Oropouche virus detection in saliva and urine

Oropouche virus (OROV) is an arthropod-borne virus of the Peribunyaviridae family, transmitted to humans primarily by Culicoides paraensis. It is one of the main arboviruses infecting humans in Brazil, primarily in the Amazon Region. Here, we report the detection of OROV in the saliva and urine of a patient whose samples were collected five days after the onset of symptoms. Nucleotide sequencing and phylogenetic analysis further confirmed the results. To our knowledge, this is the first study reporting the detection of OROV in the saliva and urine of an infected patient. In addition, the results of our study expand the current knowledge pertaining to the natural history of Oropouche fever.

Human parvovirus B19 genotype 1 in suspected dengue patients of Tefé, Amazonas State, Brazil

Abstract INTRODUCTION: Human parvovirus B19 (B19V) is a common pathogen, which on infection causes variety of clinical conditions from benign self-limiting exanthematous disease and other similar pathologies to fetal death. METHODS: We collected 341 serum samples between the first and fourth day after the onset of symptoms from all patients suspected of dengue fever who were attended at Regional Hospital of Tefé. Initially, patients were screened for malaria by blood smear test and negative samples were sent to Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD) situated in Manaus (AM) for dengue testing using semi-nested multiplex PCR. Further, we investigated 44 malaria and dengue-negative samples of children for B19V DNA by nested-PCR. Positive samples were analyzed by BLAST against entire public non-redundant nucleotide database and genotyped by phylogenetic analyses using neighbor-joining clustering method. RESULTS: Eight samples (18.2%) were found to be PCR positive. Fever, headache, ocular pain, and/or muscle pain were reported as the most frequent symptoms by the patients and none were diagnosed with rash at the time of sample collection. Phylogenetic analysis of major capsid protein 2 (VP2) and VP3 coding region showed high similarity with B19V genotype 1. CONCLUSIONS: Our results reveal the spread of B19V genotype 1 in Tefé. Moreover, our results emphasize the significance of laboratorial differential diagnosis using molecular techniques in patients with acute febrile, and thereby aid the health surveillance system in improving patient care even in the remote areas of Amazon.

Molecular characterisation of the emerging measles virus from Roraima state, Brazil, 2018

Measles is a human infectious disease of global concern that is caused by the measles virus. In this study, we report the complete genome sequencing of one measles virus isolate, genotype D8, that was obtained directly from a urine sample in Boa Vista city, the capital of Roraima state in Brazil. Phylogenetic reconstruction grouped the genome described in this study with that of samples from Australia, South Korea, and Italy. To our knowledge, this is the first complete genome sequence of a wild-type measles virus reported from Latin America. Therefore, the present data strengthen the current knowledge on the molecular epidemiology of measles worldwide.

Multiplexed reverse transcription real-time polymerase chain reaction for simultaneous detection of Mayaro, Oropouche, and Oropouche-like viruses

ABSTRACT We describe a sensitive method for simultaneous detection of Oropouche and Oropouche-like viruses carrying the Oropouche S segment, as well as the Mayaro virus, using a multiplexed one-step reverse transcription real-time polymerase chain reaction (RT-qPCR). A chimeric plasmid containing both Mayaro and Oropouche targets was designed and evaluated for the in vitro production of transcribed RNA, which could be easily used as a non-infectious external control. To track false-negative results due to PCR inhibition or equipment malfunction, the MS2 bacteriophage was also included in the multiplex assay as an internal positive control. The specificity of the multiplex assay was evaluated by Primer-Blast analysis against the entire GenBank database, and further against a panel of 17 RNA arboviruses. The results indicated an accurate and highly sensitive assay with amplification efficiency greater than 98% for both targets, and a limit of detection between two and 20 copies per reaction. We believe that the assay described here will provide a tool for Mayaro and Oropouche virus detection, especially in areas where differential diagnosis of Dengue, Zika and Chikungunya viruses should be performed.

Desenvolvimento da CEL: equipamento de baixo-custo parareação e leitura de ensaios LAMP - Loop-mediated Isothermal Amplification / Development of CEL: a low-cost equipment for Loop-mediated Isothermal Amplification (LAMP) assays

