Previous phylogenetic analyses indicated that the ZIKV epidemic was caused by the introduction of a single Asian genotype lineage into the Americas around late 2013, at least one year before its detection there 4 . An estimated 100 million people in the Americas are predicted to be at risk of acquiring ZIKV once the epidemic has reached its full extent 5 . However, little is known about the genetic diversity and transmission history of the virus in different regions in Brazil 6 . Reconstructing ZIKV spread from case reports alone is challenging because symptoms (typically fever, headache, joint pain, rashes, and conjunctivitis) overlap with those caused by co-circulating arthropod-borne viruses 7 and due to a lack of nationwide ZIKV-specific surveillance in Brazil before 2016. [Figure 1 around here]To address this we undertook a collaborative investigation of ZIKV molecular epidemiology in Brazil, including results from a mobile genomics laboratory that travelled through NE Brazil during June 2016 (the ZiBRA project; http://www.zibraproject.org). Of five regions of Brazil (Fig. 1a), the Northeast region (NE Brazil) has the most notified ZIKV cases (40% of Brazilian cases) and the most confirmed microcephaly cases (76% of Brazilian cases, to 31 Dec 2016 2 ), raising questions about why the region has been so severely affected 8 . Further, NE Brazil is the most populous region of Brazil with the potential for year-round ZIKV transmission 9 . With the support of the Brazilian Ministry of Health and other institutions (Acknowledgements), the ZiBRA lab screened 1330 samples (almost exclusively serum or blood) from patients residing in 82 municipalities across five federal states in NE Brazil ( Fig. 1 On average, ZIKV viremia persists for 10 days after infection; symptoms develop ~6 days after infection and can last 1-2 weeks 10 . In line with previous observations in Colombia 11 , we found that the RT-qPCR+ samples in NE Brazil were, on average, collected only two days after onset of symptoms. The median RT-qPCR cycle threshold (Ct) value of positive samples was correspondingly high, at 36 (Extended Data Fig. 1). For NE Brazil, the time series of RT-qPCR+ cases was positively correlated with the number of weekly-notified cases (Pearson's ρ=0.62; Fig. 1b).The ability of the mosquito vector Aedes aegypti to transmit ZIKV is determined by ecological factors that affect adult survival, viral replication, and infective periods 12 .To investigate the receptivity of each Brazilian region to ZIKV transmission, we used a measure of vector climatic suitability derived from monthly temperature, relative humidity, and precipitation data 9 . Using linear regression we find that, for each Brazilian region, there is a strong association between estimated climatic suitability and weekly notified cases (Figs. 1b,1c; adjusted R 2 >0.84, P<0.001; Extended Data Table 2). Similar to previous findings obtained for dengue virus outbreaks 13,14 , notified ZIKV cases lag climatic suitability by ~4 to 6 weeks in all regions, except NE Brazil,...

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Hepatitis E virus (HEV) circulation in humans and swine has been extensively studied in South America over the last two decades. Nevertheless, only 2.1% of reported HEV strains are available as complete genome sequences. Therefore, many clinical, epidemiological, and evolutionary aspects of circulating HEV in the continent still need to be clarified. Here, we conducted a retrospective evolutionary analysis of one human case and six swine HEV strains previously reported in northeastern, southern, and southeastern Brazil. We obtained two complete and four nearly complete genomic sequences. Evolutionary analysis comparing the whole genomic and capsid gene sequences revealed high genetic variability. This included the circulation of at least one unrecognized unique South American subtype. Our results corroborate that sequencing the whole capsid gene could be used as an alternative for HEV subtype assignment in the absence of complete genomic sequences. Moreover, our results substantiate the evidence for zoonotic transmission by comparing a larger genomic fragment recovered from the sample of the autochthonous human hepatitis E case. Further studies should continuously investigate HEV genetic diversity and zoonotic transmission of HEV in South America.

