Oropouche Virus Isolation, Southeast Brazil

An Oropouche virus strain was isolated from a novel host (Callithrix sp.) in Arinos, Minas Gerais State, southeastern Brazil. The virus was identified by complement fixation test and confirmed by reverse transcription–polymerase chain reaction. Phylogenetic analysis identified this strain as a genotype III isolate previously recognized only in Panama

Reemergence of Oropouche Fever, Northern Brazil

Oropouche fever has reemerged in Parauapebas and Porto de Moz municipalities, Pará State, Brazil. Serologic analysis (immunoglobulin M–ELISA) and virus isolation confirmed Oropouche virus (OROV) in both municipalities. Nucleotide sequencing of 2 OROV isolates from each location indicated genotypes I (Parauapebas) and II (Porto de Moz) in Brazil

Natural infection of Aedes aegypti by Chikungunya and Dengue type 2 Virus in a transition area of north-northeast Brazil

Dengue fever, chikungunya, and Zika are diseases caused by viruses transmitted by Aedes aegypti and Aedes albopictus. In Brazil, the number of human infections is high, but few studies are performed in mosquito vectors. This study aimed to investigate the presence of Zika, Dengue and Chikungunya viruses in Ae. aegypti and Ae. albopictus from the municipalities of Alto Alegre, Caxias, Codó, and São Mateus do Maranhão, located in the state of Maranhão, Northeast Brazil. The mosquitoes were collected with a mechanical aspirator, identified, triturated, and then submitted to RNA extraction and RT-qPCR. The positive samples were confirmed by virus isolation and genome sequencing. Three hundred and forty-eight Ae. aegypti (176 males and 172 females) and 12 Ae. albopictus (eight males and four females) were collected and tested. Ae. aegypti was the only vector positive in two municipalities-Codó, with detection of Chikungunya virus (CHIKV) belonging to the East-Central-South African genotype, and in Caxias, with detection of Dengue virus (DENV)-2 belonging to the Asian/American genotype. The detection of CHIKV and DENV-2 is evidence that those viruses are maintained in arthropod vectors, and shows the epidemiological risk in the area for chikungunya cases and a possible increase of severe dengue cases, associated with the occurrence of dengue hemorrhagic fever. © 2019 by the authors

Prevalence of arbovirus antibodies against the family Bunyaviridae in water buffaloes

The State of Pará comprises 26% of Brazilian Amazon region where a large diversity of arboviruses has been described. This study sought to assess the prevalence and distribution of haemagglutination-inhibition antibodies against antigens of nine different types of arbovirus of the Bunyaviridae family, where eight were Orthobunyavirus: Guaroa virus, Maguari virus, Tacaiuma virus, Utinga virus, Belem virus, Caraparu virus, Oropouche virus and Catu virus, and one Phlebovirus: Icoaraci virus in sera samples of water buffaloes in Pará State, Brazil. For all Arboviruses investigated there were antibodies, with the exception of Belem virus. Antibodies to Maguari viruswere more prevalent (7.33%). The water buffaloes of the present study showed variable levels of antibodies in monotypic and heterotypic reactions that may indicate there are movements from most bunyavirus studied in domestic buffaloes in the state of Pará, and the Maguari virus presents the largest circulation. Therefore, further studies are needed to investigate the role of water buffalo in the maintenance and dispersal of arboviruses, as well as whether these viruses can cause disease in that species, especially in cases of birth defects and abortions.O Estado do Pará corresponde a 26% da Amazônica brasileira, onde uma grande quantidade de Arbovírus tem sido descrito. O presente trabalho teve como objetivo determinar a prevalência de anticorpos detectados pela técnica de inibição de hemaglutinação contra nove tipos diferentes de arbovírus da família Bunyaviridae, sendo oito do gênero Orthobunyavirus: vírus Guaroa, vírus Maguari, vírus Tacaiuma, vírus Utinga, vírus Belem, vírus Caraparu, vírus Oropouche e vírus Catu e um do gênero Phlebovirus: vírus Icoaraci, em soros de búfalos de água no Estado do Pará, Brasil. Para todos os Arbovírus investigados houve presença de anticorpos, com exceção do vírus Belém. Anticorpos para o vírus Maguari foram mais prevalentes (7,33%). O rebanho bubalino do presente estudo mostrou variáveis níveis de anticorpos em reações heterotípicas e monotípicas podendo indicar que há circulação da maioria dos bunyavírus estudados em búfalos domésticos no estado do Pará, e que o vírus Maguari é o de maior circulação. Por isso, são necessários outros estudos para investigar o papel dos búfalos de água na manutenção e dispersão de arbovírus, assim como se esses vírus podem causar enfermidades na referida espécie, principalmente, em casos de defeitos congênitos e abortamentos

The Acre Project: the epidemiology of malaria and arthropod-borne virus infections in a rural Amazonian population

The authors describe the baseline malaria prevalence and arbovirus seroprevalence among 467 subjects in an ongoing cohort study in rural Amazonia. Most subjects (72.2%) reported one or more previous episodes of malaria, and 15.6% had been hospitalized for malaria, but only 3.6% of individuals five years or older had malaria parasites detected by microscopy (10 with Plasmodium vivax and 4 with P. falciparum). Antibodies to Alphavirus, Orthobunyavirus, and/or Flavivirus were detected by hemagglutination inhibition (HI) in 42.6% of subjects aged five years or older, with a higher seropositivity rate among males (49.2%) than females (36.2%). Since 98.9% of subjects had been immunized for yellow fever, the presence of cross-reactive antibodies to dengue and other Flaviviruses cannot be ruled out, but at least 12 subjects (3.3%) with IgM antibodies to dengue virus detected by ELISA had a putative recent exposure to this virus

Serological evidence for Saint Louis encephalitis virus in free-ranging New World monkeys and horses within the upper Paraná River basin region, Southern Brazil

Introduction Saint Louis encephalitis virus (SLEV) primarily occurs in the Americas and produces disease predominantly in humans. This study investigated the serological presence of SLEV in nonhuman primates and horses from southern Brazil. Methods From June 2004 to December 2005, sera from 133 monkeys (Alouatta caraya, n=43; Sapajus nigritus, n=64; Sapajus cay, n=26) trap-captured at the Paraná River basin region and 23 blood samples from farm horses were obtained and used for the serological detection of a panel of 19 arboviruses. All samples were analyzed in a hemagglutination inhibition (HI) assay; positive monkey samples were confirmed in a mouse neutralization test (MNT). Additionally, all blood samples were inoculated into C6/36 cell culture for viral isolation. Results Positive seroreactivity was only observed for SLEV. A prevalence of SLEV antibodies in sera was detected in Alouatta caraya (11.6%; 5/43), Sapajus nigritus (12.5%; 8/64), and S. cay (30.8%; 8/26) monkeys with the HI assay. Of the monkeys, 2.3% (1/42) of A. caraya, 6.3% 94/64) of S. nigritus, and 15.4% (4/26) of S. cay were positive for SLEV in the MNT. Additionally, SLEV antibodies were detected by HI in 39.1% (9/23) of the horses evaluated in this study. Arboviruses were not isolated from any blood sample. Conclusions These results confirmed the presence of SLEV in nonhuman primates and horses from southern Brazil. These findings most likely represent the first detection of this virus in nonhuman primates beyond the Amazon region. The detection of SLEV in animals within a geographical region distant from the Amazon basin suggests that there may be widespread and undiagnosed dissemination of this disease in Brazil