Joaquim Pinto Nunes Neto

Mayaro Fever Virus, Brazilian Amazon

In February 2008, a Mayaro fever virus (MAYV) outbreak occurred in a settlement in Santa Barbara municipality, northern Brazil. Patients had rash, fever, and severe arthralgia lasting up to 7 days. Immunoglobulin M against MAYV was detected by ELISA in 36 persons; 3 MAYV isolates sequenced were characterized as genotype D.

Yellow fever virus in Haemagogus leucocelaenus and Aedes serratus mosquitoes, southern Brazil, 2008.

Yellow fever virus (YFV) was isolated from Haemagogus leucocelaenus mosquitoes during an epizootic in 2001 in the Rio Grande do Sul State in southern Brazil. In October 2008, a yellow fever outbreak was reported there, with nonhuman primate deaths and human cases. This latter outbreak led to intensification of surveillance measures for early detection of YFV and support for vaccination programs. We report entomologic surveillance in 2 municipalities that recorded nonhuman primate deaths. Mosquitoes were collected at ground level, identified, and processed for virus isolation and molecular analyses. Eight YFV strains were isolated (7 from pools of Hg. leucocelaenus mosquitoes and another from Aedes serratus mosquitoes); 6 were sequenced, and they grouped in the YFV South American genotype I. The results confirmed the role of Hg. leucocelaenus mosquitoes as the main YFV vector in southern Brazil and suggest that Ae. serratus mosquitoes may have a potential role as a secondary vector.

Arbovirus eco-epidemiology in the area affected by the Cuiabá-Santarém Highway (BR-163), Pará State, Brazil

The current study describes the eco-epidemiological aspects of arbovirus diseases in the municipalities (counties) of Novo Progresso and Trairao, Para State, Brazil, in the area affected by highway BR-163. Hemagglutination inhibition (HI) antibodies to different arboviruses were detected, with monotypic reactions to MAYV and OROV, two important arboviruses associated with epidemics in the Amazon. IgM antibodies to OROV and MAYV were found in human sera, suggesting recent infections by these viruses. Two DENV-3 strains were isolated from febrile patients in Novo Progresso and identified as genotype III strains. In general, the data suggest that the area displays ideal conditions for maintenance and circulation of arboviruses, plus a population with low immunization levels. Dynamic surveillance of local immigrants and wild animals is thus important, focusing on antibody prevalence and isolation of arboviruses, thereby allowing effective control of infections by these viral agents in the resident population along highway BR-163 in Para State.

Full-length sequencing and genetic characterization of Breu Branco virus (Reoviridae, Orbivirus) and two related strains isolated from Anopheles mosquitoes.

Breu Branco virus (BE AR 492347) was isolated from Anopheles (Nyssorhynchus) triannulatus mosquitoes captured in Tucuruí, Pará State, northern Brazil, in 1988. No cross-reactivity by complement-fixation tests was observed between Breu Branco virus and other known arboviruses. Results of electron microscopy and physicochemical tests suggested that Breu Branco virus may be a member of the family Reoviridae. In order to elucidate its taxonomic status, a comprehensive genetic characterization was conducted for Breu Branco virus and related strains (BE AR 494475 and BE AR 486204) that were also isolated from Anopheles mosquitoes in the same area. This included full-length genome sequencing, determination of genetic traits and phylogenetic analysis. Breu Branco virus showed a similar genome organization to members of the genus Orbivirus, family Reoviridae. Genetically, Breu Branco virus was indistinguishable from strains BE AR 494475 and BE AR 486204. Phylogenetic analysis suggested that Breu Branco virus BE AR 492347 and its related strains constitute a novel species of the genus Orbivirus. Breu Branco virus is the first Brazilian orbivirus and the fifth orbivirus in the world to be sequenced fully.

Emergence of New Insect-Restrictive Viruses in the Amazon Region

ABSTRACT The complete genome was determined for 12 viruses isolated from 8 different pools of mosquitoes (Culex sp. and Psorophora ferox) collected at Brejeira farm, Canaan dos Carajas, Para state in northern Brazil. Eight of the viruses were distantly related to Piura virus, hereafter designated as Brejeira virus; the other 4 were similar to Wallerfield virus.

