores.


Subject(s)
Review , Evidence-Based Practice , Dengue , Malaria , Culicidae
5.
Front Public Health ; 12: 1377966, 2024.
Article in English | MEDLINE | ID: mdl-39319292

ABSTRACT

Several countries of the Guiana Shield are aiming at the control and elimination of malaria in areas where Artisanal and Small-scale Gold Mining (ASGM) activities predominate, raising questions about how to strengthen community engagement to improve the effectiveness of health programs. The Curema project focuses its intervention on the mobile and hard-to-reach ASGM population, complementing the efforts of national programs in the Guiana Shield. The Curema intervention combines targeted drug administration for suspected Plasmodium vivax asymptomatic carriers, the Malakit distribution, and health education activities. The primary goals of this manuscript are to outline a pathway to foster community participation in the Curema project aimed at eliminating malaria. Thus, it presents a vision of the challenges that the AGSM community poses in terms of community participation for an asymptomatic problem; and highlights the community-based model and the Information, Education and Communication (IEC) components as foundations for participation. In addition, it also presents culturally sensitive IEC strategies designed through iterative and collaborative consultative processes and other bottom-up outreach activities. The community engagement approach facilitates adaptability and responsiveness in a complex, evolving context increasing the effectiveness of interventions.


Subject(s)
Community Participation , Humans , Health Education/methods , Guyana , Malaria, Vivax/prevention & control , Disease Eradication , Malaria/prevention & control , Mining , Antimalarials/therapeutic use , Gold
6.
Malar J ; 23(1): 285, 2024 Sep 19.
Article in English | MEDLINE | ID: mdl-39300444

ABSTRACT

BACKGROUND: Severe malaria can cause respiratory symptoms, which may lead to malaria-acute lung injury (MA-ALI) due to inflammation and damage to the blood-gas barrier. Patients with severe malaria also often present thrombocytopenia, and the use of acetylsalicylic acid (ASA), a commonly used non-steroidal anti-inflammatory drug with immunomodulatory and antiplatelet effects, may pose a risk in regions where malaria is endemic. Thus, this study aimed to investigate the systemic impact of ASA and dihydroartemisinin (DHA) on ALI induced in mice by Plasmodium berghei NK65 (PbNK65). METHODS: C57BL/6 mice were randomly divided into control (C) and PbNK65 infected groups and were inoculated with uninfected or 104 infected erythrocytes, respectively. Then, the animals were treated with DHA (3 mg/kg) or vehicle (DMSO) at the 8-day post-infection (dpi) for 7 days and with ASA (100 mg/kg, single dose), and analyses were performed at 9 or 15 dpi. Lung mechanics were performed, and lungs were collected for oedema evaluation and histological analyses. RESULTS: PbNK65 infection led to lung oedema, as well as increased lung static elastance (Est, L), resistive (ΔP1, L) and viscoelastic (ΔP2, L) pressures, percentage of mononuclear cells, inflammatory infiltrate, hemorrhage, alveolar oedema, and alveolar thickening septum at 9 dpi. Mice that received DHA or DHA + ASA had an increase in Est, L, and CD36 expression on inflammatory monocytes and higher protein content on bronchoalveolar fluid (BALF). However, only the DHA-treated group presented a percentage of inflammatory monocytes similar to the control group and a decrease in ΔP1, L and ΔP2, L compared to Pb + DMSO. Also, combined treatment with DHA + ASA led to an impairment in diffuse alveolar damage score and lung function at 9 dpi. CONCLUSIONS: Therapy with ASA maintained lung morpho-functional impairment triggered by PbNK65 infection, leading to a large influx of inflammatory monocytes to the lung tissue. Based on its deleterious effects in experimental MA-ALI, ASA administration or its treatment maintenance might be carefully reconsidered and further investigated in human malaria cases.


