Otitis media is the medical term for middle ear infection. The main symptom for ear infection is ear pain; other probable symptoms include fever, and irritability. The common cause of all forms of otitis media is blockage of the Eustachian tube. This may due to swelling of the mucous membranes in the nasopharynx, which may have resulted from a viral upper respiratory infection or by allergies. Pneumococcal conjugate vaccines when given during infancy are believed to have decreased rates of acute otitis media by 6-7%. Children with recurrent episodes of acute otitis media and those with otitis media with effusion or chronic otitis media are seen to have higher risks of developing sensorineural hearing loss.