Célio Rodrigues de Almeida

Estudos bacteriológicos e sorológicos de um surto de peste no Estado da Paraíba, Brasil

During a plaque outbreak in the Borborema Plateau focus (Paraiba), bacteriological and serological studies were carried out in material from 452 patients (48 positives), 1,938 rodents and other small mammals (75 positives), 4,756 dogs (141 positives) and 2,047 cats (57 positives) obtained from 41 counties (out of which, 21 produced positive samples). Twenty Yersinia pestis strains isolated from material from 3 patients and 17 rodents, displayed biochemical reactions, virulence factors, antibiotic susceptibility and animal experimental pathogenicity similar to those observed in strains previously isolated. According to our findings this recent plague outbreak did not exhibit different factors from those observed during prior outbreaks in other plague foci in the northeast of Brazil.During a plague outbreak in the Borborema Plateu focus (Paraiba), bacteriological and serological studies were carryed out in material from 452 patients (48 positives), 1,938 rodents and other small mammals (75 positives), 4,756 dogs (141 positives) and 2,047 cats (57 positives) obtained from 41 counties (out of which, 21 produced positive samples). Twenty Yersinia pestis strains isolated from material from 3 patients ans 17 rodents, displayed biochemical reactions, virulence factors, antibiotic susceptibility and animal experimental pathogenicity similar to those observed in strains previously isolated. According to our findings this recent plague outbreak did not exhibite different factors from those observed during prior outbreaks in other plague foci in the northeast of Brazil.

Isolamento da Yersinia pestis nos focos pestosos do Nordeste do Brasil no período de 1966 a 1982

From 1966 to 1982, 861 strains of Yersinia pestis were isolated from plague foci in Northeastern Brazil. The source of these isolates were: 471 rodents, 236 pools of fleas, 2 pools of Ornithodorus and 152 humans beings. Zygodontomys lasiurus pixuna was the rodent specie that produced mostly of the isolates as well as mostly of the infected pools of fleas mainly of the Polygenis species. The infected samples were originated from municipalities of Pernambuco (13) Ceara (7) ParaibaIII PiauiI and BahiaI States. This geographic distribution shows that plague remains a health problem in Brazil and deserves attention. The bigger numbers of isolates and affected areas in Pernambuco State does not necessarily indicates a higher infection incidence in such State but results from a more intense surveillance and skilled Laboratories for plague diagnosis.

Plague surveillance in Brazil: 1983 - 1992

Plague caused by Yersinia pestis, has persisted in Brazil in several natural foci spread throughout rural areas in the States of Ceara, Paraiba, Pernambuco, Piaui, Rio Grande do Norte, Alagoas, Bahia, Minas Gerais and Rio de Janeiro. Nationwide surveillance of plague in Brazil based on serological testing started in 1983. We now present an update report of the examinations carried out in our laboratory from 1983 to 1992. The passive hemagglutination test for antibodies against fraction 1A antigen of Y. pestis and the passive hemagglutination inhibition control were employed for testing a total of 220,769 sera. Samples analyzed included 2,856 sera from clinically diagnosed plague cases or suspects, 49,848 sera from rodents of 24 species and 2 species of small wild carnivores (marsupials), 122,890 sera from dogs, and 45,175 sera from cats. Specific antibodies were found in 92 (3.22%) human sera; 143 (0.29%) sera from rodents of 8 species and from the two species of marsupials, 1,105 (0.90%) sera from dogs and 290 (0.64%) sera from cats. The presence of significant levels of specific anti-F1A antibodies among rodents and wild or domestic carnivores (dogs and cats) indicates that all the Brazilian plague foci remain active in spite of the absence of human cases in some of them.

Importância dos carnívoros domésticos (cães e gatos) na epidemiologia da peste nos focos do nordeste do Brasil

Soros de carnivoros domesticos (caes e gatos), roedores, e pacientes suspeitos de peste, obtidos durante dois surtos de peste humana e de roedores, um em 1982, no foco da Serra de Baturite/CE e o outro, em 1986, no Planalto da Borborema/PB e soros de carnivoros e de roedores do foco da Chapada do Araripe/PE, obtidos, em 1986, na ausencia de casos humanos, foram analisados pelas micro tecnicas de hemaglutinacao passiva para anticorpos especificos, contra a fracao antigenica purificada - F1A - de Yersinia pestis e inibicao da hemaglutinacao. Os altos percentuais de carnivoros, sorologicamente, positivos encontrados durante os surtos de peste humana, confirmam que esses animais estao implicados no ciclo epidemiologico da peste, nos focos do Nordeste do Brasil, e representam valiosos indicadores das atividades da infeccao.

