Simian virus nomenclature, 1980.

Approximately 75 simian viruses, counterparts of other animal viruses, are recognized. Nomenclature of these isolates, in general, consists of an SV (simian virus) or SA (simian agent) numerical series with no attempt to group them according to virus families. The biologic characteristics of these viruses indicate they may be classified into recognized families and groups. A simple sequential numerical designation is recommended as a nomenclature within virus families and groups. Finalization of nomenclature would follow approval by the Study Groups of the International Committee on Taxonomy of Viruses.

Isolation of simian virus 40 from rhesus monkeys (Macaca mulatta) with spontaneous progressive multifocal leukoencephalopathy.

Isolates of virus from the brain tissue of two naturally occurring cases of progressive multifocal leukoencephalopathy in rhesus monkeys (Macaca mulatta) have been characterized. Both isolates were demonstrated to be simian virus 40 (SV40) by serological tests and analysis of cleavage fragments of viral deoxyribonucleic acid produced by restriction endonuclease from Haemophilus influenzae. SV40 virions and the nonvirion T antigen were demonstrated in the brain lesions of one monkey by the fluorescent antibody staining technique. SV40 was not demonstrated in the brain of normal rhesus monkeys from the same colony with use of the same methods of viral isolation or demonstration of antigen.

Transmission of Creutzfeldt-Jakob disease to the stumptail macaque (Macaca arctoides).

The successful transmission of Creutzfeldt-Jakob disease from both affected human and chimpanzee brain to stumptail macaques has been accomplished. The incubation period of 5 yr was the same for both animals; however, the course of the disease was longer in the animal receiving the human brain. In both cases, initial mild symptoms slowly remitted only to reappear some 4 mo later. Muscle biopsies revealed changes suggestive of a mild neuropathy. In addition, there appeared to be an increased ability to incorporate 3H-thymidine in untreated cultures of lymphocytes from peripheral blood.

Recovery from encephalomyelitis caused by Herpesvirus simiae. Report of a case.

A 29-year-old monkey handler developed an acute encephalomyelitis with neuromuscular dysfunction that progressed to respiratory arrest on the 18th day of illness. Thereafter, with supportive care, the patient's condition improved steadily. The titer of neutralizing antibodies to H simiae rose from 1:4 (eighth day of illness) to 1:512 (47th day of illness). Apparently the fifth known survivor of H simiae (herpesvirus B) encephalomyelitis, this patient is also remarkable because of virtually complete recovery, apparently the second documented instance of a good outcome.

Simian hemorrhagic fever: Studies of coagulation and pathology.

Simian hemorrhagic fever (SHF) was induced in three species of monkeys (Macaca mulatta, M. radiata and M. fascicularis) using plasma from animals that died with SHF in the 1967 outbreak at the California Primate Research Center. The disease was uniformly fatal in all three species with death occurring by day 5 in M. radiata and M. fascicularis and by day 7 in M. mulatta. Serial studies of hemostasis were consistent with the occurrence of disseminated intravascular coagulation, particularly in the M. mulatta. Studies of pathology were typical of previously reported findings in SHF and support the possibility of intravascular coagulation. The role of intravascular coagulation in the pathogenesis and outcome of SHF remains uncertain but studies of the influence of heparin on the disease are in progress.

Transmission of Creutzfeldt-Jakob disease to the patas monkey (Erythrocebus patas) with cytopathological changes in in vitro cultivated brain cells.

The transmission of Creutzfeldt-Jakob disease (CJD) to the patas monkey, Erythrocebus patas, has been accomplished. Clinical neurological disease was first noticed 47 months and 23 days after intracerebral inoculation of infected squirrel monkey brain. The disease progressed slowly and lasted 8 months. Microscopic examination of the brain and spinal cord revealed lesions of status spongiosus and astrogliosis in the cortical gray matter consistent with a diagnosis of experimental CJD. A vacuolating 'spongiform' cytopathological effect was seen in many of the in vitro cultivated brain cells in the outgrowth from explanted brain tissue of this monkey.

Comparison of Tanapox virus and Yaba-like viruses causing epidemic disease in monkeys.

The virus of Tanapox isolated from the lesions of patients during an outbreak of mild disease in Africa has been found to be indistinguishable in its biological and serological properties from a virus isolated from outbreaks of a pox virus infection in monkeys in primate centres in America. The natural hosts of this virus are believed to be African monkeys and ;Tanapox virus' is proposed as a suitable designation for the virus.