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Locally acquired dengue cases in the continental U.S. are rare. However, outbreaks of dengue-1 during 2009, 2010, and 2013 in Florida and dengue-1 and −2 in Texas suggest vulnerability to transmission. Travel and commerce between ...
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Locally acquired dengue cases in the continental U.S. are rare. However, outbreaks of dengue-1 during 2009, 2010, and 2013 in Florida and dengue-1 and −2 in Texas suggest vulnerability to transmission. Travel and commerce between Puerto Rico and the U.S. mainland is common, which may pose a risk for traveler-imported dengue cases. Mosquitoes were collected in Florida and used to evaluate their susceptibility to dengue viruses (DENV) from Puerto Rico. Aedes aegypti and Ae. albopictus were susceptible to virus infection with DENV-1 and −2. No significant differences were observed in rates of midgut infection or dissemination between Ae. aegypti or Ae. albopictus for DENV-1 (6–14%). Aedes aegypti was significantly more susceptible to midgut infection with DENV-2 than Ae. albopictus (Ae. aegypti, ∼28%; Ae. albopictus, ∼9%). The dissemination rate with dengue-2 virus for Ae. aegypti (23%) was greater than Ae. albopictus (0%), suggesting that Ae. albopictus is not likely to be an important transmitter of the DENV-2 isolate from Puerto Rico. These results are discussed in light of Florida's vulnerability to DENV transmission.
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Introduction: the increase in the incidence of congenital microcephaly in Brazil has been associated to the Zika virus outbreak. This case report aimed to describe the neurological impairment of monozygotic twins presumably due to...
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Introduction: the increase in the incidence of congenital microcephaly in Brazil has been associated to the Zika virus outbreak. This case report aimed to describe the neurological impairment of monozygotic twins presumably due to an intrauterine infection by Zika virus during the Brazilian outbreak in 2015. Case description: The monozygotic twins born at term with severe congenital microcephaly were taken to the Outpatient Pediatric Service of a University Hospital. The 17-yearold mother, primigravida, lives in the Northeast region of Brazil, has a normal body mass index, no family history of microcephaly, no clinical history of viral diseases, or exposure to drugs and/or radiation during pregnancy. Serological tests for toxoplasmosis, rubella, syphilis, cytomegalovirus and HIV were negative at the prenatal evaluation and the obstetrical ultrasounds showed a monochorionic, diamniotic twin pregnancy without any evidence of neurological abnormalities. In the post-natal, the imaging of the skull, was evidenced of a great neurological impairment in one of the twins, who, in addition to presenting cerebral calcifications, gliosis and subependymal cysts, also had ventriculomegaly with hydrocephalus of supratentorial predominance and more pronounced cerebral atrophy compared to the other twin. Both presented delayed neuropsychomotor development. Discussion: distinct neurological alterations in the monochorionic twins with an infection presumed by Zika virus may raise the hypothesis of the existence of predisposing factors or protection against this viral agent.
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Background: Dengue fever is a commonly encountered arthropod-borne viral disease. The spectrum of the disease varies widely, and at times it may present with unusual complications. One such dreaded but rare complication is diffuse...
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Background: Dengue fever is a commonly encountered arthropod-borne viral disease. The spectrum of the disease varies widely, and at times it may present with unusual complications. One such dreaded but rare complication is diffuse alveolar hemorrhage (DAH). Case Report: A 42 years old lady having no co-morbidities presented with dengue infection. The presentation included fever, gum bleed, and asthenia. The examination showed low oxygen saturation and clear chest. The discordance between clinical findings and the oxygen saturation led to a cascade of investigations, culminating in the diagnosis of DAH. She was managed symptomatically, with full recovery. Conclusion: DAH is an uncommon, life-threatening, complication of dengue infection. A high index of suspicion, prompt evaluation and early institution of appropriate therapy hold the key to successfully manage such patients.
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Koutango virus (KOUV), a close relative of West Nile virus, is highly neuroinvasive in animal models and has been associated with human disease. The complete genome of the KOUV prototype strain DakAnD5443 is reported here and may ...
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Koutango virus (KOUV), a close relative of West Nile virus, is highly neuroinvasive in animal models and has been associated with human disease. The complete genome of the KOUV prototype strain DakAnD5443 is reported here and may facilitate development of infectious clones for further characterization of this novel flavivirus.
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Mosquito-borne viruses are an increasing health threat to humans, and potentially other vertebrates, in areas where they have not previously existed or from which they had been eradicated. Chikungunya virus emergence exemplifies h...
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Mosquito-borne viruses are an increasing health threat to humans, and potentially other vertebrates, in areas where they have not previously existed or from which they had been eradicated. Chikungunya virus emergence exemplifies how multiple factors can act synergistically resulting in rapid, large-scale redistribution and establishment. Despite our increased capacity to collect and analyze large amounts of data, we still lack epidemiological models to facilitate accurate predictions of when and where new diseases may occur. Models focusing on climate changes may have long-term value; however, there is an urgent need for mathematical modeling of viral epidemiology to enable forecasting immediate or near-term threats.
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Dozens of orthobunyaviruses have been isolated in Brazil, and at least thirteen have been associated with human disease. The Oropouche virus has received most attention for having caused explosive epidemics with hundreds of thousa...