Subject(s)
Acute Lung Injury , Antimalarials , Artemisinins , Aspirin , Lung , Malaria , Mice, Inbred C57BL , Plasmodium berghei , Animals , Artemisinins/pharmacology , Acute Lung Injury/drug therapy , Acute Lung Injury/parasitology , Aspirin/pharmacology , Aspirin/administration & dosage , Malaria/drug therapy , Malaria/complications , Mice , Antimalarials/pharmacology , Plasmodium berghei/drug effects , Lung/pathology , Lung/drug effects , Drug Therapy, Combination , Disease Models, Animal , Male , Respiratory Function Tests
7.
ACS Infect Dis ; 10(10): 3607-3617, 2024 Oct 11.
Article in English | MEDLINE | ID: mdl-39303151

ABSTRACT

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe complications that can occur in infections caused by any Plasmodium species. Due to the high lethality rate and the lack of specific treatment for ALI/ARDS, studies aimed at understanding and searching for treatment strategies for such complications have been fundamental. Here, we investigated the protective role of dietary supplementation with DHA-rich fish oil against lung damage induced by Plasmodium berghei ANKA in a murine model. Our results demonstrated that alveolar vascular damage, lung edema, and histopathological alterations were significantly reduced in mice that received dietary supplementation compared to those that did not receive the supplementation. Furthermore, a significant reduction in the number of CD8+ T lymphocytes, in addition to reduced infiltration of inflammatory cells in the bronchoalveolar lavage fluid was also observed. High levels of IL-10, but not of TNF-α and IFN-γ, were also observed in infected mice that received the supplementation, along with a reduction in local oxidative stress. Together, the data suggest that dietary supplementation with DHA-rich fish oil in malarial endemic areas may help reduce lung damage resulting from the infection, thus preventing worsening of the condition.


Subject(s)
Dietary Supplements , Disease Models, Animal , Docosahexaenoic Acids , Malaria , Plasmodium berghei , Animals , Plasmodium berghei/drug effects , Mice , Docosahexaenoic Acids/pharmacology , Docosahexaenoic Acids/administration & dosage , Lung/pathology , Lung/drug effects , Lung/parasitology , Bronchoalveolar Lavage Fluid/chemistry , Fatty Acids, Omega-3/pharmacology , Fatty Acids, Omega-3/administration & dosage , Oxidative Stress/drug effects , Acute Lung Injury/prevention & control , Acute Lung Injury/drug therapy , CD8-Positive T-Lymphocytes/immunology , Interleukin-10 , Fish Oils/pharmacology , Fish Oils/administration & dosage
8.
Washington, D.C.; OPS; 2024-09-23. (OPS/CDE/VT/24-0013).
in Spanish | PAHO-IRIS | ID: phr-61621

ABSTRACT

Este documento es una nota técnica con propuestas de intervenciones para la atención, la prevención y la vigilancia de la malaria en poblaciones migrantes y en comunidades de acogida, especialmente en países de Centroamérica, considerando el reciente incremento del número de personas que se movilizan a través de la subregión. La nota está enmarcada en los elementos de la estrategia de la Organización Panamericana de la Salud para el Acceso Universal a la Salud y la Cobertura Universal. Las intervenciones propuestas toman en cuenta los riesgos individuales de transmisión de la malaria para el migrante, así como los riesgos colectivos que se deben al aumento de la receptividad y de la vulnerabilidad a la enfermedad en los territorios de tránsito y las comunidades de acogida. Las intervenciones específicas promovidas por esta nota técnica, que se implementarán en el marco de una coordinación intra e intersectorial, al igual que a través de la cooperación interfronteriza, incluyen el refuerzo de la vigilancia y el uso de información como fundamento de las demás acciones, y la ampliación de las iniciativas de detección temprana y del tratamiento de todo caso de malaria. Además, la nota describe intervenciones reactivas para captar y tratar más casos en torno a los casos índice, acciones de quimioprevención en determinados casos, así como medidas para contener la transmisión en las comunidades de acogida. Entre todas las intervenciones, se destaca como principal medida para abordar la malaria en la población migrante la realización de un esfuerzo sistemático e intensivo para orientar y alentar adecuadamente a las personas a que accedan a un diagnóstico oportuno sin barreras y a un tratamiento gratuito. Esta acción debe sincronizarse en el ámbito local con medidas concretas para la mejora permanente de la oferta de diagnóstico y tratamiento en múltiples puntos de la ruta migratoria.


