The authors report 41 patients with meningitis caused by Streptococcus suis. The clinical feature of
the meningitis is characteristic with severe sensorineural hearing loss, developing early during the course of
meningitis. These patients were cured with high doses of penicillin or third generation cephalosporins but the
deafness remained permanent. The mechanism of the cochlear and vestibular damage is uncertain; presumably,
it is caused by some oto-toxins from bacteria. The disease may become an occupational risk of pork handlers
and a public health problem in Thailand.

Keywords: Streptococcus suis, Meningitis, Permanent deafness