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.