Subject(s)
Malaria , Transients and Migrants , Migrant Health , Health Services Accessibility , Equity in Access to Health Services
9.
Washington D. C; Organización Panamericana de la Salud; 1 ed; Set. 2024. 13 p. ilus.
Monography in Spanish | MINSAPERÚ, LIPECS | ID: biblio-1577313

ABSTRACT

describe intervenciones reactivas para captar y tratar más casos en torno a los casos índice, acciones de quimioterapia y prevención en determinados casos, así como medidas para contener la transmisión en las comunidades de acogida. Entre todas las intervenciones, se destaca como principal medida para abordar la malaria en la población migrante la realización de un esfuerzo sistemático e intensivo para orientar y alentar adecuadamente a las personas a que accedan a un diagnóstico oportuno sin barreras y a un tratamiento gratuito


Subject(s)
Humans , Transients and Migrants , Universal Access to Health Care Services , Disease Prevention , Migrant Health , Health Services Accessibility , Malaria
10.
Immunobiology ; 229(5): 152837, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39089130

ABSTRACT

It is known that conventional antigen presentation involves phagocytosis of antigens followed by its internalization in endocytic compartments and presentation of epitopes through MHC class II molecules for CD4 T cells. However, since 1976 a cross-presentation pathway has been studied, in which CD8 T cells are activated via MHC class I with antigens acquired through phagocytosis or endocytosis by dendritic cells (DCs). Among some important molecules involved in the cross-presentation, the C-type lectin receptor of the Dectin-1 cluster (CLECs), particularly the CLEC9A receptor, not only is expressed in dendritic cells but also presents a pivotal role in this context. In special, CLEC12A has been highlighted as a malaria pigment hemozoin (HZ) receptor. During Plasmodium infection, hemozoin crystals defend the parasite against heme toxicity within erythrocytes, as well as the released native HZ elicits pro-inflammatory responses and can induce cross-presentation. Particularly, this crystal can be synthesized from hematin anhydride and mimics the native form, and the gaps generated between the nanocrystal domains during its synthesis allow for substance coupling followed by its coating. Therefore, this study aimed to assess whether synthetic hemozoin (sHz) or hematin anhydride could be a nanocarrier and promote cross-presentation in dendritic cells. Firstly, it was verified that sHz can carry coated and coupled antigens, the compounds can associate to LAMP1-positive vesicles and decrease overall intracellular pH, which can potentially enhance the cross-presentation of ovalbumin and Leishmania infantum antigens. Thus, this study adds important data in the molecular intricacies of antigen presentation by showing not only the sHz immunomodulatory properties but also its potential applications as an antigen carrier.


Subject(s)
Antigen Presentation , Cross-Priming , Dendritic Cells , Hemeproteins , Hemeproteins/immunology , Cross-Priming/immunology , Animals , Dendritic Cells/immunology , Mice , Nanoparticles/chemistry , Humans , Malaria/immunology , Lectins, C-Type/metabolism , Lectins, C-Type/immunology , Ovalbumin/immunology
11.
Washington, D.C.; PAHO; 2024-08-20. (PAHO/CDE/VT/23-0012).
Non-conventional in English | PAHO-IRIS | ID: phr-61152

