Radio-frequency exposure of the yellow fever mosquito (A. aegypti) from 2 to 240 GHz.

Fifth generation networks (5G) will be associated with a partial shift to higher carrier frequencies, including wavelengths comparable in size to insects. This may lead to higher absorption of radio frequency (RF) electromagnetic fields (EMF) by insects and could cause dielectric heating. The yellow fever mosquito (Aedes aegypti), a vector for diseases such as yellow and dengue fever, favors warm climates. Being exposed to higher frequency RF EMFs causing possible dielectric heating, could have an influence on behavior, physiology and morphology, and could be a possible factor for introduction of the species in regions where the yellow fever mosquito normally does not appear. In this study, the influence of far field RF exposure on A. aegypti was examined between 2 and 240 GHz. Using Finite Difference Time Domain (FDTD) simulations, the distribution of the electric field in and around the insect and the absorbed RF power were found for six different mosquito models (three male, three female). The 3D models were created from micro-CT scans of real mosquitoes. The dielectric properties used in the simulation were measured from a mixture of homogenized A. aegypti. For a given incident RF power, the absorption increases with increasing frequency between 2 and 90 GHz with a maximum between 90 and 240 GHz. The absorption was maximal in the region where the wavelength matches the size of the mosquito. For a same incident field strength, the power absorption by the mosquito is 16 times higher at 60 GHz than at 6 GHz. The higher absorption of RF power by future technologies can result in dielectric heating and potentially influence the biology of this mosquito.

The austral-most record of the genus Haemagogus Williston (Diptera: Culicidae)

Abstract INTRODUCTION: The genus Haemagogus Williston is restricted to Central America and North and middle of South America and it includes numerous species of yellow fever virus vectors. METHODS: Adult female and larvae mosquitoes were collected using hand aspirators and dipper and pipette, respectively. RESULTS: The first record of a species of Haemagogus and particularly of Haemagogus spegazzinii was from La Pampa, Argentina. With this registry, the number of species found in La Pampa province rises to 18. CONCLUSIONS: New information on breeding sites for the species and implications of this new record suggest a possible extension of distribution in the near future.

Inactivation of yellow fever virus in plasma after treatment with methylene blue and visible light and in platelet concentrates following treatment with ultraviolet C light.

BACKGROUND: Yellow fever virus (YFV) is endemic to tropical and subtropical areas in South America and Africa, and is currently a major public health threat in Brazil. Transfusion transmission of the yellow fever vaccine virus has been demonstrated, which is indicative of the potential for viral transfusion transmission. An approach to manage the potential YFV transfusion transmission risk is the use of pathogen inactivation (PI) technology systems, such as THERAFLEX MB-Plasma and THERAFLEX UV-Platelets (Macopharma). We aimed to investigate the efficacy of these PI technology systems to inactivate YFV in plasma or platelet concentrates (PCs). STUDY DESIGN AND METHODS: YFV spiked plasma units were treated using THERAFLEX MB-Plasma system (visible light doses: 20, 40, 60, and 120 [standard] J/cm2 ) in the presence of methylene blue (approx. 0.8 µmol/L) and spiked PCs were treated using THERAFLEX UV-Platelets system (ultraviolet C doses: 0.05, 0.10, 0.15, and 0.20 [standard] J/cm2 ). Samples were taken before the first and after each illumination dose and tested for residual virus using a modified plaque assay. RESULTS: YFV infectivity was reduced by an average of 4.77 log or greater in plasma treated with the THERAFLEX MB-Plasma system and by 4.8 log or greater in PCs treated with THERAFLEX UV-Platelets system. CONCLUSIONS: Our study suggests the THERAFLEX MB-Plasma and the THERAFLEX UV-Platelets systems can efficiently inactivate YFV in plasma or PCs to a similar degree as that for other arboviruses. Given the reduction levels observed in this study, these PI technology systems could be an effective option for managing YFV transfusion-transmission risk in plasma and PCs.

