Hearing and vestibular loss in Streptococcus suis infection from swine and traditional raw pork exposure in northern Thailand.

Objectives: To describe a series of 40 culture-proven, Streptococcus suis infected patients, focusing on route of entry and on hearing and vestibular dysfunction. Methods: Retrospective study of patient records in a tertiary care hospital in northern Thailand, 2003―2007. Results: The majority (75 per cent) of cases were men with heavy drinking habits. A past history of the consumption of raw pork and/or pig's blood was found in 62.5 per cent of cases, whereas contact with swine products was found in 25 per cent. Thirty patients presented with sepsis, 19 with meningitis and 10 with infective endocarditis. The overall mortality rate was 20 per cent. After a mean follow up of 17 months, 73 per cent of the surviving meningitis cases had persistent sensorineural hearing loss and 50 per cent demonstrated vestibular impairment. In one patient, roentgenographic studies of the temporal bone were compatible with labyrinthitis ossificans. Conclusions: Permanent hearing loss and vestibular impairment occur frequently in persons surviving meningitis caused by Streptococcus suis.