A historical perspective on malaria control in Brazil

Malaria has always been an important public health problem in Brazil. The early history of Brazilian malaria and its control was powered by colonisation by Europeans and the forced relocation of Africans as slaves. Internal migration brought malaria to many regions in Brazil where, given suitableAnopheles mosquito vectors, it thrived. Almost from the start, officials recognised the problem malaria presented to economic development, but early control efforts were hampered by still developing public health control and ignorance of the underlying biology and ecology of malaria. Multiple regional and national malaria control efforts have been attempted with varying success. At present, the Amazon Basin accounts for 99% of Brazil’s reported malaria cases with regional increases in incidence often associated with large scale public works or migration. Here, we provide an exhaustive summary of primary literature in English, Spanish and Portuguese regarding Brazilian malaria control. Our goal was not to interpret the history of Brazilian malaria control from a particular political or theoretical perspective, but rather to provide a straightforward, chronological narrative of the events that have transpired in Brazil over the past 200 years and identify common themes

Transmission of Yellow Fever Vaccine Virus Through Blood Transfusion and Organ Transplantation in the USA in 2021: Report of an Investigation

BACKGROUND: In 2021, four patients who had received solid organ transplants in the USA developed encephalitis beginning 2-6 weeks after transplantation from a common organ donor. We describe an investigation into the cause of encephalitis in these patients. METHODS: From Nov 7, 2021, to Feb 24, 2022, we conducted a public health investigation involving 15 agencies and medical centres in the USA. We tested various specimens (blood, cerebrospinal fluid, intraocular fluid, serum, and tissues) from the organ donor and recipients by serology, RT-PCR, immunohistochemistry, metagenomic next-generation sequencing, and host gene expression, and conducted a traceback of blood transfusions received by the organ donor. FINDINGS: We identified one read from yellow fever virus in cerebrospinal fluid from the recipient of a kidney using metagenomic next-generation sequencing. Recent infection with yellow fever virus was confirmed in all four organ recipients by identification of yellow fever virus RNA consistent with the 17D vaccine strain in brain tissue from one recipient and seroconversion after transplantation in three recipients. Two patients recovered and two patients had no neurological recovery and died. 3 days before organ procurement, the organ donor received a blood transfusion from a donor who had received a yellow fever vaccine 6 days before blood donation. INTERPRETATION: This investigation substantiates the use of metagenomic next-generation sequencing for the broad-based detection of rare or unexpected pathogens. Health-care workers providing vaccinations should inform patients of the need to defer blood donation for at least 2 weeks after receiving a yellow fever vaccine. Despite mitigation strategies and safety interventions, a low risk of transfusion-transmitted infections remains. FUNDING: US Centers for Disease Control and Prevention (CDC), the Biomedical Advanced Research and Development Authority, and the CDC Epidemiology and Laboratory Capacity Cooperative Agreement for Infectious Diseases

Estudo sobre a patogenia da fibrose hepática periportal na esquistossomose do camundongo

Submitted by Repositório Arca ([email protected]) on 2019-09-04T17:22:02Z No. of bitstreams: 1 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2019-09-05T16:28:01Z (GMT) No. of bitstreams: 2 Luciana Menezes da Silva Flannery 2003.pdf: 9580525 bytes, checksum: 7e8c0cb96cf22232dbe92bd3961f0647 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Made available in DSpace on 2019-09-05T16:28:01Z (GMT). No. of bitstreams: 2 Luciana Menezes da Silva Flannery 2003.pdf: 9580525 bytes, checksum: 7e8c0cb96cf22232dbe92bd3961f0647 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2003Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil.Neste estudo, avaliou-se a participação da resposta imunológica, o papel das re-infecções e a participação de alterações vasculares sobre o determinismo da forma grave no modelo participação de alterações vasculares sobre o determinismo da forma grave no modelo murino. Camundongos BAB/c, submetidos à infecções simples ou repetidas, foram sacrificados na fase crônica da doença. Para avaliação da resposta imune, foram medidas as citocinas IL-4, IL-5 e IFN-y a partir do sobrenadante de cultura de esplenócitos, determinou-se o índice de linfoproliferação e títulos de imunoglobulinas do soro contra antígenos específicos (IgG1, IgG2a, IgGeb, IgG3) e IgE total de camundongos submetidos à infecção simples, com quadros histopatológicos distintos. Foram determinados o percentual de vasos marcados pela laminina bem como a área ocupada pelo tecido fibroso no fígado de animais com quadros histopatológicos distintos, submetidos a infecções simples ou repetidas. Moldes de vinilite do sistema porta intra-hepático foram obtidos de camundongos Swiss Webster. A avaliação da carga parasitária e a dosagem de didroxiprolina foram realizadas em todos os animais BALB/c. O perfil de resposta imune predominante foi Th2 em animais com diferentes quadros hsitopatológicos. O exame morfométrico revelou um amior percentual de tecido fibroso e vasos em animais com fibrose periportal, submetidos à re-infecção. O número de ovos por grama de fígado foi semelhante para os dois grupos, apenas o número de vermes foi maior em animais submetidos à re-infecção. O estudo de moldes vasculares da veia porta demonstrou a presença de tortuosidades, amputações e frequentes distorções, semelhantes às características anatômicas encontradas na esquistossomose humana avançada. A fibrose periportal é explicada pela contínua chegada de ovos, que se alojam em pequenos vasos colaterais do sistema porta intrahepático, provocando inflamação granulomatosa na parede vascular (pileflebite) da rede periductal e no conjuntivo periportal (peripileflebite), acompanhada de neoformação vascular (antiogênese)