Pesquisa da infecção natural por Yersinia pestis, em pulicídeos provenientes de focos pestosos do nordeste do Brasil

Three different containment transport processes of fleas were evaluated as an approach to the bacteriologic isolation of Yersinia pestis. The three methods employed were: live fleas in glass tubes containing pieces of wrapped filter paper; dead fleas in saline solution; and maceratedfleas in Cary-Blair culture medium. The two latter methods were almost equal and superior to the first method. A total of 29512 flea pools, from plague foci in Northeast Brazil collected during 1966 to 1982 were evaluated by the three methods. Among these samples, 236 (0.80%) flea pools were positive with regard to bacteriological cultivation and/or infection of susceptible animals.

Pesquisa de Yersinia pestis em roedores e outros pequenos mamíferos nos focos pestosos do Nordeste do Brasil no período 1966 a 1982

Foi feita analise da metodologia empregada e dos resultados alcancados em pesquisa de Yersinia pestis, em material de 24.703 roedores e outros pequenos mamiferos oriundos dos focos pestosos do Nordeste do Brasil, no periodo de 1966 a 1982. Concluiu-se ser necessario haver maior rapidez na realizacao dos exames para que os dados obtidos sejam convenientemente aplicados nas atividades de vigilância e controle da peste.Foi feita analise da metodologia empregada e dos resultados alcancados em pesquisa de Yersinia pestis, em material de 24.703 roedores e outros pequenos mamiferos oriundos dos focos pestosos do Nordeste do Brasil, no periodo de 1966 a 1982. Concluiu-se ser necessario haver maior rapidez na realizacao dos exames para que os dados obtidos sejam convenientemente aplicados nas atividades de vigilância e controle da peste.

Histopatologia da infecção por Yersinia pestis em roedores de focos de peste do Nordeste brasileiro

O presente trabalho mostra a histopatologia da infeccao pela Yersinia pestis, entre as diferentes especies de roedores silvestres e comensais (cricetideos, equimideos, murideos e cavideos) que ocorrem na zona endemica de peste do Nordeste do Brasil. Estes roedores foram encontrados naturalmente infectados nos campos ou inoculados experimentalmente no laboratorio (vias percutânea, subcutânea ou picada de pulgas) com cepas locais e/ou estrangeiras de Yersiniapestis. Quase todos os animais, exceto alguns dos cavideos, desenvolveram a forma bubosepticemica da peste. Entre as lesoes encontradas, a necrose coagulativa multifocal do figado, a pneumonite intersticial aguda difusa e a atrofia linfoide do baco, podem, por sua constância, ser consideradas como os principais indicadores histologicos da infeccao pestosa, embora estas lesoes nao sejam exclusivas da peste. A diversidade e a intensidade das lesoes entre os Zygodontomys lasiurus pixuna, podem explicar a mortalidade elevada desta especie e a disseminacao da peste nos focos naturais do Nordeste brasileiro. Cricetideos e murideos mostraram alteracoes histopatologicas qualitativamente semelhantes. A resistencia dos cavideos a infeccao pestosa foi evidenciada pela sobrevida desses roedores a fase aguda da infeccao e pelo desenvolvimento de uma reacao histiocitaria interna, delimitando as areas abscedadas. e possivel que estas lesoes cronicas abriguem bacilos virulentos, que permitirao a reinfeccao periodica das pulgas e consequente reativacao do processo epizootico.In this paper, the histopathological aspects of plague infection in different species of wild and domestic rodents (cricetidae, echymidae, muridae and cavidae) are described. All of them had been trapped in endemic plague areas and harboured natural infection, while others were laboratory infected by different routes (percutaneous, subcutaneous rout, fleas bite). Several national and foreign strains of Yersinia pestis have been studied. All the rodents, except the group of cavidae, had a bubosepticemic plague. From all the lesions described, liver multifocal coagulative necrosis, diffuse acute interstitial pneumonia and lymphoid atrophy of the spleen were the most frequent and so can be considered, for practical purposes, as histological indicators of plague infection, although they are not exclusively found in plague. The variety and intensiveness of lesions found in Zigodontomys L. pixuna, may explain the high mortality of this species of rodents, making easier the dissemination of plague in the natural foci of northeast Brazil. Similar histological lesions were detected in cricetidae and muridae. The resistance of cavidae to plague infection has become evident, since they survived to the acute phase of infection and developped an intensive histiocytic granulomatous reaction surrounding necrotic areas (abscesses). It is suggested thad these chronic lesions may harbour virulent bacilli and so explain periodic plague infection in local fleas, leading to reactivation of epizootics.