RESUMO
Gross and microscopic pathological findings are presented for an African green monkey model of fatal Bolivian hemorrhagic fever. Six animals were inoculated with 1,000 plaque-forming units of Machupo virus, the etiological agent of Bolivian hemorrhagic fever. Five of the monkeys died within 13 days with signs of fever, anorexia, shock, and hemorrhage. The sixth monkey survived until the 24th day and died with signs of central nervous system disease. Gross lesions in the five monkeys that die in the acute stage included hepatic necrosis, necrotic enteritis, bronchopneumonia, and hemorrhages in the subcutis, lungs, intestine, liver, and lymph nodes. Microscopically, necrosis was consistently seen in liver, intestine, skin, oral cavity, and adrenal cortex. Acute thrombosis was observed in four monkeys, in blood vessels of the intestine, lung and choroid of the brain. Gram-negative bacteria were seen in many tissues, suggesting terminal bacteremia. The sixth monkey was emaciated and had bronchopneumonia, but did not have the necrotic hepatic and enteric lesions observed in the other five monkeys. The significant microscopic lesions in this monkey included encephalomyelitis, ganglionitis, and bronchopneumonia.
Assuntos
Chlorocebus aethiops , Modelos Animais de Doenças , Febre Hemorrágica Americana/patologia , Animais , Haplorrinos , Intestinos/patologia , Pulmão/patologia , Tecido Linfoide/patologia , Tecido Nervoso/patologiaRESUMO
Gross and microscopic lesions of Bolivian hemorrhagic fever (BHF) are described in 10 rhesus monkeys that survived from 30 to 78 days after subcutaneous inoculation with a dose of 10(3) plaque-forming units (PFU) of Machupo virus, a dose which produces a severe and generally fatal disease. Six of the monkeys had been given low doses of homologous immune globulin when initial signs of infection appeared. Monkeys exhibited clinical signs in two phases. The initial signs of acute infection which began to appear about 1 week following inoculation included: diarrhea, depression, anorexia, dehydration, and skin rash. The survivors of this early phase of the illness usually showed improvement before relapsing into the second (or chronic) phase, which was characterized clinically by central nervous system disturbances including incoordination, tremors, convulsions, paresis, and muscle atrophy. Microscopic lesions were similar in both immune globulin-treated and untreated animals. These included widespread lymphoreticular infiltrates in the walls and adventitia of blood vessels of the brain, spinal cord, pancreas, intestine, liver kidney, adrenal, parathyroid, heart, and skeletal muscle. Diffuse lymphocytic infiltrates not confined to the vascular or perivascular tissues were present to a variable degree in many of these and other organs. Several monkeys exhibited lymphocytic inflammation of the choroid, meninges, peripheral nerves, and ganglia.
Assuntos
Febre Hemorrágica Americana/patologia , Febres Hemorrágicas Virais/patologia , Glândulas Suprarrenais/patologia , Animais , Arenavirus do Novo Mundo , Vasos Sanguíneos/patologia , Sistema Nervoso Central/patologia , Sistema Digestório/patologia , Modelos Animais de Doenças , Haplorrinos , Imunoglobulinas/administração & dosagem , Inflamação/patologia , Rim/patologia , Linfócitos/patologia , Macaca mulatta , Músculos/patologia , Miocárdio/patologia , Glândulas Paratireoides/patologiaAssuntos
Arbovírus/patogenicidade , Febres Hemorrágicas Virais/microbiologia , Animais , Arbovírus/isolamento & purificação , Bolívia , Medula Óssea/patologia , Encéfalo/patologia , Testes de Fixação de Complemento , Cricetinae , Modelos Animais de Doenças , Encefalite/complicações , Febres Hemorrágicas Virais/complicações , Fígado/patologia , Pulmão/patologia , Tecido Linfoide/patologia , Testes de Neutralização , Baço/patologia , Fatores de TempoRESUMO
Gross and microscopic lesions associated with Bolivan hemorrhagic fever virus infection in the rhesus monkey were studied in 10 animals which died following inoculation. Gross lesions included skin rash, lymphadenopathy, splenomegaly, meningeal edema, hydropericardium and enlarged friable livers. Hemorrhagic manifestations of the infection were not consistently observed, but hemorrhages were present in the skin, heart, brain and nares in some monkeys. Histopathologic lesions were fairly consistent. Hepatic necrosis with the presence of acidophilic hyaline bodies, necrotizing enteritis, epithelial necrosis and adrenal cortical necrosis were present in all monkeys. Those monkeys which died after the seventeenth day of infection had nonsupurative meningoencephalitis; lymphoid necrosis was present in 3 monkeys that died after day 18. Other microscopic lesions included myocardial degeneration, lymphoid and reticuloendothelial cell hyperplasia and lymphoid depletion. Most of the histopathologic lesions described in human autopsy material were reproduced; however, the necrosis in the skin and oral mucosa, mucosa of the gastrointestinal tract and the adrenal cortex have not been described in man. Despite these apparent discrepancies the results of this investigation indicate that the rhesus monkey is a good experimental model for the study of Bolivian hemorrhagic fever infection.
Assuntos
Febres Hemorrágicas Virais/patologia , Glândulas Suprarrenais/patologia , Animais , Temperatura Corporal , Bolívia , Medula Óssea/patologia , Encéfalo/patologia , Cricetinae , Sistema Digestório/patologia , Modelos Animais de Doenças , Enterite/microbiologia , Epitélio/patologia , Feminino , Haplorrinos , Humanos , Injeções Subcutâneas , Rim/patologia , Fígado/patologia , Pulmão/patologia , Linfonodos/patologia , Macaca , Miocárdio/patologia , Necrose , Vírus de RNA , Baço/patologiaRESUMO
Adult hamsters were infected with two avirulent strains of Venezuelan equine encephalomyelitis virus, TC-83 and the small plaque variant (SPV) of Fe 3-7c. Histologic examination showed that significant brain lesions were produced by both strains and affected primarily the olfactory bulbs, lateral olfactory tracts and the pyriform lobes of the cerebral cortex. The type of lesions produced by both strains were similar, but when the two groups were compared, more of the hamsters inoculated with SPV had lesions and they were of greater severity. Outstanding lesions observed were: vasculitis, lymphocytic perivascular cuffing and hemorrhage, demyelination of the lateral olfactory tracts and neuronal necrosis of the olfactory bulbs.