Ecological, Genetic, and Phylogenetic Aspects of YFV 2017-2019 Spread in Rio de Janeiro State.

In Brazil, a yellow fever (YF) outbreak was reported in areas considered YF-free for decades. The low vaccination coverage and the increasing forest fragmentation, with the wide distribution of vector mosquitoes, have been related to yellow fever virus (YFV) transmission beyond endemic areas since 2016. Aiming to elucidate the molecular and phylogenetic aspects of YFV spread on a local scale, we generated 43 new YFV genomes sampled from humans, non-human primates (NHP), and primarily, mosquitoes from highly heterogenic areas in 15 localities from Rio de Janeiro (RJ) state during the YFV 2016-2019 outbreak in southeast Brazil. Our analysis revealed that the genetic diversity and spatial distribution of the sylvatic transmission of YFV in RJ originated from at least two introductions and followed two chains of dissemination, here named the YFV RJ-I and YFV RJ-II clades. They moved with similar dispersal speeds from the north to the south of the RJ state in parallel directions, separated by the Serra do Mar Mountain chain, with YFV RJ-I invading the north coast of São Paulo state. The YFV RJ-I clade showed a more significant heterogeneity across the entire polyprotein. The YFV RJ-II clade, with only two amino acid polymorphisms, mapped at NS1 (I1086V), present only in mosquitoes at the same locality and NS4A (I2176V), shared by all YFV clade RJ-II, suggests a recent clustering of YFV isolates collected from different hosts. Our analyses strengthen the role of surveillance, genomic analyses of YVF isolated from other hosts, and environmental studies into the strategies to forecast, control, and prevent yellow fever outbreaks.

Back to Where It Was First Described: Vectors of Sylvatic Yellow Fever Transmission in the 2017 Outbreak in Espírito Santo, Brazil.

Evidence of sylvatic yellow fever was first reported in Atlantic Forest areas in Espírito Santo, Brazil, during a yellow fever virus (YFV) outbreak in 1931. An entomological survey was conducted in six forest sites during and after an outbreak reported ~80 years after the last case in the area. Among 10,658 mosquitoes of 78 species, Haemagogus leucocelaenus, and Hg. janthinomys/capricornii were considered the main vectors as they had a relatively high abundance, co-occurred in essentially all areas, and showed high YFV infection rates. Sabethes chloropterus, Sa. soperi, Sa. identicus, Aedes aureolineatus, and Shannoniana fluviatilis may have a secondary role in transmission. This is the first report of Sa. identicus, Ae. aureolineatus, and Sh. fluviatilis infected with YFV. Our study emphasizes the importance of entomological monitoring and maintenance of high vaccination coverage in receptive areas to YFV transmission.

Wyeomyia shannoni Lane amp; Cerqueira, 1942, a taxonomic puzzle (Diptera: Culicidae): synonymy, genus transfer, homonymy, and description of a new species of Sabethes Robineau-Desvoidy, 1827.

We discovered the immature stages of Wyeomyia shannoni Lane Cerqueira, 1942, unknown for almost 80 years, and found that they, as well as the adult male, are identical with those previously described for Sabethes (Peytonulus) paradoxus Harbach, 2002. Consequently, the species described by Lane and Cerqueira is here considered a senior synonym of Sa. paradoxus and is transferred to the genus Sabethes, hereafter named Sabethes (Peytonulus) shannoni (Lane Cerqueira, 1942), comb. n. As the name shannoni is preoccupied in the genus Sabethes, the species known as Sabethes (Sabethes) shannoni Cerqueira, 1961 is here renamed Sabethes (Sabethes) cerqueirai Nascimento-Pereira, Neves, Loureno-de-Oliveira Motta, nom. n. We improved the morphological characterization of Sa. (Pey.) shannoni (Lane Cerqueira) by including an illustration of the female genitalia, larval mouthparts and the female genital lobe of the pupa. Finally, we describe and illustrate a new species of Sabethes closely related to Sa. (Pey.) shannoni, named Sabethes (Peytonulus) harbachi Nascimento-Pereira, Guimares, Loureno-de-Oliveira Motta, sp. n.

Redescription and placement of Wyeomyia rorotai Senevet, Chabelard amp; Abonnenc (Diptera: Culicidae) in the subgenus Decamyia based on morphological and molecular analyses.

