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.

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The purpose of this paper is to discuss methods recommended and used by the Pan American Health Organization (PAHO) to monitor the interruption of indigenous measles transmission in the Region of the Americas. The methods used include house-to-house monitoring of vaccination coverage as a supervisory tool during both campaigns and routine vaccination; thoroughly investigating all measles outbreaks; performing routine surveillance, including weekly reporting from at least 80% of reporting units; and validating routine surveillance through active-case searches at health care institutions and schools and in the community. The strategies described have helped PAHO to increase the authority and accountability of vaccine program managers at the local, provincial, and national levels. Their efforts have permitted the Region of the Americas to reduce to three the number of countries with indigenous measles transmission and to reach a record low of 503 measles cases in 2001.

O objetivo deste artigo é rever o “estado da arte” dos avanços, obstáculos e estratégias para atingir a erradicação global da pólio. As ações de controle da poliomielite iniciaram na década de 1960 com o advento das duas vacinas antipoliomielíticas, a vacina oral da pólio (VOP) e a vacina inativada da pólio (VIP). No período de 1985 a 2020, são implementadas estratégias para atingir a meta de erradicação do poliovírus selvagem (WPV). Após o sucesso da interrupção da transmissão autóctone do WPV na região da Américas, foi lançada a meta da erradicação global. Descrevemos o processo de erradicação em quatro tempos: (1) O advento das vacinas VIP e VOP iniciou a era do controle da poliomielite; (2) A utilização massiva e simultânea da VOP teve impacto significativo sobre a transmissão do poliovírus selvagem no final da década de 1970 no Brasil; (3) Políticas públicas (nacionais e internacionais) decidem pela erradicação da transmissão autóctone do poliovírus selvagem nas Américas e definem as estratégias epidemiológicas para interromper a transmissão; e (4) A implantação das estratégias de erradicação interrompeu a transmissão autóctone do WPV em quase todas as regiões do mundo, exceto no Paquistão e Afeganistão, onde, em 2020, cadeias de transmissão do WPV1 desafiam as estratégias de contenção do vírus. Por outro lado, a persistência e a disseminação da circulação do poliovírus derivado da VOP, em países com baixa cobertura vacinal, somadas às dificuldades para substituir a VOP pela VIP constituem, atualmente, os obstáculos para a erradicação a curto prazo. Finalmente, discutimos as estratégias para superar os obstáculos e os desafios na era pós-erradicação.

This study is an important first step in addressing the issue of prevalence of rubella virus infection among Haitian women and in dealing with the still-underrecognized public health problem of congenital rubella syndrome in Haiti. We recommend additional research that uses randomized sampling and includes a significant proportion of women from rural areas of the country.

In 1994 Haiti completed a nation-wide catch-up vaccination campaign against measles that resulted in an estimated level of vaccine coverage of 195% of children aged 9 months to 14 years. For 6 years after the campaign, Haiti remained free of measles but the level of routine immunization remained low, with measles vaccine coverage in 1-year-old children averaging 47% (range, 32%-85%) between 1995 and 1999. Consequently, there was an accumulation of 11 million susceptible children below age 5 years. Other vaccines had similar coverage. For example, during the same time period, 3 doses of diphtheria-tetanus toxoids-pertussis vaccines were given to 34%-59% of children !1 year old. A follow-up measles vaccination campaign was conducted in 1999, but the estimated coverage was only 70%-80% of the target population. As a result, Haiti

O sucesso da erradicação da transmissão autóctone do vírus da poliomielite nas Américas, levou os Ministros da Saúde dos países membros da Organização Pan-Americana da Saúde -OPAS a assumirem, em 1994, a meta de eliminação do sarampo até o ano 2000. O Plano de Eliminação do Sarampo inclui as estratégias: imunização das crianças de 9 meses a 14 anos de uma só vez e a manutenção de altas coberturas vacinais em menores de 1 ano; campanhas periódicas a cada 2 a 4 anos para menores de 4 anos; a implementação dos sistemas de vigilância epidemiológica, para detectar casos suspeitos de sarampo. O impacto das ações adotadas em vários países da América caracterizou-se pela drástica redução da incidência da doença, estimulando a OPAS a realizar uma avaliação, visando conhecer a verdadeira situação epidemiológica da doença e a capacidade dos sistemas de vigilância epidemiológica em detectar casos/surtos oportunamente e aplicar as medidas de controle de forma ágil. A metodologia, desenvolvida pela OPAS, é de caráter qualitativo com componentes quantitativos. Apresenta-se neste trabalho a avaliação realizada no Brasil nos Estados de São Paulo e Bahia. Os resultados apontam para um sistema de vigilância moroso, que não permite a detecção oportuna de casos ou surtos e que o Plano de Eliminação não representava prioridade política nos anos posteriores a sua implementação em 1992.Palavras-Chave: Vigilância Epidemiológica; Sarampo; Plano de Eliminação do Sarampo. SummaryThe successful eradication of the transmission of autochthonous wild poliomyelitis virus in the Americas, encouraged the Ministers of Health of the members States of the Pan-American Health Organization -PAHO -in 1994 to adopt the goal of eliminating measles in the Region by the year 2000. The Measles Elimination Plan consist of four basic strategies: a one time vaccination of all children between 9 months and 14 years in national campaign; maintenance of high vaccination coverages in children less than 1 year; periodic vaccination campaigns, every 2/4 years to detect suspected cases of measles in children less than 4 years and the implementation and strengthening of epidemiological surveillance system. A drastic reduction in the incidence of the disease was observed in the Americas which stimulated PAHO, to carry out an evaluation of the measles epidemiological surveillance system with the objective to determine the true epidemiological situation and the systems capacity in to detect suspected cases of measles or outbreaks and implement control measures in a timely fashion. The methodology was developed by PAHO, and consists mainly on qualitative attributes with quantitative components. The evaluation was realized in the Brazilian States of Bahia and São Paulo and revealed that the measles surveillance system is slow, not allowing the timely detection of cases or outbreaks and that the Elimination Plan was not considered a political priority in the years following its implementation in 1992.

This article describes the process by which some concepts of epidemiological surveillance are elaborated and turned into operational categories to comprise the so-called epidemiological surveillance system for two specific diseases. The authors describe some epidemiological concepts and categories which were elaborated over the course of the smallpox eradication program and more recently in the poliomyelitis eradication program. Such concepts and categories as outbreak containment, cross-notification, and case definitions are described as they fit into a series of actions which make up the epidemiological surveillance system. Finally, it is worth noting that the description developed in this article is based on personal observations, since the authors participated in the smallpox eradication program in Bangladesh and Somalia as well as in the regional poliomyelitis eradication program in the Americas.