RESUMO
The waves of yellow fever transmission in the Region of the Americas in 2016–2018 involved the largest number of human and epizootic cases to be reported in several decades. Yellow fever is a serious viral hemorrhagic disease that poses a challenge for health professionals. It requires early recognition of signs and symptoms, which are often nonspecific, and it can mimic other acute febrile syndromes. Early detection of suspected or confirmed cases, monitoring of vital signs, life support measures, and treatment of acute kidney failure continue to be the recommended strategies for case management. This report is the result of discussions among experienced specialists in the Americas on the clinical management of yellow fever patients, especially during outbreaks and epidemics, in the context of current medical and scientific evidence and taking into account the technical guidelines already available in the countries of the Region. It includes flowcharts for initially addressing patients with clinical suspicion of yellow fever and proposes a minimum package of laboratory tests that may be useful in contexts where resources are limited. In addition, it considers aspects of health system organization for dealing with yellow fever outbreaks and epidemics.
Assuntos
Febre Amarela , Febres Hemorrágicas Virais , Epidemias , Prevenção de Doenças , Serviços de Saúde , Regulamento Sanitário InternacionalRESUMO
Las olas de transmisión de la fiebre amarilla ocurridas en la Región de las Américas entre el 2016 y el 2018 causaron el mayor número de casos humanos y epizoóticos registrados en varios decenios. La fiebre amarilla es una enfermedad hemorrágica viral grave que representa un desafío para el profesional de salud: exige el reconocimiento temprano de signos y síntomas muchas veces inespecíficos, que pueden parecerse a otros síndromes febriles agudos. La detección temprana de los casos sospechosos o confirmados, el monitoreo de los signos vitales y las medidas de soporte vital, y el tratamiento de la insuficiencia hepática aguda siguen siendo las estrategias recomendadas para el manejo de los casos. El presente informe es el resultado de las deliberaciones sobre la experiencia de expertos de la Región en cuanto al manejo clínico de pacientes con fiebre amarilla, especialmente en brotes y epidemias, mediante la contextualización de esa experiencia en el conjunto actual de la evidencia médico-científica y la consideración de las directrices técnicas ya disponibles en los países de la Región. Presenta flujogramas para la evaluación inicial del paciente con sospecha clínica de fiebre amarilla y sugiere un conjunto mínimo de pruebas de laboratorio que puede ser útil cuando hay pocos recursos; además, detalla aspectos de la organización de los sistemas de salud para enfrentar brotes y epidemias de fiebre amarilla.
Assuntos
Febre Amarela , Febres Hemorrágicas Virais , Epidemias , Prevenção de Doenças , Serviços de Saúde , Regulamento Sanitário InternacionalRESUMO
BACKGROUND: In June 2019, the Bolivian Ministry of Health reported a cluster of cases of hemorrhagic fever that started in the municipality of Caranavi and expanded to La Paz. The cause of these cases was unknown. METHODS: We obtained samples for next-generation sequencing and virus isolation. Human and rodent specimens were tested by means of virus-specific real-time quantitative reverse-transcriptase-polymerase-chain-reaction assays, next-generation sequencing, and virus isolation. RESULTS: Nine cases of hemorrhagic fever were identified; four of the patients with this illness died. The etiologic agent was identified as Mammarenavirus Chapare mammarenavirus, or Chapare virus (CHAPV), which causes Chapare hemorrhagic fever (CHHF). Probable nosocomial transmission among health care workers was identified. Some patients with CHHF had neurologic manifestations, and those who survived had a prolonged recovery period. CHAPV RNA was detected in a variety of human body fluids (including blood; urine; nasopharyngeal, oropharyngeal, and bronchoalveolar-lavage fluid; conjunctiva; and semen) and in specimens obtained from captured small-eared pygmy rice rats (Oligoryzomys microtis). In survivors of CHHF, viral RNA was detected up to 170 days after symptom onset; CHAPV was isolated from a semen sample obtained 86 days after symptom onset. CONCLUSIONS: M. Chapare mammarenavirus was identified as the etiologic agent of CHHF. Both spillover from a zoonotic reservoir and possible person-to-person transmission were identified. This virus was detected in a rodent species, O. microtis. (Funded by the Bolivian Ministry of Health and others.).
