Seronegativity to polio viruses among previously immunized adult candidates to solid organ transplantation

ABSTRACT In the current effort to eliminate polio from the world, it is important to recognize and vaccinate susceptible groups, especially immunocompromised patients living in countries where attenuated polio vaccine is still used. In this report, we describe the frequency of protective antibodies in a small sample of adult SOT candidates in whom previous vaccination could be ascertained. Patients included in this report were selected among the participants of an ongoing prospective study carried out at the Reference Center for Special Immunobiologicals of the Evandro Chagas National Institute of Infectious Diseases in Rio de Janeiro, Brazil. Among the first 100 patients enrolled in this study, only seven adult SOT candidates had proven polio vaccination at childhood. Three of these seven patients (43%) had no protective antibody titers to one or more poliovirus subtype before solid organ transplant. Proven childhood vaccination against polio does not reliably provide lifelong protective antibody titers for adult SOT candidates and should not be used as a criterion to analyze the need for vaccination in this population.

Polio vaccination; knowledge, attitude, and practice in district Abbottabad, Khyber Pakhtunkhwa, Pakistan

To assess knowledge, attitude and practice [KAP] about poliomyelitis [polio] vaccination in District Abbottabad, province Khyber Pakhtunkhwa [KPK], Pakistan, to identify reasons of failure of polio vaccination/ eradication campaign and to make recommendations in the light of the study. District Abbottabad, province KPK, Pakistan including both urban and rural areas. Three months from 1st June to 31st August 2012. This cross-sectional descriptive explorative study was conducted in District Abbottabad, of province KPK, Pakistan. A structured questionnaire was submitted to people in the urban and rural population using convenient sampling. Out of 200, only 142 questionnaires were filled by interviewing parents and guardians of the children followed by focused group discussions with the community heads and the parents of the children. Majority [61.78%] of respondents were of low income category with the mean age of 31 years. Amongst those [75%] were earning Rs.7,000-12,000 per month. Literacy rate was low with 45.77%. Out of which 40.67% fathers and 59.33% mothers were illiterate. Therefore a few respondents were aware about the mode of transmission of polio. Majority [80%] said that polio could be prevented by polio drops and about 86% said that this vaccine had no side effects. About 45% respondents refused to cooperate with polio teams, and 28% respondents believed, that Abbottabad Operation had bad effect on anti-polio campaign. Regarding the use of boiled drinking water, 95.8% respondents knew that it was good for health. While only 4.20% were using boiled water for drinking. Advice of the health professionals [69.71%] and other family members [7.74%] was respected in making health care decisions, therefore it was an opportunity for the government to involve these persons as well as media men in conveying message to the community to achieve ultimate goal of polio free Pakistan. Unawareness among the population of District Abbottabad, especially the knowledge about the disease, mode of transmission and its prevention are the most deficient areas. Secondly misconceptions about the nature of polio drops, and religious misinterpretations in masses, created by general public and religious leaders, are the major obstacles in the real success of vaccination campaign

La vacuna polio oral en lactantes no interfiere con la detección de enterovirus en sangre / Oral polio vaccine in infants does not interfere in detection of enterovirus in blood

Introduction: There is not known if a viraemia post-oral polio vaccine (OPV) is detectable by modern molecular techniques. Such viraemia could affect the performance of the real time-polymerase chain reaction (PCR) for non polio enterovirus (EV) detection, technique of growing clinical use for the study of febrile infants. Objective: To determine viraemia post-first dose of OPV in healthy infants, by molecular techniques. Patients and Methods: 50 infants less than three months without previous VPO were randomized in 5 groups: a control group with pre-vaccination blood sample (BS), group 1 BS at day 2, group 2 BS at day 4, group 3, BS at day 6 and group 4, BS at day 8 post-vaccination. Conventional and specific PCR for poliovirus and real time PCR for non polio EV were performed in BS and in OPV samples. Results: No genetic material of poliovirus was detected in any infant, while in 9 of them (18%) non polio EV was identified. Real time PCR for EV did not amplify poliovirus from OPV samples. Discussion: Results suggest that no post VPO viraemia detectable by molecular methods exists. Considering that real time PCR for EV does not allow to identify polio virus, no false positives of the test are expected as a result of a recent VPO vaccination. We documented presence of non polio EV in blood of healthy asymptomatic infants.

