Epidemiological aspects of the Oropouche virus (Orthobunyavirus) in South America: A systematic review

SUMMARY Introduction: The Oropouche virus (OROV) is an arbovirus that belongs to the genus Orthobunyavirus and family Peribunyaviridae, responsible for causing Oropouche fever (OF) in humans. The clinical diagnosis of is doubtful due to the non-specificity of the symptoms, which can lead to a mistaken diagnosis of other arboviruses. Thus, the survey of epidemiological data on the occurrence of has been a major challenge for public health authorities, especially in of South America. Aim: To determine the general exposure rate of OROV in Brazil and other countries in South America by a systematic review. An article search was carried out in the Pubmed/ Medline, Scopus, Cochrane, Lilacs, Electronic Scientific Online Library (SciELO) and Virtual Health Library (VHL) databases. Results: 18 studies were selected as eligible to compose this review on epidemiological aspects of OROV. The studies were published from 1989 to 2020. Most studies were carried out in Brazil (12/18; 66.66%) and Peru (5/18; 27.77%), only one study collected samples from Peru, Ecuador, Bolivia and Paraguay. The test for the OROV was realized mainly by serological analysis. Of the 8005 samples analyzed, 1570 tested positive for the presence of OROV thus accounting a general exposure rate in South America of 19.61%. Brazil was responsible for more than half of the cases of OROV identified in South America (855/1570; 54.46%), however Peru has the highest rate of exposure to the virus (23.43% of frequency in Peru vs. 16.77% of frequency in Brazil). Conclusion: OROV stands out as an important public health problem in Amazonian countries in South America.

Introdução: o virus Oropouche (OROV) é um arbovírus pertencente ao gênero Orthobunyavirus e família Peribunyaviridae, responsável por causar a febre Oropouche (FO) em humanos. O diagnóstico clínico da FO é duvidoso devido à não especificidade dos sintomas, o que pode levar a um diagnóstico equivocado de outras arboviroses. Assim, o levantamento de dados epidemiológicos sobre a ocorrência de FO tem sido um grande desafio para as autoridades de saúde pública, principalmente na América do Sul. Objetivo: determinar a taxa geral de exposição de OROV no Brasil e em outros países da América do Sul por meio de uma revisão sistemática. Foi realizada busca de artigos nas bases de dados Pubmed/ Medline, Scopus, Cochrane, Lilacs, Electronic Scientific Online Library (SciELO) e Virtual Health Library (BVS). Resultados: 18 estudos foram selecionados como elegíveis para compor esta revisão sobre aspectos epidemiológicos da OROV. Os estudos foram publicados de 1989 a 2020. A maioria dos estudos foi realizada no Brasil (18/12; 66,66%) e Peru (18/5; 27,77%), apenas um estudo coletou amostras do Peru, Equador, Bolívia e Paraguai. O teste para o OROV foi realizado principalmente por análise sorológica. Das 8005 amostras analisadas, 1570 testaram positivo para a presença de OROV, representando assim uma taxa de exposição geral na América do Sul de 19,61%. O Brasil foi responsável por mais da metade dos casos de OROV identificados na América do Sul (855/1570; 54,46%), porém o Peru tem a maior taxa de exposição ao vírus (23,43% de frequência no Peru vs. 16,77% de frequência em Brasil). Conclusão: OROV destaca-se como um importante problema de saúde pública nos países amazônicos da América do Sul.

Introducción: el virus Oropouche (OROV) es un arbovirus que pertenece al género Orthobunyavirus y familia Peribunyaviridae, responsable de causar la fiebre de oropouche (FO) en humanos. El diagnóstico clínico de FO es dudoso debido a la inespecificidad de los síntomas, lo que puede conducir a un diagnóstico erróneo de otros arbovirus. Por lo tanto, el levantamiento de datos epidemiológicos sobre la ocurrencia de FO ha sido un gran desafío para las autoridades de salud pública, especialmente en el sur de América del Sur. Objetivo: determinar la tasa de exposición general de OROV en Brasil y otros países de América del Sur mediante una revisión sistemática. Se realizó una búsqueda de artículos en las bases de datos Pubmed/ Medline, Scopus, Cochrane, Lilacs, Electronic Scientific Online Library (SciELO) y Virtual Health Library (BVS). Resultados: 18 estudios fueron seleccionados como elegibles para esta revisión sobre aspectos epidemiológicos de OROV. Los estudios se publicaron entre 1989 y 2020. La mayoría de los estudios se realizaron en Brasil (12/18; 66,66 %) y Perú (5/18; 27,77 %), solo un estudio recolectó muestras de Perú, Ecuador, Bolivia y Paraguay. La prueba para el OROV se realizó principalmente por análisis serológico. De las 8005 muestras analizadas, 1570 dieron positivo a la presencia de OROV, lo que representa una tasa de exposición general en América del Sur del 19,61 %. Brasil fue responsable de más de la mitad de los casos de OROV identificados en América del Sur (855/1570; 54,46 %), sin embargo, Perú tiene la tasa más alta de exposición al virus (23,43 % de frecuencia en Perú vs. 16,77 % de frecuencia en Brasil). Conclusión: OROV se destaca como un importante problema de salud pública en los países amazónicos de América del Sur.

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.

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.