Outbreak of Oropouche virus in frontier regions in western Amazon.

Oropouche virus (OROV) is characterized as a re-emerging arbovirus of great concern for public health, being responsible for several outbreaks of acute fever identified in Latin American countries, registering more than half a million reported cases. The incidence of reports of this virus is intrinsically favored by environmental conditions, in which such characteristics are related to the increase and distribution of the vector population to areas of human traffic. Moreover, there is a problem regarding the lack of diagnosis in Brazil that aggregates the success of the etiologic agent. Thus, by means of molecular techniques, we identified 27 positive cases of the OROV circulating in border locations in western Amazon, with 44.44% (12/27) of the cohort characterized as infected individuals with reported symptoms, mainly ranging from fever, myalgia, and back pain. Among the positive samples, it was possible to obtain a total of 48.14% (13/27) samples to analyze the S and M segments of Oropouche, which showed similarities among the Brazilian sequences. Thus, it was possible to verify the circulation of the OROV in Rondonia and border areas, in which the tracking of neglected arboviruses is necessary for the genomic surveillance of emerging and re-emerging viruses.IMPORTANCEThe western Amazon region is known for outbreaks of acute febrile illnesses, to which the lack of specific diagnostics for different pathogens hinders the management of patients in healthcare units. The Oropouche virus has already been recorded in the region in the 1990s. However, this is the first study, after this record, to perform the detection of individuals with acute febrile illness using a screening test to exclude Zika, dengue, and chikungunya, confirmed by sequencing the circulation of the virus in the state of Rondonia and border areas. We emphasize the importance of including diagnostics for viruses such as Oropouche, which suffers underreporting for years and is related to seasonal periods in Western Amazon locations, a factor that has a direct influence on public health in the region. In addition, we emphasize the importance of genomic surveillance in the elucidation of outbreaks that affect the resident population of these locations.

DENV-2 Outbreak Associated With Cosmopolitan Genotype Emergence in Western Brazilian Amazon.

Background: Dengue virus (DENV) causes an important disease and directly affects public health, being the arbovirus that presents the highest number of infections and deaths in the Western Brazilian Amazon. This virus is divided into 4 serotypes that have already circulated in the region. Methodology: Molecular characterization of a cohort containing 841 samples collected from febrile patients between 2021 and 2023 was analyzed using a commercial kit to detect the main arboviruses circulating in Brazil: Zika, DENV-1, DENV-2, DENV-3, DENV-4 and, Chikungunya. Subsequently, Sanger sequencing was performed for positive samples. Results: The cohort detected 162 positive samples, 12 for DENV-1 and 150 identified as DENV-2, indicating co-circulation of serotypes. The samples were subjected to sequencing and the analysis of the sequences that obtained good quality revealed that 5 samples belonged to the V genotype of DENV-1 and 46 were characterized as DENV-2 Cosmopolitan genotype-lineage 5. Conclusion: The results allowed us to identify for the first time the Cosmopolitan genotype in Rondônia, Brazilian Western Amazon, and its fast spread dispersion.

Genetic diversity of HBV in indigenous populations on the border between Brazil and Bolivia

Abstract Hepatitis B is considered an important public health problem worldwide because it is a chronic infection with a risk factor for cirrhosis and cellular hepatocellular carcinoma. In Brazil, the Rondônia State ranks first in the Northern region regarding the number of deaths due to hepatitis B. In the Amazon basin, genotype F is considered specific to the Americas identified in native populations. But few data on HBV genotyping and phylogenetic analysis are available. The objective of this study was to evaluate the genotypes and subgenotypes of the hepatitis B virus in indigenous people chronic carriers residing in cities of Guajará Mirim and Nova Mamoré in state of Rondônia/Brazil, on the border with Bolivia. A fragment of 417 bp (S gene) was amplified by PCR and submitted to nucleotide sequencing. The genotypes and subgenotypes of the HBV strains were determined through phylogenetic inference using genomic sequences from 197 representatives of the genotypes (A-H). Of the 41 chronic hepatitis B patients enrolled in this study, 27 were HBV-DNA positive. Of the 27 DNA-HBV positives, 39% (17/41) had individual HBV infection and 27% (10/41) were coinfected with HDV. The frequency of genotypes was 40.7% (11/27) for genotype D (HBV-D), 33.3% (9/27) for genotype F (HBV-F) and 25.9% (7/27) for genotype A (HBV-A) with circulating subgenotypes F2, F4, D2, D3, A1, and A2. We characterized the genotypes and subgenotypes of HBV circulating among in indigenous in the State of Rondônia shows for the first time the HBV/D genotype whit greater frequency circulating in nativos of state Rondônia. In conclusion, our findings showed a diversity of HBV genotypes, which is also found in other Brazilian geographical regions.

Dengue na Amazônia: aspectos epidemiológicos no Estado de Rondônia, Brasil, de 1999 a 2010 / Dengue in the Amazon: epidemiological aspects in Rondônia State, Brazil, from 1999 to 2010

A dengue é uma doença viral, aguda e sistêmica, que é transmitida principalmente pelo mosquito Aedes aegypti. Está presente em todos os 26 Estados da Federação Brasileira e no Distrito Federal e no país registram-se, aproximadamente, 70 por cento das notificações mundiais. O objetivo deste estudo é analisar a epidemiologia da dengue entre os anos 1999 e 2010 no Estado de Rondônia, comparando os dados obtidos com a situação do país no período equivalente. Utilizaram-se como fonte de informações os registros oficiais do Sistema Nacional de Agravos de Notificação, da Agência Estadual de Vigilância Sanitária e do Departamento de Informática do SUS. Os dados são referentes ao período de 1999, início das notificações, a 2010, último ano com números completos. Foram coletadas informações referentes aos casos notificados e confirmados, formas graves da doença, taxa de incidência, número de óbitos, entre outros...

Dengue is a viral, acute, and systemic disease that is mainly transmitted by the mosquito Aedes aegypti. It is spread through all 26 states of the Brazilian Federation and in the Federal District, and approximately 70 per cent of all the world’s notifications of dengue are recorded in Brazil. The objective of the present study is to analyze the epidemiology of dengue between 1999 and 2010 in Rondônia State, comparing the data obtained with that of the country as a whole during this period. As information sources, we used the official records from the National System for Notifiable Diseases (Sistema Nacional de Agravos de Notificação), the State Agency of Sanitary Surveillance (Agência Estadual de Vigilância Sanitária), and the Department of Informatics (Departamento de Informática) of the Brazilian Unified Health System (DATASUS). The data refer to the period from 1999 (the beginning of the notifications) to 2010 (the last year with complete data). Information was collected regarding the notified and confirmed cases, severe forms of the disease, the incidence rate, and the number of deaths. From the beginning of documentation, there was an exponential increase in the cases of dengue in the state...