Recent studies in leptospirosis

Thesis (M.A.)--Boston UniversityThe leptospiral infections from the aspects of the characteristics of the aetiologic agents, pathogenicity, immunity, diagnosis, treatment and epidemiology have been discussed. The type organism (Leptospira icterohaemorrhagiae) which belongs to the order Spirochaetales and family Treponemataceae is a strikingly flexible, motile microorganism measuring seven to fourteen microns in length with exceptionally long forms measuring from thirty to forty microns due to delayed transverse fission. The organisms are finely coiled with regular spirals measuring 0.45 to 0.5 micron in amplitude, and 0.3 micron in depth. There are one of more undulations throughout the entire length and the body culminates in finely pointed ends. The organism may be demonstrated as a fine tapering filament which may assume the forms of semicircles, figures-of-eight, and S-shapes from a liquid culture medium, and serpentine, undulating or bent forms from a semi-solid medium. The leptospira may be stained by Giemsa's or Fontana's silver impregnation methods. The leptospi rae are morphologically undistinguishable. They are facultative aerobes and require one or more of the thermolabile factors in the serum of rabbits, horses, guinea-pigs or humans for growth. Optimal growth occurs at a pH of 7.2 and a temperature range from thirty to thirty-seven degrees Centigrade. The pathogenic leptospirae live exclusively on proteins. Optimum growth requires a period of seven days to reach its peak in contrast to twenty-four hours for most of the other microorganisms. The media in use today are either liquid or semi-solid that contain a 10 per cent concentration of suitable animal serum and are buffered to a pH of 7.2. Examples of these are Schuffner's liquid and Chang's (1947) semi-solid media. Studies of the antigenicity of the leptospirae show that they may arbitrarily be placed into two groups. The first group is called the Cosmopolitan group, which includes Leptospira icterohaemorrhagiae, Leptospira canicola, and Leptospira grippotyphosa. The second group is called the Far East Group, which includes Leptospira auturnnalis, Leptospira hebidomadis, and Leptospira febrilis (Leptospira pyrogenes). The organisms are all antigenically related since they show varying degrees of antigen-antibody reactions in their heterologous antisera. One species of leptospirae (Leptospira piflexa) is unique in its non-pathogenicity, simple growth requirements, and distinct antigenicity. The pathogenicity of the two groups of leptospirae depends upon the species (and even strains) in question and the host infected. The wild rat (Rattus species) is an asymptomatic host of the organisms. The organisms attack the liver, kidneys, and capillaries causing icterus, uremia, and haemorrhage in the susceptible host. Guinea-pigs, hamsters, and young albino mice (Mus musculus) are susceptible hosts to Leptospira icterohaemorrhagiae, and Leptospira canicola. They may be used as test animals for diagnosis of these agents. Lepto-spira canicola and Leptospira grippotyphosa, and the miscellaneous leptospirae of Asia seldom show icterus or the severe symptoms t hat the other leptospiral agents demonstrate in man and test animals. In leptospiral infections, the aetiological agent may be demonstrated in the blood during the primary toxemic stage. The organisms are found in the liver and kidneys in the secondary stage. This stage is manifested by icterus, hemorrhage into the subcutaneous tissues, and uremia. Postmortarn examination shows hemorrhages of the internal organs. Agglutinins may be demonstrated in the tertiary stage (seventh to twentieth day of infection), and can be detected in incr easing titers for weeks thereafter. Lasting immunity is established after an attack, and agglutinins have been detected as long as twenty years after the initial infection. The diagnostic agglutinin titer is 1:300 and may run as high as 1:30,000. Diagnosis of a leptospiral infection is confirmed by darkfield examination or culture of the blood during the primary stage. Inoculation of emulsions of kidney or liver from infected hosts into test animals will reproduce the disease. Antibodies may be detected during convalescent and latent periods. Effective treatment must be started before the onset of icterus for the best therapeutic response. Serum therapy has been used experimentally to protect guinea-pigs, hamsters and young white mice (Mus musculus) from infection. Penicillin in concentrations of 0.4 u/ml. has been shown to have a leptospiristatic effect on the organisms in vitro. Leptospira icterohaemorrhagiae has been shown to have a sensitivity variance to 0.1 - 70.5 u./ml. of penicillin when tested in vitro. Leptospira grippotyphosa was found to be sensitive to 0.25 u./ml., Leptospira canicola to 0.5 u./ml., and Leptospira bataviae to 0.1 u./ml. when tested in vitro. Guinea-pigs have been effectively treated against Leptospira icterohaemorrhagiae when 1500 units of penicillin a day was given early and in maintained doses. General treatment consists of intravenous fluids and the administration of agents that will ameliorate the symptoms. Leptospirosis is endemic in Japan, Holland, South Central Europe, England, and in parts of the United States. The disease prevails in groups that are in proximity to the infective agents. Lepta-spira canicola infects dogs and those who are closely associated with dogs, i.e., veterinarians, and dog owners. Weil' s disease is seen in persons who are in proximity to infected rats. Leptospira grippotyphosa and Leptospira hebdomadis are neted among field workers who contact the disease from infective soil. Wild rats (Rattus species) have been shown to be infected with Leptospira icterohaemorrhagia in incidences of ten to thirty per cent from surveys conducted in Japan, Holland, England, and some of the major cities in the United States. Prophylactic measures should include rat proofing and extermination. Occupational groups should wear gloves to protect themselves from leptospirae-containing urine. Field workers should protect their feet with boots. Rat excreta may be sterilized with sodium hypochlorite 1:64. Health education should be stressed in endemic areas