Introducción: No existen estudios que indiquen si la vacuna polio oral (VPO) produce viremia detectable mediante métodos moleculares. Una eventual viremia podría afectar el rendimiento de la RPC tiempo real para detectar enterovirus (EV) no polio, examen de creciente uso clínico en lactantes pequeños con fiebre sin foco. Objetivo: Determinar viremia post VPO en lactantes sanos, por métodos moleculares. Métodos: 50 menores de 3 meses, al momento de recibir su primera VPO se distribuyeron en forma aleatoria en 5 grupos: control, muestra de sangre pre-vacunación; grupo 1, muestra al 2° día; grupo 2, al 4° día; grupo 3, al 6° día y grupo 4, al 8° día post-vacunación. Se realizó RPC convencional específica para virus polio y RPC tiempo real para EV no polio en las muestras de sangre y en muestras de VPO. Resultados: No se identificó presencia de material genético de virus polio en lactante alguno, mientras que en 9 (18%) se identificó presencia de EV no polio. La RPC tiempo real para EV no polio no amplificó material genético a partir de las muestras de VPO. Discusión: Los resultados sugieren que no existe viremia post-VPO detectable por métodos moleculares. Considerando que la RPC tiempo real de EV no polio de uso clínico no permite identificar la presencia de virus polio, estos hallazgos indican que no existirán falsos positivos de este examen como resultado de una vacunación VPO reciente. Adicionalmente se documentó presencia de EV no polio en sangre de lactantes asintomáticos.

A RT-PCR method for selective amplification and phenotypic characterization of all three serotypes of Sabin-related polioviruses from viral mixtures

Outbreaks caused by vaccine-derived polioviruses are challenging the final eradication of paralytic poliomyelitis. Therefore, the surveillance of the acute flaccid paralysis cases based on poliovirus isolation and characterization remains an essential activity. Due to the use of trivalent oral poliovirus vaccine (OPV), mixtures containing more than one serotype of Sabin-related polioviruses are frequently isolated from clinical samples. Because each poliovirus isolate needs to be individually analyzed, we designed polymerase chain reaction primers that can selectively distinguish and amplify a genomic segment of the three Sabin-related poliovirus serotypes present in mixtures, thus, optimizing the diagnosis and providing prompt information to support epidemiologic actions.

Poliomielite associada à vacina oral: aspectos clínico-epidemiológicos e laboratoriais, Brasil, 1989-2009 / Poliomyelitis associated with oral vaccine: clinical, epidemiological and laboratory, Brazil, 1989-2009

Introdução: A poliomielite paralítica associada ao vírus vacinal (vaccine-associated paralytic poliomyelitis, VAPP), é o principal evento adverso relacionado ao uso da vacina oral de vírus atenuado (OPV/Sabin), descrita desde a sua introdução. A partir da Certificação em 1994, os únicos casos de pólio causados por poliovírus, no Brasil e nas Américas, são de origem vacinal. Objetivos: Descrever a ocorrência de poliomielite associada ao vírus vacinal no Brasil, e estimar o risco desse evento por dose administrada (1989-2009). Metodologia: Foi realizado um estudo, descritivo, retrospectivo do tipo série de caso, a partir de 11.892 notificações de paralisia flácida aguda (PFA) registradas no Poliomyelitis Eradication Surveillance System (PESS), destes 46 casos de VAPP e 120 compatíveis foram objeto desse estudo com posterior validação ou reclassificação pelo Comitê Nacional. Definições de Caso: Considerou-se caso de VAPP, indivíduo com PFA iniciada entre 4-40 ou 4-60 dias após OPV para a Categoria de VAPP Oficial e 4-85 dias em Contato, ambas com isolamento de vírus vacinal em amostra de fezes e seqüela compatível com poliomielite após 60 dias do início da deficiência motora (DM); para a categoria de VAPP Elegível considerou-se apenas PFA de 4-40 dias, com ou sem isolamento viral e seqüela compatível com pólio evidenciada em eletroneuromiografia (ENMG).

