title: Encephalitis and chorioretinitis associated with neurotropic African horsesickness virus infection in laboratory workers. Part III. Virological and serological investigations.
abstract: Four cases of encephalitis with chorioretinitis occurred in the vaccine-packing section of a veterinary research institute: 1 in 1982, 1 in 1985 and 2 in 1989. No viruses were isolated from patients and serological tests failed to reveal significant antibodies to a range of viruses incorporated in veterinary vaccines or to other likely pathogens, except for low titres of complement-fixing antibody to African horsesickness (AHS) virus in all 4 patients. In confirmatory tests, high enzyme immunoassay titres of antibody to AHS virus occurred in the 4 patients and lower titres in 5/58 other workers at the institute. The 4 patients had significant plaque reduction neutralisation antibody titres to some of the strains of virus incorporated in AHS vaccine, particularly to serotypes 1 and 6, which had undergone neuro-adaptation through serial intracerebral passage in mice and which were known to be encephalitogenic following intranasal instillation in horses, guinea pigs and dogs. It is believed that the patients may have acquired aerosol infection with AHS virus as a result of accidental breakage of freeze-dried vaccine bottles.
authors.affiliation: National Institute for Virology, University of the Witwatersrand, Sandringham, Tvl.
authors.forename: R
authors.initials: R
authors.lastname: Swanepoel
authors.forename: B J
authors.initials: BJ
authors.lastname: Erasmus
authors.forename: R
authors.initials: R
authors.lastname: Williams
authors.forename: M B
authors.initials: MB
authors.lastname: Taylor
mesh_terms: D000328:Adult; D000355:African Horse Sickness / Q000150:complications / Q000175:diagnosis*; D000356:African Horse Sickness Virus / Q000276:immunology / Q000302:isolation & purification*; D000914:Antibodies, Viral / Q000032:analysis*; D002825:Chorioretinitis / Q000209:etiology*; D004660:Encephalitis / Q000209:etiology*; D006801:Humans; D007757:Laboratory Infection / Q000150:complications / Q000175:diagnosis*
chemical_list: D000914:Antibodies, Viral