Commerce, conflict, and contamination: yellow fever in early-independence Veracruz in the US imaginary, 1821-1848 / Comércio, conflito e contaminação: imaginário estadunidense sobre a febre amarela na recém-independente Veracruz

Abstract While commercial links between Mexico and the United States through the port city of Veracruz brought significant economic and social advantages in the early nineteenth century, public health concerns around yellow fever produced fascination and fear among US audiences (in southern and eastern port cities) from times of peace until the US invasion and occupation of Mexico (1846-1848). This article addresses the complex linkages between commerce, conflict, and contamination in reference to the port city of Veracruz and the United States in Mexico's early decades of independence. More specifically, this article addresses the concern in early nineteenth-century US periodicals around yellow fever outbreaks and potential contamination, showing the constant presence of yellow fever in Veracruz in the US imaginary.

Resumo Enquanto os vínculos comerciais entre México e EUA por meio da cidade portuária de Veracruz trouxe vantagens econômicas e sociais significativas no início do século XIX, preocupações em torno da febre amarela produziram medo e fascínio entre o público estadunidense (em cidades portuárias do sul e do leste) desde os tempos de paz até a invasão e ocupação estadunidense do México (1846-1848). O artigo aborda os complexos vínculos entre comércio, conflito e contaminação relacionados à cidade portuária de Veracruz e aos EUA nas primeiras décadas da independência do México. Especificamente, trata a preocupação com surtos de febre amarela e a potencial contaminação encontrada em periódicos estadunidenses no início do século XIX, mostrando a presença constante da febre amarela em Veracruz no imaginário estadunidense.

Yellow fever.

The yellow fever (YF) virus is a Flavivirus, transmitted by Haemagogus, Sabethes or Aedes aegypti mosquitoes. The disease is endemic in forest areas in Africa and Latin America leading to epizootics in monkeys that constitute the reservoir of the disease. There are two forms of YF: sylvatic, transmitted accidentally when approaching the forests, and urban, which can be perpetuated by Aedes aegypti. In Brazil, the last case of urban YF occurred in 1942. Since then, there has been an expansion of transmission areas from the North and Midwest regions to the South and Southeast. In 2017, the country faced an important outbreak of the disease mainly in the states of Minas Gerais, Espírito Santo and Rio de Janeiro. In 2018, its reach extended from Minas Gerais toward São Paulo. Yellow fever has an incubation period of 3 to 6 days and sudden onset of symptoms with high fever, myalgia, headache, nausea/vomiting and increased transaminases. The disease ranges from asymptomatic to severe forms. The most serious forms occur in around 15% of those infected, with high lethality rates. These forms lead to renal, hepatic and neurological impairment, and bleeding episodes. Treatment of mild and moderate forms is symptomatic, while severe and malignant forms depend on intensive care. Prevention is achieved by administering the vaccine, which is an effective (immunogenicity at 90-98%) and safe (0.4 severe events per 100,000 doses) measure. In 2018, the first transplants in the world due to YF were performed. There is also an attempt to evaluate the use of active drugs against the virus in order to reduce disease severity.

Yellow fever

Summary The yellow fever (YF) virus is a Flavivirus, transmitted by Haemagogus, Sabethes or Aedes aegypti mosquitoes. The disease is endemic in forest areas in Africa and Latin America leading to epizootics in monkeys that constitute the reservoir of the disease. There are two forms of YF: sylvatic, transmitted accidentally when approaching the forests, and urban, which can be perpetuated by Aedes aegypti. In Brazil, the last case of urban YF occurred in 1942. Since then, there has been an expansion of transmission areas from the North and Midwest regions to the South and Southeast. In 2017, the country faced an important outbreak of the disease mainly in the states of Minas Gerais, Espírito Santo and Rio de Janeiro. In 2018, its reach extended from Minas Gerais toward São Paulo. Yellow fever has an incubation period of 3 to 6 days and sudden onset of symptoms with high fever, myalgia, headache, nausea/vomiting and increased transaminases. The disease ranges from asymptomatic to severe forms. The most serious forms occur in around 15% of those infected, with high lethality rates. These forms lead to renal, hepatic and neurological impairment, and bleeding episodes. Treatment of mild and moderate forms is symptomatic, while severe and malignant forms depend on intensive care. Prevention is achieved by administering the vaccine, which is an effective (immunogenicity at 90-98%) and safe (0.4 severe events per 100,000 doses) measure. In 2018, the first transplants in the world due to YF were performed. There is also an attempt to evaluate the use of active drugs against the virus in order to reduce disease severity.