Para a estimativa do risco, inicial e final, considerou-se apenas o período (1999-2009), e foi calculado pela razão entre o número de casos e as respectivas doses de OPV aplicadas, segundo esquema, ano de ocorrência, UF e região. Resultados: Em todo o período foram identificados 61 casos de VAPP distribuídos nas três categorias mencionadas, destes, 18 casos no segundo período do estudo (1999-2009) em que foi avaliado o risco. Houve maior evidência de inconsistência de registros e resultados no primeiro período (1989-1998) e maior ocorrência de casos em indivíduos vacinados, sexo masculino, faixa etária menor de um ano, e isolamento de vírus tipo 2, dados condizentes com a literatura. A mediana e intervalo em dias entre as variáveis recebimento de OPVxDM e DMxColeta de Fezes foram superiores as descritas em outros estudos, mais evidente no primeiro período. (...) Conclusão: Os riscos de VAPP para 1ª dose e doses totais encontrados, ainda que um pouco superior comparado aos do último estudo descrito no Brasil, permanecem inferiores comparados com a literatura internacional. No entanto, análises isoladas por ano e Unidade Federada encontraram maiores riscos. As discussões geradas a partir desse estudo corroboraram para apoiar o Programa Nacional de Imunizações (PNI) a adotar na rotina de vacinação infantil o uso da vacina inativada (IPV) no Brasil a partir do segundo semestre deste ano de 2012, em esquema seqüencial. Recomendação: Garantir elevadas e homogêneas coberturas vacinais em todos os municípios brasileiros; assegurar a qualidade da Vigilância das PFA/Pólio para manutenção da Certificação de País livre de Pólio e revisar definição de caso de VAPP.

Mothers knowledge, attitude and practice toward immunization against poliomyelitis among children up to 5 years age in Dar Saad District. Aden 2005

This work was conducted with the principal objective of contributing to the study of the accomplishment of the immunization coverage against poliomyelitis in Dar Sad district, Aden Governorate, the knowledge, attitude and practice related to this problem and the socioeconomic factors influencing it. A sample of 180 children under the age of five years was studied using stratified, cluster and random sampling methods. A closed type questionnaire was used and filled by the researcher during the interview of the mother of each selected child. An over all evaluation of the accomplishment of the immunization programs in Dar Sad district was made. The results showed a coverage level of 85% receiving complete vaccination, 12% receiving incomplete vaccination and 3% without vaccination. The drop out rate was 12.6% .The main causes for discontinuation and not doing the vaccination, and related factors to these problems were identified. Some factors were determined as strong as relationship between the educational level of both the mother and the father and the immunization coverage of children. Other influencing factors were; giving credit to rumors, no faith in immunization and ignorance of the importance of returning for the second and the third dose, prevalence of false contraindication to vaccinations among some mothers. Recommendations for increasing the rate of vaccination coverage and decreasing the drop out rate were proposed in order to improve the immunization against poliomyelitis and other types of vaccines in the future and meet the goals stated by the World Health Organization

Uso universal da vacina inativada contra poliomielite / Universal use of inactivated polio vaccine

OBJETIVOS: Apresentar uma atualização da situação da poliomielite no mundo, número de casos anuais, regiões mais atingidas pela doença, vacinas disponíveis na atualidade, seus riscos e benefícios, utilização da vacina monovalente, riscos da disseminação de um vírus mutante na comunidade, progressos que têm sido realizados em termos de erradicação mundial e as propostas da Organização Mundial da Saúde (OMS) nesse período de transição entre a erradicação global e o período pós-erradicação. FONTE DE DADOS: Foram consultadas bases de dados no período de 1955 a 2005 em MEDLINE, LILACS, The Web, Doctor's Guide; site da OMS e Organização Pan-Americana da Saúde (OPAS) e livro-texto. SíNTESE DOS DADOS: Em 1988, a OMS estabeleceu como meta a erradicação da doença e a interrupção da transmissão do vírus selvagem globalmente. Desde então, houve um dramático impacto no declínio da doença, embora em 2005 ainda existam alguns países considerados endêmicos e outros onde a pólio retornou, por conta de vírus importados. As vacinas utilizadas no mundo são as clássicas tOPV e IPV e, dentro desse processo de erradicação, o uso de vacinas mOPV tem sido estimulado nos locais em que circula apenas um tipo de poliovírus. Entretanto, as vacinas OPV, além de disseminarem o vírus na comunidade, podem causar paralisias por reversão do processo de neurovirulência. CONCLUSÕES:Para um mundo livre da doença poliomielite, será preciso retirar o vírus de circulação, o que só será possível se a vacina OPV for descontinuada, conforme propostas da OMS para esse período de transição e para a era pós-erradicação.

