RESUMO
Polio is a contagious disease that is caused by the poliovirus, an enterovirus in the family Picornaviridae. The virus enters through the oral mucosa and multiplies in epithelial cells of both the oropharynx as the gastrointestinal tract, releasing virus in oropharyngeal secretions and through the stool. The mode of transmission is fecal-oral and/or oral-oral. The virus preferentially infects children under 5 years. Most infections are asymptomatic and self-limiting gastrointestinal tract. Eventually it spreads to the central nervous system and affects the anterior horn motor neurons of the spinal cord causing paralysis and even death. We will describe host-virus interaction and the natural history of infection which depends on many factors, including the type of viral inoculum (serotypes VP1, 2 and 3) and host factors, such as nutritional status, concurrent infections and the ability to induce protective immune responses, such as, humoral anti-viral antibody responses with neutralizing antibodies, mucosal immunity and systemic adaptative immune responses. We will discuss the relevant aspects of the immuno-pathogenesis of the infection by poliovirus and the problems related to the host-virus interactions in the subjects vaccinated, with the latest advances in the strategies to develop optimal protection with the different poliovirus vaccines that could allow the development of a more effective immunization with induction of the effect or mechanisms that would prevent development of the disease, transmission of the virus, out-breaks and eventually the poliovirus eradication.
Assuntos
Poliomielite/imunologia , Vacina Antipólio Oral/imunologia , Poliovirus/imunologia , Anticorpos Antivirais/imunologia , Infecções Assintomáticas , Criança , Pré-Escolar , Erradicação de Doenças , Previsões , Humanos , Imunidade nas Mucosas/imunologia , Lactente , Poliomielite/prevenção & controle , Poliomielite/transmissão , Poliomielite/virologia , Poliovirus/fisiologia , Vacina Antipólio de Vírus Inativado/efeitos adversos , Vacina Antipólio de Vírus Inativado/imunologia , Vacina Antipólio Oral/efeitos adversos , Vacinação , Internalização do VírusRESUMO
La poliomielitis es una enfermedad infecto-contagiosa que afecta preferentemente a los niños menores de 5 años y está causada por el poliovirus, un enterovirus perteneciente a la familia Picornaviridae. El virus entra a través de la mucosa oral y se multiplica en las células del epitelio tanto de la orofaringe como del tracto gastrointestinal, liberando virus a nivel de las secreciones orofaríngeas y a través de la materia fecal. La vía de transmisión es fecal-oral y/o oral-oral. La mayoría de los casos de infección son asintomáticos y autolimitados al tracto gastrointestinal. Eventualmente puede diseminarse al sistema nervioso central y afectar a las motoneuronas del asta anterior de la médula espinal ocasionando parálisis e incluso la muerte. El curso natural de la infección depende de múltiples factores, como el tipo de inóculo viral (serotipos VP1, 2 y 3) y factores del huésped/sistema inmunológico, que incluye el estado nutricional, las infecciones concurrentes y la capacidad de inducir respuestas inmunológicas protectoras sistémicas de tipo humoral, con anticuerpos anti-víricos circulantes neutralizantes, y respuestas de la inmunidad de mucosas y adaptativa. Discutiremos los aspectos actuales de la inmunopatogénesis de la infección por el poliovirus, la interacción huésped-virus y la eficacia y los problemas en el desarrollo de las estrategias con las diferentes vacunas anti-poliovirus, para que la inmunización sea más efectiva en relación a la inducción de los mecanismos protectores que evitan el desarrollo de la enfermedad, la transmisión del virus, los rebrotes de infección y eventualmente facilitan la consecución de su erradicación (AU)
Polio is a contagious disease that is caused by the poliovirus, an enterovirus in the family Picornaviridae. The virus enters through the oral mucosa and multiplies in epithelial cells of both the oropharynx as the gastrointestinal tract, releasing virus in oropharyngeal secretions and through the stool. The mode of transmission is fecal-oral and/or oral-oral. The virus preferentially infects children under 5 years. Most infections are asymptomatic and self-limiting gastrointestinal tract. Eventually it spreads to the central nervous system and affects the anterior horn motor neurons of the spinal cord causing paralysis and even death. We will describe host-virus interaction and the natural history of infection which depends on many factors, including the type of viral inoculum (serotypes VP1, 2 and 3) and host factors, such as nutritional status, concurrent infections and the ability to induce protective immune responses, such as, humoral anti-viral antibody responses with neutralizing antibodies, mucosal immunity and systemic adaptative immune responses. We will discuss the relevant aspects of the immuno-pathogenesis of the infection by poliovirus and the problems related to the host-virus interactions in the subjects vaccinated, with the latest advances in the strategies to develop optimal protection with the different poliovirus vaccines that could allow the development of a more effective immunization with induction of the effector mechanisms that would prevent development of the disease, transmission of the virus, out-breaks and eventually the poliovirus eradication (AU)
