RESUMO
The status of the various recombinant DNA and RNA-derived candidate vaccines, as well as the Venezuelan equine encephalomyelitis virus (VEEV) replicon vaccine system against extremely hazardous viral hemorrhagic fevers, were reviewed. The VEEV-based replication-incompetent vectors offer attractive features in terms of safety, high expression levels of the heterologous viral antigen, tropism to dendritic cells, robust immune responses, protection efficacy, low potential for pre-existing anti-vector immunity and possibility of engineering multivalent vaccines were tested. These features of the VEEV replicon system hold much promise for the development of new generation vaccine candidates against viral hemorrhagic fevers.
Assuntos
Anticorpos Antivirais/biossíntese , Antígenos Virais/imunologia , Vírus da Encefalite Equina Venezuelana/imunologia , Encefalomielite Equina Venezuelana/prevenção & controle , Febres Hemorrágicas Virais/prevenção & controle , Vacinas Virais/imunologia , Animais , Antígenos Virais/genética , Proteção Cruzada , Células Dendríticas/imunologia , Células Dendríticas/virologia , Vírus da Encefalite Equina Venezuelana/patogenicidade , Encefalomielite Equina Venezuelana/imunologia , Encefalomielite Equina Venezuelana/virologia , Febres Hemorrágicas Virais/imunologia , Febres Hemorrágicas Virais/virologia , Cavalos , Humanos , Replicon , Vacinação , Vacinas Atenuadas , Vacinas Sintéticas , Vacinas Virais/administração & dosagem , Vacinas Virais/biossínteseRESUMO
Two Institute of Medicine reports since 1992 have emphasized the dangerous and continuing threat to the world from emerging infectious diseases. Working with viral hemorrhagic fevers provides a number of lessons related to the processes that control emergence, the pattern of disease after emergence, and how to cope with these incidents. This short paper uses two arenavirus hemorrhagic fevers to illustrate some of these principles. Argentine and Bolivian hemorrhagic fevers first came to medical attention in the 1950's. The forces that underlie the emergence of disease in Argentina are not understood, but the Bolivian episode has a reasonably understandable train of events behind it. The Argentine disease had serious impact on the large agricultural economy, and the ecology of the rodent reservoir did not lend itself to control; a vaccine was developed by Argentina and the U.S. with the latter motivated largely by biodefense. The Bolivian disease was controlled in large part by eliminating rodents that invaded towns, and the impact was subsequently below the level needed to trigger drug or vaccine development. These two viruses were important in the recognition of a new family of viruses (Arenaviridae), and this finding of new taxons during the investigation of emerging infectious diseases continues.
Assuntos
Doenças Transmissíveis Emergentes/prevenção & controle , Febres Hemorrágicas Virais/prevenção & controle , Animais , Argentina/epidemiologia , Bolívia/epidemiologia , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/história , Vetores de Doenças , Saúde Global , Febres Hemorrágicas Virais/epidemiologia , Febres Hemorrágicas Virais/história , História do Século XX , Humanos , Fatores de Risco , Roedores/virologiaRESUMO
Infection control faces radical changes at the beginning of the third millennium. The first part of this review focuses on problems not yet solved, such as 1) surveillance systems, which should be active and extremely flexible; 2) infection outbreaks in hospitals and strategies to avoid them; 3) hand washing and alternatives such as rapid hand antisepsis; 4) water and food in the hospital as potential reservoirs of nosocomial pathogens; 5) upgrading of infection control programs to turn them into systems to improve the quality of care; 6) fatal Gram-negative bacteremias in hospitals from developing countries, which can be avoided with better standards of care; 7) the elemental role of the microbiology laboratory in the prevention and control of infections; 8) the unprecedented crisis due to the emergence of specific multi-resistant pathogens; 9) the risks for healthcare workers, such as tuberculosis, hepatitis, HIV, SARS, and hemorrhagic fevers; and 10) the need for the consistent application of guidelines. The second part of this review focuses on new challenges for infection control, such as 1) the ever-growing number of immunocompromised patients and basic control measures to avoid opportunistic infections; 2) the concerns about the capacity of the public health systems to deal with terrorist acts; 3) the practice of high-risk procedures in facilities lacking trained personnel, efficient laboratories, and protective items; and 4) gene therapy and its potential infectious complications. Consideration is given to the asymmetric development of infection control globally.