ABSTRACT

All malaria-endemic countries in the Region of the Americas have taken on the challenge of eliminating malaria and have focused their health programs and strategies on that goal. The risk of emergence of artemisinin resistance in the Americas, the characteristics of P. falciparum parasite, and the epidemiological evidence of subnational territories experiencing reintroduction of P. falciparum urge for a call to push for P. falciparum elimination as an intermediate goal of the elimination of all malaria human species. Derived from the elimination of P. falciparum, other important results are expected, such as the empowerment of different actors and entities for the elimination of malaria inspired by the achievements of the elimination of P. falciparum, using early victories as a catalyst. This technical note provides guidance on actions to accelerate P. falciparum elimination in areas close to achieving this goal without compromising unified malaria elimination efforts (P. vivax - P. falciparum), while contributing to the country's ultimate goal of eliminating malaria overall. The acceleration of P. falciparum elimination has several goals: mitigating the risk that resistance to artemisinin and associated drugs will emerge and spread; accelerating the reduction in the total number of malaria cases in areas with a significant proportion of P. falciparum; accelerating malaria elimination (both P. vivax and P. falciparum), considering that P. falciparum is one of the triggers of P. vivax relapses; developing capacities in interventions to accelerate malaria elimination by building on the experience of P. falciparum elimination; and empowering different actors, including high-level authorities, donors, municipalities, and other entities involved in malaria elimination, by inspiring them with the achievements of P. falciparum elimination.


Subject(s)
Malaria , Communicable Diseases , National Health Programs , Vector Borne Diseases
12.
Emerg Infect Dis ; 30(9): 1884-1894, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39174028

ABSTRACT

Malaria is increasingly diagnosed in urban centers across the Amazon Basin. In this study, we combined repeated prevalence surveys over a 4-year period of a household-based random sample of 2,774 persons with parasite genotyping to investigate the epidemiology of malaria in Mâncio Lima, the main urban transmission hotspot in Amazonian Brazil. We found that most malarial infections were asymptomatic and undetected by point-of-care microscopy. Our findings indicate that as malaria transmission decreases, the detection threshold of microscopy rises, resulting in more missed infections despite similar parasite densities estimated by molecular methods. We identified genetically highly diverse populations of Plasmodium vivax and P. falciparum in the region; occasional shared lineages between urban and rural residents suggest cross-boundary propagation. The prevalence of low-density and asymptomatic infections poses a significant challenge for routine surveillance and the effectiveness of malaria control and elimination strategies in urbanized areas with readily accessible laboratory facilities.


Subject(s)
Microscopy , Brazil/epidemiology , Humans , Prevalence , Microscopy/methods , Female , Male , Adult , Adolescent , Malaria, Vivax/epidemiology , Malaria, Vivax/parasitology , Child , Malaria, Falciparum/epidemiology , Malaria, Falciparum/parasitology , Malaria, Falciparum/prevention & control , Malaria/epidemiology , Malaria/transmission , Malaria/prevention & control , Malaria/parasitology , Plasmodium vivax/genetics , Urban Population , Child, Preschool , Plasmodium falciparum/genetics , Middle Aged , Young Adult , Infant , History, 21st Century
13.
Malar J ; 23(1): 234, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-39103843

ABSTRACT

BACKGROUND: More than 95% of malaria transmission in Brazil occurs in the Legal Amazon Region, which in 2010 recorded around 333,429 cases reported in the Epidemiological Surveillance Information System-Malaria (Sivep_malaria), presenting an annual parasitic incidence (IPA) of 13.1 cases/1000 inhabitants. METHODS: This was a descriptive study that measured the community prevalence of Plasmodium infection and its relationship with land use in Três Fronteiras District, Colniza Municipality, Mato Grosso State. Data were collected during household visits in July 2011, with blood collection from finger pricks for the preparation of thick smear slides, and completion of a standardized case notification form. A georeferenced database was analysed, with land use evaluated as categorical variables. A kernel density map was built to show the density of cases and their location. RESULTS: Of the 621 respondents, 68(11%) had Plasmodium infection: 39 (57.4%) with Plasmodium vivax, 27(39.7%) with Plasmodium falciparum and two (2.9%) with mixed infections. Among infected individuals, 49 (72.1%) were men. Cases of malaria were distributed over the district, with greater occurrence of cases per household in open areas close to the mining company and artisanal mining sites. The was a greater density of cases located in the gold mining region. CONCLUSION: Transmission of malaria in Três Fronteiras District has a heterogeneous distribution. Individuals residing in mining and timber extraction sites have increased occurrence of Plasmodium infection.