Yellow fever and Max Theiler: the only Nobel Prize for a virus vaccine

In 1951, Max Theiler of the Rockefeller Foundation received the Nobel Prize in Physiology or Medicine for his discovery of an effective vaccine against yellow fever—a discovery first reported in the JEM 70 years ago. This was the first, and so far the only, Nobel Prize given for the development of a virus vaccine. Recently released Nobel archives now reveal how the advances in the yellow fever vaccine field were evaluated more than 50 years ago, and how this led to a prize for Max Theiler

Actinomyces pyogenes in Embryonic Loss in Cattle

Actinomyces pyogenes is one of the bacteria commonly found in the bovine reproductive tract and it has been considered not to be a primary pathogen. The bacteria has also been isolated from foetuses and pus after abortion but its role as a primary or secondary pathogen in bovine abortion has remained an area of controversy and as yet little experimental work has been carried out to determine its role. In this thesis the potential role of A. pyogenes in bovine embryonic loss is examined

Medical Microbiology, Virology & Immunology

УЧЕБНЫЕ ПОСОБИЯМИКРОБИОЛОГИЯВИРУСОЛОГИЯИММУНОЛОГИЯАЛЛЕРГОЛОГИЯ И ИММУНОЛОГИЯВ пособие включены разделы по общей микробиологии и медицинской иммунологии

Construction of an International Public Health Model : Rockefeller Foundation Yellow Fever Laboratories program in the United States, South America and Africa (1935-1950)

