RESUMEN
Bovine vaccinia (BV), caused by Vaccinia virus (VACV), is a zoonotic disease characterized by exanthematous lesions on the teats of dairy cows and the hands of milkers, and is an important public health issue in Brazil and South America. BV also results in economic losses to the dairy industry, being a burden to the regions involved in milk production. In the past 20 years, much effort has been made to increase the knowledge regarding BV epidemiology, etiologic agents, and interactions with the hosts and the environment. In the present study, we evaluated milking practices that could be associated with VACV infections in an endemic area in Brazil and proposed an educational tool to help prevent VACV infections. In our survey, 124 individuals (51.7%) from a total of 240 had previously heard of BV, 94 of which knew about it through BV outbreaks. Although most individuals involved in dairy activities (n = 85/91) reported having good hygiene practices, only 29.7% used adequate disinfecting products to clean their hands and 39.5% disinfected cows' teats before and after milking. Furthermore, 46.7% of individuals reported having contact with other farm and domestic animals besides dairy cattle. We also evaluated the presence of IgG and IgM antibodies in the surveyed population. Overall, 6.1% of likely unvaccinated individuals were positive for anti-Orthopoxvirus IgG antibodies, and 1.7% of all individuals were positive for IgM antibodies. Based on our findings, we proposed educational materials which target individuals with permanent residence in rural areas (mainly farmers and milkers), providing an overview and basic information about preventive measures against VACV infections that could enhance BV control and prevention efforts, especially for vulnerable populations located in endemic areas.
RESUMEN
The aim of this study was to evaluate the possibility of free-ranging animals/hunting dogs as sources of infection in the vaccinia virus (VACV) transmission chain. Serological, cell culture and molecular assays were conducted in 56 free-ranging animals and 22 hunting dogs. ELISA/neutralizing assays showed that two (2.5%) capybaras (Hydrochoerus hydrochaeris) had anti-OPV positive antibodies, while all samples tested negative through PCR/cell culture. After being hit by cars on roads, capybaras that exhibited neither clinical signs nor any association with bovine outbreaks had neutralizing antibodies against the Orthopoxvirus, as detected through plaque-reduction neutralizing tests and ELISA. Evidence exists regarding peridomestic capybaras acting as a source of the virus and serving as a link between wild and urban environments, thus contributing to viral maintenance.
Asunto(s)
Reservorios de Enfermedades/veterinaria , Enfermedades de los Perros/transmisión , Enfermedades de los Roedores/epidemiología , Roedores/virología , Virus Vaccinia/inmunología , Vaccinia/veterinaria , Animales , Animales Salvajes , Anticuerpos Neutralizantes , Brasil/epidemiología , Bovinos , Reservorios de Enfermedades/virología , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/virología , Perros , Pruebas de Neutralización/veterinaria , Enfermedades de los Roedores/virología , Vaccinia/epidemiología , Vaccinia/transmisión , Vaccinia/virología , Virus Vaccinia/aislamiento & purificación , ZoonosisRESUMEN
Saint Louis encephalitis virus (SLEV) is a mosquito-borne flavivirus that occurs throughout the Americas, and is considered a public health threat. In Brazil, SLEV has been detected from human cases associated with dengue-like disease, but no neurological symptoms were reported. Furthermore, the epidemiology of SLEV in human populations is still poorly explored in the country. We reported serological and molecular detection of SLEV in a healthy population of equids and humans from rural areas in Southeast Brazil. A plaque reduction neutralization test was applied, and neutralizing antibodies were detected in 11 individuals (4.6%) and 60 horses (21.5%). A qPCR targeting the 5'UTR region and reverse transcription-PCR (RT-PCR) targeting the non-structural protein (NS5) gene were performed and three individuals tested positive in both assays. Subsequent phylogenetic analysis confirmed SLEV circulation and its findings suggest the occurrence of an asymptomatic or subclinical presence in human and animal cases, correlating with the risks for outbreaks and consequently burden of SLEV infections to public health. Preventive strategies should include improved surveillance in regions with a high probability of SLEV occurrence, improvement in diagnostic methods, and evaluation of exposure/risk factors that can favor SLEV emergence.
Asunto(s)
Virus de la Encefalitis de San Luis , Encefalitis de San Luis , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Infecciones Asintomáticas , Brasil/epidemiología , Dengue/diagnóstico , Diagnóstico Diferencial , Virus de la Encefalitis de San Luis/genética , Virus de la Encefalitis de San Luis/inmunología , Virus de la Encefalitis de San Luis/aislamiento & purificación , Encefalitis de San Luis/diagnóstico , Encefalitis de San Luis/transmisión , Encefalitis de San Luis/veterinaria , Encefalitis de San Luis/virología , Flaviviridae/aislamiento & purificación , Genes Virales , Enfermedades de los Caballos/diagnóstico , Enfermedades de los Caballos/virología , Caballos , Humanos , Pruebas de Neutralización , Filogenia , Estudios SeroepidemiológicosRESUMEN
Rio Negro virophage (RNV) was co-isolated with a strain of mimivirus named sambavirus, from Brazilian Amazon. We report the near complete genome sequence of RNV, the first virophage isolated in Brazil. We also present new microscopical data demonstrating that RNV particles have similar dimensions to that described to sputnik virophages.