O sistema de saúde brasileiro é constituído por um conjunto de ações e serviços que prestam assistência a população por meio de estratégias que visam a promoção, proteção e recuperação da saúde. Um dos pontos de maior destaque é a prevenção, na qual incluem-se o diagnóstico e o tratamento precoce das doenças. A detecção e a identificação clássica de patógenos baseiam-se na microscopia e cultura, entretanto a baixa sensibilidade; a necessidade de profissionais capacitados e de infraestrutura adequada resultam, em alguns casos, na falha do diagnóstico e no atraso para o início do tratamento. Objetivo: desenvolver um equipamento para realização de ensaios LAMP (Loop Mediated Isothermal Amplification) em ambientes com reduzida infraestrutura laboratorial. Resultados: Foram padronizados protocolos para cinco importantes doenças encontradas na região amazônica: tuberculose, malária, dengue e as febres mayaro e oropouche para utilização na CEL, equipamento portátil para a realização dos ensaios LAMP. O equipamento possui detecção fotométrica integrada, com capacidade de oito reações simultâneas, detectando a alteração da cor nas reações positivas. O resultado é mostrado em um display alfanumérico, de fácil leitura, mesmo para pessoas sem experiência com a técnica. Os resultados também podem ser transferidos por bluetooth para um smartphone, onde é possível, com o aplicativo próprio fazer a visualização gráfica. Conclusão: por se tratar de um equipamento de baixo-custo, desenvolvido para a aplicação em diagnóstico molecular, pode representar uma alternativa para ampliação da oferta de diagnóstico molecular nos serviços da rede básica de saúde, permitindo maior acesso da população, mesmo em áreas remotas.

The Brazilian Health System consists of a set of actions and services that assist the population through strategies aimed at the promotion, protection, and health recovery. One of the highlights is prevention, which includes the diagnosis and early treatment of diseases. The detection and classical identification of pathogens are based on microscopy and culture, however the low sensitivity; the need for trained professionals and adequate infrastructure leads, in some cases, to the failure of the diagnosis and in the delay to start treatment. Objective: to develop CEL, an equipment for LAMP (Loop-Mediated Isothermal Amplification) assays for use in low-resource settings laboratories. Results: Protocols were standardized for five important diseases found in the Amazon region: tuberculosis, malaria, dengue, mayaro and oropouche fevers. The equipment has integrated photometric detection, with the capacity of eight simultaneous reactions, detecting the color change observed in the positive reactions. The results are shown in an easy-to-read alphanumeric display, even for people with no experience with the technique. The results can also be transferred by bluetooth to a smartphone with the CEL App, where it is possible to see the results in a graphical interface. Conclusion: Once CEL is a low-cost device, developed for molecular diagnostics, it can represent an alternative to the expansion of the molecular diagnosis in the services of the primary health attention, allowing higher population access, even in remote areas.

Detection of Oropouche virus segment S in patients and inCulex quinquefasciatus in the state of Mato Grosso, Brazil

This study aimed to investigate the circulation of Orthobunyavirus species in the state of Mato Grosso (MT) Brazil. During a dengue outbreak in 2011/2012, 529 serum samples were collected from patients with acute febrile illness with symptoms for up to five days and 387 pools of female Culex quinquefasciatuscaptured in 2013 were subjected to nested-reverse transcription-polymerase chain reaction for segment S of the Simbu serogroup followed by nucleotide sequencing and virus isolation in Vero cells. Patients (5/529; 0.9%) from Cuiabá (n = 3), Várzea Grande (n = 1) and Nova Mutum (n = 1) municipalities were positive for the S segment of Oropouche virus (OROV). Additionally, eight/387 Cx. quinquefasciatuspools were positive for the segment, with a minimum infection rate of 2.3. Phylogenetic analysis indicated that all the samples belong to the subgenotype Ia, presenting high homology with OROV strains obtained from humans and animals in the Brazilian Amazon. The present paper reports the first detection of an Orthobunyavirus, possibly OROV, in patients and in Cx. quinquefasciatus mosquitoes in MT. This finding reinforces the notion that arboviruses frequently reported in the Amazon Region circulate sporadically in MT during dengue outbreaks.

Detection of Mycobacterium leprae in saliva and the evaluation of oral sensitivity in patients with leprosy

The aim of this study was to investigate sensitivity disorders in the oral cavity related to the presence of Mycobacterium leprae in the saliva of treatment-naïve patients with leprosy in the state of Amazonas, Brazil. A cross-sectional study was conducted involving 45 subjects with leprosy. The subjects were interviewed to evaluate the sensitivity of the oral cavity. For the detection of M. leprae, saliva and slit-skin smear samples were collected. The samples were analysed using a bacteriological index (BI) protocol and the real-time quantitative polymerase chain reaction (qPCR). The results indicated that 15 of the 45 (33.3%) subjects with leprosy showed decreased oral sensitivity, which confirmed the importance of the oral cavity sensitivity evaluation. There was not a direct relationship between the presence of M. leprae in saliva and changes in oral sensitivity. Positive saliva qPCR results from six (31.6%) of 19 paucibacillary (PB) patients suggested the possibility of a new site for sample collection. Positive results using these diagnostic techniques (BI, slit-skin smear and saliva qPCR) increased to 55.5%, thus opening the possibility of combining these different techniques to increase the rate of positive diagnoses, especially in PB patients.