Orientador: Cristina de CamposTese (doutorado) - Universidade Estadual de Campinas, Instituto de GeociênciasResumo: A presente pesquisa analisou o trajeto percorrido pelo programa da febre amarela da Fundação Rockefeller, que teve uma duração de mais de 30 anos (1916 a 1950). Este programa foi dividido em duas fases, a primeira através de campanhas anti-larvas, em cooperação e parcerias com governos de diferentes países da América Latina onde a doença era notificada, e a segunda caracterizada pela construção de laboratórios estrategicamente localizados no Brasil, Colômbia, Uganda e Nigéria, que por sua vez foram impulsionadas por um laboratório central localizado nos Estados Unidos. O objetivo desta pesquisa foi realizar um estudo histórico-analítico do programa de febre amarela da Fundação Rockefeller. Entre as principais contribuições pode-se ressaltar que a febre amarela foi uma doença que forneceu uma plataforma para o diálogo entre países, e iniciou as bases para construir o conceito de saúde Internacional, fomentando a ideia de que o conhecimento médico não tem limites nacionais, e as fronteiras internacionais não formam nenhuma barreira contra a doença.  Além disso, se alcançou identificar que as atividades da Fundação Rockefeller foram de caráter intervencionista, mas o valor que conseguiu frente ao desenvolvimento da saúde internacional não teve precedentes. Sem duvida, a Fundação Rockefeller foi uma das instituições que participou ativamente da saúde pública, conseguindo contribuir na difusão e consolidação de um modelo universal de saúde. Uma de suas políticas mais claras foi em relação ao laboratório, a partir de 1930 se tornou na espinha dorsal para a saúde moderna e preventiva. Por outo lado, se identificou que entre 1935 a 1950, a Fundação Rockefeller logrou organizar uma rede de conexões científicas no continente americano e africano, foi neste momento que a medicina tropical deixou de ser vista como atos de filantropia científica para se tornar em uma disciplina de produção de conhecimento. Esta pesquisa histórica evidenciou o poder de divulgação da Fundação Rockefeller, pois sua liderança conseguiu unir a distintos países em prol de solucionar um problema em comum que beneficiaria o mundo todo promovendo um campo que formularia ao longo do tempo um modelo de saúde pública, baseado na pesquisa de laboratório permanecendo até a atualidade. A principal contribuição da tese, foi demostrar que sem a ajuda e a disposição dos governos - tanto do Brasil como da Colômbia e da colônia de Nigéria como do protetorado de Uganda ¿ o projeto mundial não fosse sido possível. A conexão entre os pesquisadores e os governos foi decisiva para contribuir na organização da disciplina que na atualidade é conhecida como saúde internacionalAbstract: This Ph.D. thesis aimed to analyze the course of the Rockefeller Foundation's yellow fever program, which lasted more than 30 years (1916 to 1950). Such a program was divided into two steps, the first one through anti-larval campaigns, in cooperation and partnerships with governments of different Latin American countries where the disease was notified. The second step was characterized by the construction of laboratories strategically located in Brazil, Colombia, Uganda and Nigeria, which in turn were driven by a central laboratory located in the United States. The main goal of this research project was to conduct a historical-analytical study of the Rockefeller Foundation's yellow fever program. Among the most important contributions of this research, it can be highlighted that the yellow fever was a disease that provided a platform for dialogues between countries and laid the foundations for building the concept of international health, promoting the idea that the medical knowledge does not have national limits, and the international borders do not form any barrier against the disease. In addition, it was possible to identify that the activities of the Rockefeller Foundation were of an interventionist nature, but the value achieved by them in the development of international health was unprecedented. There is no doubt that the Rockefeller Foundation was one of the institutions that actively participated in the field of public health, contributing to the dissemination and consolidation of a universal health model. One of its clearer policies was in relation to the laboratory, from the 1930's it became the backbone for modern and preventative health. On the other hand, it was identified that between 1935 and 1950, the Rockefeller Foundation managed to organize a network of scientific connections in the American and African continent, it was at this moment that tropical medicine ceased to be seen as acts of scientific philanthropy to become a discipline of knowledge production. This historical research evidenced the power of the Rockefeller Foundation to spread, as its leadership was able to unite different countries to solve a common problem that would benefit the whole world by promoting a field that would formulate over time a public health model based on laboratory research, which remains nowadays. The most important contribution of this thesis was to demonstrate that without the help and willingness of governments - from Brazil as well as from Colombia and the colony of Nigeria and the Uganda protectorate - the world project would not have been possible The connection between researchers and governments was valuable in contributing to the organization of the discipline that is now known as international healthDoutoradoPolitica Cientifica e TecnologicaDoutora em Política Científica e Tecnológica2013/13033-4FAPES