Yellow fever outbreak in Brazil: the puzzle of rapid viral spread and challenges for immunisation

We discuss the complex eco-social factors involved in the puzzle of the unexpected rapid viral spread in the ongoing Brazilian yellow fever (YF) outbreak, which has increased the reurbanisation risk of a disease without urban cases in Brazil since 1942. Indeed, this rapid spatial viral dissemination to the Southeast and South regions, now circulating in the Atlantic Forest fragments close to peri-urban areas of the main Brazilian megalopolises (São Paulo and Rio de Janeiro) has led to an exponential increase in the number of yellow fever cases. In less than 18 months, 1,833 confirmed cases and 578 deaths were recorded most of them reported in the Southeast region (99,9%). Large epizooties in monkeys and other non-human primates (NHPs) were communicated in the country with 732 YF virus (YFV) laboratory confirmed events only in the 2017/2018 monitoring period. We also discuss the peculiarities and similarities of the current outbreak when compared with previous great epidemics, examining several hypotheses to explain the recent unexpected acceleration of epizootic waves in the sylvatic cycle of the YFV together with the role of human, NHPs and mosquito mobility with respect to viral spread. We conclude that the most feasible hypothesis to explain this rapidity would be related to human behavior combined with ecological changes that promoted a significant increase in mosquito and NHP densities and their contacts with humans. We emphasize the urgent need for an adequate response to this outbreak such as extending immunisation coverage to the whole Brazilian population and developing novel strategies for immunisation of NHPs confined in selected reserve areas and zoos. Finally, we stress the urgent need to improve the quality of response in order to prevent future outbreaks and a catastrophic reurbanisation of the disease in Brazil and other South American countries. Continuous monitoring of YFV receptivity and vulnerability conditions with effective control of the urban vector Aedes aegypti and significant investments in YF vaccine production capacity and research and development for reduction of adverse effects are of the highest priority.

Presencia de Aedes ( Stegomyia ) aegypti (Linnaeus, 1762) y su infección natural con el virus del dengue en alturas no registradas para Colombia / Presence of Aedes ( Stegomyia ) aegypti (Linnaeus, 1762) and its natural infection with dengue virus at unrecorded heights in Colombia

Introducción. Aedes aegypti es el principal vector de fiebre amarilla urbana, dengue, chikungunya y zika. Se ha demostrado que la distribución biogeográfica de esta especie se ha expandido debido al calentamiento global y a factores socioeconómicos y culturales. Los cambios en los patrones de la distribución altitudinal de este vector y su infección con el virus son prioridades de la investigación encaminada a desarrollar estrategias de vigilancia entomológica y virológica en salud pública. Objetivo. Evaluar la presencia de A. aegypti y su infección natural por el virus del dengue en alturas superiores a los 1.800 msnm en dos municipios periféricos del Valle de Aburrá, Antioquia, Colombia. Materiales y métodos. Se instalaron 21 ovitrampas en los municipios de Bello y San Pedro de los Milagros, en un rango altitudinal de 1.882 a 2.659 msnm. Los adultos que emergieron de las ovitrampas se evaluaron con reacción en cadena de la polimerasa en tiempo real (RT-PCR) para la detección del virus del dengue. Resultados. Se recolectaron 367 adultos de A. aegypti , siete de los cuales se encontraron a una altitud de 2.302 msnm en Tierradentro, Bello. Se detectaron 12 especímenes de A. aegypti positivos para dengue serotipo 2 en el barrio París de Bello, a 1.984 msnm. Conclusión. Por primera vez se registró A. aegypti a 2.302 msnm, la mayor altitud registrada para este vector en Colombia. De igual forma, se encontró infección con el virus del dengue a 1.984 msnm. Estos hallazgos son significativos, ya que determinan regiones de Colombia con riesgo potencial de transmisión autóctona de dengue y otros arbovirus por A. aegypti .