Assessment of functioning of Pulse Polio Kendras and house to house activity in Delhi: is there any scope for improvement?

A cross sectional study was done to assess the performance of Pulse Polio Immunization Booths on National Pulse Polio Immunization day (NID) observed on 2nd December 2001. 55 booths located in Delhi were visited. House to house visits were made on 5 successive days to assess out-reach activities and hold focus group discussions with workers and mothers of the beneficiaries. Majority of the booths were within walking distance (96.4%) and accessible (94.5%) to the beneficiaries, had adequate trained staff reporting in time (88.5-90.4%), displayed IEC material (89.1%), marked the tally sheets in a correct manner (86.5%) and were administering polio vaccine within acceptable norms. Correct knowledge regarding vaccine vial monitor (VVM) was present among workers of 82.7% booths. The marking of children was not being done correctly in 38.2% booths. Efforts to disseminate key messages of next date of NID and routine immunization schedule, information about the disease and it's impact on life and removal of misconceptions regarding polio was observed to be poor (28.9-48.1%). During house-to-house visits coverage was found to be excellent barring a few isolated cases of unimmunized children due to various reasons. The finding of the study implies increased focus on training of the workers manning these booths, especially on dissemination of key messages and information about early symptoms and signs of polio, removal of misconceptions, correct marking of the children and houses and countering resistance to immunization.

Dos vacunas antipoliomielíticas: ventajas y desventajas / Two antipoliomyelitis vaccines: advantages and disadvantages

La vacuna oral antipoliomielítica elaborada con virus vivos atenuados es actualmente la de elección en México. En 1978 van Wezel incrementó la antigenicidad de la vacuna elaborada con virus inactivados por rayos ultravioleta, a la cual se denominó vacuna de potencia incrementada (elPV, enhanced inactivated polio vaccine). Existe clara evidencia en países europeos de que también con esta última se obtiene una protección adecuada, lo que ha permitido considerarla como una alternativa en los esquemas de inmunización. Se describen las dos vacunas, oral y elPV, los esquemas de inmunización que actualmente se proponen y sus ventajas y desventajas

Effect of passively transferred anti-poliovirus antibodies on seroconversion.

A prospective study enrolling 50 mother-infant pairs was undertaken to determine the effect of maternal antibodies on poliovirus antibody titres and seroconversion rates in infants and to determine the difference in titres and seroconversion rates following three and five doses of oral poliovaccine (OPV). Cord blood samples and samples collected 4 weeks after 3rd and 5th doses of trivalent oral poliovaccine were processed for estimation of anti-poliovirus antibody titres. These were expressed as geometric mean titres (GMT). Significance was analyzed using unpaired 't' test. The relationship between maternal antibody titres and seroconversion was determined by correlation coefficient test. Post OPV5 titres were significantly higher than post OPV3 titres for type 1 and type 2 polioviruses. Seroconversion rates against type 1, 2 and 3 polioviruses were 92.9%, 100.0% and 92.9% following OPV3 and 100.0%, 100.0% and 93.2% following OPV5. The cord blood titres did not have any relation to post-OPV3 or post-OPV5 titres. Although there is significant passive transfer of poliovirus antibodies across the placenta, this does not affect titres achieved after immunization. Post-OPV5 titres against type 1 and type 2 viruses are significantly higher than post-OPV3 titres. The seroconversion rates following OPV5 are higher than those obtained post-OPV3 but this difference is not statistically significant.