Decamyia Dyar is a subgenus of Wyeomyia Theobald with three valid species. Wyeomyia rorotai Senevet, Chabelard Abonnenc, a species originally described rather briefly in the subgenus Dendromyia, is without subgeneric position in the genus. In the present work, we redescribe Wy. rorotai in all life stages and formally define its taxonomic placement in the subgenus Decamyia by combining morphological and molecular analyses based on the mitochondrial cytochrome c oxidase subunit I gene. We also show that Decamyia is a rather homogeneous group of four species, i.e. Wy. ulocoma (Theobald), Wy. pseudopecten Dyar Knab, Wy. felicia Dyar Núñez Tovar and Wy. rorotai, the immature stages of which almost exclusively inhabit the flower bracts of Heliconiaceae.

Survey on Non-Human Primates and Mosquitoes Does not Provide Evidences of Spillover/Spillback between the Urban and Sylvatic Cycles of Yellow Fever and Zika Viruses Following Severe Outbreaks in Southeast Brazil.

In the last decade, Flaviviruses such as yellow fever (YFV) and Zika (ZIKV) have expanded their transmission areas. These viruses originated in Africa, where they exhibit both sylvatic and interhuman transmission cycles. In Brazil, the risk of YFV urbanization has grown, with the sylvatic transmission approaching the most densely populated metropolis, while concern about ZIKV spillback to a sylvatic cycle has risen. To investigate these health threats, we carried out extensive collections and arbovirus screening of 144 free-living, non-human primates (NHPs) and 5219 mosquitoes before, during, and after ZIKV and YFV outbreaks (2015-2018) in southeast Brazil. ZIKV infection was not detected in any NHP collected at any time. In contrast, current and previous YFV infections were detected in NHPs sampled between 2017 and 2018, but not before the onset of the YFV outbreak. Mosquito pools screened by high-throughput PCR were positive for YFV when captured in the wild and during the YFV outbreak, but were negative for 94 other arboviruses, including ZIKV, regardless of the time of collection. In conclusion, there was no evidence of YFV transmission in coastal southeast Brazil before the current outbreak, nor the spread or establishment of an independent sylvatic cycle of ZIKV or urban Aedes aegypti transmission of YFV in the region. In view of the region's receptivity and vulnerability to arbovirus transmission, surveillance of NHPs and mosquitoes should be strengthened and continuous.

Haemagogus leucocelaenus and Haemagogus janthinomys are the primary vectors in the major yellow fever outbreak in Brazil, 2016-2018.

The yellow fever virus (YFV) caused a severe outbreak in Brazil in 2016-2018 that rapidly spread across the Atlantic Forest in its most populated region without viral circulation for almost 80 years. A comprehensive entomological survey combining analysis of distribution, abundance and YFV natural infection in mosquitoes captured before and during the outbreak was conducted in 44 municipalities of five Brazilian states. In total, 17,662 mosquitoes of 89 species were collected. Before evidence of virus circulation, mosquitoes were tested negative but traditional vectors were alarmingly detected in 82% of municipalities, revealing high receptivity to sylvatic transmission. During the outbreak, five species were found positive in 42% of municipalities. Haemagogus janthinomys and Hg. leucocelaenus are considered the primary vectors due to their large distribution combined with high abundance and natural infection rates, concurring together for the rapid spread and severity of this outbreak. Aedes taeniorhynchus was found infected for the first time, but like Sabethes chloropterus and Aedes scapularis, it appears to have a potential local or secondary role because of their low abundance, distribution and infection rates. There was no evidence of YFV transmission by Aedes albopictus and Aedes aegypti, although the former was the most widespread species across affected municipalities, presenting an important overlap between the niches of the sylvatic vectors and the anthropic ones. The definition of receptive areas, expansion of vaccination in the most affected age group and exposed populations and the adoption of universal vaccination to the entire Brazilian population need to be urgently implemented.

Mosquitoes (Diptera: Culicidae) From the Northwestern Brazilian Amazon: Araçá River.

