title: Encephalitis and chorioretinitis associated with neurotropic African horsesickness virus infection in laboratory workers. Part I. Clinical and neurological observations.
abstract: Four laboratory workers from the same vaccine-packing facility developed at different times over an 8-year period an illness characterised by encephalitis (in 3 workers) and uveochorioretinitis (in 4). Low complement fixation titres were detected in all 4 patients to African horsesickness (AHS) virus and enzyme immunoassay and plaque reduction neutralising tests were positive, the latter against both serotypes 1 and 6. Five of 15 laboratory workers from the same facility who were healthy on clinical and ophthalmological examination showed positive plaque reduction neutralising tests but none to both serotypes 1 and 6. It is postulated that the encephalitis with the predominant temporal lobe involvement was caused by an airborne transnasal route of infection of the neurotropic AHS virus released in dried powder form, secondary to the accidental breaking of vaccine bottles. This is possibly the first report of subclinical and probable clinical neurotropic AHS infection in man.
authors.affiliation: Department of Neurology, University of Pretoria.
authors.forename: C H
authors.initials: CH
authors.lastname: van der Meyden
authors.forename: B J
authors.initials: BJ
authors.lastname: Erasmus
authors.forename: R
authors.initials: R
authors.lastname: Swanepoel
authors.forename: O W
authors.initials: OW
authors.lastname: Prozesky
mesh_terms: D000293:Adolescent; D000328:Adult; D000355:African Horse Sickness / Q000000981:diagnostic imaging / Q000209:etiology*; D001921:Brain / Q000000981:diagnostic imaging; D002825:Chorioretinitis / Q000000981:diagnostic imaging / Q000209:etiology*; D004660:Encephalitis / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D007757:Laboratory Infection / Q000209:etiology*; D008279:Magnetic Resonance Imaging; D014057:Tomography, X-Ray Computed