Neutralizing antibodies to simian papovavirus SA12 in Old World primates in laboratory colonies: high prevalence in baboons.

Sera from 517 laboratory-housed nonhuman primates representing five genera and from 13 laboratory workers were examined for the presence of neutralizing antibodies to SA12 virus. The antibody prevalences were as follows: baboons, 66%; patas and vervet monkeys, 24%; macaques, 8%, and chimpanzees, 2%. The serum of one laboratory worker had antibodies. These results suggest that SA12 virus is a common infection of nonhuman primates in laboratory colonies, especially baboons.

Some infectious diseases of wild vervet monkeys (Cercopithecus aethiops pygerythrus) in South Africa.

Our surveys indicate that nearly all batches of vervet monkeys arriving at the National Institute for Virology from various areas of South Africa, are infected with foamy viruses and there is evidence that intra-urterine infection also occurs. Monkeys from certain areas of South Africa are apparently infected with the protozoal parasite Entopolypoides macaci in a sub-clinical state which becomes active when the monkeys are splenectomised. Serological studies indicate that infections with schistosomes, tick-bite fever (Rickettsia conori), chlamydsiae and occasionally by leptospirae, occur in monkeys in the Kruger National Park. Complement fixation tests for antibodies to R. mooseri and R. prowazeki were also sometimes positive; a finding of doubtful importance. There was a high percentage with positive antibody tests to chikungunya virus in a certain age group suggesting that there had been an outbreak of this disease in the Kruger Park in the late summer and autumn of 1976. This coincided with a human outbreak. Large numbers of vervet and baboon sera were tested for antibodies against SA 12 virus, a polyoma virus. A high percentage of baboons but only a small number of monkeys was found to be positive and it is concluded that SA 12 is probably a baboon virus which is occasionally transmitted to monkeys by contact. It is pointed out that these studies only indicate diseases from which monkeys recover and they do not indicate prevalence of severe disease causing grave illness or death.

Characterization of SA12 as a simian virus 40-related papovavirus of chacma baboons.

SA12 virus, originally isolated from an uninoculated South African vervet monkey kidney culture, was identified as a new member of the simian virus 40 (SV40)-polyoma subgroup of papovaviruses. The virus produced a cytopathic effect with nuclear enlargement in primary rhesus kidney cells. The virion had papovavirus morphology and a diameter of 44 to 45 nm. The DNA of the virus was a circular, double-stranded, superhelical molecule with a mean length 101% that of SV40 DNA and an estimated molecular weight of 3.3 X 10(6). The virus was found to be unrelated to other papovaviruses by neutralization, immune electron microscopy, and immunofluorescence tests with antiviral sera. SA12 virus-infected cells exhibited a capsid antigen, which has recently been found to be common to viruses of the SV40-polyoma subgroup. The virus readily transformed kideny cells from 10-day-old hamsters. Inoculation of transformed cells produced tumors in 3- to 4-week-old hamsters. The T antigens of SA12 and SV40 viruses were strongly and reciprocally cross-reactive. A high proportion of the sera of chacma baboons, Papio ursinus, and a comparatively lower proportion of the sera of vervet monkeys, Cercopithecus pygerythrus, had neutralizing antibodies to SA12 virus