The mosquito fauna (Diptera: Culicidae) from two remote localities along the Araçá River, within the Municipality of Barcelos, towards the northern border of the Brazilian State of Amazonas, were sampled using CDC, Shannon, Malaise, and Suspended traps, along with net sweeping and immature collections. During June 2010, 111 collections yielded more than 23,500 mosquitoes distributed in 15 genera, representing 119 different species, together with eight morphospecies, which may represent undescribed new taxa. Among the species collected, there is one new distributional record for Brazil and nine new distributional records for the State of Amazonas. With the highest number of species, the genus Culex Linnaeus also had the largest number of individuals followed by Aedes Meigen with the second highest number of species. The most abundant species was Culex (Melanoconion) gnomatos Sallum, Hutchings & Ferreira followed by Culex (Melanoconion) portesi Senevet & Abonnenc, Culex (Culex) mollis Dyar & Knab, Aedes (Ochlerotatus) fulvus (Wiedemann), Culex (Melanoconion) pedroi Sirivanakarn & Belkin, Culex (Melanoconion) crybda Dyar, Aedes (Ochlerotatus) nubilus (Theobald), and Anopheles (Anopheles) peryassui Dyar & Knab. The epidemiological implications of mosquito species found are discussed and are compared with other mosquito inventories from the Amazon region. As the first standardized mosquito inventory of the Araçá River, with the identification of 127 species level taxa, the number of mosquito species which have been collected along the northern tributaries of the middle Rio Negro Basin (i.e., Padauari and Araçá Rivers) increased significantly.

Potential risk of re-emergence of urban transmission of Yellow Fever virus in Brazil facilitated by competent Aedes populations.

Yellow fever virus (YFV) causing a deadly viral disease is transmitted by the bite of infected mosquitoes. In Brazil, YFV is restricted to a forest cycle maintained between non-human primates and forest-canopy mosquitoes, where humans can be tangentially infected. Since late 2016, a growing number of human cases have been reported in Southeastern Brazil at the gates of the most populated areas of South America, the Atlantic coast, with Rio de Janeiro state hosting nearly 16 million people. We showed that the anthropophilic mosquitoes Aedes aegypti and Aedes albopictus as well as the YFV-enzootic mosquitoes Haemagogus leucocelaenus and Sabethes albiprivus from the YFV-free region of the Atlantic coast were highly susceptible to American and African YFV strains. Therefore, the risk of reemergence of urban YFV epidemics in South America is major with a virus introduced either from a forest cycle or by a traveler returning from the YFV-endemic region of Africa.

Wyeomyia exallos, a new species of sylvatic mosquito (Diptera: Culicidae) from Brazil.

Wyeomyia exallos, a new mosquito species from Atlantic Forest of southeastern Brazil, is described based on morphological characters of the adult female, male, male genitalia, pupa and fourth-instar larva. The morphological characters of Wy. exallos sp. nov. are compared with those of different subgenera of Wyeomyia as well as of species without subgeneric position. It is proposed that the new species should be placed in genus Wyeomyia Theobald without subgeneric assignment.

Wyeomyia exallos, a new species of sylvatic mosquito (Diptera: Culicidae) from Brazil

Wyeomyia exallos, a new mosquito species from Atlantic Forest of southeastern Brazil, is described based on morphological characters of the adult female, male, male genitalia, pupa and fourth-instar larva. The morphological characters of Wy. exallos sp. nov. are compared with those of different subgenera of Wyeomyia as well as of species without subgeneric position. It is proposed that the new species should be placed in genus Wyeomyia Theobald without subgeneric assignment.

Redescription of Anopheles (Nyssorhynchus) antunesi Galvão & Amaral and description of a new species of the Myzorhynchella Section (Diptera: Culicidae) from Serra da Mantiqueira, Brazil.

Anopheles (Nyssorhynchus) pristinus Nagaki & Sallum, n. sp. of the Myzorhynchella Section is described based on morphological characters of adult females, males, fourth-instar larvae, pupae and male genitalia. Anopheles (Nyssorhynchus) antunesi Galvão & Amaral is characterized to fix its identity and distinguish it from An. pristinus. The eggs of An. antunesi are described for the first time. Molecular characterization employing sequences of the COI mitochondrial gene and the ITS2 region of ribosomal DNA are provided for each species. An. antunesi and An. pristinus are compared with morphologically similar species of the Myzorhynchella Section. The results of the present study suggest that the new species has been misidentified as both An. antunesi and Anopheles lutzii Cruz. An. antunesi and An. pristinus are sympatric, occurring at high altitudes in Serra da Mantiqueira, Southeastern Brazil.

