Understanding Sabiá virus infections (Brazilian mammarenavirus).

BACKGROUND: Only two naturally occurring human Sabiá virus (SABV) infections have been reported, and those occurred over 20 years ago. METHODS: We diagnosed two new cases of SABV infection using metagenomics in patients thought to have severe yellow fever and described new features of histopathological findings. RESULTS: We characterized clinical manifestations, histopathology and analyzed possible nosocomial transmission. Patients presented with hepatitis, bleeding, neurological alterations and died. We traced twenty-nine hospital contacts and evaluated them clinically and by RT-PCR and neutralizing antibodies. Autopsies uncovered unique features on electron microscopy, such as hepatocyte "pinewood knot" lesions. Although previous reports with similar New-World arenavirus had nosocomial transmission, our data did not find any case in contact tracing. CONCLUSIONS: Although an apparent by rare, Brazilian mammarenavirus infection is an etiology for acute hemorrhagic fever syndrome. The two fatal cases had peculiar histopathological findings not previously described. The virological diagnosis was possible only by contemporary techniques such as metagenomic assays. We found no subsequent infections when we used serological and molecular tests to evaluate close contacts.

A Review of Mammarenaviruses and Rodent Reservoirs in the Americas.

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.

De la Peste Antonina a la Peste de Cipriano: alcances y consecuencias de las pestes globales en el Imperio Romano en el siglo III dC / From the Antonine Plague to the Cyprian Plague: scopes and consequences of global plagues in the Roman Empire in the 3rd century AD

Resumen El Imperio Romano sufrió entre el siglo II y III dos grandes pestes, la Peste Antonina, de la cual existe bibliografía, y la Peste de Cipriano, que es menos conocida. Como una visión de conjunto, ambas pandemias se asemejan a la crisis que en el 2020 el coronavirus está generando en muchos aspectos de la vida humana. Este artículo se centra en el impacto que la peste de Cipriano tuvo en el contexto de la crisis del siglo III; su mortalidad se estima entre 10-20% de la población en los lugares afectados y finalmente sus efectos generaron varias de las condiciones necesarias para la transición del mundo antiguo al medieval. Se trata de comprender cómo el ciclo de pestes que va desde el siglo II al siglo III cambió la fisonomía del mundo romano y que lecciones nos entrega la historia 1700 años después.

Abstract Between the 2nd and 3rd centuries the Roman Empire suffered two great plagues, the Antonine Plague, of which there is a bibliography, and the lesser known Plague of Cyprian. As an overview, both pandemics resemble the crisis that in 2020 the Coronavirus is generating in many aspects of human life. This article focuses on the impact that the Cyprian plague had in the context of the crisis of the third century, its mortality is estimated between 10-20% of the population in the affected places, finally its effects generated several of the necessary conditions for the transition from the ancient to the medieval world. It is about understanding how the cycle of plagues that went from the 2nd century to the 3rd century changed the appearance of the Roman world and what lessons history gives us 1700 years later.

Sabiá Virus-Like Mammarenavirus in Patient with Fatal Hemorrhagic Fever, Brazil, 2020.

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.

T-Cell Response to Viral Hemorrhagic Fevers.

Viral hemorrhagic fevers (VHF) are a group of clinically similar diseases that can be caused by enveloped RNA viruses primarily from the families Arenaviridae, Filoviridae, Hantaviridae, and Flaviviridae. Clinically, this group of diseases has in common fever, fatigue, dizziness, muscle aches, and other associated symptoms that can progress to vascular leakage, bleeding and multi-organ failure. Most of these viruses are zoonotic causing asymptomatic infections in the primary host, but in human beings, the infection can be lethal. Clinical and experimental evidence suggest that the T-cell response is needed for protection against VHF, but can also cause damage to the host, and play an important role in disease pathogenesis. Here, we present a review of the T-cell immune responses to VHF and insights into the possible ways to improve counter-measures for these viral agents.

