RESUMO
The family Picornaviridae is a large and diverse group of viruses that infect humans and animals. Picornaviruses are among the most common infections of humans and cause a wide spectrum of acute human disease. This study began as an investigation of acute flaccid paralysis (AFP) in a small area of eastern Bolivia, where surveillance had identified a persistently high AFP rate in children. Stools were collected and diagnostic studies ruled out poliovirus. We tested stool specimens from 51 AFP cases and 34 healthy household or community contacts collected during 2002-2003 using real-time and semi-nested reverse transcription polymerase chain reaction assays for enterovirus, parechovirus, cardiovirus, kobuvirus, salivirus and cosavirus. Anecdotal reports suggested a temporal association with neurological disease in domestic pigs, so six porcine stools were also collected and tested with the same set of assays, with the addition of an assay for porcine teschovirus. A total of 126 picornaviruses were detected in 73 of 85 human individuals, consisting of 53 different picornavirus types encompassing five genera (all except Kobuvirus). All six porcine stools contained porcine and/or human picornaviruses. No single virus, or combination of viruses, specifically correlated with AFP; however, the study revealed a surprising complexity of enteric picornaviruses in a single community.
Assuntos
Infecções por Picornaviridae/epidemiologia , Infecções por Picornaviridae/virologia , Picornaviridae/classificação , Picornaviridae/genética , Adolescente , Animais , Bolívia/epidemiologia , Criança , Pré-Escolar , Fezes/virologia , Feminino , Humanos , Lactente , Masculino , Epidemiologia Molecular , Dados de Sequência Molecular , Paraplegia/epidemiologia , Paraplegia/virologia , Picornaviridae/isolamento & purificação , Infecções por Picornaviridae/veterinária , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , População Rural , Análise de Sequência de DNA , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Adulto JovemRESUMO
Según lo establecido por la Organización Panamericana de la Salud (OPS), conseguir una alta cobertura de vacunación es una meta esencial para la Región de las Américas. Es indispensable lograr niveles de cobertura de 95 por ciento o mayores para poder alcanzar los objetivos de la OPS de eliminar el sarampión y la rubéola, controlar las enfermedades prevenibles mediante la vacunación, y hacer perdurar la eliminación de la poliomielitis en territorio americano. Para poder alcanzar esos niveles, es imprescindible que las estadísticas de vacunación sean fiables y que las autoridades sanita- rias midan y monitoreen los niveles de cobertura a lo largo del tiempo. Los métodos elegidos por los directores de los programas de vacunación para calcular la cobertura dependerán de la información que haga falta. En general, los directores del Programa Ampliado de Inmunización (PAI) necesitarán información acerca de la cobertura para poder: 1) determinar la verdadera cobertura en los niveles nacional y local, 2) determinar cuán adecuada es la cobertura en una zona determinada, 3) monitorear las tendencias a lo largo del tiempo, y 4) monitorear las actividades de vacunación mientras se están llevando a cabo. Para lograr lo primero -determinar cuáles son los niveles verdaderos de cobertura-, los administradores tienen dos opciones: a) valerse de los datos acerca de las dosis administradas (es decir, el número de dosis de la vacuna que se ha administrado, dividido por la población que debió recibir una dosis) o b) llevar a cabo una encuesta para determinar la cobertura. Para lograr lo segundo -saber si la cobertura en una zona determinada es adecuada (por ej., mayor de 90 por ciento)-, se puede realizar un muestreo por lotes para garantizar la calidad (MLGC). El MLGC es una metodología de encuesta basada en el uso de muestras pequeñas que permite determinar si la cobertura en una zona determinada es adecuada o no, pero no sirve para estimar el nivel de cobertura. Para el tercer propósito -monitorear las tendencias a lo largo del tiempo-, se pueden usar los datos correspondientes al número de dosis administradas. Para lograr el cuarto propósito -determinar si procede vacunar o llevar a cabo una campaña de vacunación u otra actividad afín-, la "herramienta de monitoreo rápido" creada por la OPS es una magnífica solución. Cada uno de estos métodos posee ventajas y desventajas. Los datos sobre el número de dosis...
Assuntos
Vacinação , Vacinas , Programas de ImunizaçãoRESUMO
Twenty-one cases of acute flaccid paralysis (AFP) were reported on the island of Hispaniola in 2000. Laboratory analysis confirmed the presence of circulating vaccine-derived poliovirus (cVDPV) type 1 in stool samples obtained from patients. As a complement to the active search for cases of AFP, environmental sampling was conducted during November and December 2000, to test for cVDPV in sewage, streams, canals, and public latrines. Fifty-five environmental samples were obtained and analyzed for the presence of polioviruses by use of cell culture followed by neutralization and reverse-transcription polymerase chain reaction. Of the 23 positive samples, 10 tested positive for poliovirus type 1, 7 tested positive for poliovirus type 2, 5 tested positive for poliovirus type 3, and 1 tested positive for both poliovirus type 2 and type 3. By sequence analysis of the complete viral capsid gene 1 (VP1), a 2.1%-3.7% genetic sequence difference between 7 type 1 strains and Sabin type 1 vaccine strain was found. Phylogenetic analysis showed that these viruses are highly related to cVDPV isolated from clinical cases and form distinct subclusters related to geographic region. Our findings demonstrate a useful role for environmental surveillance of neurovirulent polioviruses in the overall polio eradication program.