Assuntos
Controle de Doenças Transmissíveis , Infecção Hospitalar/prevenção & controle , Infecções por HIV/prevenção & controle , Febres Hemorrágicas Virais/prevenção & controle , Controle de Infecções , Síndrome Respiratória Aguda Grave/prevenção & controle , Controle de Doenças Transmissíveis/métodos , Controle de Doenças Transmissíveis/organização & administração , Controle de Doenças Transmissíveis/tendências , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/prevenção & controle , Doenças Transmissíveis Emergentes/transmissão , Infecção Hospitalar/epidemiologia , Países em Desenvolvimento , Infecções por HIV/epidemiologia , Infecções por HIV/transmissão , Febres Hemorrágicas Virais/epidemiologia , Febres Hemorrágicas Virais/transmissão , Humanos , Controle de Infecções/normas , Controle de Infecções/tendências , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/transmissãoAssuntos
Ebolavirus , Febres Hemorrágicas Virais/epidemiologia , Côte d'Ivoire/epidemiologia , República Democrática do Congo/epidemiologia , Surtos de Doenças/prevenção & controle , Ebolavirus/patogenicidade , Febres Hemorrágicas Virais/prevenção & controle , Febres Hemorrágicas Virais/transmissão , Humanos , América do Sul/epidemiologiaAssuntos
HIV-1 , HIV-2 , Atitude Frente a Saúde , Controle de Doenças Transmissíveis/métodos , Defesa do Paciente , Direitos Civis , Estados Unidos/epidemiologia , Febres Hemorrágicas Virais/epidemiologia , Febres Hemorrágicas Virais/prevenção & controle , Febres Hemorrágicas Virais/transmissão , Hanseníase/epidemiologia , Hanseníase/prevenção & controle , Hanseníase/transmissão , Júpiter/epidemiologia , Peste/epidemiologia , Peste/prevenção & controle , Peste/transmissão , Política de Saúde , Quarentena , Síndrome da Imunodeficiência Adquirida/epidemiologia , Síndrome da Imunodeficiência Adquirida/prevenção & controle , Síndrome da Imunodeficiência Adquirida/transmissão , Valores SociaisRESUMO
Cross-protection between Junin virus and five other Tacaribe complex viruses and the serological response of guinea pigs inoculated with Tacaribe virus are reported here. Previous infection with Tamiami or Pichinde viruses significantly delayed guinea pig deaths. A 58% survival rate was found among animals immunized with three doses of Amapari virus, while guinea pigs inoculated with one dose of Machupo or Tacaribe virus were fully protected against Junin virus. Neutralization tests performed in serum samples of guinea pigs immunized with five doses of Tacaribe virus showed that they developed monologous and heterologous neutralizing antibodies.
Assuntos
Anticorpos Antivirais/análise , Formação de Anticorpos , Arbovírus/imunologia , Arenavirus do Novo Mundo/imunologia , Febre Hemorrágica Americana/prevenção & controle , Febres Hemorrágicas Virais/microbiologia , Febres Hemorrágicas Virais/prevenção & controle , Animais , Reações Cruzadas , Cobaias , Febres Hemorrágicas Virais/imunologia , Testes de NeutralizaçãoRESUMO
Bolivian haemorrhagic fever (BHF) caused by Machupo virus is acquired by contact with the excretions and secretions of Calomys callosus, an indigenous cricetine rodent which is preadapted to peridomestic habitats. It competes successfully with Mus musculus, but not with Rattus rattus. A successful disease control programme has functioned in Beni Department since 1964. It is based on trapping surveys and the detection of splenomegaly in Calomys rodents as an index of chronic virus infection. Mass trapping and poisoning are used initially, and regular trapping is employed to control Calomys populations in towns where disease has occurred. More than 1000 cases of BHF were recorded from 1960-1964, but less than 200 in the past 10 years. The cost of this programme is approximately $30 000 annually.
Assuntos
Cricetinae , Febre Hemorrágica Americana/prevenção & controle , Febres Hemorrágicas Virais/prevenção & controle , Controle de Roedores/métodos , Animais , Arenavirus do Novo Mundo/isolamento & purificação , Bolívia , Cricetinae/microbiologia , Reservatórios de Doenças , Febre Hemorrágica Americana/epidemiologia , Humanos , CamundongosRESUMO
Bolivian haemorrhagic fever immunoglobulin of human origin, given either prior to or shortly after experimental infection with Machupo virus, protected rhesus and cynomolgus monkeys against initial clinical illness. Some survivors developed severe neurological signs 30-47 days after virus inoculation and died 4-6 days later. Results from one of the experiments suggested that the development of neurological signs was associated more frequently with high doses of immunoglobulin than with intermediate or low doses.