Introduction: Aedes aegypti is the main vector of urban yellow fever, dengue, chikungunya and Zika viruses. The biogeographical distribution of this species has expanded due to global warming, and socioeconomic and cultural factors. The changes in the altitudinal distribution patterns of this vector and its natural infection are priority fields of research to develop entomological, virological and public health surveillance strategies. Objective: To evaluate the presence of A. aegypti and its natural infection with dengue virus in altitudes above 1.800 meters above sea level in two peripheral municipalities of the Valle de Aburrá, Antioquia, Colombia. Materials and methods: Twenty-one ovitraps were set in the municipalities of Bello and San Pedro de los Milagros, at altitudes ranging from 1.882 to 2.659 masl. Emerged adults caught in the ovitraps were tested by RT-PCR for dengue virus detection. Results: We collected 367 A. aegypti adults, seven of which were found as high as 2.302 masl in Tierradentro, Bello. We detected serotype 2 dengue infection in 12 A. aegypti specimens collected in the neighbourhood of París, in Bello, at 1.984 masl. Conclusion: We recorded A. aegypti at 2.302 masl, so far the highest altitudinal record in Colombia for this vector. Furthermore, mosquitoes collected at 1.984 masl were positive for dengue virus. These findings are significant as they identify regions in Colombia at risk of potential autochthonous transmission of dengue and other arboviruses by A. aegypti .

Características epidemiológicas da febre amarela no Brasil, 2000-2012 / Características epidemiológicas de la fiebre amarilla en Brasil en el período 2000-2012 / Epidemiological characteristics of yellow fever in Brazil, 2000-2012

OBJETIVO: o estudo visa descrever as características epidemiológicas da febre amarela no Brasil no período de 2000 a 2012. MÉTODOS: estudo epidemiológico, ecológico, descritivo, utilizando informações dos bancos de dados do Ministério da Saúde. RESULTADOS: foram confirmados 326 casos de febre amarela no país nesse período, com 156 óbitos e taxa de letalidade média de 47,8%; o grupo de adultos jovens do sexo masculino foi o mais acometido; nas epizootias, foi identificado um total de 2.856 primatas não humanos notificados com suspeita de febre amarela, 31,1% deles confirmados laboratorialmente; no período estudado, foi identificada expansão da área de transmissão silvestre da doença para regiões densamente povoadas, como Sul, Sudeste e Centro-Oeste. CONCLUSÃO: persiste o risco de transmissão urbana da febre amarela, pois a incidência silvestre da doença tem se expandido para regiões onde existe alta infestação do Aedes aegypti, mosquito transmissor do ciclo urbano da doença.

OBJETIVO: el estudio tiene como objetivo describir las características epidemiológicas de la fiebre amarilla en Brasil entre 2000 y 2012. MÉTODOS: estudio epidemiológico descriptivo, ecológico, utilizando información de bases de datos del Ministerio de Salud. RESULTADOS: se confirmaron 326 casos de fiebre amarilla en el país en este periodo, con un total de 156 muertes y una tasa de letalidad de 47,8%; el grupo de adultos jóvenes del sexo masculino fue el más afectado; se identificó un total de 2.856 primates notificados sospechosos de fiebre amarilla, de los cuales 31,1% fueron confirmados laboratoriálmente; en el período estudiado, identificamos una expansión del área de transmisión silvestre de la enfermedad a zonas densamente pobladas como el Sur, Sudeste y Centro-Oeste. CONCLUSIÓN: persiste el riesgo de transmisión de fiebre amarilla, ya que la incidencia de la enfermedad se ha extendido a regiones donde hay una alta infestación de Aedes aegypti, el mosquito transmisor del ciclo urbano de la enfermedad.