Assuntos
Surtos de Doenças , Poliomielite/virologia , Vacinas contra Poliovirus/análise , Poliovirus/isolamento & purificação , Esgotos/virologia , Microbiologia da Água , Animais , República Dominicana/epidemiologia , Feminino , Haiti/epidemiologia , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Testes de Neutralização , Poliomielite/epidemiologia , Poliovirus/genética , Vacinas contra Poliovirus/efeitos adversos , Vacinas contra Poliovirus/genética , Vacinas contra Poliovirus/isolamento & purificação , Prevalência , RNA Viral/química , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genéticaRESUMO
Measles incidence in Bolivia declined after the introduction of campaign strategies in the 1980s. From 1990 to 1993, the peak incidence of measles (59 cases/100,000 population) was in 1992. In 1994, after the goal of interruption of measles transmission was adopted, a national vaccination campaign targeting children <15 years old was conducted and achieved 96% coverage. During 1995-1997, cases declined, although routine coverage was <90% in most years. During 1998-2000, a nationwide epidemic occurred among 2567 case-patients, most of whom were unvaccinated. A national vaccination campaign, with strong supervision, was conducted during November and December 1999 and targeted areas with low coverage. Only 122 cases were confirmed in 2000, with the last confirmed case occurring in October. Crucial to the control of the outbreak were sufficient resources and political support, intensive local planning, door-to-door vaccination with strict supervision, and rapid house-to-house coverage monitoring that improved accountability at the local level and timely and thorough outbreak investigations.
Assuntos
Programas de Imunização/métodos , Vacina contra Sarampo/administração & dosagem , Sarampo/prevenção & controle , Adolescente , Bolívia/epidemiologia , Criança , Pré-Escolar , Humanos , Programas de Imunização/normas , Incidência , Lactente , Sarampo/epidemiologia , Sarampo/transmissão , Vírus do Sarampo , Vigilância da PopulaçãoRESUMO
On 8 March 2000 a case of laboratory-confirmed measles was detected in Haiti. Over the ensuing months, an explosive epidemic occurred that spread to 8 of the 9 departments of Haiti, including the nation's capital, Port au Prince. After peaking in the last half of November 2000, the epidemic began a rapid decline. The date of onset for the last confirmed case was 26 September 2001. During the 18 months of the epidemic, 1149 cases were confirmed. To control the epidemic, various strategies were employed, including vaccination campaigns that used fixed posts and door-to-door activities. Critical factors in the success of these campaigns were thorough training and supervision of field staff; a high-quality door-to-door vaccination strategy; multiple visits to homes; and monitoring of vaccine coverage by household during the course of the campaigns.
Assuntos
Surtos de Doenças , Programas de Imunização/métodos , Vacina contra Sarampo/administração & dosagem , Sarampo/prevenção & controle , Adolescente , Criança , Pré-Escolar , Haiti/epidemiologia , Humanos , Programas de Imunização/normas , Lactente , Sarampo/epidemiologia , População Rural , Vigilância de Evento Sentinela , População UrbanaRESUMO
An outbreak of paralytic poliomyelitis occurred in the Dominican Republic (13 confirmed cases) and Haiti (8 confirmed cases, including 2 fatal cases) during 2000-2001. All but one of the patients were either unvaccinated or incompletely vaccinated children, and cases occurred in communities with very low (7 to 40%) rates of coverage with oral poliovirus vaccine (OPV). The outbreak was associated with the circulation of a derivative of the type 1 OPV strain, probably originating from a single OPV dose given in 1998-1999. The vaccine-derived poliovirus associated with the outbreak had biological properties indistinguishable from those of wild poliovirus.
Assuntos
Surtos de Doenças , Poliomielite/epidemiologia , Poliomielite/virologia , Vacina Antipólio Oral/efeitos adversos , Poliovirus/genética , Poliovirus/patogenicidade , Regiões 5' não Traduzidas , Adolescente , Animais , Capsídeo/genética , Proteínas do Capsídeo , Criança , Pré-Escolar , República Dominicana/epidemiologia , Feminino , Genes Virais , Haiti/epidemiologia , Humanos , Programas de Imunização , Lactente , Masculino , Camundongos , Dados de Sequência Molecular , Mutação Puntual , Poliomielite/prevenção & controle , Poliomielite/transmissão , Poliovirus/classificação , Poliovirus/isolamento & purificação , Vigilância da População , Recombinação Genética , Vacinação , VirulênciaRESUMO
In October 2000, the Ministries of Helth of the Dominican Republic and Haiti notified two cases of acute flaccid paralyis (AFP) in rural areas, one of them in a 9-month-old female, and the other in a 2-year-old female, respectively. Stool samples that were obtained from these cases, which occured in July and August 2000, after a 9-year interruption of wild poliovirus circulation in the Western Hemisphere, revealed the presence of type 1 poliovirus. Genetic sequencing, which was later performed at the CEnters for Disease Control and Prevention, in Atlanta, Georgia, United States of America, revealed an atypical descendant of the virus used in the manufacture of the oral polio vaccine (OPV), but with 3 percent genetic divergence with respect to the parent strain. Normally, viral isolates that derive from vaccine components show 99.5 percent genetic agreement with the parent strain; in wild polioviruses, on the other hand, this agreement is usually less than 82.0 percent. Thus, the 3 percent genetic divergence detected in this study suggests that, in areas with low vaccine coverage, the virus used in the vaccine remained in circulation for at least two years, during which it recovered the neurovirulence and communicability of wild poliovirus type 1. This report describes the characteristics and results of the active search for cases of AFP that was sparked by the detection of the two index cases. It also looks at the public health implications of this outbreak for the entire Region of the Americas (AU)
Assuntos
Lactente , Humanos , Poliomielite/transmissão , América , Surtos de Doenças , Haiti , Poliovirus/isolamento & purificação , República Dominicana , Vacina Antipólio de Vírus Inativado/análiseRESUMO
El presente documento contiene el informe final de misión con las actividades y acciones desarrolladas durante el periodo de duración de la misión en Bolivia (sept. 2001 a dic. 2003), como epidemiología del programa ampliado de inmunización