Immunization Related Terms
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Optic Neuritis
A medical condition where vision deteriorates rapidly over hours or days. One or both eyes may be affected. This condition results for the demyelination of optic nerves. In most cases, the cause of optic neuritis is unknown. Patients may regain their vision or be left with permanent impairment. Also see demyelinating disorders.
Orchitis
A complication of mumps infection occurring in males (who are beyond puberty). Symptoms begin 7-10 days after onset of mumps and include inflammation of the testicles, headache, nausea, vomiting, pain and fever. Most patients recover but in rare cases sterility occurs.
Otitis Media
A viral or bacterial infection that leads to inflammation of the middle ear. This condition usually occurs along with an upper respiratory infection. Symptoms include earache, high fever, nausea, vomiting and diarrhea. In addition, hearing loss, facial paralysis and meningitis may result.
Outbreak
Sudden appearance of a disease in a specific geographic area (e.g. neighborhood or community) or population (e.g. adolescents).
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