Listeria may cause hearing loss and vertigo. With the recent outbreak of Listeriosis in South Africa (SA) it is important that the public be made aware off the potential complications of hearing loss, vertigo, disequilibrium and facial nerve palsy.
In SA more that 60 patients have recently died from Listeria, a bacterial infection caused by food poisoning. It is more common to occur in pregnant woman, new-borns, patients with impaired immune systems and the elderly. Listeria monocytogenes, as the bacterium is called, occurs in soil and water. It then contaminates vegetables, meat and dairy products. Unpasteurised milk, cheese and processed food may also harbour the bacterium. There are means and ways to limit exposure to Listeria.
When infected a patient may present with flu like symptoms, diarrhoea, fever, headache, stiff neck, muscle pains and nausea. Any patient, especially the high risk group mentioned above, with these symptoms should consult a medical doctor. When it spreads to the nervous system, Listeria may cause hearing loss and vertigo.
When Listeria infects the meninges (brain sac) or cerebrospinal fluid, meningitis may develop. A complication of meningitis is hearing loss and deafness due to involvement of the cochlea of the inner ear or the hearing nerve. Spread to the cochlea may lead to ossification (new bone formation) in the cochlea, making it difficult to perform a cochlear implant(CI) for the deafness at later stage. Listeria meningitis may also lead to facial nerve palsy, mimicking Bell’s palsy.
When the Listeria effects the labyrinth a patient may develop vertigo and even loss of vestibular function.
Encephalitis (involvement of the brainstem) may cause central vertigo due to brain involvement, dizziness, hearing loss and facial nerve palsy.
Listeria is usually diagnosed after clinical examination, blood and cerebrospinal fluid analysis. Treatment usually include antibiotics but it should be noted that the anti-biotics may also cause hearing loss and vestibular loss. A CI may be required in some patients with hearing loss.
It is strongly advised that any patient with Listeria infection undergo a hearing test within one month to rule out hearing loss. With cochlear ossification, cochlear implantation may be difficult, thus diagnosis of hearing loss should be made before cochlear ossification occurs. This is of critical importance. When dizzy, suffering from vertigo or loss of balance vestibular testing is advised.
