Encephalitis and chorioretinitis associated with neurotropic African horsesickness virus infection in laboratory workers. Part III. Virological and serological investigations.

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.

Ear involvement in human brucellosis.

A case report of mixed-type hearing loss following brucella infection is presented. Damage to the ear in brucellosis is well documented in the Polish literature whereas, surprisingly, it is not mentioned in the otolaryngologic and microbiologic English literature. Otolaryngologists should be aware of possible ear damage in brucellosis, in order to be helpful in the diagnostic process, with the aim of starting antibiotic treatment as soon as possible, in order to prevent irreversible ear damage.