Use of Malachite Green-Loop Mediated Isothermal Amplification for Detection of Plasmodium spp. Parasites.

Malaria elimination efforts are hampered by the lack of sensitive tools to detect infections with low-level parasitemia, usually below the threshold of standard diagnostic methods, microscopy and rapid diagnostic tests. Isothermal nucleic acid amplification assays such as the loop-mediated isothermal amplification (LAMP), are well suited for field use as they do not require thermal cyclers to run the test. However, the use of specialized equipment, as described by many groups, reduces the versatility of the LAMP technique as a simple tool for use in endemic countries. In this study, the use of the malachite green (MG) dye, as a visual endpoint readout, together with a simple mini heat block was evaluated for the detection of malaria parasites. The assay was performed for 1 hour at 63°C and the results scored by 3 independent human readers. The limit of detection of the assay was determined using well-quantified Plasmodium spp. infected reference samples and its utility in testing clinical samples was determined using 190 pre-treatment specimens submitted for reference diagnosis of imported malaria in the United States. Use of a simplified boil and spin methods of DNA extraction from whole blood and filter paper was also investigated. We demonstrate the accurate and sensitive detection of malaria parasites using this assay with a detection limit ranging between 1-8 parasites/μL, supporting its applicability for the detection of infections with low parasite burden. This assay is compatible with the use of a simple boil and spin sample preparation method from both whole blood and filter papers without a loss of sensitivity. The MG-LAMP assay described here has great potential to extend the reach of molecular tools to settings where they are needed

Comparison of MG-LAMP to PET-PCR.

<p>Comparison of MG-LAMP to PET-PCR.</p

Determination of the optimum MG concentration for use in the LAMP assay.

<p>Determination of the optimum MG concentration for use in the LAMP assay.</p

Expected results for the MG-LAMP assay.

<p>Expected results for the MG-LAMP assay.</p

Still Searching for a Suitable Molecular Test to Detect Hidden Plasmodium Infection: A Proposal for Blood Donor Screening in Brazil.

BACKGROUND:Efforts have been made to establish sensitive diagnostic tools for malaria screening in blood banks in order to detect malaria asymptomatic carriers. Microscopy, the malaria reference test in Brazil, is time consuming and its sensitivity depends on microscopist experience. Although molecular tools are available, some aspects need to be considered for large-scale screening: accuracy and robustness for detecting low parasitemia, affordability for application to large number of samples and flexibility to perform on individual or pooled samples. METHODOLOGY:In this retrospective study, we evaluated four molecular assays for detection of malaria parasites in a set of 56 samples previously evaluated by expert microscopy. In addition, we evaluated the effect of pooling samples on the sensitivity and specificity of the molecular assays. A well-characterized cultured sample with 1 parasite/μL was included in all the tests evaluated. DNA was extracted with QIAamp DNA Blood Mini Kit and eluted in 50 μL to concentrate the DNA. Pools were assembled with 10 samples each. Molecular protocols targeting 18S rRNA, included one qPCR genus specific (Lima-genus), one duplex qPCR genus/Pf (PET-genus, PET-Pf) and one duplex qPCR specie-specific (Rougemont: Roug-Pf/Pv and Roug-Pm/Po). Additionally a nested PCR protocol specie-specific was used (Snou-Pf, Snou-Pv, Snou-Pm and Snou-Po). RESULTS:The limit of detection was 3.5 p/μL and 0.35p/μl for the PET-genus and Lima-genus assays, respectively. Considering the positive (n = 13) and negative (n = 39) unpooled individual samples according to microscopy, the sensitivity of the two genus qPCR assays was 76.9% (Lima-genus) and 72.7% (PET-genus). The Lima-genus and PET-genus showed both sensitivity of 86.7% in the pooled samples. The genus protocols yielded similar results (Kappa value of 1.000) in both individual and pooled samples. CONCLUSIONS:Efforts should be made to improve performance of molecular tests to enable the detection of low-density parasitemia if these tests are to be utilized for blood transfusion screening