Enfermedad por el virus Ébola medidas de bioseguridad / Ebola virus disease biosafety measures

Resumen El virus Ébola representa el patógeno prototipo de fiebre hemorrágica viral, causando una enfermedad severa de alta tasa de mortalidad. Esta alta mortalidad, combinada con la ausencia de vacunación y de un tratamiento específico, hace que el virus Ébola sea un patógeno importante para la salud pública. La fiebre hemorrágica de Ébola se cree es una zoonosis con persistencia del virus en especies de reservorios encontrados en áreas endémicas. A pesar de todos los esfuerzos realizados en cada brote para identificar los reservorios naturales no se conocen huéspedes potenciales ni los artrópodos vectores. El manejo de los casos está basado en el aislamiento de los pacientes y en el uso de barreras de aislamiento, tales como ropa e implementos de protección como respiradores. Debido a su rápida propagación la OMS declaró que la enfermedad por el virus Ébola representa una emergencia de salud pública más allá de las fronteras y exhortó a la comunidad internacional a tomar las acciones necesarias para detener la epidemia.

Abstract Ebola virus is regarded as the prototype pathogen of viral hemorrhagic fever, causing severe disease and high case fatality rates. This high fatality, combined with the absence ot treatment and vaccination options, makes Ebola virus an important public health pathogen. Ebola hemorrhagic fever is thought to be a classic zoonosis with persistence of the Ebola virus in a reservoir species generally found in endemic areas. Although much effort has been made to identify the natural reservoirs with every large outbreak of Ebola hemorrhagic fever, neither potential hosts norarthropod vectors have been identified. Case management is based on isolation of patients and use of strict barrier nursing procedures, such as protective clothing and respirators. In addition, its rapid propagation has led the Word Health Organization (WHO) to declare on August 2014 that Ebola virus disease represents a public health emergency of international concern and urged the international community to take action to stop its spread.

Pathogenesis of Bolivian Hemorrhagic Fever in Guinea Pigs.

Machupo virus, the cause of Bolivian hemorrhagic fever, is a highly lethal viral hemorrhagic fever with no Food and Drug Administration-approved vaccines or therapeutics. This study evaluated the guinea pig as a model using the Machupo virus-Chicava strain administered via aerosol challenge. Guinea pigs (Cavia porcellus) were serially sampled to evaluate the temporal progression of infection, gross and histologic lesions, and sequential changes in serum chemistry and hematology. The incubation period was 5 to 12 days, and complete blood counts revealed leukopenia with lymphopenia and thrombocytopenia. Gross pathologic findings included congestion and hemorrhage of the gastrointestinal mucosa and serosa, noncollapsing lungs with fluid exudation, enlarged lymph nodes, and progressive pallor and friability of the liver. Histologic lesions consisted of foci of degeneration and cell death in the haired skin, liver, pancreas, adrenal glands, lymph nodes, tongue, esophagus, salivary glands, renal pelvis, small intestine, and large intestine. Lymphohistiocytic interstitial pneumonia was also present. Inflammation within the central nervous system, interpreted as nonsuppurative encephalitis, was histologically apparent approximately 16 days postexposure and was generally progressive. Macrophages in the tracheobronchial lymph node, on day 5 postexposure, were the first cells to demonstrate visible viral antigen. Viral antigen was detected throughout the lymphoid system by day 9 postexposure, followed by prominent spread within epithelial tissues and then brain. This study provides insight into the course of Machupo virus infection and supports the utility of guinea pigs as an additional animal model for vaccine and therapeutic development.

Enfermedad por el virus Ébola medidas de bioseguridad / Ebola virus disease biosecurity measures

El virus Ébola representa el patógeno prototipo de fiebre hemorrágica viral, causando una enfermedad severa de alta tasa de mortalidad. Esta alta mortalidad, combinada con la ausencia de vacunación y de un tratamiento específico, hace que el virus Ébola sea un patógeno importante para la salud pública. La fiebre hemorrágica de Ébola se cree es una zoonosis con persistencia del virus en especies de reservorios encontrados en áreas endémicas. A pesar de todos los esfuerzos realizados en cada brote para identificar los reservorios naturales no se conocen los huéspedes potenciales ni los artrópodos vectores. El manejo de los casos está basado en el aislamiento de los pacientes y en el uso de barreras de aislamiento, tales como ropa e implementos de protección como respiradores. Debido a su rápida propagación la OMS declaró que la enfermedad por el virus Ébola representa una emergencia de salud pública más allá de las fronteras y exhortó a la comunidad internacional a tomar las acciones necesarias para detener la epidemia.