Mayaro virus (MAYV) is transmitted by Haemagogus spp. mosquitoes and has been circulating in Amazon areas in the North and Central West regions of Brazil since the 1980s, with an increase in human case notifications in the last 10 years. MAYV introduction in urban areas is a public health concern once the infection can cause severe symptoms similar to other Alphaviruses. Regarding to urban transmission, studies with Aedes aegypti demonstrate the potential vector competence of the species and the detection of MAYV in urban populations of mosquitoes. Considering the two most abundant urban mosquito species in Brazil, we investigated the dynamics of MAYV transmission by Ae. aegypti and Culex quinquefasciatus in a mice model. Mosquito colonies were artificially fed with blood containing MAYV and infection (IR) and dissemination rates (DR) were evaluated. On the 7th post-infection day (dpi), IFNAR BL/6 mice were made available as a blood source to both mosquito's species. After the appearance of clinical signs of infection, a second blood feeding was performed with a new group of non-infected mosquitoes. RT-q PCR and plaque assay were carried out with animal and mosquito's tissues. We found for Ae. aegypti a IR of 97,5-100% and a DR of 100% in both 7th and 14th dpi. Regarding Cx. quinquefasciatus, the IR found was 13.1-14.81% and DR ranged from 60% to 80%. To evaluate the mosquito-mice transmission rate, 18 mice were evaluated (Test=12 and Control=6) for Ae. aegypti and 12 animals (Test=8 and Control=4) for Cx. quinquefasciatus. All mice bitten by infected Ae. aegypti showed clinical signs of infection while all mice exposed to infected Cx. quinquefasciatus mosquitoes remained healthy. Viremia found in those animals ranged from 2.5 x 108 to 5 x 109 PFU/ml. Ae. aegypti from the second blood feeding showed a 50% infection rate. Our study showed the applicability of an efficient model to complete arbovirus transmission cycle studies and suggests that the Ae. aegypti population evaluated is a competent vector for MAYV highlighting the risk of establishment of MAYV urban cycle. The mice model employed here can be used more extensively for arthropod-vector transmission studies, with laboratory and field mosquito populations, as well as with other arboviruses.

Duas tecnologias alternativas para o controle de Aedes aegypti foram avaliadas: a aplicação espacial de larvicida biológico-Bti em potenciais criadouros peridomiciliares, e a liberação de machos estéreis para inviabilização reprodutiva das fêmeas do mosquito. As ações foram realizadas pelos Agentes dos Serviços de Saúde em 15 vilas da Ilha de Fernando de Noronha, e em uma área (900 imóveis) no bairro da Várzea/Recife/Pernambuco. A efetividade dos métodos foi avaliada por indicadores entomológicos, estimados pela presença, quantidade e viabilidade de ovos do mosquito, coletados em armadilhas, e por marcadores genéticos. A aplicação de Bti, com atomizador costal, ocorreu a cada 30 dias em ambas as áreas. Uma redução importante e sustentável da população de A. aegypti, por este método, foi alcançada em 2015/2016 na Várzea e, em 2016, na Ilha, onde a remoção de 18 toneladas de resíduos sólidos em 2015 contribuiu possivelmente para os resultados. Machos esterilizados com radiação gama foram produzidos em massa no laboratório e liberados em uma das vilas da Ilha. A análise espaço-temporal dos indicadores, de dez/2015 a ago/2016, revelou redução expressiva da densidade populacional do mosquito e da diversidade genética da população local. Ambas as abordagens parecem ter reduzido o contato homem-vetor e os riscos de transmissão de arboviroses na Ilha, apesar da elevada competência vetorial da população local do mosquito para os vírus Zika e Dengue. Os métodos testados se mostraram eficientes e passíveis de serem integradas às ações do SUS voltadas ao controle de A. aegypti.

Among invasive species known to occur in South America, the bivalve mollusc Limnoperna fortunei, which the presence is linked to several environmental and economic problems. Early detection and mitigation actions are needed to limit its impact in the remaining L. fortunei-free areas. PCR-based molecular methods have become the gold standard methodology for L. fortunei detection. However, PCR-based methods require complex logistics from field sampling to laboratory processing. Thus, the use of methods that can be directly applied in the field can speed up the detection process. This work aimed to establish, for the first time, the loop-mediated isothermal amplification (LAMP) method for the detection of L. fortunei, with perspectives for in situ application. A set of primers designed for LAMP was tested for amplification of DNA from L. fortunei adult tissues and environmental samples containing bivalve larvae. The test showed a limit of detection as low as 0.01 ng of DNA obtained from adult tissue samples and a minimum reaction time of 60 min. The set of primers used seems to be specific for L. fortunei, since there was no cross-amplification with other bivalve or invasive molluscs that co-occur with the golden mussel in the same environment. The LAMP technique also proved to be efficient in amplifying DNA derived from L. fortunei larvae, demonstrating it to be a robust method regarding potential environmental reaction inhibitors. Although the results obtained here were acquired under controlled laboratory conditions, the LAMP method is a promising tool to integrate L. fortunei invasion monitoring protocols.

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Zika virus (ZIKV) has been intensively studied in Brazil since 2015-2016 epidemics, but little is known about the virus in Midwest region of the country. We report here two ZIKV complete genomes, which were isolated during arboviral surveillance in Sinop city, southern border of the Amazonian forest, Midwest Brazil, 2015.Zika virus (ZIKV) is a mosquito-borne arbovirus that has a positive-sense single-stranded RNA genome. This virus belongs to the Flaviviridae family, Flavivirus genus, and has recently emerged as one of the most serious global public health threat. Symptoms are usually mild and up to 80% of ZIKV infections can be asymptomatic ( 1 ). However, ZIKV has been associated to neurological complications such as congenital Zika syndrome in newborns, Guillain-Barré syndrome and other neurological complications in adults ( 2, 3, 4 ).