Current polio status in the world / Estado atual de poliomielite no mundo

ABSTRACT Poliomyelitis is still an endemic disease in Afghanistan, Nigeria, and Pakistan despite the efforts to eradicate the disease. Therefore, there is a potential risk of international spread. Since the start of the polio eradication program by the Global Polio Eradication Initiative in 1988, the incidence of polio has been reduced by 99%. In the last decade, wild poliovirus type 2 (WPV2) was eliminated and declared eradicated in 2015. Wild poliovirus type 3 (WPV3) was last reported in November 2012. These changes have allowed the removal of Sabin poliovirus type 2 from the oral poliovirus vaccine (OPV) in April 2016 and countries either introduced bivalent OPV (bOPV) containing Sabin types 1 + 3 poliovirus or added at least one dose of inactivated poliovirus vaccine (IPV) into their routine immunization schedule. Many efforts are needed to eradicate polio, and new strategies should be implemented such as the development and approval of new genetically stable OPV, and vaccines that do not require infectious processes for virus growth, such as virus-like particles (VLPs), or packing-cell technology. IPV will increasingly be produced from Sabin strains, and further attenuated or genetically modified strains. Furthermore, there is also a need for the development of antiviral drugs to treat immunodeficient patients who are long-term excretors infected with poliovirus, thus avoiding contamination of individuals susceptible to polioviruses, due to reversal of pathogenicity. If all these measures are successfully implemented, the world will be close to the global

RESUMEN La poliomielitis sigue siendo una enfermedad endémica en Afganistán, Nigeria y Pakistán a pesar de los esfuerzos por erradicar la enfermedad. Por lo tanto, existe un riesgo de propagación mundial. Desde el inicio del programa de erradicación de la poliomielitis por la Iniciativa de Erradicación Mundial de la Poliomielitis [Global Polio Eradication Initiative (GPEI)] en 1988, la incidencia de la poliomielitis se ha reducido en un 99%. En la última década, el poliovirus salvaje tipo 2 (WPV2) fue eliminado y declarado erradicado en 2015. El poliovirus salvaje tipo 3 (WPV3) se informó por última vez en noviembre de 2012. Estos cambios han permitido la eliminación del poliovirus Sabin tipo 2 de la vacuna antipoliomielítica oral (VPO) en abril de 2016, y los países introdujeron la VPO de tipo bivalente (bVPO), que contiene poliovirus Sabin tipos 1 y 3, o agregaron al menos una dosis de vacuna antipoliomielítica inactivada (VPI) al programa de inmunización de rutina. Se necesitan muchos esfuerzos para erradicar la poliomielitis y se deben implementar nuevas estrategias, como el desarrollo y aprobación de nuevas VPO genéticamente estables y vacunas que no requieren procesos infecciosos para el crecimiento del virus, como partículas pseudovirales (VLP) o tecnología de células empaquetadas (packing-cell). La VIP se producirá cada vez más a partir de cepas Sabin y otras cepas más atenuadas o modificadas genéticamente. Además, también es necesario desarrollar fármacos antivirales para tratar a pacientes inmunodeficientes que son excretores a largo plazo, evitando así la contaminación de individuos susceptibles a poliovirus, debido a la reversión de la patogenicidad. Si todas estas medidas se implementan con éxito, el mundo estará cerca de la interrupción global de la transmisión del WPV y la erradicación de la poliomielitis.

