Listeriosis at Vancouver General Hospital, 1965-79

The records were reviewed of all patients treated at the Vancouver General Hospital over the 15 years from 1965 through 1979 for infections proved by culture to have been caused by Listeria monocytogenes. Although listeriosis is not common in humans, certain groups seem to be susceptible - immunocompromised patients, pregnant women, neonates and the elderly. All these groups were represented among the 22 cases reviewed. There were 17 adults, 3 of whom were pregnant women who had only a mild influenza-like illness. Of the remaining 14 adults 9 were immunocompromised and 5 apparently immunocompetent; 7 presented with meningitis and 7 with bacteremia only. Of the five infants with neonatal listeriosis, two had early-onset disease (bacteremia) and three had the late-onset form (meningitis). Seven patients were treated with penicillin alone, seven with ampicillin alone and eight with penicillin or ampicillin combined with kanamycin, gentamicin or chloramphenicol. There were eight deaths: several were directly attributable to the listeriosis, but in others the severity of the underlying illness was an important factor. Serotypes 1 and 4b were equally common among the 16 specimens of L. monocytogenes that were typed.