Vigilância sorológica para arbovírus em Juruti, Pará, Brasil

This study aimed to measure the prevalence of antibodies to arboviruses in the area affected by the Juruti Project before local mining operations. A total of 1,597 human and 85 wild animal sera were examined, using the hemagglutination inhibition test against 19 antigens from the most prevalent arboviruses in the Brazilian Amazon and IgM-ELISA for dengue and yellow fever. Positive sera for Mayaro and Oropouche viruses were also tested by IgM-ELISA. Prevalence of hemagglutination inhibition antibodies to alphaviruses, flaviviruses, and orthobunyaviruses in humans was 28.7%, while for wild animals it was 8.2% for flaviviruses. Recent infections based on presence of IgM was confirmed for Mayaro (n = 5), Oropouche (n = 23), and dengue (n = 20). The results showed active circulation of the dengue, Mayaro, and Oropouche viruses in Juruti, as well as flaviviruses in wild animals, suggesting the circulation of these viruses in the Municipality of Juruti.

Occurrence of Aedes aegypti (Diptera, Culicidae) in a Dengue Transmission Area at Coastal Maranhão State, Brazil

This study aimed to estimate the occurrence of Aedes aegypti adults at distinct climatic seasons at neighbor- hoods from the municipality of Sao Luis, Maranhao State, Brazil, as well as to verify the presence of Dengue virus (DENV) in the specimens collected. A total of 320 properties were visited in eight neighborhoods that were previously randomly chosen. Samplings were made at three periods: dry season/2008, rainy season/2009 and dry season/2009. A to- tal of 563 Ae. aegypti mosquitoes were collected, with 141 of them collected during dry season/2008, 272 during rainy season/2009 and the remnant, during dry season/2009. Specimen were divided into lots and subjected to RT-semi-nested- PCR analysis and virus isolation was carried out using cell culture (C6/36 clone) of Ae. albopictus. The number of adults significantly varied at the neighborhoods of Coreia de Baixo, Lira, Joao Paulo, and Conjunto Cohatrac I. Molecular anal- yses of specimens showed no positivity for DENV. At the municipality of Sao Luis, seasonal climate variation might in- fluence the density of Ae. aegypti adults, however, other factors such as population density, sanitation conditions, and the presence of mosquito breeding sites ought to be assessed as important parameters influencing vector dispersion.

Description and phylogeny of the mitochondrial genome of Sabethes chloropterus, Sabethes glaucodaemon and Sabethes belisarioi (Diptera: Culicidae)

Mosquitoes as Sabethes chloropterus, Sabethes glaucodaemon, Sabethes belisarioi are species of medical and epidemiological importance for arboviruses transmission such as yellow fever and St. Louis encephalitis. Despite this, no information about these three species mitochondrial DNA has been found in literature. Our study presents a mitochondrial genome description, including identity, SNPs, mutation rate, and phylogeny analysis using COX1, COX2, NADH4, NADH5, CYOB genes. The Sa. chloropterus, Sa. glaucodaemon and Sa. belisaroi mitochondrial genome sizes 15.609 bp, 15.620 bp, 15.907 bp, respectively, with 37 functional genes, presenting about 4.982 single nucleotide polymorphisms and 13.291 identical sites between them, besides all genes with dN/dS < 1 ratio, and also a greater approximation between Sa. glaucodaemon and Sa. chloropterus than with Sa. belisarioi. Due to the importance of mitochondrial DNA for population structure studies, evolution, and others, we expect that this data can contribute to other studies related to these mosquitoes and their viruses.

Circulation of Chikungunya virus in Aedes aegypti in Maranhão, Northeast Brazil

The simultaneous circulation of Dengue virus (DENV), Chikungunya virus (CHIKV) and Zika virus (ZIKV) arboviruses have placed Brazil among the main worldwide endemic areas. Brazilian Northeast region concentrates the highest incidence of infections caused by CHIKV and ZIKV. In Maranhão, the second biggest northeastern state, there are cases of human infections caused by these three arboviruses and presence of Aedes aegypti and Aedes albopictus vectors. In this context, this study aimed to investigate the circulation of CHIKV, DENV and ZIKV in Ae. aegypti and Ae. albopictus mosquitoes collected in urban areas of Barra do Corda, Caxias, Codó, São Luís and São Mateus do Maranhão municipalities in the state of Maranhão through Quantitative Reverse Transcription Polymerase Chain Reaction (RT-qPCR) technique. 428 Ae. aegypti and 1 Ae. albopictus were collected, which formed 44 pools. Three of these showed positive results for CHIKV: AR832767 (five Ae. aegypti female collected in Caxias), AR832784 and AR832785 (both composed of 20 Ae. aegypti female collected in São Mateus do Maranhão). This study consolidates information about CHIKV circulation in state of Maranhão, as well as the role of Ae. aegypti in the transmission of CHIKV in urban area.