Padronização de teste para quantificar anticorpos anti-poliovírus utilizando vírus vacinal / Standardization of a test for quantifying the antibodies against poliovirus using the vaccine virus

A poliomielite é uma doença endêmica no Afeganistão e no Paquistão, apesar dos esforços para ser erradicada, representando uma ameaça para outros países principalmente devido às viagens internacionais. A Organização Mundial da Saúde (OMS) tem como objetivo erradicar a poliomielite causada pelo poliovírus selvagem no mundo. O requisito essencial para a erradicação da poliomielite é a eliminação da cepa do poliovírus selvagem, que é empregada no teste padrão-ouro. Com o intuito de auxiliar na erradicação do poliovírus selvagem, o objetivo deste estudo foi modificar o teste padrão-ouro usando o poliovírus derivado da vacina oral atenuada. Foram testados 63 soros pelo ensaio de neutralização utilizando-se antígenos vacinais. A concordância do sorotipo 1 (k=0,74) foi considerada substancial, enquanto o sorotipo 2 (k=1,00) e sorotipo 3 (k= 0,95) foram consideradas quase perfeitas. A sensibilidade dos testes de soroneutralização utilizando os sorotipos 1, 2 e 3 foi de 94,83%, 100,00% e 100,00%, respectivamente. Em conclusão, o ensaio com antígenos vacinais pode ser usado como procedimento laboratorial seguro, especialmente em estudos de vigilância em larga escala.

Poliomyelitis is an endemic disease in Afghanistan and Pakistan in despite of the efforts to eradicate it, and it represents a threat to other countries mainly due to the international trips. The World Health Organization (WHO) aims at eradicating the polio disease worldwide. An essential requirement for eradicating the poliomyelitis is the elimination of the wild poliovirus strain, which is employed in the gold standard test. As a support for the eradication of wild poliovirus, the present study aimed at modifying the gold standard test by using poliovirus derived from the oral attenuated vaccine. Sixty-three sera samples were tested by neutralization assay using vaccine antigens. The degree of agreement of the serotype 1 (k=0.74) was considered substantial, while the serotype 2 (k=1.00) and 3 (k= 0.95) showed almost perfect agreement. The sensitivity of serotypes 1, 2 and 3 was 94.83%, 100.00% and 100.00%, respectively. In conclusion, the assay with the vaccine antigens can be used as a safe application, especially for large-scale surveillance studies.

Poliomyelitis eradication remains a challenge in Africa

During the last two decade; twelve wild type 1 poliovirus genotypes have been characterized in Africa. Several distinct clusters have been identified within some of them and appeared to be segregated geographically. This distribution could represent newly emerging genotypes and independent sustained circulation of these lineages or cross border transmission between countries of a single genotype followed by a different natural evolution in each country. Concurrent circulation of more than one poliovirus genotype was seen in Nigeria; Togo; Central Africa Republic and South Africa. The present study which has generated a meaningful overview of the endemic circulation of wild type 1 poliovirus in Africa; could be a basis for further evaluation of the impact of mass vaccination campaigns on wild type 1 poliovirus

Síndrome pós-poliomielite / Post-poliomyelitis syndrome

A poliomielite é uma doença erradicada no Brasil, desde os anos 80, mas atualmente estão aparecendo novos sintomas relacionados a essa patologia, a síndrome pós-polio, que é caracterizada por uma nova desordem neurológica. Esses sintomas aparecem 30 a 40 anos após a infecção aguda da poliomielite e, como é uma patologia recente, há poucos estudos e casos diagnosticados. O objetivo deste estudo é descrever o aparecimento do caso dessa síndrome, através do relato de caso de uma paciente que realiza tratamento fisioterapêutico na clínica de Fisioterapia do Hospital Regional de Araranguá, localizado na cidade de Araranguá/SC, em agosto de 2006. Conforme a literatura, os sinais e sintomas que foram relatados pelo estudo são considerados como uma conseqüência tardia da infecção aguda da poliomielite, devido à degeneração dos brotamentos dos axônios atingidos pela poliomielite há 40 anos.

The poliomyelitis disease was eradicated in Brazil in the eighties, but now new symptoms related to this pathology are rising, like the post-polio syndrome, which is characterized by a new neurological disorder. These symptoms rise 30 to 40 years after the acute poliomyelitis infection and, as it is a recent pathology, studies and diagnosed cases are scarce. The objective of this study was to describe the onset of this syndrome, through the case of a patient attended in a Physical Therapy Clinic of a Regional Hospital of Araranguá, located in the city of Araranguá/SC, Brazil, in August 2006. According to literature, signs and symptoms reported in the study are considered as the consequence of acute poliomyelitis infection, due to degeneration of budding axons damaged by the poliomyelitis 40 years ago.

Detecting polio through surveillance for acute flaccid paralysis (AFP).

Accurate surveillance for polio is essential for eradication. Surveillance systems for polio has been developed under the guidance of the global polio eradication initiative. Surveillance of cases of acute flaccid paralysis among children less than 15 years of age is a key component for a well functioning polio surveillance system. The surveillance system works through a network of surveillance medical officers, the responsibility of them lies in assisting the health services departments of all states and maintaining a network of acute flaccid paralysis reporting sites and rapidly investigating the cases. Surveillance activities begin when a child comes in contact with a healthcare provider who in turn informs the officer in charge of acute flaccid paralysis surveillance. The goal of the polio network laboratories is to provide accurate and timely results of wild poliovirus detection in stool samples of cases of acute flaccid paralysis. Strong linkages have been established between the acute flaccid paralysis surveillance system and the laboratory network. Laboratories complete poliovirus isolation and if poliovirus is isolated, these are submitted for intratypic differentiations. Acute flaccid paralysis surveillance in India has demonstrated that the eradication activities implemented in India led to dramatic reduction and restriction in the number of cases and geographic spread of poliovirus transmission.