Poliomielitis paralítica asociada a vacuna: presentación de dos casos / Vaccine associated paralytic poliomyelitis: report of 2 cases

Ante la erradicación de la poliomielitis y de la circulación del virus polio salvaje en América y su importante disminución en el mundo los casos de polio paralítica asociada a vacuna (PPAV), aunque poco frecuentes, adquieren gran relevancia. Se presenta dos casos diagnosticados en el Hospital Dr. E. González Cortés, en los años 1992 y 1997. Los grupos de mayor riesgo de PPAV son los receptores de vacuna polio oral, especialmente lactantes después de la primera dosis, en adultos en contacto con receptores de vacuna y personas immunodeficientes. Esto ha llevado a muchos países a modificar su esquema de vacunación, incorporando la vacuna polio inactivada (VPI), que tiene igual efectividad y no encierra el riesgo de PPAV. Se destaca la necesidad de disponer en nuestro país de vacuna VPI para los pacientes inmunodeficientes y sus contactos

Effect of administration of 200,000 IU of vitamin A to women within 24 hrs after delivery on response to PPV administered to the newborn.

OBJECTIVE: To explore the effect of maternal supplementation of vitamin A on the immune response to oral polio vaccine in breastfed infants. DESIGN: Randomized controlled trial. SETTING: Hospital based. METHODS: One hundred mothers having uncomplicated deliveries randomly received either 200,000 IU vitamin A orally (Experimental) or placebo (Control). All the newborns were given a dose of oral polio vaccine within 72 hours after birth and were breastfed. Type specific neutralizing antibodies to polio viruses in test sera diluted from 1:4 to 1:512 and serum retinol levels were determined from the cord blood and at the age of 6 weeks. Breast milk retinol levels were determined at 3, 10, 30, 45 and 90 days of lactation. RESULTS: Seroconversion to OPV and geometric means of antibody titers to the three types of polio viruses were comparable between the groups of infants belonging to the experimental and control mothers. Breast milk retinol levels were significantly higher in the experimental group upto 45-90 days of lactation. Majority of the infants at birth had serum retinol levels < 15 micrograms/dl which improved significantly by 6 weeks irrespective of the maternal supplementation status. CONCLUSIONS: Maternal vitamin A supplementation soon after delivery improves vitamin A intakes of breastfed infants during the first 3 months and has no interference with the seroconversion to a neonatal dose of OPV. OPV administered to newborn in turn has no adverse effect on the vitamin A status of the breastfed infants.

Seroconversion following killed polio vaccine in neonates.

The study was carried out to evaluate the efficacy of IPV in neonates and to study the additive effect of IPV or OPV at birth on seroconversion with three subsequent doses of OPV. Addition of IPV or OPV at birth to the conventional OPV schedule resulted in significantly higher seroconversion rates than in the controls, who received three doses of OPV. Three doses of IPV beginning from birth resulted in significantly better seroconversion rates than in the control group. Children receiving 3 doses of IPV showed significantly greater seroconversion rates against type III polio virus than those receiving IPV/OPV at birth followed by 3 doses of OPV. The difference in the seroconversion rates against the other virus types was not significant. A significantly greater number of children who received some vaccine at birth (IPV or OPV) were protected against poliomyelitis by 6 weeks age as compared to those who received no immunization at birth. The study recommends that seroconversion rates following three doses of IPV are satisfactory. Addition of IPV or OPV at birth to the conventional schedule markedly increases the seroconversion rates. Immunization can be started at birth to ensure early protection against poliomyelitis.

Poliomielite: situacao epidemiologica e dificuldades para a erradicacao global / Poliomyelitis: epidemiological situation and difficulties for global eradication

O uso disseminado da vacina oral contra a poliomielite levou a eliminacao da doenca no hemisferio ocidental e tem-se observado significativos progressos no mundo todo para a erradicacao do poliovirus selvagem. Este artigo e uma revisao da situacao epidemiologica da polio, das estrategias recomendadas pela OMS para a erradicacao global da doenca e das dificuldades para obtencao desse objetivo