OBJECTIVE: this study aims to describe the epidemiological characteristics of yellow fever in Brazil in the period 2000-2012. METHODS: this is a descriptive ecological epidemiological study, using information from Ministry of Health databases. RESULTS: 326 cases of yellow fever were confirmed in Brazil during this period, with 156 deaths and an average case fatality rate of 47.8%; the young male adult age group was the most affected; in epizootic terms, 2,856 suspected cases of yellow fever in non-human primates were reported and 31.1% of these were confirmed by laboratory tests; during the study period the area in which sylvatic transmission of the disease occurs was found to have expanded to densely population regions, such as South, Southeast and Midwest Brazil. CONCLUSION: the risk of urban yellow fever transmission persists, as sylvatic incidence of the disease has expanded to regions with high Aedes aegypti infestation, this being the mosquito responsible for urban transmission of the disease.

Teorias sobre a propagação da febre amarela: um debate científico na imprensa paulista, 1895-1903 / Theories about the propagation of yellow fever: the scientific debate in the São Paulo press between 1895 and 1903

O artigo descreve o debate sobre as teorias de propagação da febre amarela na imprensa paulista. Nosso recorte temporal foi definido entre 1895 e 1903, período de grande incidência da enfermidade no Brasil e de crescente influência da bacteriologia nas teorias sobre as doenças. Realizou-se pesquisa documental em jornais de grande circulação de São Paulo e periódicos médicos da época. Os dados empíricos foram coletados no Arquivo Público do Estado de São Paulo e na biblioteca da Faculdade de Saúde Pública da Universidade de São Paulo. Foi identificado confronto entre as teorias de propagação da febre amarela, revelador de disputa simbólica por espaço na constituição do campo científico.

This article describes the debate over theories about the propagation of yellow fever in the São Paulo press. Our time span was defined as the period between 1895 and 1903, a time that saw high indices of the disease in Brazil. Documentary research involved mass circulation newspapers in São Paulo and medical journals of the period. The empirical data was collected from the Public Archives of the State of São Paulo and from the library of the Faculdade de Saúde Pública at Universidade de São Paulo. It was observed a clash between theories as to the propagation of yellow fever that revealed a symbolic dispute for influence in the formation of the scientific field.

Fragmentos da história da higiene e saúde públicas: a febre amarela em Campinas-SP no século XIX / Fragments of the history of hygiene and public health: yellow fever in the century in Campinas, Brazil

A febre amarela, doença viral transmitida por mosquitos, constitui um velho problema de saúde pública nacional. O presente artigo objetiva resgatar as teorias etiológicas da doença ao longo da história, suas origens no Brasil, as tentativas de combate e as repercussões das epidemias que ocorreram na cidade de Campinas-SP no fim do século XIX. Discutem-se as transformações no âmbito sanitário e higiênico promovidas pela comunidade científica e pela sociedade em geral...

Yellow fever is a viral disease transmitted by mosquitoes and is also a long standing national public health problem. This article aims to discover its etiological theories throughout history, the origins of the disease in Brazil, the attempts to combat it and, as an example, the impact of epidemics in the city of Campinas – SP at the end of the nineteenth century. We discuss the changes in the sanitary and hygienic framework promoted by the scientific community and society at large...

Ecological aspects of mosquitoes (Diptera: Culicidae) in the gallery forest of Brasilia National Park, Brazil, with an emphasis on potential vectors of yellow fever