RESUMO A poliomielite ainda é uma doença endêmica no Afeganistão, na Nigéria e no Paquistão, apesar dos esforços para erradicá-la. Portanto, há risco de propagação mundial. Desde o início do programa de erradicação da poliomielite pela Iniciativa de Erradicação Global da Pólio [Global Polio Eradication Initiative (GPEI)], em 1988, a incidência da doença foi reduzida em 99%. Na última década, o poliovírus selvagem do tipo 2 (WPV2) foi eliminado e declarado erradicado em 2015. O poliovírus selvagem do tipo 3 (WPV3) foi reportado pela última vez em novembro de 2012. Essas mudanças promoveram a remoção do poliovírus Sabin tipo 2 da vacina oral antipólio (VOP) em abril de 2016, e os países introduziram a vacina oral bivalente (VOPb), que contém os poliovírus Sabin tipos 1 + 3, ou adicionaram pelo menos uma dose da vacina inativada contra o poliovírus (VIP) no calendário de imunização. É necessário muito empenho para erradicar a poliomielite. Novas estratégias devem ser implementadas, como o desenvolvimento e a aprovação de novas VOPs geneticamente estáveis e vacinas que não requerem processos infecciosos para o crescimento do vírus, como partículas pseudovirais (VLP), ou tecnologia de células de empacotamento (packing-cell). A VIP será cada vez mais produzida a partir de cepas Sabin, de outras cepas atenuadas ou geneticamente modificadas. Além disso, é imprescindível o desenvolvimento de medicamentos antivirais para tratar os pacientes imunodeficientes que são excretores de longo prazo, evitando assim a contaminação de indivíduos suscetíveis aos poliovírus, devido à reversão da patogenicidade. Se todas essas medidas forem implementadas com sucesso, o mundo estará próximo da interrupção global de transmissão do WPV e da erradicação da poliomielite.

Experiencia argentina en la etapa final de erradicación de la polio: cambio de vacuna oral trivalente a bivalente / Argentinian experience to finish polio eradication: switch from trivalent to bivalent oral poliovirus vaccine

Entre el 17 de abril y el 1 de mayo de 2016, 155 países en todo el mundo cambiaron el uso de la vacuna oral trivalente, que protege contra los tres tipos de poliovirus (1, 2 y 3), por la vacuna oral bivalente, que protege contra los poliovirus tipo 1 y 3. Este cambio señala el mayor esfuerzocoordinado globalmente en la historia de las vacunas. En Argentina se realizó el pasado 29 de abril, con una intensa planificación previa y una posterior validación.

Prevalence of prolonged and chronic poliovirus excretion among persons with primary immune deficiency disorders in the Philippines

OBJECTIVES: As part of the global initiative to eradicate poliovirus infections this study aims to: (1) estimate the prevalence of vaccine-derived poliovirus excretion among persons diagnosed with primary immune (B-cell or combined B/T-cell) deficiency disorders (PIDD) in the Philippines; (2) describe clinical features of these PIDD patients excreting poliovirus; (3) genetically characterize vaccine-derived polioviruses isolated from persons with PIDDs; and (4) determine the duration of poliovirus excretion among subjects who tested positive for vaccine-derived poliovirus excretion. METHODS: Seventy-one (71) Filipino patients (ages 0-35 years of age) with PIDD were recruited retrospectively and prospectively over a period of 16 months. The study participants, after informed consent and administration of a questionnaire for baseline data, underwent further testing of quantitative immunoglobulin levels (IgG, IgA, and IgM) and stool poliovirus isolation using two stool samples. Stool specimens which tested positive for the poliovirus were sent to the Regional Reference Laboratory in Australia for further characterization by Intratypic Differentiation (ITD) and Vaccine-derived polioviruses (VDPV) real-time PCR. These participants were then monitored on a monthly basis until laboratory tests identified two sequential months of negative poliovirus stool specimens. RESULTS: Seventy-one (71) patients underwent interview and quantitative serum immunoglobulin testing. However, one patient expired prior to stool isolate collection. This study, then, documented that none of the remaining 70 Filipino individuals (0-35 years old) with confirmed or suspected PIDDs chronically excreted immunodeficiency-associated vaccine-derived poliovirus (IVDPV). One patient who was a recent OPV-recipient excreted poliovirus Sabin-like 1 transiently (less than 1 month) and two patients excreted non polio-enteroviruses. CONCLUSIONS: Chronic and prolonged poliovirus excretion appears to be uncommon among Filipino patients with diagnosed Primary Immunodeficiency Disease Disorders. However, as part of the continuing global initiative for poliovirus eradication, vigilance is still necessary in patients with primary immunodeficiency diseases. Adequate identification of these patients followed by monitoring their capacity for viral excretion and environmental contamination may be necessary to achieve this goal.