Ebola virus is regarded as the prototype pathogen of viral hemorrhagic fever, causing severe disease and high case-fatality rates. This high fatality, combined with the absence of treatment and vaccination options, makes Ebola virus an important public health pathogen. Ebola hemorrhagic fever is thought to be a classic zoonosis with persistence of the Ebola virus in a reservoir species generally found in endemic areas. Although much effort has been made to identify the natural reservoirs with every large outbreak of Ebola hemorrhagic fever, neither potential hosts nor arthropod vectors have been identified. Case management is based on isolation of patients and use of strict barrier nursing procedures, such as protective clothing and respirators. In addition, its rapid propagation has led the World Health Organization (WHO) to declare on August 2014 that Ebola virus disease represent a public health emergency of international concern and urged the international community to take action to stop the spread.

Research efforts to control highly pathogenic arenaviruses: a summary of the progress and gaps.

Significant progress has been made in the past 10 years in unraveling the molecular biology of highly pathogenic arenaviruses that are endemic in several West African countries (Lassa fever virus) and in some regions of South America (Argentine and Bolivian hemorrhagic fever viruses). While this has resulted in proof-of-concept studies of novel vaccine candidates in non-human primates and in the discovery of several novel antiviral small molecule drug candidates, none of them has been tested in the clinic to date. The recent Ebola outbreak in West Africa has demonstrated very clearly that there is an urgent need to develop the prophylactic and therapeutic armamentarium against viral hemorrhagic fever viruses as part of a global preparedness for future epidemics. As it pertains to this goal, the present article summarizes the current knowledge of highly pathogenic arenaviruses and identifies opportunities for translational research.

Las fiebres hemorrágicas víricas como síndromes paralelos / Viral hemorrhagic fevers as parallel syndromes

Se presentan algunos aspectos clínico-epidemiológicos, así como del tratamiento de un grupo de enfermedades de gran importancia para la medicina militar, cuyos agentes etiológicos pueden ser utilizados como armas biológicas en tiempo de guerra y actos de bioterrorismo. En eventos como estos, las enfermedades en cuestión, presentes en la práctica médica, pueden ser estudiadas y modelado el diagnóstico y la intervención terapéutica, lo que posibilita su condición de síndrome paralelo(AU)

Some clinical and epidemiological aspects as well the treatment of a group of diseases of great significant for the military medicine were presented. Their etiological agents could be used as biological weapons in war times and in bioterrorist actions. Under those circumstances, the diseases as such, which are present in the medical practice, can be studied and their diagnosis and therapeutic intervention can be modeled, which facilitates their condition as parallel syndromes(AU)

Las fiebres hemorrágicas víricas como síndromes paralelos / Viral hemorrhagic fevers as parallel syndromes

Se presentan algunos aspectos clínico-epidemiológicos, así como del tratamiento de un grupo de enfermedades de gran importancia para la medicina militar, cuyos agentes etiológicos pueden ser utilizados como armas biológicas en tiempo de guerra y actos de bioterrorismo. En eventos como estos, las enfermedades en cuestión, presentes en la práctica médica, pueden ser estudiadas y modelado el diagnóstico y la intervención terapéutica, lo que posibilita su condición de síndrome paralelo.

Some clinical and epidemiological aspects as well the treatment of a group of diseases of great significant for the military medicine were presented. Their etiological agents could be used as biological weapons in war times and in bioterrorist actions. Under those circumstances, the diseases as such, which are present in the medical practice, can be studied and their diagnosis and therapeutic intervention can be modeled, which facilitates their condition as parallel syndromes.