Introduction We analyzed the vertical and monthly distributions of culicid species in the gallery forest of Brasília National Park, with an emphasis on the potential vectors of yellow fever (YF). Methods Between September 2010 and August 2011, mosquitoes were captured on the ground and in the canopy of the forest for five consecutive days per month, from nine to 15 hours. The mosquitoes were examined to verify natural infection with flaviviruses by isolation in Aedes albopictus Skuse, 1864 cells followed by indirect immunofluorescence. Results We identified 2,677 culicids distributed in 29 species. Most of the mosquitoes were captured at ground level (69%) during the rainy season (86%). The most abundant species were Sabethes (Sabethes) albiprivus Theobald, 1903; Limatus durhamii Theobald, 1901; Haemagogus (Conopostegus) leucocelaenus Dyar & Shannon, 1924; Haemagogus (Haemagogus) janthinomys Dyar, 1921; Aedes (Ochlerotatus) scapularis Rondani, 1848; Psorophora (Janthinosoma) ferox Von Humboldt, 1819; and Aedes (Ochlerotatus) serratus Theobald, 1901. Limatus durhamii, Limatus durhamii, Psorophora ferox, Aedes scapularis and Aedes serratus showed significant differences (p<0.05) in their habitat use. Limatus durhamii was found more often in the canopy, unlike the other species. During the rainy season, the most abundant species were Sa. albiprivus, Haemagogus leucocelaenus and Limatus durhamii. During the dry season, the potential YF vectors exhibited a very low frequency and abundance, except Aedes scapularis and Aedes serratus. No flavivirus was detected in the 2,677 examined mosquitoes. Conclusions We recommend continued and systematic entomological monitoring in areas vulnerable to the transmission of YF in the Federal District of Brazil. .

Historical analysis of the records of sylvan yellow fever in the State of Amazonas, Brazil, from 1996 to 2009

Introduction Yellow fever is a non-contagious infectious disease, highly lethal, transmitted by the Aedes, Haemagogus and Sabethes. Methods Descriptive retrospective study of the yellow fever cases in Amazonas, between 1996 and 2009. Results Forty two cases of yellow fever were confirmed, with 30 deaths, 10% of which were foreigners. Conclusions The presence of Aedes aegypti and Aedes albopictus in both rural Amazonas and its capital demonstrates the dispersion of these vectors and underscores the need for better and continuous epidemiological and entomological control. .

History of domestication and spread of Aedes aegypti - A Review

The adaptation of insect vectors of human diseases to breed in human habitats (domestication) is one of the most important phenomena in medical entomology. Considerable data are available on the vector mosquito Aedes aegypti in this regard and here we integrate the available information including genetics, behaviour, morphology, ecology and biogeography of the mosquito, with human history. We emphasise the tremendous amount of variation possessed by Ae. aegypti for virtually all traits considered. Typological thinking needs to be abandoned to reach a realistic and comprehensive understanding of this important vector of yellow fever, dengue and Chikungunya.

De miasmas a mosquitos: el pensamiento médico sobre la fiebre amarilla en Yucatán, 1890-1920 / From miasmas to mosquitoes: medical thought on yellow fever in Yucatan, 1890-1920

La fiebre amarilla fue un problema de salud pública desde la época colonial debido a la frecuencia con que se presentaba en forma epidémica y a su alta letalidad. El objetivo de este trabajo es analizar el pensamiento médico y su evolución con respecto al vómito prieto entre 1890 y 1921 en Yucatán. Dos aspectos serán abordados: algunos antecedentes con respecto a la enfermedad y las ideas predominantes hasta 1881; y la propuesta de Carlos Finlay para vencer el escepticismo ante su teoría por parte de la comunidad médica. En segundo lugar se analizará la mezcla de las ideas miasmáticas y bacterianas. En tercer lugar, se mostrará cómo, a partir de la demostración de sus postulados, la mirada médica se dirigió al exterminio del mosquito transmisor de este padecimiento.

Yellow fever has been a public health concern since colonial days because of its frequent epidemics and high mortality rate. This analysis of medical thought about "the black vomit" in the Yucatan and the evolution of this thinking from 1890 through 1921 first addresses some of the disease's antecedents and preponderant ideas prior to 1881 as well as Carlos Finlay's efforts to convince the medical community that his theory was right. The article goes on to analyze the co-existence of miasmatic and bacterial ideas and to show how medical initiatives began focusing on eradication of the mosquito transmitter once Finlay's postulates had been demonstrated.