Subject(s)
Malaria, Falciparum , Malaria, Vivax , Rural Population , Brazil/epidemiology , Humans , Female , Male , Adolescent , Adult , Rural Population/statistics & numerical data , Middle Aged , Young Adult , Child , Child, Preschool , Malaria, Vivax/epidemiology , Malaria, Vivax/parasitology , Malaria, Falciparum/epidemiology , Malaria, Falciparum/parasitology , Prevalence , Infant , Aged , Incidence , Aged, 80 and over , Plasmodium vivax , Malaria/epidemiology , Malaria/transmission
14.
Anal Methods ; 16(34): 5751-5776, 2024 Aug 29.
Article in English | MEDLINE | ID: mdl-39143944

ABSTRACT

Malaria is a serious public health problem, being an endemic disease in 84 countries, mainly in Africa. This review explores the application of capillary electrophoresis (CE) techniques for analyzing antimalarial drugs, highlighting methods from 2000 to 2023 for the analysis of pharmaceutical formulations and human biological samples. The versatility, selectivity, high efficiency, cost-effectiveness, and high analytical frequency of CE techniques have become attractive choices for pharmaceutical analysis, focusing on quality control and impurity analysis applications. The evolution of achiral and chiral electromigration methods has been described based on the features of each mode of separation: capillary zone electrophoresis (CZE), micellar electrokinetic chromatography, microemulsion electrokinetic chromatography, and capillary electrochromatography. As expected, CZE is reported in most articles owing to its compatibility with drug properties and separation mode. However, it is necessary to perform other separation modes for a few drugs that are present in neutral form. After exhaustive research using different databases and statistical analyses, 27 articles using CE techniques for antimalarial drug analysis were found and are mentioned in this review.


Subject(s)
Antimalarials , Electrophoresis, Capillary , Antimalarials/analysis , Antimalarials/chemistry , Electrophoresis, Capillary/methods , Humans , Malaria/drug therapy , Drug Compounding/methods
15.
PLoS Comput Biol ; 20(8): e1012327, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39102445

ABSTRACT

Plasmodium parasites cause Malaria disease, which remains a significant threat to global health, affecting 200 million people and causing 400,000 deaths yearly. Plasmodium falciparum and Plasmodium vivax remain the two main malaria species affecting humans. Identifying the malaria disease in blood smears requires years of expertise, even for highly trained specialists. Literature studies have been coping with the automatic identification and classification of malaria. However, several points must be addressed and investigated so these automatic methods can be used clinically in a Computer-aided Diagnosis (CAD) scenario. In this work, we assess the transfer learning approach by using well-known pre-trained deep learning architectures. We considered a database with 6222 Region of Interest (ROI), of which 6002 are from the Broad Bioimage Benchmark Collection (BBBC), and 220 were acquired locally by us at Fundação Oswaldo Cruz (FIOCRUZ) in Porto Velho Velho, Rondônia-Brazil, which is part of the legal Amazon. We exhaustively cross-validated the dataset using 100 distinct partitions with 80% train and 20% test for each considering circular ROIs (rough segmentation). Our experimental results show that DenseNet201 has a potential to identify Plasmodium parasites in ROIs (infected or uninfected) of microscopic images, achieving 99.41% AUC with a fast processing time. We further validated our results, showing that DenseNet201 was significantly better (99% confidence interval) than the other networks considered in the experiment. Our results support claiming that transfer learning with texture features potentially differentiates subjects with malaria, spotting those with Plasmodium even in Leukocytes images, which is a challenge. In Future work, we intend scale our approach by adding more data and developing a friendly user interface for CAD use. We aim at aiding the worldwide population and our local natives living nearby the legal Amazon's rivers.