Assuntos
Arenavirus do Novo Mundo , Febre Hemorrágica Americana , RNA Viral , Roedores , Animais , Arenavirus do Novo Mundo/genética , Arenavirus do Novo Mundo/isolamento & purificação , Bolívia/epidemiologia , Infecção Hospitalar/transmissão , Infecção Hospitalar/virologia , Transmissão de Doença Infecciosa , Febre Hemorrágica Americana/complicações , Febre Hemorrágica Americana/genética , Febre Hemorrágica Americana/transmissão , Febre Hemorrágica Americana/virologia , Febres Hemorrágicas Virais/genética , Febres Hemorrágicas Virais/transmissão , Febres Hemorrágicas Virais/virologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Reação em Cadeia da Polimerase , RNA Viral/genética , RNA Viral/isolamento & purificação , Ratos/virologia , Roedores/virologia , Zoonoses Virais/transmissão , Zoonoses Virais/virologiaRESUMO
Guanarito virus (GTOV) is a member of the family Arenaviridae and has been designated a category A bioterrorism agent by the US Centers for Disease Control and Prevention. It is endemic to Venezuela's western region, and it is the etiological agent of "Venezuelan hemorrhagic fever" (VHF). Similar to other arenaviral hemorrhagic fevers, VHF is characterized by fever, mild hemorrhagic signs, nonspecific symptoms, thrombocytopenia, and leukopenia. Patients with severe disease usually develop signs of internal bleeding. Due to the absence of reference laboratories that can handle GTOV in endemic areas, diagnosis is primarily clinical and epidemiological. No antiviral therapies are available; thus, treatment includes only supportive analgesia and fluids. GTOV is transmitted by contact with the excreta of its rodent reservoir, Zygodontomys brevicauda. The main reasons for the emergence of the disease may be the increase in the human population, migration, and changes in land use patterns in rural areas. Social and environmental changes could make VHF an important cause of underdiagnosed acute febrile illnesses in regions near the endemic areas. Although there is evidence that GTOV circulates among rodents in different Venezuelan states, VHF cases have only been reported in the states of Portuguesa and Barinas. However, due to the increased frequency of invasions by humans into wildlife habitats, it is probable that VHF could become a public health problem in the nearby regions of Colombia and Brazil. The current Venezuelan political crisis is causing an increase in the migration of people and livestock, representing a risk for the redistribution and re-emergence of infectious diseases.
Assuntos
Infecções por Arenaviridae , Arenaviridae , Arenavirus do Novo Mundo , Febres Hemorrágicas Virais , Animais , Febres Hemorrágicas Virais/diagnóstico , Febres Hemorrágicas Virais/epidemiologia , Humanos , Roedores , SigmodontinaeRESUMO
As ondas de transmissão de febre amarela (FA) ocorridas na Região das Américas de 2016 a 2018 envolveram o maior número de casos humanos e epizoóticos registrados em várias décadas. A febre amarela é uma doença hemorrágica viral grave que representa um desafio para o profissional de saúde: requer reconhecimento precoce de sinais e sintomas muitas vezes inespecíficos e que podem mimetizar outras síndromes febris agudas. A detecção precoce dos casos suspeitos ou confirmados, a monitorização de sinais vitais e as medidas de suporte de vida e terapêutica de manejo de insuficiência hepática aguda continuam sendo as estratégias recomendadas para o manejo dos casos. Este Informe é resultado das discussões de experiência de especialistas das Américas quanto ao manejo clínico de pacientes com febre amarela, especialmente em surtos e epidemias, contextualizando essa experiência no conjunto atual de evidências médico-científicas e considerando as diretrizes técnicas já disponíveis nos países da Região. Apresenta fluxogramas para a abordagem inicial do paciente com suspeita clínica de febre amarela e sugere um pacote de exames laboratoriais mínimos que pode ser útil em contextos com poucos recursos; ainda, detalha aspectos da organização dos sistemas de saúde para o enfrentamento de surtos e epidemias de febre amarela.
Assuntos
Febre Amarela , Febres Hemorrágicas Virais , Epidemias , Prevenção de Doenças , Serviços de Saúde , Regulamento Sanitário InternacionalRESUMO
In the Americas, infectious viral diseases caused by viruses of the genus Mammarenavirus have been reported since the 1960s. Such diseases have commonly been associated with land use changes, which favor abundance of generalist rodent species. In the Americas-where the rates of land use change are among the highest worldwide-at least 1326 of all 2277 known rodent species have been reported. We conducted a literature review of studies between 1960 and 2020, to establish the current and historical knowledge about genotypes of mammarenaviruses and their rodent reservoirs in the Americas. Our overall goal was to show the importance of focusing research efforts on the American continent, since the conditions exist for future viral hemorrhagic fever (VHF) outbreaks caused by rodent-borne viruses, in turn, carried by widely distributed rodents. We found 47 species identified down to the species level, and one species identified only down to the genus level (Oryzomys sp.), reported in the Americas as reservoirs of mammarenaviruses, most these are ecological generalists. These species associate with 29 genotypes of Mammarenavirus, seven of which have been linked to VHFs in humans. We also highlight the need to monitor these species, in order to prevent viral disease outbreaks in the region.