Redescription of Anopheles (Nyssorhynchus) antunesi Galvão & Amaral and description of a new species of the Myzorhynchella Section (Diptera: Culicidae) from Serra da Mantiqueira, Brazil

Anopheles (Nyssorhynchus) pristinus Nagaki & Sallum, n. sp. of the Myzorhynchella Section is described based on morphological characters of adult females, males, fourth-instar larvae, pupae and male genitalia. Anopheles (Nyssorhynchus) antunesi Galvão & Amaral is characterized to fix its identity and distinguish it from An. pristinus. The eggs of An. antunesi are described for the first time. Molecular characterization employing sequences of the COI mitochondrial gene and the ITS2 region of ribosomal DNA are provided for each species. An. antunesi and An. pristinus are compared with morphologically similar species of the Myzorhynchella Section. The results of the present study suggest that the new species has been misidentified as both An. antunesi and Anopheles lutzii Cruz. An. antunesi and An. pristinus are sympatric, occurring at high altitudes in Serra da Mantiqueira, Southeastern Brazil.

Estudo filogenético do gênero Wyeomyia Thebald (Diptera: Culicidae) baseado em caracteres morfológicos e perfil de aloenzimas / Phylogenetic study of the sort Wyeomyia Thebald (Diptera: Culicidae) based in morphologic characters and profile of allozymes

O gênero Wyeomyia Theobald tem sido considerado como um grupo polifilético, com relacionamentos internos indefinidos e pobremente caracterizados. Desenvolveu-se estudo como objetivo de estabelecer os relacionamentos filogenéticos das espécies de Wyeomyia, testar o monofiletismo do gênero, bem como dos subgêneros e avaliar as relações filogenéticas entre os taxa. Apresentam-se os resultados de análise cladística baseada em 88 caracteres morfológicos de adultos, larva de quarto estádio e pupa. Os dados morfológicos foram coletados em de 41 espécies, além de dados genéticos de 11 loci enzimáticos de 19 espécies. Esta análise foi precedida de um estudo morfológico de espécies de Wyeomyia que permitiu a descrição de um novo subgênero, Spilonympha Motta & Lourenço-de-Oliveira, com uma espécie nova, Wy.(Spi) aningae Motta & Lourenço-de-Oliveira, que agrupou seis espécies que se achavam sem posição subgenérica dentro do gênero Wyeomyia. Do total de 41 espécies incluídas na análise cladística, duas foram usadas como grupos externos: Sabethes aurescens Lutz e Limatus durhamii Theobald e 39 espécies, representando onze subgêneros de Wyeomyia. Os resultados indicam que, como atualmente definido, o gênero Wyeomyia é polifilético. Nossos resultados também sugerem que os subgêneros Cruzmyia Lane & Cerqueira, Decamyia Dyar, Dendromyia Theobald, Spilonympha Motta & Lourenço-de-Oliveira and Prosopolepis Lutz formam linhagens monofiléticas dentro do gênero Wyeomyia. O nome Triamyia Dyar é ressuscitado como subgênero para incluir 2 espécies: Wy. aporonoma Dyar & Knab e Wy. staminifera Lourenço-de-Oliveira, Motta & Castro. O subgênero Miamyia Dyar é ressuscitado para incluir 7 espécies: Wy. codicampa Dyar & Knab, Wy lutzi (Costa Lima), Wy. limai Lane & Cerqueira, Wy. serrata (Lutz), Wy. hosautos Dyar & Knab, Wy. oblita (Lutz) and Wy. sabethea Lane & Cerqueira. Não foi obtido suporte para o reconhecimento de Onirion Harbach & Peyton, como gênero da tribo Sabethini, nem para inclusão de Phoniomyia Theobald como subgênero de Wyeomyia.

Bionomia de mosquitos (Diptera: Culicidae) em áreas da Mata Atlântica no município de Itaguaí, estado do Rio de janeiro, Brasil: I. Frequência intra, peri e extradomiciliar / Bionomics of mosquitoes (Diptera-Culicidae) in areas of the Atlantic Forest of Itaguaí municipality, Rio de Janeiro state, Brazil: I. intra, peri and extradomiciliary frequency

Along 24 consecutive months, from January 1984 to December 1986, mosquito captures were performed in a rural area of said municipality. Aiming to evaluate the comparative frequency of the mosquito species inside houses and in the immediate vicinity and far from houses, the captures were made in two types of domiciles - one permanently and the other only sporadically inhabited - as well as in surrounding woods. Variations in temperature, relative humidity and rainfall were locally recorded. A tendency for domiciliation became evident by the presence of Aedes scapularis in the human domiciles, mainly in those permantely inhabited. Culex quinquefasciatus showed to be adapted to live with humans also in rural areas, in which, in some instances, insecticides had to be used to keep in under control. Such observations, mainly in terms of Ae. scapularis, reinforce the possibility of those mosquitoes, under favourable conditions, becoming carries of arboviroses to humans in rural environments.