Asunto(s)
Acanthamoeba/virología , Genoma Viral , Togaviridae/genética , Virófagos/genética , Brasil , Microscopía Electrónica de Transmisión , Sistemas de Lectura Abierta , Filogenia , Togaviridae/aislamiento & purificación , Togaviridae/ultraestructura , Virófagos/aislamiento & purificación , Virófagos/ultraestructuraRESUMEN
New World orthohantaviruses are emerging RNA viruses that cause hantavirus cardiopulmonary syndrome (HCPS). These viruses are a burden to public health around the world with a lethality rate of around 60%. In South America, rodents of Sigmodontinae subfamily are the main reservoirs of orthohantaviruses. We described a serosurvey for orthohantaviruses circulation in an apparently healthy human population and small mammals from rural areas in Central Minas Gerais State, Brazil. A total of 240 individuals and 50 small mammals (26 rodents belonging to 10 different species and 24 marsupials from 4 different species) were sampled during 2012-2013. The seroprevalence rates of IgG/IgM antibodies in humans were 7.1 and 1.6%, respectively. Only one rodent, an Oligoryzomys nigripes captured in peridomestic area, tested positive for IgG antibodies and viral RNA. Our findings suggest a silent circulation of orthohantaviruses in a region of intensive agriculture production. The detection of seropositive humans in an area with a lack of previous HCPS reports highlights potential oligosymptomatic cases and the need for surveillance strategies that could reduce the risk of future outbreaks.
Asunto(s)
Reservorios de Enfermedades/virología , Infecciones por Hantavirus/transmisión , Mamíferos/virología , Orthohepadnavirus/aislamiento & purificación , Roedores/virología , Animales , Brasil/epidemiología , Infecciones por Hantavirus/epidemiología , Humanos , Estudios SeroepidemiológicosRESUMEN
Rio Negro virophage (RNV) was co-isolated with a strain of mimivirus named sambavirus, from Brazilian Amazon. We report the near complete genome sequence of RNV, the first virophage isolated in Brazil. We also present new microscopical data demonstrating that RNV particles have similar dimensions to that described to sputnik virophages.(AU)
RESUMEN
ABSTRACT Rio Negro virophage (RNV) was co-isolated with a strain of mimivirus named sambavirus, from Brazilian Amazon. We report the near complete genome sequence of RNV, the first virophage isolated in Brazil. We also present new microscopical data demonstrating that RNV particles have similar dimensions to that described to sputnik virophages.
Asunto(s)
Togaviridae/genética , Acanthamoeba/virología , Genoma Viral , Virófagos/genética , Filogenia , Togaviridae/aislamiento & purificación , Togaviridae/ultraestructura , Brasil , Sistemas de Lectura Abierta , Microscopía Electrónica de Transmisión , Virófagos/aislamiento & purificación , Virófagos/ultraestructuraRESUMEN
ABSTRACT Rio Negro virophage (RNV) was co-isolated with a strain of mimivirus named sambavirus, from Brazilian Amazon. We report the near complete genome sequence of RNV, the first virophage isolated in Brazil. We also present new microscopical data demonstrating that RNV particles have similar dimensions to that described to sputnik virophages.
RESUMEN
Vaccinia virus naturally circulates in Brazil and is the causative agent of a zoonotic disease known as bovine vaccinia (BV). We retrospectively evaluated two populations from the Amazon and Southeast Regions. BV outbreaks had not been reported in these regions before sample collection. Neutralising antibodies were found in 13 individuals (n = 132) with titres ranging from 100 ≥ 6,400 neutralising units/mL. Univariate analysis identified age and vaccination as statistically significant risk factors in individuals from the Southeast Region. The absence of detectable antibodies in vaccinated individuals raises questions about the protection of smallpox vaccine years after vaccination and reinforces the need for surveillance of Orthopoxvirus in Brazilian populations without evidence of previous outbreaks.
Asunto(s)
Anticuerpos Antivirales/aislamiento & purificación , Orthopoxvirus/inmunología , Población Rural , Vaccinia/prevención & control , Adolescente , Adulto , Factores de Edad , Anciano , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales/sangre , Brasil/epidemiología , Bovinos , Niño , Preescolar , Brotes de Enfermedades , Monitoreo Epidemiológico , Femenino , Humanos , Masculino , Vacunación Masiva , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Vaccinia/epidemiología , Virus Vaccinia/inmunología , Adulto Joven , Zoonosis/epidemiologíaRESUMEN
In 2011, vaccinia virus caused an outbreak of bovine vaccinia, affecting dairy cattle and dairy workers in Brazil. Genetic and phenotypic analyses identified this isolate as distinct from others recently identified, thereby reinforcing the hypothesis that different vaccinia virus strains co-circulate in Brazil.