Subject(s)
Microscopy , Humans , Microscopy/methods , Plasmodium falciparum/pathogenicity , Plasmodium vivax , Computational Biology/methods , Malaria/parasitology , Plasmodium , Deep Learning , Databases, Factual , Image Processing, Computer-Assisted/methods , Malaria, Falciparum/parasitology , Diagnosis, Computer-Assisted/methods
16.
Am J Trop Med Hyg ; 111(4): 770-779, 2024 Oct 02.
Article in English | MEDLINE | ID: mdl-39137752

ABSTRACT

The Ministry of Public Health and Population in Haiti is committed to malaria elimination. In 2017, we used novel methods to conduct a census, monitor progress, and return to sampled households (HH) before a cross-sectional survey in La Chapelle and Verrettes communes in Artibonite department ("the 2017 Artibonite HH census"). Geospatial PDFs with digitized structures and basemaps were loaded onto tablets. Enumerators captured GPS coordinates and details of each HH and points of interest. The census used 1 km2 enumeration areas (EAs) to draw a representative sample. Three remote sampling frames were compared with the 2017 Artibonite HH census. First, 2003 census EAs with 2012 population estimates from the Haitian Institute of Statistics and Informatics were standardized to the study EAs. The second sampling frame used the 2016 LandScanTM population estimates and study EAs. The third sampling frame used structures ≥3 m2 manually digitized using Maxar satellite images. In each study EA, 70% of structures were estimated to be inhabited with 4.5 persons/HH. The census identified 33,060 inhabited HHs with an estimated population of 121,593 and 6,126 points of interest. Using daily coverage maps and including digitized structures were novel methods that improved the census quality. Manual digitization was closest to the census sampling frame results with 30,514 digitized structures in the study area. The LandScanTM method performed better in urban areas; however, it produced the highest number of HHs to sample. If a census is not possible, when feasible, remotely digitizing structures and estimating occupancy may provide a close estimate.


Subject(s)
Censuses , Family Characteristics , Malaria , Haiti/epidemiology , Humans , Malaria/epidemiology , Cross-Sectional Studies , Geographic Information Systems
18.
Washington, D.C.; PAHO; 2024-07-29. (PAHO/CDE/VT/23-0013).
in English | PAHO-IRIS | ID: phr-60868

ABSTRACT

All malaria-endemic countries in the Region of the Americas have taken on the challenge of eliminating the disease and have focused their health programs and strategies on that goal. This technical note provides guidance on actions to expand access to malaria diagnosis and treatment. Access to diagnosis is the foundation of the entire response to the disease. Despite repeated calls and efforts emphasizing the importance of early diagnosis and treatment for malaria elimination in the Americas, significant gaps remain. Lack of detection and/or late detection of cases undoubtedly continue to be factors that perpetuate malaria transmission in the Region. In areas with malaria transmission, diagnosis and treatment need to be available as close to people as possible: at the first point of contact with the health system, and in hard-to-reach areas, within the community itself. The Pan American Health Organization (PAHO) proposes a framework for action to improve access to malaria diagnosis and treatment based on expanded access to diagnosis, including expanded use of rapid diagnostic tests (RDTs) and immediate comprehensive treatment. This framework considers diagnostic methods and antimalarial drugs to be public goods. To achieve this change in malaria operations, it will be necessary to involve many more actors from the health system, affected communities, and society in general in malaria diagnosis and treatment. This strategy calls for an expansion of the diagnosis-treatment (DT) component of the Diagnosis, Treatment, Investigation, and Response (DT-IR) strategy that PAHO and partners in the Region have been promoting for malaria elimination in the Americas.