Assuntos
Arenaviridae , Roedores , América , Animais , Arenaviridae/classificação , Arenaviridae/genética , Reservatórios de Doenças/virologia , Febres Hemorrágicas Virais/virologia , Roedores/virologiaRESUMO
BACKGROUND: With more than 300 million potentially infected people every year, and with the expanded habitat of mosquitoes due to climate change, Dengue virus (DENV) cannot be considered anymore only a tropical disease. The RNA secondary structure is a functional characteristic of RNA viruses, and together with the accumulated high-throughput sequencing data could provide general insights towards understanding virus biology. Here, we profiled the RNA secondary structure of > 7000 complete viral genomes from 11 different species focusing on viral hemorrhagic fevers, including DENV serotypes, EBOV, and YFV. RESULTS: In our work we demonstrated that the secondary structure and presence of protein-binding domains in the genomes can be used as intrinsic signature to further classify the viruses. With our predictive approach, we achieved high prediction scores of the secondary structure (AUC up to 0.85 with experimental data), and computed consensus secondary structure profiles using hundreds of in silico models. We observed that viruses show different structural patterns, where e.g., DENV-2 and Ebola virus tend to be less structured than the other viruses. Furthermore, we observed virus-specific correlations between secondary structure and the number of interaction sites with human proteins, reaching a correlation of 0.89 in the case of Zika virus. We also identified that helicases-encoding regions are more structured in several flaviviruses, while the regions encoding for the contact proteins exhibit virus-specific clusters in terms of RNA structure and potential protein-RNA interactions. We also used structural data to study the geographical distribution of DENV, finding a significant difference between DENV-3 from Asia and South-America, where the structure is also driving the clustering more than sequence identity, which could imply different evolutionary routes of this subtype. CONCLUSIONS: Our massive computational analysis provided novel results regarding the secondary structure and the interaction with human proteins, not only for DENV serotypes, but also for other flaviviruses and viral hemorrhagic fevers-associated viruses. We showed how the RNA secondary structure can be used to categorise viruses, and even to further classify them based on the interaction with proteins. We envision that these approaches can be used to further classify and characterise these complex viruses.
Assuntos
Vírus da Dengue , Dengue , Febres Hemorrágicas Virais , Infecção por Zika virus , Zika virus , Animais , Ásia , Vírus da Dengue/genética , Humanos , Sorogrupo , América do SulRESUMO
New World arenaviruses can cause chronic infection in rodents and hemorrhagic fever in humans. We identified a Sabiá virus-like mammarenavirus in a patient with fatal hemorrhagic fever from São Paulo, Brazil. The virus was detected through virome enrichment and metagenomic next-generation sequencing technology.
Assuntos
Arenaviridae , Arenavirus do Novo Mundo , Febre Hemorrágica Americana , Febres Hemorrágicas Virais , Arenavirus do Novo Mundo/genética , Brasil , Febres Hemorrágicas Virais/diagnóstico , HumanosRESUMO
Hemorrhagic fevers (HF) resulting from pathogenic arenaviral infections have traditionally been neglected as tropical diseases primarily affecting African and South American regions. There are currently no FDA-approved vaccines for arenaviruses, and treatments have been limited to supportive therapy and use of non-specific nucleoside analogs, such as Ribavirin. Outbreaks of arenaviral infections have been limited to certain geographic areas that are endemic but known cases of exportation of arenaviruses from endemic regions and socioeconomic challenges for local control of rodent reservoirs raise serious concerns about the potential for larger outbreaks in the future. This review synthesizes current knowledge about arenaviral evolution, ecology, transmission patterns, life cycle, modulation of host immunity, disease pathogenesis, as well as discusses recent development of preventative and therapeutic pursuits against this group of deadly viral pathogens.
Assuntos
Infecções por Arenaviridae , Arenavirus/imunologia , Surtos de Doenças , Febres Hemorrágicas Virais , Tolerância Imunológica , Ribavirina/uso terapêutico , África/epidemiologia , Infecções por Arenaviridae/tratamento farmacológico , Infecções por Arenaviridae/epidemiologia , Infecções por Arenaviridae/imunologia , Febres Hemorrágicas Virais/tratamento farmacológico , Febres Hemorrágicas Virais/epidemiologia , Febres Hemorrágicas Virais/imunologia , Humanos , América do Sul/epidemiologiaRESUMO
This article will outline surveillance approaches for viral hemorrhagic fevers. Specific methods for surveillance of clinical samples will be emphasized. Separate articles will describe methods for surveillance of rodent-borne viruses (roboviruses) and arthropod-borne viruses (arboviruses). Since the appearance of hantaviruses and arenaviruses in the Americas, more than 30 different species in each group have been established, and therefore they have become the most frequently emerging viruses. Flaviviruses such as yellow fever and dengue viruses, although easier to recognize, are also more widely spread and therefore considered a very important public health issue, particularly for under-developed countries. On the other hand, marburgviruses and ebolaviruses, previously thought to be restricted to the African continent, have recently been shown to be more global. For many of these agents virus isolation has been a challenging task: trapping the specific vectors (mosquitoes and ticks), and reservoirs (rodents and bats), or obtaining the samples from suspected clinical human cases demands special protective gear, uncommon devices (respirators), special facilities (BSL-3 and 4), and particular skills to recognize the slow and inapparent cytopathic effects in cell culture. Alternatively, serological and molecular approaches have been very helpful in discovering and describing newly emerging viruses in many areas where the previous resources are unavailable. Unfortunately, in many cases, detailed studies have been performed only after outbreaks occur, and then active surveillance is needed to prevent viral dissemination in human populations.