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Dozens of orthobunyaviruses have been isolated in Brazil, and at least thirteen have been associated with human disease. The Oropouche virus has received most attention for having caused explosive epidemics with hundreds of thousands of cases in the north region between the 1960sand the 1980s, and since then has been sporadically detected elsewhere in the country. Despite their importance, little is known about their enzootic cycles of transmission, amplifying hosts and vectors, and biotic and abiotic factors involved in spillover events to humans. This overview aims to combine available data of neglected orthobunyaviruses of several serogroups, namely, Anopheles A, Anopheles B, Bunyamwera, California, Capim, Gamboa, Group C, Guama, Simbu and Turlock, in order to evaluate the current knowledge and identify research gaps in their natural transmission cycles in Brazil to ultimately point to the future direction in which orthobunyavirus research should be guided.
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The impact of anticipated changes in global climate on the arboviruses and the diseases they cause poses a significant challenge for public health. The past evolution of the dengue and yellow fever viruses provides clues about the...
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The impact of anticipated changes in global climate on the arboviruses and the diseases they cause poses a significant challenge for public health. The past evolution of the dengue and yellow fever viruses provides clues about the influence of changesin climate on their future evolution. The evolution of both viruses has been influenced by virus interactions involving the mosquito species and the primate hosts involved in virus transmission; and by their domestic and sylvatic cycles. Information isneeded on how viral genes in general influence phenotypic variance for important viral functions. Changes in global climate will alter the interactions of mosquito species with their primate hosts and with the viruses in domestic cycles, and greater attention should be paid to the sylvatic cycles. There is great danger for the evolution of novel viruses, such as new serotypes, that could compromise vaccination programs and jeopardize public health. It is essential to understand (a) both sylvatic and domestic cycles and (b) the role of virus genetic and environmental variances in shaping virus phenotypic variance to more fully assess the impact of global climate change.
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In nature, insects face a constant threat of infection by numerous exogeneous viruses, and their intestinal tracts are the predominant ports of entry. Insects can acquire these viruses orally during either blood feeding by hematop...
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In nature, insects face a constant threat of infection by numerous exogeneous viruses, and their intestinal tracts are the predominant ports of entry. Insects can acquire these viruses orally during either blood feeding by hematophagous insects or sap sucking and foliage feeding by insect herbivores. However, the insect intestinal tract forms several physical and immunological barriers to defend against viral invasion, including cell intrinsic antiviral immunity, the peritrophic matrix and the mucin layer, and local symbiotic microorganisms. Whether an infection can be successfully established in the intestinal tract depends on the complex interactions between viruses and those barriers. In this review, we summarize recent progress on virus-intestinal tract interplay in insects, in which various underlying mechanisms derived from nutritional status, dynamics of symbiotic microorganisms, and virus-encoded components play intricate roles in the regulation of virus invasion in the intestinal tract, either directly or indirectly.Expected final online publication date for the Annual Review of Virology, Volume 8 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Chikungunya virus, first isolated in the 1950s, has since reemerged to cause several epidemics and millions of infections throughout the world. What was once blurred and confused with dengue virus in both diagnosis and name has si...
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Chikungunya virus, first isolated in the 1950s, has since reemerged to cause several epidemics and millions of infections throughout the world. What was once blurred and confused with dengue virus in both diagnosis and name has since become one of the best-characterized arboviral diseases. In this review, we cover the history of this virus, its evolution into distinct genotypes and lineages, and, most notably, the convergent evolution observed in recent years. We highlight research that reveals to what extent convergent evolution, and its inherent predictability, may occur and what genetic or environmental factors may hinder it.
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Arboviruses are diseases of worldwide importance in the field of communicable diseases. In Brazil, the reemergence of dengue and the emergence of chikungunya and Zika since 2014 have led to epidemic waves of great magnitude and ra...
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Arboviruses are diseases of worldwide importance in the field of communicable diseases. In Brazil, the reemergence of dengue and the emergence of chikungunya and Zika since 2014 have led to epidemic waves of great magnitude and rapid spread. However, their diffusion patterns vary and change over time. This study analyzes the spatial diffusion of the simultaneous circulation of three arboviruses transmitted by the same vector in a large urban space over two epidemic waves in consecutive years. An ecological study of spatial and temporal aggregates on the occurrence of dengue, chikungunya, and Zika, from 2014 to 2019, in Feira de Santana, Bahia State, was carried out using data of cases reported to the national surveillance system. Four different methods were used to analyze the spatial diffusion: Kernel Estimation with sequential maps, cumulative nearest-neighbor ratios (NNI) over time, spatial correlograms and local autocorrelation changes (LISA) over time. From 2014–2019, there were 21,723 confirmed cases of arboviruses. The highest incidences were among women (496.9, 220.2, and 91.0 cases/100,000 women for dengue, chikungunya and Zika respectively). By age group, the highest incidences were from ages 10–19 years old (609.3 dengue cases/100,000), from 60 and more (306.7 chikungunya cases/100,000), and from 0-9 years old (124.1 Zika cases/100,000 inhabitants). The temporal distribution demonstrated two epidemic waves of simultaneous circulation in 2014 and 2015. Kernel maps indicate that arboviruses spread to neighboring areas near the first hotspots, suggesting an expansion diffusion pattern. The NNI, spatial correlograms and LISA changes results suggest expansion patterns for the three arboviruses in all periods. The spatial diffusion pattern of dengue, Zika, and chikungunya in the 2014–2015 epidemics in Feira de Santana was expansion. These findings are useful to guide prevention measures and reduce occurrence in other areas.
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