Diagnosis of acute flaccid paralysis: injection injury or polio?

In many countries, the treatment of choice for all fevers is one or more injections. These injections are associated with a risk of nerve damage. If cases of poliomyelitis are not to be missed, the diagnosis of injection trauma or traumatic neuritis (TN) must be exact. The guides for distinguishing between TN and polio are not clear. It is probable that some cases of polio are misdiagnosed as TN. As three-quarters of children with paralytic polio receive injections just before the onset of paralysis, their paralysis may be mistaken for TN. Clearer guidelines are proposed, together with suggestions for better documentation of muscles injected and paralysed. All cases of reported TN should be monitored and new diagnostic guidelines published. To protect their children, mothers must be educated to understand that injections for fever can cause harm. This must be an important part of the eradication programme for poliomyelitis.

Vaccine-associated paralytic poliomyelitis: a case report of domiciliary transmission

Poliomyelitis associated with live strain vaccine is defined as the paralytic form of the acute anterior poliomyelitis related to the vaccine strain. Since these strains behave similarly to the wild-type virus, we can differentiate, epidemiologically, two types of vaccine-associated poliomyelitis: cases in which the patient was vaccinated and cases in which the patient had had contact with vaccinated individuals. We herein present the case of an unvaccinated child, with a clinical picture of an acute anterior poliomyelitis associated with the live strain vaccine, whose brother received the Sabin vaccine 20 days before the onset of the symptoms. Vaccine strain of the type 3 poliovirus was isolated in fecal culture and a presented mutation in nucleotide 472 (C(r)U) in the 5' non-coding region, which is strongly related to the higher strain virulence

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

Poliomyelitis in India: past, present and future.

In that they were made in temperate countries, most of the studies on poliomyelitis may not apply in sub-continent of endemic infantile paralysis. This review brings together data on polio in India, to present any changes which may have occurred since 1940. Only about 2% of children with polio die in the acute illness; about 95% of all cases have paralysis of one or both legs. In lameness surveys the adjustments for deaths and for arm paralysis are unnecessary and inflate the prevalence. Surveys suggest that prevalence has risen, but there may be other explanations for the figures. Around sentinel centres with effective cold chains, prevalence has decreased rapidly. The figures of the National Baseline Prevalence survey are examined. There are few cases of provocation, but a new phenomenon of aggravation by unnecessary intramuscular injections given to children with fever has been described. Such unnecessary injections are thought to be the cause of more severe paralysis in about 45% of cases and of converting a non-paralytic attack into paralysis in another 30% of the perhaps 200,000 cases in India each year. Aggravation is thought to be caused by a mechanism similar to the effects of physical activity. It is possible that massage might have a similar effect. Abscesses or their treatment may precipitate paralysis. The median age of paralysis fell by almost a half from about 2 yr to 1 yr, but may now have risen as many younger children receive vaccine. Rehabilitation has been neglected, with long lasting consequences. Assessment of disability should be based on need and not on current ability. Ethically, prevalence surveys should offer opportunity for immunization and rehabilitation. Prevalence of paralysis, numbers attending for rehabilitation and immunization have been analysed by gender and differences examined. The gender-gap widens with age after paralysis: there may be a high mortality among girls with paralysis. Past prevalence calculated from surveys might be seriously underestimated if many girls have died. The monthly pattern of polio was no different in epidemic years. Pulse immunization could be tried just before the seasonal rise each year. Difficulties of comparing vaccination schedules and the criteria for assessing the potency of vaccine are analysed. Paralysis among Indian soldiers in World War II suggests that adult cases may occur, but are not reported. Present investigations should concentrate on babies and adult cases. Research using virulent strains should be prohibited. The very low case-fatality rate suggests that many of the circulating viruses are of low virulence. The increasing proportion of cases with unnecessary injections just prior to paralysis might have caused the lower median age of paralysis, the severity of paralysis and at least part of the increasing prevalence of polio. The seasonal increases of polio might, in part, be a reflection of the injections given for fever caused by other infections. A national campaign against unnecessary injections for young children is urgently required. For children with fever, there is a strong case for postponing even DPT injections.

Nerve conduction studies and its importance in diagnosis of acute poliomyelitis.

Motor nerve conduction velocities was performed on 50 subjects in the pediatric age group. Thirty two patients with acute poliomyelitis and 18 controls. The MNCV was studied in the median nerve in the upper limb and the posterior tibial in the lower limb. The motor nerve conduction velocity in polio patients matched well with the controls, as well as within the accepted standards for normal. The MNCV of the median nerve ranged from 41.8 +/- 2.76 m/sec in under 1 year to 44 +/- 2.1 m/sec in 3-8 years, in polio patients, while the range in controls varied from 37 to 53 m/sec. Similarly, for the posterior tibial nerve, in polio patients the value of MNCV varied from 38.7 +/- 4.9 m/sec to 42.5 +/- 3.1 m/sec. In the controls, also the MNCV ranged from 38.5 +/- 6.3 m/sec to 48.4 +/- 3.42 m/sec. Thus, no delay on the motor nerve conduction velocity was seen. Poliomyelitis is a major problem in developing countries like Pakistan and India, where serological diagnosis is a luxury. The determination of motor nerve conduction velocity provides a quick and easy method of distinguishing poliomyelitis from other motor nerve disorders esp. Guillain Barre syndrome.