Subject(s)
Malaria , Rapid Diagnostic Tests , Early Diagnosis , Time-to-Treatment , Vector Borne Diseases
19.
An Acad Bras Cienc ; 96(3): e20230347, 2024.
Article in English | MEDLINE | ID: mdl-39046019

ABSTRACT

Oxidative stress is involved in the pathogenesis of malaria, causing anemia, respiratory complications, and cerebral malaria. To mitigate oxidative stress, we investigated the effect of nutritional supplementation whit lycopene (LYC) on the evolution of parasitemia and survival rate in mice infected with Plasmodium berghei ANKA (Pb), comparing to the effects promoted by N-acetylcysteine (NAC). Therefore, 175 mice were randomly distributed into 4 groups; Sham: untreated and uninfected animals; Pb: animals infected with Pb; LYC+Pb: animals treated with LYC and infected with Pb; NAC+Pb: animals treated with NAC and infected with Pb. The animals were followed for 12 days after infection, and survival and parasitemia rates were evaluated. There was a 40.1% increase in parasitemia in the animals of the Pb group on the 12th day, and a survival rate of 45%. LYC supplementation slowed the development of parasitemia to 19% and promoted a significative increase in the survival rate of 80% on the 12th day after infection, compared to the Pb group, effects superior to those promoted by NAC, providing strong evidence of the beneficial effect of LYC on in vivo malaria and stressing the importance of antioxidant supplementation in the treatment of this disease.


Subject(s)
Acetylcysteine , Antioxidants , Dietary Supplements , Lycopene , Malaria , Parasitemia , Plasmodium berghei , Animals , Lycopene/therapeutic use , Lycopene/administration & dosage , Lycopene/pharmacology , Parasitemia/drug therapy , Mice , Malaria/drug therapy , Acetylcysteine/administration & dosage , Acetylcysteine/therapeutic use , Acetylcysteine/pharmacology , Plasmodium berghei/drug effects , Antioxidants/therapeutic use , Antioxidants/administration & dosage , Oxidative Stress/drug effects , Carotenoids/therapeutic use , Carotenoids/administration & dosage , Male , Disease Models, Animal , Random Allocation
20.
Malar J ; 23(1): 221, 2024 Jul 24.
Article in English | MEDLINE | ID: mdl-39049091

ABSTRACT

BACKGROUND: In the scientific literature on Malaria in Pregnancy (MiP), no studies have been conducted on lifestyles based on critical theory. The objective of this study was to analyse the lifestyles or singular processes of social determination of health in MiP in northwestern Colombia. METHODS: Mixed QUAN-QUAL convergent triangulation study. In the quantitative component, a psychometric evaluation and a cross-sectional design were conducted in 400 pregnant women to whom the Pender-Walker lifestyle scale and a survey on MiP prevention were applied. In the qualitative study, a critical ethnography was conducted with 46 pregnant women in whom their narratives and practices regarding lifestyles at home and healthcare were described. RESULTS: The frequency of MiP was 9%, and a higher occurrence of the disease was identified in those who did not control stagnant water (29%), did not use insecticide-treated net (16%) and went to the hospital (14%) or the microscopist (20%) when they had fever. This coincides with the presence of unhealthy lifestyles, little knowledge about malaria, and a low perception of the risk of getting sick, as well as meanings and experiences about MiP, maternity, and pregnancy that show a high clinical, cultural, and socioeconomic burden for the women studied. CONCLUSION: This epidemiological profile and the approach to lifestyles based on the postulates of critical theory in health evidence that pregnant women exposed to malaria suffer serious social, cultural and health injustices that are not possible to impact with the current health model of malaria control in Colombia guided by aetiopathogenic, biomedical, positivist and utilitarian theories.


Subject(s)
Life Style , Malaria , Humans , Female , Colombia/epidemiology , Pregnancy , Adult , Malaria/epidemiology , Malaria/prevention & control , Cross-Sectional Studies , Young Adult , Adolescent , Pregnancy Complications, Parasitic/epidemiology , Pregnancy Complications, Parasitic/prevention & control
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